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Title:
METAL/OXYGEN BATTERY
Document Type and Number:
WIPO Patent Application WO/2018/014927
Kind Code:
A1
Abstract:
The invention relates to a metal/oxygen battery with a layered galvanic stack com- prising one or more anode layers, one or more cathode layers, and one or more separator layers. Each of the separator layers is arranged between one of the anode layers and a neighboring one of the cathode layers, is adapted to conduct ions, and is in ionically conductive contact with each of said neighboring anode layer and cathode layer. The stack of the metal/oxygen battery unit comprises a channel ex- tending from a surface of the stack across its layers, wherein each of the layer is provided with a through-hole overlapping with the through-holes of its respective neighboring layers, such as to form the channel.

Inventors:
NUERNBERGER SIMON (DE)
TSIOUVARAS NIKOLAOS (DE)
PASCHOS ODYSSEAS (DE)
LAMP PETER (DE)
HANDA TOKUHIKO (JP)
NISHIKOORI HIDETAKA (JP)
INOUE TOSHIHIKO (JP)
Application Number:
PCT/EP2016/067022
Publication Date:
January 25, 2018
Filing Date:
July 18, 2016
Export Citation:
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Assignee:
BAYERISCHE MOTOREN WERKE AG (DE)
TOYOTA MOTOR CORP (JP)
International Classes:
H01M12/06; H01M50/502
Foreign References:
US20150037693A12015-02-05
Attorney, Agent or Firm:
WALLINGER RICKER SCHLOTTER TOSTMANN (DE)
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Claims:
CLAIMS

A metal/oxygen battery unit (1 ), comprising:

a layered galvanic stack (2) comprising one or more anode layers (3), one or more cathode layers (4), and one or more separator layers (5);

wherein:

each of the separator layers (5) is arranged between one of the anode layers (3) and a neighboring one of the cathode layers (4), is adapted to conduct ions, and is in ionically conductive contact with each of said neighboring anode layer (3) and cathode layer (4);

the stack (2) comprises a channel (6) extending from a surface of the stack across at least a subset of consecutive ones of its layers (3,4,5,8i,1 1 ,12), wherein each of the layers (3,4,5, 8i,1 1 ,12) of the subset is provided with a through-hole (7) overlapping with the through-holes (7) of its respective neighboring layers (3,4,5,8i,1 1 ,12), such as to form the channel (6); and

the channel (6) is adapted to exchange an oxygenous medium with the cathode layers (4) connected to the channel (6) for maintaining oxygen-based galvanic reactions at said cathode layers (4).

The metal/oxygen battery unit (1 ) according to claim 1 , wherein:

the channel (6) extends through all layers (3,4,5, 8i,1 1 ,12) of the stack (2); and

a first end of the channel (6') is located at a first end face of the stack (2) and a second end of the channel (6") is located at a second opposing end face of the stack (2), such as to allow said oxygenous medium to move into and out of the stack (2) through said first and second ends (6',6") of the channel.

The metal/oxygen battery unit (1 ) according to claim 1 or 2, wherein the outside surface of the stack (2) is adapted to exchange said oxygenous medium with a periphery of the battery unit (1 ).

The metal/oxygen battery unit (1 ) according to any one of the preceding claims, comprising a battery unit housing (8), which at least partially encloses the stack (2);

wherein the housing (8) has one or more apertures (9) and is adapted: to support the exchange of the oxygenous medium and/or a cooling medium between the channel (6) and a periphery of the battery unit (1 ) through at least one of said apertures (9), said aperture (9) overlapping with the through-hole (7) of an outmost layer (3,4,5, 8i,1 1 ,12) at an end face of the stack; and/or

to support the exchange of the oxygenous medium and/or the cooling medium between an outside surface portion of the stack (2) and a periphery of the battery unit (1 ) through at least one of said apertures (9), said aperture being in fluid connection with said outside surface portion.

5. The metal/oxygen battery unit (1 ) according to any one of the preceding claims, wherein:

at least said anode layers (3), said cathode layers (4), and said separator layers (5) are at least substantially rotationally symmetric with respect to an axis (AA) defined along the direction of stacking of the layers.

The metal/oxygen battery unit (1 ) according to any one of the preceding claims, wherein:

said through-holes (7) of at least said anode layers, said cathode layers, and said separator layers are at least substantially centered with respect to at least one direction orthogonal to the axis (AA) defined along a direction of stacking of the layers, such that the channel (6) formed by the through- holes (7) is at least substantially centered; and/or

said through-holes (7) of at least said anode layers, said cathode layers, and said separator layers are at least substantially rotationally symmetric around the axis (AA) defined along the direction of stacking of the layers (3,4,5,8i,1 1 ,12), such that the channel (6) formed by the through-holes is at least substantially rotationally symmetric.

The metal/oxygen battery unit (1 ) according to any one of the preceding claims, comprising a fixing element (10) adapted to engage with a corresponding fixing element (10) of a second battery unit, in particular according to any one of the preceding claims, such as to enable fixing of at least one of the relative position and the relative orientation of said battery units (1 ). The metal/oxygen battery unit (1 ) according to any one of the preceding claims,

wherein the battery unit is adapted to enhance the exchange of the oxygenous medium between the channel (6) and the cathode layers (4) in that: said cathode layers (4) are permeable to the oxygenous medium or at least permeable to oxygen; and/or

one or more ventilation layers (1 1 ) are provided, each ventilation layer being permeable to the oxygenous medium and being positioned on a principal face of one of said cathode layers opposite to the respective separator layer (5).

The metal/oxygen battery unit (1 ) according to any one of the preceding claims,

wherein the battery unit is adapted to enhance the charge transfer from and to galvanic reaction sites of at least one of the anode and/or cathode layers (3,4) in that:

this layer (3,4) is electrically conductive; and/or

this layer (3,4) comprises a current collector (12) that is integrated in this at least one of the anode and/or cathode layers or positioned on a principal face of this at least one of the anode and/or cathode layers (3,4) opposite to the separator (5) layer of the electrochemical cell comprising said at least one of the anode and/or cathode layers, wherein the current collector (12) is provided with a through-hole (7) overlapping that of said layer (3,4).

The metal/oxygen battery unit (1 ) according to any one of the preceding claims,

wherein:

the anode layers (3) of the stack are electrically interconnected by one or more anode interconnects (13,13');

the cathode layers (4) of the stack are electrically interconnected by one or more cathode interconnects (14,14'); and

at least one (13, 13', 14, 14') of the anode interconnects and cathode interconnects extends through the channel (6).

