Technical field

Aspects of the present invention relate to an electric battery cell unit comprising a stack of electrodes comprising a first electrode and a second electrode. Further, aspects of the present invention relate to an electric battery arrangement comprising a plurality of electric battery cell units of the above-mentioned sort.

Background

An electric battery cell can be seen as a container chemically storing energy. The electric battery cells may come in various forms and shapes. The electric battery cells may be connected in series and in parallel, into an electric battery arrangement, which may be called an electric battery pack, in order to attain the desired voltage and energy capacity. A conventional electric battery pack may be the complete enclosure or entity that delivers electric power to a product or equipment, for example an electric vehicle, such as a battery electric vehicle or a hybrid electric vehicle. In general, a conventional electric battery pack includes or contains electric battery cells, a control or management system, which may be called a battery management system (BMS) and may, for example, be implemented partly as software, and often also a cooling and/or heating system. Conventionally, the electric battery cells of an electric battery pack may be arranged in modules to attained serviceable units. A conventional module may be a frame holding a plurality of electric battery cells, and a conventional electric battery pack is assembled by interconnecting the modules. A conventional electric battery cell and/or a conventional electric battery pack may be provided with one or more protection arrangements, for example for short-circuit protection and/or overvoltage protection.

Summary

The inventors of the present invention have found drawbacks in conventional solutions for protecting the electric battery cells and/or the electric battery pack, for example for protecting the electric battery cells and/or the electric battery pack against overvoltage. For example, the inventors of the present invention have found that conventional protection measures to protect the electric battery cells and/or the electric battery pack are not sufficient.

An object of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

The above and further objects are solved by the subject matter of the independent claims. Further advantageous embodiments of the invention can be found in the dependent claims.

According to a first aspect of the invention, the above mentioned and other objects are achieved with an electric battery cell unit comprising a stack of electrodes comprising a first electrode and a second electrode, a first terminal, a second terminal, a cell fuse, and a casing for housing the stack of electrodes and the cell fuse, wherein the first terminal is electrically connected to the first electrode, wherein the second terminal is electrically connected to the second electrode, wherein the casing comprises an overpressure relief arrangement, and wherein the cell fuse is located between the overpressure relief arrangement and the stack of electrodes.

An advantage of the electric battery cell unit according to the first aspect is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided. The location of the cell fuse between the overpressure relief arrangement and the stack of electrodes positions the cell fuse close to the overpressure relief arrangement such that a tripping of the cell fuse, which for example may be the result of an overvoltage, will have at least a weaking effect on the overpressure relief arrangement, which will result in a quicker opening of the overpressure relief arrangement due to overpressure, and/or such that a tripping of the cell fuse will immediately open the overpressure relief arrangement. By way of the opening of the overpressure relief arrangement, heat, or thermal power, can be efficiently released from the electric battery cell unit and away from the stack of electrodes, thereby protecting the stack of electrodes and preventing a cell thermal runaway and propagation between electric battery cells and/or electric battery cell units.

A cell thermal runaway and propagation between electric battery cells located in a module and/or an electric battery pack is a thermal event that may be descried as an unstoppable chain reaction between electric battery cells. In general, a thermal runaway, or a cell thermal runaway and propagation, between electric battery cells is caused by a temperature increase in an electric battery cell which effects a thermal event in the electric battery cell which then propagates to neighboring electric battery cells which in turn experience a temperature increase effecting a thermal event in the neighboring electric battery cells, which propagates to further neighboring electric battery cells etc. In general, a thermal runaway will destroy electric battery cells and the electric battery pack. A thermal runaway may damage a vehicle which carries the electric battery cells and the electric battery pack.

The inventors of the present invention have found that at high voltages, or overvoltage, for example voltages exceeding 100 V, the tripping, or disconnection, of the cell fuse may cause long-lived arcs emitting excessive thermal power, or heat, that may melt the electric battery cell and ignite the stack of electrodes. The stack of electrodes may include an electrolyte which may be sensitive to overtemperatures and may at overtemperatures at least partly cause a thermal event. Upon overtemperatures and/or a thermal runaway, gas or gases may be produced from the stack of electrodes which may form an overpressure in the casing. By releasing the heat from the interior of the casing upon the tripping of the cell fuse and upon overvoltage by quickly evacuate, or vent, hot gas or gases from the interior of the casing to the external surroundings, the heat and hot gas/gases are disturbed away from the electric battery cell having the tripping cell fuse to a larger area outside the electric battery cell, whereby the excessive heat is manageable and a thermal event and melting of the electric battery cell is prevented, and hence a thermal runaway between electric battery cells is prevented in an efficient manner. An advantage of the electric battery cell unit according to the first aspect is that an improved short-circuit protection and/or overvoltage protection of the electric battery cell and/or the electric battery pack is/are provided. An advantage of the electric battery cell unit according to the first aspect is that an improved protection of the electric battery cell/cells and/or the electric battery pack against overtemperatures, thermal events and/or thermal runaway is provided. An advantage of the electric battery cell unit according to the first aspect is that an improved protection of the stack of electrodes is provided. An advantage of the electric battery cell unit according to the first aspect is that an improved protection of the stack of electrodes against overtemperatures is provided.