A metal/oxygen battery (20), in particular for a vehicle (30), comprising a first and a second battery unit (1 ,1 ',1 "), each according to any one of the preceding claims;

wherein:

the first and the second battery unit (1 ',1 ") each comprise an anode interconnect (13,13') connected to at least one of the anode layers (3) of the respective battery unit and a cathode interconnect (14,14') connected to at least one of the cathode layers (4) of the respective battery unit (1 ',1 ");

the anode interconnect (13,13') and the cathode interconnect (14,14') of the first battery unit (1 ') and the anode interconnect (13,13') and the cathode interconnect (14,14') of the second battery unit (1 ") are arranged such that: in a first predefined relative position or orientation of said battery units the battery units (1 ',1 ") are connected in parallel; and

in a second predefined relative position or orientation of said battery units the battery units (1 ',1 ") are connected in series.

The metal/oxygen battery (20) according to claim 1 1 , wherein:

the anode and cathode interconnect of the first battery unit (1 ') and the anode interconnect of the second battery unit (1 ") arranged, such that:

in the first relative orientation of said battery units the anode interconnect (13, 13') of the first battery unit (1 ') faces and is electrically connected to the anode interconnect (13,13') of the second battery unit (1 "); and in the second relative orientation of said battery units (1 ',1 "), in which the first battery (1 ) unit is rotated by a predetermined angle relative to the second battery unit (1 ") around an axis (AA) defined along the direction of stacking of the layers of the first battery unit, the cathode interconnect (14,14') of the first battery unit (1 ') faces and is electrically connected to the anode interconnect (13,13') of the second battery unit (1 ").

A method of manufacture of a metal/oxygen battery comprising two or more battery units (1 ,1 ',1 "), in particular manufacture of a battery (20) according to claim 1 1 or 12, comprising the steps:

- (S1 ) providing a battery housing (21 );

- (S2) providing two or more battery units (1 ,1 ',1 ") according to any one of the claims 1 to 10; - (S3) inserting said battery units in said battery housing (21 ), wherein at least the relative position and/or orientation of said battery units is controlled and set to a predefined position or orientation; and

- (S4) fixing at least one of the relative position and the relative orientation of said battery units by one or more fixing elements (10) of said battery units and/or by a matching and/or engagingly fitting inner shape of said battery housing and outer shape of said battery units.

A vehicle (30), in particular an electric vehicle or a plug-in hybrid electric vehicle, comprising one or more batteries (20) according to claim 1 1 or 12 or one or more batteries manufactured according to claim 13.

The vehicle according to claim 14, wherein at least of said one or more batteries (20) is arranged such that its channel (6) extends along a direction that is at least substantially parallel to the top-bottom direction of the vehicle.

Description:
METAL/OXYGEN BATTERY

TECHNICAL FI ELD The present invention relates to the field of metal/oxygen batteries, in particular for a vehicle powered by such a battery. Specifically, the invention is directed to a metal/oxygen battery unit for a metal/oxygen battery, to a metal/oxygen battery comprising multiple of such battery units, and to a vehicle with such batteries, such as an electric vehicle or a plug-in hybrid electric vehicle.

BACKGROUND

While traditionally most long-range vehicles, such as cars, trucks, buses, motorcycles, and non-electric railway locomotives, have been powered by gasoline or diesel engines, in recent years the development of electric or hybrid vehicles, in particular automobiles that are at least partially powered by electric motors, has been steadily increasing. For that purpose, various different battery systems have been developed as suitable storage for electric energy, including in particular lithium-ion batteries, which are used for most of today's electric and hybrid cars. One disadvantage of such lithium-ion batteries is their limited energy density, i.e. stored electrical energy per battery mass or per battery volume. This limitation is - amongst others - caused by the fact that all chemical components/compounds needed for the electrochemical reactions, taking place in the battery cells, are already contained in the charged battery, thus adding to its weight or volume.

To overcome this limitation, another battery type has been developed, which is commonly known as "metal/air battery" or "metal/oxygen battery". Such a battery comprises one or more electrochemical cells. Each cell comprises an electrode referred to as "anode" that is made of or at least contains a suitable metal, and an electrode referred to as "cathode" that works with ambient air or oxygen. Moreover, each cell comprises a separator located between the two electrodes, i.e. between the anode and the cathode, to electrically separate them and to conduct ions, in particular ions of the suitable metal. Under typical operating conditions the anode is negatively charged and the cathode is positively charged. In particular, the anode can comprise an alloy having such a metal as a first component and one or more further metal or non-metal components, such as carbon (C), tin (Sn) or silicon (Si), wherein the metal component in such anode remains available to participate in the electricity generating chemical reactions of an electrochemi- cal, i.e. galvanic cell. Instead of such an alloy a transition metal oxide may be used as an anode material. Furthermore, an electrolyte, which in particular may be in the aqueous or solid form, is present in the cathode and optionally in the separator. In particular, the usage of zinc, aluminum or lithium as the metal for the anode is known in the art.

At the cathode side, oxygen is the relevant electrochemical component/compound, and unlike in lithium-ion batteries, it does not have to be present in the charged battery from the beginning, but can rather be taken from ambient air or be delivered to the battery, preferably in the form of air or pure oxygen from a source such as a tank, (gas) cylinder, or other reservoir during discharging of the battery. This way, batteries having a much higher energy density than traditional lithium-ion batteries become feasible. Furthermore, when such a battery is re-charged, oxygen is generated at the cathode and can be re-used in a subsequent discharging cycle. However, the maximum rate of galvanic reactions in such a battery is limited - amongst others - by the required supply and/or discharge of some of the components/compounds of the chemical reactions, because not all components/compounds of the chemical reaction are stored at the electrochemical cells of such a battery. In particular, the maximum power that such a battery can deliver is limited by the supply of oxygen. Likewise, when such a battery is re-charged, oxygen needs to be discharged from the cathode.

DE 10 2012 200 862 A1 discloses a gas battery, in particular a lithium/air battery, with a multitude of disc shaped layers, wherein each of the layers at least comprises a current collector layer, an anode layer, a polymer electrolyte layer, and a cathode layer. Furthermore, the gas battery comprises a housing, wherein the disc shaped layers are stacked in the housing, such that a free space is radially formed between the stack of the layers and the inner wall of the housing for the supply of air or oxygen. WO 2010/132357 A1 discloses an electrochemical metal-air cell in which a low temperature ionic liquid is used. The cell comprises a flexible fuel electrode, a flexible air electrode, and an ionically conductive medium, comprising said low temperature ionic liquid. The flexible fuel electrode and the flexible air electrode are arranged in a compacted non-linear configuration with an external surface of the air electrode being exposed to absorb gaseous oxygen. In particular, the flexible electrode can be rolled. Furthermore, the cell can comprise a housing, wherein said housing has an open axial airflow receiving end and wherein an axial airflow receiving end of the rolled electrodes faces the open axial airflow receiving end of the housing.

SUMMARY OF THE INVENTION

It is an object of the present invention to enhance the efficiency and performance of metal/oxygen battery units and of batteries formed thereof.

A solution to this problem is provided by the teaching of the independent claims, specifically by a metal/oxygen battery unit according to claim 1 , a metal/oxygen battery according to claim 1 1 , a method of manufacture of a metal/oxygen battery according to claim 13, and a vehicle according to claim 14. Various preferred embodi- ments of the present invention and further improvements are in particular provided by the teachings of the dependent claims.

A first aspect of the present invention is directed to a metal/oxygen battery unit, in particular for a metal/oxygen battery, comprising a layered galvanic stack. The lay- ered galvanic stack comprises one or more anode layers, one or more cathode layers, and one or more separator layers. Each of the separator layers is arranged between one of the anode layers and a neighboring one of the cathode layers, is adapted to conduct ions, and is in ionically conductive contact with each of said neighboring anode layer and cathode layer. Particularly, each of the anode layers may comprise a suitable metal, and each of the separator layers is ionically conductive for ions of said suitable metal. Preferably, each of the separator layers is impermeable to oxygen, in particular molecular oxygen or oxygen ions, and thus prevents the passage of oxygen to the respective anode layer and a chemical reaction at said anode layer with oxygen passing through said separator layer. The stack of the metal/oxygen battery unit comprises a channel extending from a surface of the stack across at least a subset of consecutive ones of its layers, wherein each of the layers of the subset is provided with a through-hole, overlapping with the through- holes of its respective neighboring layers, such as to form the channel. Preferably, the channel extends at least substantially along an axis defined along the direction of stacking of the layers. The channel is adapted to exchange an oxygenous medi- urn with the cathode layers connected to the channel for maintaining oxygen-based galvanic reactions at said cathode layers.

The term "metal/oxygen battery unit" in the sense of the present invention refers to a galvanic element comprising one or more metal/oxygen electrochemical cells as described in detail above, and which is configured such as to support a combination with one or more further ones of such battery units to form a multi-unit metal/oxygen battery. In a metal/oxygen electrochemical cell, the electrochemically relevant chemical component/compound of one of the electrodes, particularly of the anode, is a suitable metal and the electrochemically relevant chemical component/compound of another of the electrodes, particularly of the cathode, is oxygen, in particular molecular oxygen, preferably 0 2 . To support the galvanic reactions taking place at the cell, an oxygenous medium is provided to the cathode of the cell. Preferably, the cell uses air as oxygenous medium. A battery or battery unit comprising such cells is a particular embodiment of a metal/oxygen battery respectively metal/oxygen battery unit and is typically referred to as "metal/air battery" respectively "metal/air battery unit".

The term "oxygenous medium" in the sense of the invention refers to a medium that contains oxygen, in particular atomic or molecular oxygen, and is in principle capa- ble of transporting and supplying such oxygen to a galvanic reaction taking place in a metal/oxygen cell and of accepting and transporting away oxygen from such a galvanic reaction. Preferably, such an oxygenous medium is electrically nonconduc- tive. Otherwise, a battery using an electrically conductive oxygenous medium has to be provided with insulation means that electrically insulate all parts of this battery, which has an electrical potential different from the one or more cathodes of this battery, from the oxygenous medium, and all cathodes of this battery have to be connected in parallel. Preferably, the oxygenous medium is gaseous and preferably features a low viscosity. In particular, each of an oxygenous gas, gaseous oxygen, especially molecular oxygen such as 0 2 , air, and oxygen enriched air is an oxyge- nous medium in the sense of the present invention. Alternatively, the oxygen medi- um may be in liquid form. Typically, it will then have a higher thermal conductivity and/or heat capacity than a gas.

The term "separator layer", as used herein, relates to a layer that is adapted to, when placed between the anode and the cathode of an electrochemical cell, spatially and electrically separate an anode and a corresponding cathode of the cell from each other, while allowing for the passage of ionic charge carriers through the layer which are needed to support the transformation of chemical energy into electrical energy during operation of the cell. In particular, a solid-state electrolyte layer meet- ing the requirements described above is also a "separator layer" in the sense of the present invention.

By the term "adapted", as used herein, it is to be understood particularly that the corresponding apparatus is already set or arranged or is adjustable - i.e. adaptable - to perform a particular function. Preferably, the adaptation may be performed via a corresponding setting of parameters of a process flow or of switches or the like, for activating functions or settings. Also preferably, the adaptation of the apparatus may be performed via an appropriate arrangement of parts of said apparatus. A battery unit, as defined above, may in particular provide one or more of the following advantages: The channel of the stack beneficially allows for exchanging the oxygenous medium with the cathode layers, i.e. in particular to supply oxygen to the cathode layers, when the battery unit discharges, and/or to discharge or vent oxygen from the cathode layers, when the battery unit is re-charged. In comparison to conventional metal/oxygen battery designs, where the oxygen is supplied and discharged at one or more outside faces of the cell stack, the channel formed inside the stack effectively reduces the diffusion paths for the oxygen within the cathode layers. Therefore, oxygen can be supplied or discharged more efficiently than in a conventional metal/oxygen battery with cathodes of similar dimensions, and thus, the performance of the cell, in particular its maximum output power can be increased. Furthermore, the layered stack may reduce the shearing forces and/or compression forces, e.g. compared to a cylindrical cell with a rolled arrangement of anodes and cathodes. Thus, in particular, the reliability of the battery unit or battery comprising such a battery unit is improved. A further advantage is that the cathode layers may have a larger surface area compared to a conventional battery, in particular a prismatic battery without channel, while maintaining a good supply and/or discharge of oxygen, thereby increasing the output power. Finally, the through-holes in the cathode layers and the exchange of the oxygenous medium with the cathode layers, by means of the channel, provide an improved, in particular a more homogeneous, oxygen distribution at the cathodes, thereby especially improving the reliabil- ity, operability, or output power.

In the following, preferred embodiments of the battery unit are described, which may be arbitrarily combined with each other or with other aspects of the present invention, unless such combination is explicitly excluded or technically impossible.

According to a first preferred embodiment, the channel extends through all layers of the stack. Furthermore, a first end of the channel is located at a first end face of the stack and a second end of the channel is located at a second opposing end face of the stack, such as to allow the oxygenous medium to move into and out of the stack through said first and second ends of the channel. Accordingly, the exchange of oxygenous medium is further increased and the related advantages described above are enhanced further. Moreover, the channel with two open ends allows for a continuous flow of said oxygenous medium through said channel. Thus, in particular, oxygen, other reactants, or heat can be efficiently, and preferably actively trans- ported to and from the layers, particularly compared to a transport by diffusion or similar processes.