According to an advantageous embodiment of the electric battery cell unit according to the first aspect, the overpressure relief arrangement is configured to release heat from the interior of the casing to prevent thermal runaway of the stack of electrodes. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to a further advantageous embodiment of the electric battery cell unit according to the first aspect, the cell fuse is located in the proximity of the overpressure relief arrangement. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to another advantageous embodiment of the electric battery cell unit according to the first aspect, a first space is defined by and formed between the overpressure relief arrangement and the cell fuse, wherein the first space is empty of any heat blocking item blocking a transfer of heat produced from the tripping of the cell fuse from the cell fuse to the overpressure relief arrangement.

An advantage of this embodiment is that an efficient heat transfer from the tripping cell fuse to the overpressure relief arrangement is provided. An advantage of this embodiment is that a further improved protection of the electric battery cell/cells and/or the electric battery pack is provided. According to yet another advantageous embodiment of the electric battery cell unit according to the first aspect, the cell fuse is located at a position in relation to the overpressure relief arrangement such that the overpressure relief arrangement is weakened by way of the tripping of the cell fuse. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to still another an advantageous embodiment of the electric battery cell unit according to the first aspect, the cell fuse is located at a position in relation to the overpressure relief arrangement such that the overpressure relief arrangement is weakened by way of heat produced from the tripping of the cell fuse. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to an advantageous embodiment of the electric battery cell unit according to the first aspect, the cell fuse is located at a position in relation to the overpressure relief arrangement such that the overpressure relief arrangement is opened at least partly by way of the tripping of the cell fuse. An advantage of this embodiment is that a quick and/or immediate opening of the overpressure relief arrangement is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to a further advantageous embodiment of the electric battery cell unit according to the first aspect, the cell fuse is configured to be in any one of an electric current passing state and an electric current interrupting state, wherein the tripping of the cell fuse comprises the transition of the cell fuse from the electric current passing state to the electric current interrupting state.

An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to another advantageous embodiment of the electric battery cell unit according to the first aspect, the cell fuse comprises one or more electrically conductive members configured to break when an electric overcurrent flows through the electrically conductive member to interrupt an electric current. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to yet another advantageous embodiment of the electric battery cell unit according to the first aspect, a second space is defined by and formed between the overpressure relief arrangement and the stack of electrodes, wherein the electrically conductive member is located within the second space.

An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to still another advantageous embodiment of the electric battery cell unit according to the first aspect, the electric battery cell unit comprises a heat guide, wherein the casing houses the heat guide, and wherein the heat guide is located between the cell fuse and the stack of electrodes.

An advantage of this embodiment is that heat from the tripping cell fuse is prevented from reaching the stack of electrodes, or the heat from the tripping cell fuse reaching the stack of electrodes is at least efficiently reduced, and the stack of electrodes is efficiently protected. An advantage of this embodiment is that an improved protection of the stack of electrodes is provided. An advantage of this embodiment is that an improved protection of the stack of electrodes against overtemperatures is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack against overtemperatures, thermal events and/or thermal runaway is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to an advantageous embodiment of the electric battery cell unit according to the first aspect, the heat guide is configured to guide heat from the cell fuse in the direction toward the overpressure relief arrangement. An advantage of this embodiment is that heat from the tripping cell fuse is prevented from reaching the stack of electrodes, or the heat from the tripping cell fuse reaching the stack of electrodes is at least efficiently reduced, and the stack of electrodes is efficiently protected. An advantage of this embodiment is that an improved protection of the stack of electrodes is provided. An advantage of this embodiment is that an improved protection of the stack of electrodes against overtemperatures is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack against overtemperatures, thermal events and/or thermal runaway is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to a further advantageous embodiment of the electric battery cell unit according to the first aspect, the heat guide is arranged such that any imaginary straight line from the cell fuse to the stack of electrodes penetrates the heat guide. An advantage of this embodiment is that heat from the tripping cell fuse is efficiently prevented from reaching the stack of electrodes, or the heat from the tripping cell fuse reaching the stack of electrodes is at least efficiently reduced, and the stack of electrodes is efficiently protected. An advantage of this embodiment is that an improved protection of the stack of electrodes is provided. An advantage of this embodiment is that an improved protection of the stack of electrodes against overtemperatures is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack against overtemperatures, thermal events and/or thermal runaway is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to another advantageous embodiment of the electric battery cell unit according to the first aspect, the heat guide comprises one or more heat guiding plates. An advantage of this embodiment is that heat from the tripping cell fuse is efficiently prevented from reaching the stack of electrodes, or the heat from the tripping cell fuse reaching the stack of electrodes is at least efficiently reduced, and the stack of electrodes is efficiently protected. An advantage of this embodiment is that an improved protection of the stack of electrodes is provided. An advantage of this embodiment is that an improved protection of the stack of electrodes against overtemperatures is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack against overtemperatures, thermal events and/or thermal runaway is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to yet another advantageous embodiment of the electric battery cell unit according to the first aspect, the heat guide comprises a concave surface facing the cell fuse. An advantage of this embodiment is that heat from the tripping cell fuse is efficiently guided from the cell fuse in the direction toward the overpressure relief arrangement and thus away from the stack of electrodes. An advantage of this embodiment is that an improved protection of the stack of electrodes is provided. An advantage of this embodiment is that an improved protection of the stack of electrodes against overtemperatures is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack against overtemperatures, thermal events and/or thermal runaway is provided. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to still another advantageous embodiment of the electric battery cell unit according to the first aspect, the first terminal is electrically connectable to the first electrode via the cell fuse.