According to a further preferred embodiment, the outside surface of the stack is adapted to exchange said oxygenous medium with a periphery of the battery unit. Accordingly, the exchange of oxygenous medium is further increased and the related advantages described above are enhanced further.

According to a further preferred embodiment, the battery unit comprises a battery unit housing, which at least partially encloses the stack. The battery unit housing has one or more apertures and is adapted to support the exchange of the oxygenous medium and/or a cooling medium. In a first preferred variant, the battery unit housing is adapted to support the exchange of the oxygenous medium and/or the cooling medium between the channel and a periphery of the battery unit through at least one of said apertures, said aperture overlapping with the through-hole of an outmost layer at an end face of the stack. In an additional or alternative second preferred variant, the battery unit housing is adapted to support the exchange of the oxygenous medium and/or the cooling medium between an outside surface portion of the stack and a periphery of the battery unit through at least one of said apertures, said aperture being in fluid connection with said outside surface portion. Preferably, the periphery of the first and/or second variant is defined by a further battery unit, in particular by a battery unit according to the first aspect of the invention, and preferably by the channel of such a further battery unit. In a further preferred variant said periphery of the battery or battery unit is in a fluid connection with a temperature control system, which is adapted to exchange the oxygenous medium and/or the cooling medium with the battery or battery unit, and to control the temperature of the oxygenous medium and/or cooling medium. In a further preferred variant, the battery unit housing comprises at least two apertures according to the first preferred variant, wherein one of said at least two apertures faces the stack at a first end face of the stack and another of said at least two apertures faces the stack at an opposing second end face of the stack, whereby, in particular, a flow of the oxygenous medium and/or of the cooling medium through the channel can be supported.

The term "cooling medium" in the sense of the present invention refers to a medium, in particular a gas or liquid, for transferring heat. Preferably, the oxygenous medium may also serve as a cooling medium in the sense of the present invention. Alterna- tively, another medium, in particular not containing, carrying, releasing, receiving, or absorbing oxygen may serve as a cooling medium in the sense of the present invention. In particular, inert gases such as gaseous nitrogen, water, oil, or wax are cooling media in the sense of the present invention. Preferably, the cooling medium is electrically nonconductive. Otherwise, if the cooling medium is electrically conduc- tive, it has to be electrically insulated from electrically charged parts of the battery unit. Preferably, the battery unit is provided with a guiding means for the cooling medium, particularly with a cooling pipe.

Accordingly, the oxygenous medium can be exchanged with a periphery of the bat- tery unit. In particular, said periphery can serve as an external source of oxygen, such that no or at least less oxygen has to be stored in the battery unit itself for its operation and thus, the energy density of the battery unit can be increased. Furthermore, this embodiment allows for providing a steady exchange of oxygenous medium, and thereby a steady supply and/or discharge of oxygen or other reactants. In this manner, the output power, the reliability, or operability of the battery unit is improved. Moreover, the exchange of cooling medium allows for transferring heat to and from said battery unit, whereby the temperature of said battery unit may be controlled. That temperature control is particularly beneficial for enhancing the operabil- ity and/or output power, and for increasing the durability or operating time of the battery unit, as it allows to keep the battery unit in a temperature range that is suita- ble, in particular optimal for its unimpaired operation. In particular, variants of this preferred embodiment providing a flow through the channel may be advantageous, when a high output power is required, i.e. a high amount of oxygen is required and/or a high amount of heat has to be transferred from the battery unit. According to a further preferred embodiment, the battery unit comprises a battery unit housing adapted to electrically insulate at least portions of the battery unit, in particular all or at least one portion of the stack, relative to the environment of the battery unit. Preferably, the housing comprises or is made of an electrically insulating material. In particular, this embodiment may be advantageous in that helps to prevent potential electrical short-cuts, which might occur, when electrically charged portions of the battery unit come into contact with an electrically conductive material such as a battery housing, interconnects or manufacturing machines. Accordingly, the handling of such a battery unit and, in particular the manufacturing of a battery comprising such battery units, may be simplified and more effective. In particular, when stacking such battery units, no additional insulation means are required.

According to a further preferred embodiment of the battery unit, at least said anode layers, said cathode layers, and said separator layers are at least substantially rota- tionally symmetric with respect to an axis defined along the direction of stacking of the layers. In a preferred variant, the battery unit is at least substantially rotationally symmetric with respect to said axis. In an additional or alternative preferred variant, principal faces of neighboring layers have at least substantially the same shape and size, whereby, in particular, a non-overlapping area of said principal faces, which might impair the efficiency of the battery unit, can be reduced or preferably even avoided. In an additional or alternative preferred variant, the layers of the stack are discs. In an additional or alternate preferred variant, the layers of the stack each have the shape of a rectangle, the shape of a regular polygon such as an equilateral triangle, of a square, or of a regular hexagon, or the shape of an ellipse, preferably the shape of a circle. Accordingly, the external outline of said battery unit is more compact than a battery unit without such a rotational symmetry. Moreover, the rotational symmetry of said layers allows for providing oxygen to the cathode layers in a substantially uniform manner, because the distance of different parts of said cathode layers from the oxygen source is more uniform, than in the non-symmetric case.

According to a further preferred embodiment, the through-holes of at least said an- ode layers, said cathode layers, and said separator layers are at least substantially centered with respect to at least one direction orthogonal to an axis defined along the direction of stacking of the layers, such that the channel formed by the through- holes is at least substantially centered. Accordingly, the centered channel beneficially minimizes the average distance, i.e. the average diffusion path for oxygen, be- tween the channel and those portions of the cathode layers, which are most distant from the channel. Thus, in particular, the supply and/or discharge of oxygen is enhanced and/or the cooling or heating of the stack by means of the cooling medium is improved. According to a further preferred embodiment, in particular of the previous preferred embodiment, the through-holes of at least said anode layers, said cathode layers, and said separator layers are at least substantially rotationally symmetric around the axis defined along the direction of stacking of the layers, such that the channel formed by the through-holes is at least substantially rotationally symmetric. The ad- vantages described above in relation to the previous preferred embodiment apply similarly to this embodiment. Furthermore, the rotationally symmetric channel may enhance said advantages even further.