According to an advantageous embodiment of the electric battery cell unit according to the first aspect, the cell fuse is configured to be in any one of an electric current passing state and an electric current interrupting state, and wherein, when the cell fuse is in the electric current passing state, the first terminal is electrically connected to the first electrode via the cell fuse.

According to a further advantageous embodiment of the electric battery cell unit according to the first aspect, the casing encloses the stack of electrodes and the cell fuse. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided. According to another advantageous embodiment of the electric battery cell unit according to the first aspect, the overpressure relief arrangement is configured to be in any one of an open state and a closed state, and wherein in the open state the overpressure relief arrangement is configured to provide an opening in the casing to vent gas away from the interior of the casing. An advantage of this embodiment is that an improved protection of the electric battery cell/cells and/or the electric battery pack is provided.

According to still another advantageous embodiment of the electric battery cell unit according to the first aspect, the electric battery cell unit comprises one or more first electrode tabs electrically connected to the first electrode, and one or more second electrode tabs electrically connected to the second electrode, wherein the first terminal is electrically connected to the one or more first electrode tabs, wherein the second terminal is electrically connected to the one or more second electrode tabs, and wherein the casing houses the one or more first electrode tabs and the one or more second electrode tabs. The innovative arrangement of the cell fuse is advantageous for an electric battery cell unit including electrode tabs.

According to a second aspect of the invention, the above mentioned and other objects are achieved with an electric battery arrangement comprising two or more electric battery cell units according to any one of the embodiments disclosed above or below.

Advantages of the electric battery arrangement according to the second aspect and its embodiments correspond to the above- or below-mentioned advantages of the electric battery cell unit according to the first aspect and its embodiments.

According to a third aspect of the invention, the above mentioned and other objects are achieved with a method for protecting an electric battery cell unit from thermal runaway of a stack of electrodes included in the electric battery cell unit, wherein the electric battery cell unit comprises a stack of electrodes comprising a first electrode and a second electrode, a first terminal, a second terminal, a cell fuse, and a casing housing the stack of electrodes and the cell fuse, wherein the first terminal is electrically connected to the first electrode, wherein the second terminal is electrically connected to the second electrode, and wherein the casing comprises an overpressure relief arrangement, wherein the method comprises: positioning the cell fuse between the overpressure relief arrangement and the stack of electrodes to effect the opening of the overpressure relief arrangement at least party by way of the tripping of the cell fuse in response to an overvoltage in order to release heat from the interior of the casing.

Advantages of the method according to the third aspect and its embodiments correspond to the above- or below-mentioned advantages of the electric battery cell unit according to the first aspect and its embodiments and to the above- or below- mentioned advantages of the electric battery arrangement according to the second aspect and its embodiments.

According to a fourth aspect of the invention, the above mentioned and other objects are achieved with a vehicle comprising one or more of the group of:

• an electric battery cell unit according to any one of the embodiments disclosed above or below; and

• an electric battery arrangement according to any one of the embodiments disclosed above or below.

The advantages of the vehicle according to the fourth aspect and its embodiments correspond to the above- or below-mentioned advantages of the electric battery cell unit according to the first aspect and its embodiments and to the above- or below- mentioned advantages of the electric battery arrangement according to the second aspect and its embodiments.

The vehicle may be a wheeled vehicle, i.e. a vehicle having wheels. The vehicle may for example be a bus, a tractor vehicle, a heavy vehicle, a truck, or a car. The tractor vehicle, and/or the truck, may, or may be configured to, haul, or pull, a trailer. However, other types of vehicles are possible. The vehicle may be referred to as a motor vehicle. The vehicle may be an electric vehicle, EV, for example a hybrid vehicle or a hybrid electric vehicle, HEV, or a battery electric vehicle, BEV. Thus, a hybrid electric vehicle, HEV, and a battery electric vehicle, BEV, are versions, or examples, of an electric vehicle, EV. The EV may comprise one or more electric motors or electrical machines. The vehicle may comprise a combustion engine. For some embodiments, the vehicle may include only a combustion engine for the propulsion of the vehicle.

The vehicle may comprise a powertrain. The powertrain may be configured in accordance with any one of the embodiments disclosed above or below. The powertrain of the vehicle may comprise one or more of the group of: a combustion engine; an electric battery cell unit; an electric battery arrangement; and an electric battery pack.

The above-mentioned features and embodiments of the electric battery cell unit, the electric battery arrangement, the method and the vehicle, respectively, may be combined in various possible ways providing further advantageous embodiments.

Further advantageous embodiments of the electric battery cell unit, the electric battery arrangement, the method and the vehicle according to the present invention and further advantages with the embodiments of the present invention emerge from the detailed description of embodiments.

Brief Description of the Drawings

Embodiments of the invention will now be illustrated, for exemplary purposes, in more detail by way of embodiments and with reference to the enclosed drawings, where similar references are used for similar parts, in which: Figure 1 is a schematic cross-sectional side view of a first embodiment of the electric battery cell unit according to the first aspect of the invention;

Figure 2 schematically illustrates a cross-section of the electric battery cell unit along A-A in figures 1 and 3;

Figure 3 is a schematic top view of the electric battery cell unit of figure 1 illustrating an embodiment of the overpressure relief arrangement;

Figure 4 is a schematic cross-sectional side view of a second embodiment of the electric battery cell unit according to the first aspect of the invention;

Figure 5 is a schematic side view of the heat guide of the embodiment of figure 4;

Figures 6A-D are schematic cross-sectional side views of alternative embodiments of the heat guide of embodiments of the electric battery cell unit;

Figure 7 is a schematic flow chart illustrating aspects of embodiments of the method according to the third aspect of the invention;

Figure 8 is a schematic diagram illustrating aspects of an embodiment of the electric battery arrangement according to the second aspect of the invention;

Figure 9 is a schematic diagram illustrating further aspects of the embodiment of the electric battery arrangement of figure 8; and

Figure 10 is a schematic side view of an embodiment of the vehicle according to the fourth aspect.

Detailed Description

With reference to reference to figure 1 , a first embodiment of the electric battery cell unit 100 according to the first aspect of the invention is schematically illustrated. The electric battery cell unit 100 includes a first terminal 102 and a second terminal 104. Each one 102, 104 of the first and second terminals 102, 104 may be described as electrically conductive or as an electrical conductor. Each one 102, 104 of the first and second terminals 102, 104 may at least partly be made of an electrically conductive material. Each one 102, 104 of the first and second terminals 102, 104 may be made of an electrically conductive material. Each one 102, 104 of the first and second terminals 102, 104 may be made of a material comprising a metal or a metal alloy. Flowever, other materials are possible. With reference to figure 2, the electric battery cell unit 100 includes a stack of electrodes 106. The stack of electrode 106 may be described as an arrangement, or configuration, of electrodes 108, 110. The stack of electrodes 106 includes a first electrode 108 and a second electrode 110. The stack of electrodes 106 may comprise an electrolyte. The stack of electrodes 106 may comprise a separator 111 for separating the first and second electrodes 108, 110. One or more of the first electrode 108, the second electrode 110 and the separator 111 may be formed as a sheet. The one or more sheets may be rolled to form a roll. The stack of electrodes 106 may comprise a jelly roll stack comprising the first electrode 108 and the second electrode 110. In some embodiments, the jelly roll stack may comprise one or more jelly rolls. The jelly roll stack may include the electrolyte and the separator 111. However, it is to be understood that other types, or other configurations, of stacks of electrodes in addition to the jelly roll stack are possible. In general, it is to be understood that an electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit, for example an electrolyte, a vacuum, air, or a semiconductor. The electrical battery cell unit 100 may comprise a lead-acid battery cell, a Li-ion battery cell, or a NiMH battery cell, but is not limited thereto.

With reference to figure 2, for some embodiments, one 108, 110 of the first and second electrodes 108, 110 may be described as a positive electrode 108, 110 while the other one 108, 110 of the first and second electrodes 108, 110 may be described as a positive electrode 108, 110. For some embodiments, one 108, 110 of the first and second electrodes 108, 110 may be described as an anode 108, 110 while the other one 108, 110 of the first and second electrodes 108, 110 may be described as a cathode 108, 110.

With reference to figure 2, the first terminal 102 is electrically connected, or connectable, to the first electrode 108. The first terminal 102 may also be described to be mechanically connected, or connectable, to the first electrode 108. The second terminal 104 is electrically connected, or connectable, to the second electrode 110. The second terminal 104 may also be described to be mechanically connected, or connectable, to the second electrode 110. In the context of this disclosure, “electrically connected” is to be understood as directly electrically connected, or indirectly electrically connected. For example, when two items are described as electrically connected to one another, it is to be understood that these two items may be directly electrically connected to one another or indirectly electrically connected to one another, for example via one or more intermediate electrical conductors 113, or internal busbars.

With reference to figure 1 , the electric battery cell unit 100 includes a cell fuse 112. The cell fuse 112 may be described as an electric current interrupter, for example a cell-internal electric current interrupting device or element. For some embodiments, the cell fuse 112 is configured to be in any one of an electric current passing state and an electric current interrupting state. The cell fuse 112 may be configured to trip upon an electric overcurrent. The tripping of the cell fuse 112 may comprise the transition of the cell fuse 112 from the electric current passing state to the electric current interrupting state. The cell fuse 112 may be described as a cell fuse 112 for protection. For some embodiments, the cell fuse 112 provides an overcurrent protection. The cell fuse 112 may be described as a cell fuse 112 for short-circuit protection, overvoltage or high-voltage protection and/or overcurrent protection. In some embodiments, the cell fuse 112 may comprise, or be, a melt fuse, or a pyrotechnic fuse (or pyro fuse). Flowever, other types of fuses are possible for the cell fuse 112.