According to a further preferred embodiment, the battery unit comprises a fixing el- ement adapted to engage with a corresponding fixing element of a second battery unit, in particular a battery unit according to the first aspect of the invention, such as to enable fixing of at least one of the relative position and the relative orientation of said battery units. Accordingly, when manufacturing a battery containing two or more battery units according to this embodiment, said battery units can fix their rela- tive position and/or relative orientation. This may facilitate the manufacture of such a battery. Furthermore, this allows for combining two or more of said battery units in two or more different ways by changing and fixing their relative position and/or orientation. According to a further preferred embodiment, the battery unit is adapted to enhance exchange of the oxygenous medium between the channel and the cathode layers. In a first preferred variant thereof the battery unit is adapted in that said cathode layers are permeable to the oxygenous medium or at least permeable to oxygen. In a second preferred variant thereof the battery unit is adapted in that one or more ventilation layers are provided, each ventilation layer being permeable oxygenous medium and being positioned on a principal face of one of said cathode layers opposite to the respective separator layer. Preferably, at least one of the ventilation layers is formed as a gap between the respective cathode layer and a neighboring layer of the stack. Also preferably, at least one of the ventilation layers is made of a material permeable to the oxygenous medium or a cooling medium, particularly being a porous material and/or comprising channels for said medium.

Accordingly, oxygenous medium or at least oxygen may flow and/or diffuse along, and preferably through, the respective cathode layers. Preferably, the oxygenous medium can flow from the channel to the outside surface of the stack, whereby oxy- gen or other reactants are supplied to or discharged from the respective cathode layers and/or heat is transferred to or from the layered stack. Thus, this embodiment may beneficially further enhance the output power, the operability, the reliability, and durability of the battery unit. Especially, this embodiment may be beneficially combined with an embodiment having a centered and/or rotationally symmetric channel, as described above, wherein the beneficial effects synergistically enhance each other. In particular, an improved, and especially homogeneous, supply or discharge of oxygen and/or a homogeneous temperature of the respective cathode layers are provided. Moreover, in a preferred variant with electrically insulating ventilation layers, said ventilation layers may serve as an electrical insulation between the respec- tive cathode layers and a neighboring layers of the stack or layers of a stack of a further battery unit.

According to a further preferred embodiment, the battery unit is adapted to enhance the charge transfer from and to galvanic reaction sites of at least one of the anode and/or cathode layers. In a first preferred variant thereof, the battery unit is adapted in that this at least one of the anode and/or cathode layers is electrically conductive. In an additional or alternative second preferred variant, the battery unit is adapted in that this at least one of the anode and/or cathode layers comprises a current collector that is integrated in this layer or positioned on a principal face of this layer oppo- site to the separator layer of the electrochemical cell comprising said at least one of the anode and/or cathode layers, wherein the current collector is provided with a through-hole overlapping that said layer. Accordingly, the conductivity of the battery unit is increased and/or the internal resistance of the battery unit is decreased, because the battery unit is adapted to enhance the charge transfer from and to galvanic reaction sites. Thus, in particular, the maximum output power is increased and/or heat dissipation during discharging and/or re-charging is reduced.

According to a further preferred embodiment of the battery unit, the anode layers of the stack are electrically interconnected by one or more anode interconnects, and the cathode layers of the stack are electrically interconnected by one or more cath- ode interconnects. Furthermore, at least one of the anode and cathode interconnects extends through the channel. Accordingly, compared to an embodiment without the electrical interconnections, the length of the electrical path, i.e. the electron diffusion path, extending from the interconnect to the reaction sites in the anode or cathode is reduced. Thus, in particular, the internal resistance of the battery unit is decreased. Preferably, the arrangement of at least one of the interconnects in the channel is particularly advantageous, if the channel is centered in the stack. Furthermore, the interconnects may be advantageously combined with said current collectors discussed above, whereby the internal resistance is decreased further. Preferably, at least one of the cathode interconnects extends through the channel, because the cathode layers typically have higher electrical resistance than the anode layers.

A second aspect of the invention is directed to a metal/oxygen battery, in particular for a vehicle, comprising a first second battery unit and a second battery unit, each according to the first aspect of the present invention. The first and the second battery unit each comprise an anode interconnect connected to at least one of the anode layers of the respective battery unit and a cathode interconnect connected to at least one of the cathode layers of the respective battery unit. Furthermore, the anode interconnect and the cathode interconnect of the first battery unit and the anode interconnect and the cathode interconnect of the second battery unit are arranged such that: in a first predefined relative position or orientation of said battery units the battery units are connected in parallel, and in a second predefined relative position or orientation of said battery units the battery units are connected in series. The embodiments and variants as well as potential benefits as already described in detail above in connection with the first aspect of the present invention also apply correspondingly to the metal/oxygen battery according to the present invention. In particular, an embodiment according to the second aspect of the invention may be advantageous in that based on same first and second battery units a battery with a higher output voltage or output current can be manufactured by defining the relative position and/or orientation of said battery units. So, manufacturing of such batteries may be facilitated and/or manufacturing costs may be reduced, in particular because different arrangements of battery units and thus a range of different embodiments of batteries formed thereof may be made from identical battery units. Moreover, compared to conventional battery units, additional materials and/or manufacturing steps for connecting the battery units may be avoided, especially rendering the manufacture more effective and the battery more reliable.

According to a first preferred embodiment, the battery comprises a battery housing, which at least partially encloses the battery units. The battery housing has one or more apertures and is adapted to support the exchange of the oxygenous medium and/or optionally of a cooling medium between a periphery of the battery and of the battery units. In a preferred variant, at least one of the apertures of said battery housing is adapted to guide said medium to a corresponding aperture of at least one of the battery units. In an additional or alternative preferred variant, at least one of the apertures is adapted to receive said medium from a corresponding aperture of at least one of the battery units. Preferably, at least two of the battery units are linearly arranged and each comprise two apertures such as to form a channel through said battery units to beneficially enable a flow of oxygenous medium and/or cooling medium from one of the apertures of the battery, through said battery units, and to an- other one of the apertures of the battery.

In a further preferred embodiment of the battery, the anode and cathode interconnects of the first battery unit and the anode interconnect of the second battery unit are arranged such that in the first relative orientation of said battery units the anode interconnect of the first battery unit faces and is electrically connected to the anode interconnect of the second battery unit and/or the cathode interconnects of said first and second battery unit face each other and are electrically connected. Additionally, said interconnects are arranged such that in the second relative orientation of said battery units, in which the first battery unit is rotated by a predetermined angle rela- tive to the second battery unit around an axis defined along the direction of stacking of the layers of the first battery unit, the cathode interconnect of the first battery unit faces and is electrically connected to the anode interconnect of the second battery unit, while, in particular, the anode interconnect of the first battery unit and the cathode interconnect of the second battery unit are not connected. Accordingly, by rotating the battery units relative to each other, batteries with different voltage and cur- rent ratings can be manufactured. Preferably, for this embodiment rotationally symmetric battery units are used, whereby, in particular, the requirements for a housing of the battery are simplified. In a preferred variant of this combination, the battery units are rotationally symmetric but not circular, preferably having a shape of a regular hexagon, and a housing of the battery has a corresponding inner shape, such that, after manufacture, the battery units of the battery are secured against rotation relative to each other by the housing of the battery in which they are inserted and kept in place and orientation by the matching between the outer shape of the battery units and the inner shape of the housing. Further disclosed is a variant of a rotationally symmetric metal/oxygen battery unit that has all features of the first aspect of the present invention, except the channel respectively the through-holes forming the channel, and a corresponding rotationally symmetric metal/oxygen battery formed of such battery units. The embodiments and variants and advantages based on a rotational symmetry, as already described in detail above in connection with the first, and/or second aspect of the present invention also apply correspondingly to this rotationally symmetric metal/oxygen battery unit or metal/oxygen battery.