With reference to figure 1 , the cell fuse 112 may include one or more electrically conductive members 114a, 114b configured to break, for example through melting, when an electric overcurrent flows through the electrically conductive member 114a, 114b to interrupt an electric current. The electrically conductive member 114a, 114b may be seen as an intended, or designed, weakening or weakness, of an electrical conductor 116 or of an electrically conductive element, or busbar, of the cell fuse 112. In some embodiments, the electrically conductive member 114a, 114b may be limited, or defined to a certain extent, by one or more recesses 118a, 118b and one or more through-holes 120 formed, or defined, by the cell fuse 112, or by the electrical conductor 116. In the shown embodiment, the cell fuse 112 includes two electrically conductive members 114a, 114b separated, or weakened, by one through-hole 120 formed by the electrical conductor 116 of the cell fuse 112. Further, each one 114a, 114b of the two electrically conductive members 114a, 114b is limited, or weakened, by a recess 118a, 118b. However, it is to be understood that several other configurations of the cell fuse 112 in addition to the embodiment shown in figure 1 are possible. For example, in other embodiments, the electrically conductive member may comprise an electrically conductive wire or strip. The electrically conductive member 114a, 114b of the cell fuse 112 may be made of a material comprising a metal or a metal alloy. However, other materials are possible.

With reference to figure 1 , the electric battery cell unit 100 includes a casing 122 for housing the stack of electrodes 106 and the cell fuse 112. In the embodiment shown in figures 1 to 3, the casing 122 houses the stack of electrodes 106 and the cell fuse 112. When the stack of electrodes 106 includes an electrolyte, the casing 122 houses the electrolyte. When the stack of electrodes 106 includes a separator 111 , the casing 122 houses the separator 111. For some embodiments, it may be defined that the casing 122 encloses the stack of electrodes 106 and the cell fuse 112. When the stack of electrodes 106 includes an electrolyte, the casing 122 may enclose the electrolyte. When the stack of electrodes 106 includes a separator 111 , the casing 122 may enclose the separator 111. For some embodiments, the first and second terminals 102, 104 may be attached to the casing 122.

With reference to figures 1 and 3, the casing 122 includes an overpressure relief arrangement 124. It may be defined that the casing 122 has one or more walls 125. For some embodiments, it may be defined that the one or more walls 125 of the casing 122 comprises, or forms, the overpressure relief arrangement 124. It may be defined that the overpressure relief arrangement 124 is configured to be in any one of an open state and a closed state, wherein in the open state the overpressure relief arrangement 124 is configured to provide an opening in the casing 122 to vent gas, or gases, away from the interior 126 of the casing 122, for example to the to the external surroundings 127. It may be defined that the overpressure relief arrangement 124 is configured to release heat from the interior 126 of the casing 122 to prevent thermal runaway of the stack of electrodes 106. It may be defined that the overpressure relief arrangement 124 is configured to release overpressure and heat from the interior 126 of the casing 122.

In the embodiment shown in figures 1 and 3, the overpressure relief arrangement 124 comprises one or more recesses 128, or notches, for example one or more longitudinal recesses 128. Alternatively, it may be defined that the overpressure relief arrangement 124 comprises an arrangement 130 of one or more recesses 128, or notches. The one or more recesses 128, or notches, may be configured to open upon overpressure in the interior 126 of the casing 122 to provide an opening in the casing to vent gas away from the interior of the casing 122 and to provide a transition of the overpressure relief arrangement 124 to the open state. The one or more recesses 128 may be disclosed as a weakness, or weaknesses, in the casing 122, or in the wall 125 of the casing 122. However, it is to be understood that other kinds of overpressure relief arrangements are possible. For example, the overpressure relief arrangement 124 may comprise one or more overpressure relief valves. For example, the overpressure relief arrangement

124 may comprise a wall portion of a wall 125 of the casing 122, wherein said wall portion may have a thickness which is less than the general thickness of the wall/walls

125 of the casing 122. Thus, the thickness of the wall/walls 125 of the casing 122 outside said wall portion may exceed the thickness of said wall portion. With reference to figure 3, the one or more recesses 128, or notches, may have extensions and shapes different from the recesses 128 illustrated in figure 3.