A third aspect of the present invention is directed to a method of manufacture of a metal/oxygen battery comprising two or more battery units, in particular a method of manufacture of a battery according to the second aspect of the present invention. The method of manufacture comprises the following steps: In a first step, a battery housing is provided. In a second step, two or more battery units according to the first aspect of the present invention are provided. In a third step, said battery units are inserted in said battery housing, wherein the relative position and/or orientation of said battery units is controlled and set to a predefined position or orientation. In a fourth step, at least one of the relative position and the relative orientation of said battery units is fixed. In a preferred variant, the relative position or orientation is fixed by one or more fixing elements of said battery units. In an additional or alternate variant, the relative position or orientation is fixed by a matching and/or engagingly fitting inner shape of said battery housing and outer shape of said battery units. In an additional or alternative variant relating to the manufacturing of batteries from battery units having anode and cathode interconnects adapted such as to provide a connection in parallel or in series depending on the relative position or orientation of said battery units, the method comprises the step of arranging each battery unit in a predetermined positions and/or orientation relative to its neighboring battery units such as to electrically connect it in parallel or series to each of those neighboring battery units. This method relates in particular to the manufacturing of batteries according to the second aspect of the present invention. In particular, this method may also be used in connection with the various embodiments and variants described herein. Furthermore, the method and its variants may also be used for manufacturing the variant of the battery disclosed in the previous paragraph.

A fourth aspect of the present invention is directed to a vehicle, in particular an electric vehicle or a plug-in hybrid electric vehicle, comprising one or more battery units according to the first aspect of the invention, in particular comprising one or more batteries according to the second aspect of the invention are comprising one or more batteries manufactured according to the third aspect of the invention.

The embodiments and variants as well as potential benefits as already described in detail above in connection with the first, second, and/or third aspect of the present invention also apply correspondingly to the vehicle according to the present invention.

According to a first preferred embodiment, at least one of said one or more battery units or at least one of said one or more batteries is arranged such that its channel extends along a direction that is at least substantially parallel to the top-bottom direction of the vehicle. Accordingly, one may take advantage of convection of the oxygenous medium and/or cooling medium, in particular to exchange said medium and/or to provide a flow of said medium through the channel. A further advantage may arise from the fact that, in particular, the layered stack is particularly robust against shocks along its direction of stacking. Thus, in particular, compared to a vehicle without such an arrangement of batteries, a more reliable and/or robust vehicle with a longer lifetime may be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

Further advantageous, features and applications of the present invention are provided in the following detailed description of the exemplary embodiments and the appended figures, wherein:

Fig. 1 schematically illustrates a side view of a metal/oxygen battery unit according to a preferred embodiment of the present invention;

Fig. 2 shows a top view of the preferred embodiment;

Fig. 3 shows a cross-section through a metal/oxygen battery unit according to a further preferred embodiment of the present invention;

Fig. 4 shows a stack of the previous embodiment;

Fig. 5 schematically illustrates a side view of a metal/oxygen battery unit according to a further preferred embodiment of the present invention;

Fig. 6 schematically illustrates a metal/oxygen battery according to a further preferred embodiment of the present invention;

Fig. 7 illustrates a method of manufacture of a metal/oxygen battery according to the present invention;

Fig. 8 shows a vehicle with one or more batteries according to a further preferred embodiment of the present invention;

Fig. 9 schematically illustrates two alternative implementations of a metal/oxygen battery unit in a top view, i.e. (i) a further embodiment according to the present invention having a channel and (ii) a related implementation without a channel.

First, reference is made to Figure 1 , which shows a side view of a metal/oxygen battery unit 1 according to a preferred embodiment of the present invention. A metal/oxygen battery unit 1 comprises a layered galvanic stack 2. This layered galvanic stack 2 comprises a repeating sequence of layers forming three electrochemical cells, which are separated as well as electrically and ionically insulated from each other by ventilation layers 1 1 . In particular, such a layered galvanic stack may also contain less than or more than three electrochemical cells. Layered galvanic stack 2 comprises said ventilation layers 1 1 , three current collector layers 12 electrically connected to and facing three cathode layers 3, three separator layers 5 each facing a neighboring one of the cathode layers 4, three anode layers 3 each facing a neighboring one of the separator layers 5, and three additional current collector layers 12 each electrically connected to a facing one of said three anode layers 3. The direction of stacking of said layers 3, 4, 5, 1 1 , and 12 defines an axis AA along this direction. Furthermore, layered galvanic stack 2 comprises two anode interconnects 13, 13' and two cathode interconnects 14,14', wherein the anode interconnect 13' and the cathode interconnect 14' extend through a channel 6 of stack 2 and are thus, not depicted in the side view. Anode and cathode interconnects 13, 13', 14', 14' are electrically connected to respective anode or cathode layers 3 or 4 by corre- sponding current collector layers 12. Ventilation layers 1 1 beneficially allow to improve the distribution of oxygen, in particular of an oxygenous medium, along cathode layers 4. Furthermore, ventilation layers 1 1 separate and insulate the electrochemical cells, such that a connection in series or an ionic a shortcut of the electrochemical cells is avoided. Specifically, the three electrochemical cells are connected in parallel by anode interconnects 13, 13' and cathode interconnects 14, 14'.

A top view of the embodiment of Figure 1 is shown in Figure 2. The current collector layer 12 is provided with a through-hole 7. Moreover, also the other layers 3, 4, 5, 1 1 , 12, not depicted in Figure 2, of stack 2 are provided with the through-holes 7. Through-holes 7 form said channel 6 extending through the stack 2. Both anode interconnects 13, 13' and both cathode interconnects 14, 14' are depicted. Especially, anode interconnect 13' and cathode interconnect 14' extending through the channel 6 are depicted in Figure 2. The interconnects extending through channel 6 advantageously allow for reducing the electrical resistance of an electrical path ex- tending from the reaction sites of the cathode and anode layers 4,3 to the respective interconnect, compared to an electrical connection of the layers solely on the outside surface of stack 2. Moreover, channel 6 can support the exchange of said oxygenous medium, particularly air or oxygen, between a periphery of the metal/oxygen battery unit and cathode layers 4. Moreover, stack 2, and in particular layers 3, 4, 5, 1 1 , and 12 of stack 2, have a circular shape when viewed from the top and thus, in particular have cylindrical shape with respect to axis AA, which is not depicted in Figure 2 as it projects out of the plane of drawing. Preferably, battery unit 1 has an at least substantially cylindrical shape, in particular a cylindrical outer shape, whereby two of such battery units which are co-axially arranged relative to each other to form a joint cylinder, can be rotated relative to each other around their common axis without substantially affecting the form of the joint cylinder. This may, in particular, facilitate inserting said battery units in a battery housing having a cylindrical inner shape. Preferably, said bat- tery housing may comprise multiple receiving regions to receive anode interconnect 13 and cathode interconnect 14, which are located outside of stack 2, even when interconnects 13, 14 are not arranged in a rotationally symmetric manner around stack 2. Furthermore, interconnects 13, 13', 14, and/or 14' of two of such battery units may fix the relative position or orientation of said to battery units when con- nected.

Now, reference is made to Figure 3, which shows a cross-section through a metal/oxygen battery unit 1 according to a further preferred embodiment of the present invention, which is similar to that of Figures 1 and 2, particularly with the exception that some layers are missing and battery unit 1 comprises a battery unit housing 8. Specifically, galvanic stack 2 of unit battery 1 comprises three anode layers 3, three cathode layers 4, and five separator layers 5, wherein the inner anode and cathode layers face of one of the separator layers 5 on both sides and thus, five electrochemical cells are formed. So, in particular, a more compact battery unit, specifically a battery unit with a higher energy density, can be built. Battery unit housing 8 contains stack 2 with layers 3, 4, 5 and, preferably, electrically insulates the surface of stack 2, whereby stacking of multiple such battery units 1 may be facilitated.

Furthermore, in a preferred variant the battery unit 1 , and in particular at least one of the anode or cathode interconnects 13, 14, comprises a fixing element 10 by means of which the relative position or orientation of two of such battery units 1 can be secured. Preferably, said interconnect may serve as such fixing element, in which case additional fixing elements can be avoided. Additionally or alternatively, the outer shape of the layers and/or the housing 8 can be formed such that their relative ori- entation or position of at least two of such battery units 1 can be defined and fixed in cooperation with a housing of a battery comprising such battery units. Moreover, housing 8 of battery unit 1 comprises two apertures 9, adapted to guide said oxygenous medium and/or a cooling medium to channel 6, in particular to a first end of said channel 6', and/are adapted to receive said medium from channel 6, in particular from a second end of said channel 6". This can especially be beneficial for providing a flow of oxygenous medium and/or cooling medium.

Finally, all interconnects - anode interconnects 13 and cathode interconnects 14, wherein cathode interconnects 14 are not depicted - preferably extend through channel 6, whereby parts protruding outwards may be avoided and/or a more compact form of battery unit 1 may be achieved.

A top view of stack 2 of Fig. 3 is shown in Figure 4. Again, layers 3, 4, 5 are provided with through-holes 7 forming channel 6. The two anode interconnects 13 and the two cathode interconnects 14 extend through channel 6, which is substantially centered with respect to the layers. Moreover, interconnects 13, 14 are arranged such that, when stacking two of such battery units 1 , in a first position, the anode interconnects 13 of one of the two battery units can face and be in electric contact with the anode interconnects 14 of the other one of the two battery units. The same ap- plies to the cathode interconnects 14, and thus both battery units can be connected in parallel. Moreover, in a second position, in which one of the two battery units is rotated by an angle of 120° around the axis AA, the anode interconnects 13 of one of the two battery units can be in electric contact with the cathode interconnects in my 14 of the other of the two battery units, while the other interconnects are electri- cally disconnected. Thus, in the second position, the two battery units can be connected in series.

Furthermore, at least layers 3, 4, or 5 preferably have the shape of a regular polygon, in particular the shape of a hexagon as depicted in Figure 4. In this manner, when two of such battery units 1 are inserted in a battery housing with a corresponding inner shape, e.g. a hexagonal shape of an adequate size, the relative orientation of said battery units is fixed by said battery housing.

Now, reference is made to Figure 5, which shows a side view of a metal/oxygen battery unit 1 according to a further preferred embodiment of the present invention, which is similar to that of Figures 1 , 2, 3, and 4, particularly with the exception of a different arrangement of stack 2. Stack 2 comprises three electrochemical cells each with a anode layer 3, a separator layer 5, the cathode layer 4, and a current collector layer 12 facing and electrically connected to the respective cathode layer 4. The current collector layers 12 separate and ionically insulate the corresponding anode layers 3 from the cathode layers 4 on the opposite side of the respective current collector layer 12. Moreover, neighboring anode and current collector layer are electrically connected. Thus, the three electrochemical cells are electrically connected in series. Accordingly, the anode interconnect 13 is connected only to the topmost anode layer and the cathode interconnect is connected only to the lowermost current collector layer 12. Finally, stack 2 comprises an insulation layer 8i to electrically insulate the lowermost current collector layer 12. This may be particularly beneficial for stacking of such stacks or battery units.

Now, reference is made to Figure 6, which schematically illustrates a metal/oxygen battery 20 according to a further preferred embodiment of the present invention. Battery 20 comprises a first battery unit V and a second battery unit 1 ", a battery housing 21 , a first aperture 22, a second aperture 23, anode electrical connector 24, and a cathode electrical connector 25. As depicted, first battery unit V is rotated relative to second battery unit 1 " by an angle of about 120° around the axis AA and so arranged, as to electrically connect the cathode interconnect 14 of first battery unit 1 ' to the anode interconnect 13 of second battery unit 1 ". Consequently, battery units 1 ' and 1 " are connected in series.

Furthermore, anode electrical connector 24 is electrically connected to the anode interconnect 13 of first battery unit 1 ', which is not depicted in Figure 6, and cathode electrical connector 25 is electrically connected to the cathode interconnect 14 of second battery unit 1 ".