With reference to figures 1 and 3, for some embodiments, it may be defined that, when the overpressure relief arrangement 124 is in the closed state, the casing 122 is configured to separate, or seal off, the stack of electrodes 106 and the cell fuse 112, and/or separate, or seal off, the interior 126 of the casing 122, from the external surroundings 127 outside the casing 122, possibly with the assistance of the overpressure relief arrangement 124. When the stack of electrodes 106 includes an electrolyte, it may be defined that, when the overpressure relief arrangement 124 is in the closed state, the casing 122 is configured to separate, or seal off, the electrolyte from the from the external surroundings 127 outside the casing 122, possibly with the assistance of the overpressure relief arrangement 124. When the stack of electrodes 106 includes a separator 111 , it may be defined that, when the overpressure relief arrangement 124 is in the closed state, the casing 122 is configured to separate, or seal off, the separator 111 from the from the external surroundings 127 outside the casing 122, possibly with the assistance of the overpressure relief arrangement 124.

With reference to figures 1 and 3, the first terminal 102 may be electrically connectable to the first electrode 108 via the cell fuse 112, for example via the one or more electrically conductive members 114a, 114b. More specifically, it may be defined that when the cell fuse 112 is in the electric current passing state, the first terminal 102 is electrically connected to the first electrode 108 via the cell fuse 112.

With reference to figure 1 , the cell fuse 112 is located between the overpressure relief arrangement 124 and the stack of electrodes 106. It may be defined that the cell fuse 112 is located in the proximity of the overpressure relief arrangement 124. For some embodiments, the cell fuse 112 may be spaced apart from the overpressure relief arrangement 124, i.e. the cell fuse 112 may be positioned with a distance, for example a small distance, to the overpressure relief arrangement 124, and/or there may be a gap between the cell fuse 112 and the overpressure relief arrangement 124. A first space 132 may be defined by the overpressure relief arrangement 124 and the cell fuse 112, and the first space 132 may be formed between the overpressure relief arrangement 124 and the cell fuse 112. For some embodiments, the first space 132 is empty of any heat blocking item blocking a transfer of heat produced from the tripping of the cell fuse 112 from the cell fuse 112 to the overpressure relief arrangement 124. For some embodiments, the first space 132 is empty of any item.

With reference to figure 1 , for some embodiments, the cell fuse 112 is located at a position in relation to the overpressure relief arrangement 124 such that the overpressure relief arrangement 124 is weakened by way of the tripping of the cell fuse 112. For some embodiments, the cell fuse 112 is located at a position in relation to the overpressure relief arrangement 124 such that the overpressure relief arrangement 124 is weakened by way of heat produced from the tripping of the cell fuse 112. For some embodiments, the cell fuse 112 is located at a position in relation to the overpressure relief arrangement 124 such that the overpressure relief arrangement is opened at least partly by way of the tripping of the cell fuse. For some embodiments, the cell fuse 112 is located at a position in relation to the overpressure relief arrangement 124 such that the overpressure relief arrangement 124 is thermally weakened or opened least partly by way of the tripping of the cell fuse 112. As mentioned above, the tripping of the cell fuse 112 may comprise the transition of the cell fuse 112 from the electric current passing state to the electric current interrupting state. The overpressure relief arrangement 124 may be weakened by the embodiments mentioned above or below by lessen the strength of the overpressure relief arrangement 124. The overpressure relief arrangement 124 may be weakened by the embodiments mentioned above or below by making the overpressure relief arrangement 124 more inclined to release overpressure, or gas, or collapse. The overpressure relief arrangement 124 may be weakened by the embodiments mentioned above or below by reducing the overpressure relief arrangement’s 124 resistance to pressure.

With reference to figure 1 , for some embodiments, when the cell fuse 112 comprises, or is, a melt fuse, the melting time of the cell fuse 112 upon overvoltage and/or overcurrent, i.e. the time it takes for cell fuse 112 to break through melting in order to interrupt an electric current, may be less than 10 ms, for example less than 8 ms.

With reference to figure 1 , for some embodiments, a second space 134 may be defined by the overpressure relief arrangement 124 and the stack of electrodes 106, and the second space 134 may be formed between the overpressure relief arrangement 124 and the stack of electrodes 106. For some embodiments, the electrically conductive member 114a, 114b is located within the second space 134.

With reference to figure 4, a second embodiment of the electric battery cell unit 200 according to the first aspect of the invention is schematically illustrated. Several features of the second embodiment of the electric battery cell unit 200 may correspond to the features of the first embodiment of the electric battery cell unit 100 disclosed above in connection with figures 1 to 3 and are thus not repeated here. In addition to the features which the second embodiment of the electric battery cell unit 200 may have in common with the first embodiment of the electric battery cell unit 100, the electric battery cell unit 200 in figure 4 comprises a heat guide 236. The heat guide 236 may referred to as a thermal guide. For some embodiments, the heat guide 236 may be described as a thermal reflector or a heat reflector for reflecting heat. For some embodiments, the heat guide 236 may be described as a heat or thermal radiation reflector and/or a thermal conductive guide. When the heat guide 236 is included, the casing 122 houses the heat guide 236, wherein the heat guide 236 is located between the cell fuse 112 and the stack of electrodes 106. For some embodiments, it may be defined that the heat guide 236 is configured to guide heat from the cell fuse 112 in the direction 138 toward the overpressure relief arrangement 124. For some embodiments, it may be defined that the heat guide 236 is configured to focus and redirect heat from the cell fuse 112 in the direction 138 toward the overpressure relief arrangement 124.