Finally, the first aperture 22 is overlapping with an aperture 9 of a housing of first battery unit V and the second aperture 23 is overlapping with an aperture 9 of the housing of second battery unit 1 ". Preferably, the apertures of the battery housing 21 , the apertures of the battery units V and 1 ", and channels 6 of said battery units jointly form a channel through battery 20, which preferably extends along axis AA, to support the exchange of oxygenous medium and special cooling medium between the inside of battery 20, in particular the channels 6, and a periphery of battery 20. Now, reference is made to Figure 7, which illustrates a method of manufacture of a metal/oxygen battery 20 according to a further preferred embodiment of the present invention. In a first step S1 , a battery housing 21 is provided. In a second step S2, two or more battery units 1 , 1 ', 1 " are provided. In a third step S3, said battery units 1 , 1 ', 1 " are inserted in battery housing 21 , wherein the relative position and/or orientation of said battery units 1 , 1 ', 1 " is controlled and set to a predefined position or orientation. In a fourth step S4, at least one of the relative position and the relative orientation of said battery units is fixed. In a preferred variant, the relative position or orientation is fixed by one or more fixing elements 10 of said battery units 1 , 1 ', 1 ". In an additional or alternate variant, the relative position or orientation is fixed by a matching and/or engagingly fitting inner shape of said battery housing and outer shape of said battery units. In an additional or alternate variant comprising battery units with anode and cathode interconnects 13, 13', 14, 14' adapted such as to provide a connection in parallel or in series depending on the relative position or orien- tation of said battery units 1 ', 1 ", the relative position or orientation may be chosen such that said battery units 1 ', 1 " are connected in parallel or in series. This may be particularly beneficial to manufacture batteries 20 with different voltage and/or current ratings based on the same battery units 1 , 1 ', 1 " whereby, in particular, a higher number of equal battery units can be produced, manufacturing is more efficient, or the rejection rate can be minimized.

Now, reference is made to Figure 8, which schematically illustrates a vehicle 30 according to a further preferred embodiment of the invention. Vehicle 30 comprises one or more, in the depicted variant in particular eight, metal/oxygen batteries 20, a temperature control system 31 , at least one supply channel 32, and at least one exhaust channel 33. Preferably, batteries 20 are arranged such that their channels or the channels 6 of their battery units extend along a direction that is at least substantially parallel to the top-bottom direction of the vehicle. Moreover, batteries 20 are connected to temperature control system 31 by supply channel 32. Preferably, supply channel 32 is connected to one or more second apertures 23 of the battery housings 21 of batteries 20. Also preferably, exhaust channel 33 is connected to one or more first apertures 22 of the battery housings 21 of batteries 20. Temperature control system 31 is adapted to supply the oxygenous medium to batteries 20. Especially, temperature control system 31 controls the temperature of the oxyge- nous medium, whereby the temperature of batteries 20 may be controlled by means of the oxygenous medium additionally serving as the cooling medium. Moreover, temperature control system 31 may, at least partially, recycle the oxygenous medium by exhaust channel 33. Accordingly, batteries 20 can be supplied with oxygen and cooled or heated at the same time by temperature control system 31 . Preferably, when charging batteries 20, oxygen released by the galvanic reaction may, at least partially, be guided to a tank by temperature control system 31 and/or exhaust channel 33. Also preferably, when batteries 20 discharge, oxygen from said tank and/or from a periphery of vehicle 30, e.g. air, may be guided to batteries 20 by temperature control system 31 and/or supply channel 32. In this advantageous manner, the power and durability of batteries 20 can be improved. This may be par- ticularly beneficial to improve the driving performance of vehicle 30, especially when one or more propulsion engines of vehicle 30 are powered by batteries 20.

Finally, reference is made to Fig. 9, which schematically illustrates two alternative implementations of a metal/oxygen battery unit in a top view, i.e. (i) a further embod- iment according to the present invention having a channel and (ii) a related implementation without a channel. For both implementations, the metal/oxygen battery unit of Fig. 9 is similar to that of Figs. 1 and 2, however with the exception that in implementation (ii) the layers are not provided with through-holes and consequently battery unit 1 lacks a channel and the particular advantages related thereto, as dis- cussed above. In implementation (i), however, the battery unit 1 is provided with a channel 6 and respective through-holes as depicted by the dashed line. Metal/oxygen battery unit 1 is rotationally symmetric for rotations of 60°. A stack 2 of battery unit 1 comprises at least an anode layer 3 as well as a cathode layer and a separator layer, wherein said cathode layer and said separator layer are not depict- ed in Fig. 9. Furthermore, stack 2 may comprise additional layers as described above and/or a multitude of such layers. An anode interconnect 13, a cathode interconnect 14, and an electrically non-conductive fixing element 10 are each arranged around a portion of the circumference of stack 2 and form in cooperation a battery unit housing 8. As depicted, anode interconnect 13 and cathode interconnect 14 each extend around at least 40° of the circumference of stack 2, and thus may provide an electrical contact to the anode or cathode layers of stack 2 with a low electrical resistance. From the depicted arrangement a further benefit may arise, in that battery unit 1 features a high degree of rotational symmetry. Two or more of such battery units 1 may be stacked together. When said battery units 1 are not rotated with respect to each other, e.g. fixing element 10 of one of said battery units is facing a fixing element 10 of another one of said battery units, said battery units are connected in parallel. When said battery units 1 are rotated by 120° with respect to each other, the fixing element of one of said battery units faces the anode or the cathode interconnect of the other one of said battery units, and thus said battery units are connected in series. Preferably, fixing element 10, anode interconnect 13, and/or cathode interconnect 14 are adapted to engage with another fixing element, anode or cathode interconnect of another battery unit 1 , when stacked together. Also preferably fixing element 10, anode interconnect 13, and/or cathode interconnect 14 are provided with channels for providing the oxygenous medium and/or a cooling medium.

While above at least one exemplary embodiment has been described, it has to be noted that a great number of variations thereto exists. It is also noted that the described exemplary embodiments represent only non-limiting examples and that it is not intended that the scope, the applicability or the configuration of the here- described apparatus and methods is thereby limited. Rather, the preceding description will provide the person skilled in the art with directions for the implementation of at least one of the exemplary embodiments, while it has to be appreciated that various different modifications of the functionality and the arrangement of the elements described in connection with the exemplary embodiments may be made without deviating from the scope of the invention as defined in the appended claims and its legal equivalents.

LIST OF REFERENCE SIGNS

1 metal/oxygen battery unit

V first battery unit

1 " second battery unit

2 layered galvanic stack

3 anode layer

4 cathode layer

5 separator layer

6 channel

6' first end of channel

6" second end of channel

7 through-hole

8 battery unit housing

8i insulation layer

9 aperture of battery unit housing

10 fixing element

1 1 ventilation layer

12 current collector, in particular current collector layer or integrated in anode layer or cathode layer

13, 13' anode interconnect

14, 14' cathode interconnect

20 metal/oxygen battery

21 battery housing

22 first aperture of battery housing

23 second aperture of battery housing

24 anode electrical connector

25 cathode electrical connector 30 vehicle

31 temperature control system of vehicle

32 supply channel

33 exhaust channel

S1 to S1 manufacturing steps

AA axis defined along the direction of stacking of the layers