With reference to figures 6A to 6D, alternative embodiments of the heat guide 236a, 236b, 236c, 236d of embodiments of the electric battery cell unit 200 are schematically illustrated.

With reference to figures 4, 5 and 6A to 6D, the heat guide 236, 236a, 236b, 236c, 236d may comprises one or more heat guiding plates 240, 240a, 240b, 240c, 240d, or one or more heat reflecting plates. With reference to figures 6A to 6D, the heat guide 236a, 236b, 236c, 236d may comprise a concave surface 242a, 242b, 242c, 242d facing the cell fuse 112.

With reference to figure 6A, for some embodiments, the heat guide 236a is arranged, or configured, such that any imaginary straight line 244 from the cell fuse 112 to the stack of electrodes 106 penetrates the heat guide 236a. By arranging the heat guide 236a in this manner, heat from the tripping cell fuse 112 is efficiently prevented, or blocked, from reaching the stack of electrodes 106, or the heat from the tripping cell fuse 112 which reaches the stack of electrodes 106 is at least efficiently reduced. Expressed alternatively, it may be described that the heat guide 236a is arranged, or configured, such that the stack of electrodes 106 is not visible from the position of the cell fuse 112, or such that the view of the stack of electrodes 106 is completely blocked from the position of the cell fuse 112. With reference to figures 4, 5 and 6A to 6D, the heat guide 236, 236a, 236b, 236c, 236d may be attached to the casing 122. It is to be understood that other shapes and configurations of the heat guide 236, 236a, 236b, 236c, 236d are possible.

With reference to figure 5, the heat guide 236 may comprise a first layer 246 and a second layer 248. Each one 246, 248 of the first and second layer 246, 248 may be an outer layer or a surface layer. The fist layer 246 is configured to face the cell fuse 112. It may be defined that the second layer 248 is configured to face the stack of electrodes 106. The first layer 246 may be a highly reflective layer in order to reflect or radiate heat toward, or in a direction 138 toward, the overpressure relief arrangement 124. The first layer 246 may be made of a material comprising a metal or a metal alloy, for example, but not limited thereto, silver, gold, aluminium, chromium, or a glass fiber- enforced polymer. Other materials are also possible for the first layer 246. The first layer 246 may be applied to the heat guide 236 as a coating. The fist layer 246 may be a film or a foil. The second layer 248 may be a low thermal conductivity layer in order to minimize heat transfer to the stack of electrodes 106. The second layer 248 may be made of a material comprising a metal or a metal alloy, a ceramic material, or an organic material. Other materials are also possible for the second layer 248. For some embodiments, the heat guide 236, 236a, 236b, 236c, 236d may be described as a guide to guide the heat substantially in only one direction 138, which is toward the overpressure relief arrangement 124.

Otherwise, the electric battery cell unit 200 of figure 4 may correspond to the electric battery cell unit 100 of figures 1 to 3.

With reference to figures 1 , 2 and 4, for some embodiments, the electric battery cell unit 100; 200 may comprise one or more first electrode tabs 150 electrically connected to the first electrode 108. For some embodiments, the electric battery cell unit 100; 200 may comprise one or more second electrode tabs 152 electrically connected to the second electrode 110. When the one or more first electrode tabs 150 and the one or more second electrode tabs 152 are present, the first terminal 102 may be electrically connected, or connectable, to the one or more first electrode tabs 150 while the second terminal 104 may be electrically connected, or connectable, to the one or more second electrode tabs 152. When the one or more first electrode tabs 150 and the one or more second electrode tabs 152 are present, it may be defined that the first terminal 102 is electrically connected, or connectable, to the first electrode 108 via the one or more first electrode tabs 150 while the second terminal 104 is electrically connected, or connectable, to the second electrode 110 via the one or more second electrode tabs 152. However, for some embodiments, the electric battery cell unit 100; 200 may be free of any electrode tab 150, 152, i.e. the electrode tabs 150, 152 may be excluded.

With reference to figures 1 and 4, the electric battery cell unit 100; 200 may be configured for high voltage. A normal cell voltage of a normal electric battery cell may be equal to 4 V, 5 V, or 10 V. For some embodiments, a high voltage with the regard to the electric battery cell unit 100; 200 may be a voltage above the normal cell voltage. For some embodiments, a high voltage with the regard to the electric battery cell unit 100; 200 may be a voltage above any one of the normal cell voltages mentioned above.

For some embodiments, the properties of the overpressure relief arrangement 124 may be tuned based on the tripping properties of the cell fuse 112 and arcing at different voltages. For some embodiments, the tripping properties of the cell fuse 112 may be tuned based on the properties of the overpressure relief arrangement 124.

With reference to figures 1 and 4, the electric battery cell unit 100; 200 may be configured for propulsion of a vehicle 600 (see figure 10).

With reference to figure 7, aspects of embodiments of the method for protecting an electric battery cell unit 100; 200 from thermal runaway of a stack of electrodes 106 included in the electric battery cell unit 100; 200 according to the third aspect are schematically illustrated, wherein the electric battery cell unit 100; 200 includes a stack of electrodes 106 comprising a first electrode 108 and a second electrode 110, a first terminal 102, a second terminal 104, a cell fuse 112, and a casing 122 housing the stack of electrodes 106 and the cell fuse 112, wherein the first terminal 102 is electrically connected to the first electrode 108, wherein the second terminal 104 is electrically connected to the second electrode 110, and wherein the casing 122 comprises an overpressure relief arrangement 124, wherein the method comprises: positioning 301 the cell fuse 112 between the overpressure relief arrangement 124 and the stack of electrodes 106 to effect the opening 302 of the overpressure relief arrangement 124 at least party by way of the tripping of the cell fuse 112 in response to an overvoltage in order to release heat from the interior 126 of the casing 122.

With reference to figure 8, an embodiment of the electric battery arrangement 400 according to the second aspect of the invention is schematically illustrated in the form of a schematic circuit diagram, wherein the electric battery arrangement 400 includes two or more, i.e. a plurality of, electric battery cell units 100; 200, according to any one of the embodiments disclose above or below. The illustrated electric battery arrangement 400 may be carried by, or included in, a vehicle 600 and/or included in a powertrain 606 of the vehicle 600 (see figure 10).

With reference to figure 8, each electric battery cell unit 100; 200 can be seen as a container chemically storing energy and may be a rechargeable electric battery cell unit 100; 200. The electric battery cell units 100; 200 may be electrically connected in series and/or in parallel, into the electric battery arrangement 400, which also may be referred to as, or form, an electric battery pack 500 (see figure 9), in order to attain the desired voltage and energy capacity. In the shown embodiment, the electric battery cell units 100; 200 are electrically connected in series with one another. In shown embodiment, the electric battery cell units 100; 200 are part of a main power line 401 . However, in some embodiments, the main power line 401 may be excluded and the electric battery cell units 100; 200 may be electrically interconnected in other ways. The electric battery arrangement 400, or pack 500, may form the complete enclosure that delivers electric power to a product or equipment, for example an electric vehicle, EV. With reference to figure 8, the electric battery arrangement 400 may include a cell controller 402 which may be electrically connected in parallel with each electric battery cell unit 100; 200 by way of a plurality of electrical lines 404, for example electrical wires. The cell controller 402 may be called a cell module controller (CMC). As disclosed above, the electric battery cell unit 100; 200 includes a cell fuse 112, for example, for short-circuit and/over voltage protection.

With reference to figure 8, for some embodiments, the electrical battery arrangement 400 has two outputs 408, 410 for connecting the electrical battery arrangement 400 to one or more electrical loads, for example via a vehicle electrical system 610 (see figure 10) and/or electrical conductors. The two outputs 408, 410 may be referred to as electrical contacts. One 408, 410 of the two outputs 408, 410 may be a negative terminal having a negative pole, while the other one 408, 410 of the two outputs 408, 410 may be a positive terminal having a positive pole.

With reference to figure 8, the electric battery arrangement 400 may be configured for propulsion of a vehicle 600 (see figure 10).

One or more of the embodiments of the electrical battery arrangement 400, for example as illustrated in figure 8, may be included in, or form, an electric battery pack 500 schematically illustrated in figure 9, for example suitable for a vehicle 600 (see figure 10). It may be defined that the electric battery pack 500 is configured for propulsion of a vehicle 600 (see figure 10). The electrical battery arrangement 400 illustrated in figure 8 may be referred to as a module. With reference to figure 9, the electric battery pack 500 may comprise one or more electrical battery arrangements 400 according to embodiments of the electrical battery arrangement 400, for example as illustrated in figure 8. The electric battery pack 500 may have two end terminals 510, 512 (DC positive and DC negative) for electric power, or current, transfer, to be connected to one or more electrical loads, for example via a vehicle electrical system 610 (see figure 10) and/or electrical conductors. The above-mentioned two outputs 408, 410 may be connected to the two end terminals 510, 512 of the electric battery pack 500. With reference to figure 9, the electric battery pack 500 may comprise one or more internal contactors 502 switchable between an open position, or a non-conducting state, and a closed position, or a conducting state. When the internal contactor 502 is in the closed position, the internal contactor 502 is configured to conduct an electric current or allow an electric current to pass. When the internal contactor 502 is in the open position, the internal contactor 502 is configured to interrupt an electric current, or an electrical conductivity, such that no electric current can pass through the internal contactor 502. The electric battery pack 500 may include a battery management system 504, BMS. The battery management system 504, BMS, may be described as a control system for controlling the electric battery pack 500. The one or more internal contactors 502 of the electric battery pack 500 may be controlled by the battery management system 504. The battery management system 504 may be connected to and communicate with the above-mentioned cell module controller, CMC, 402 of the electric battery arrangement 400 shown in figure 8.

With reference to figure 9, the electric battery pack 500 may include a pre-charge contactor 506 switchable between an open position, or a non-conducting state, and a closed position, or a conducting state. In general, when the battery management system 504 is activated or active, a pre-charging of an electrical system (such as a vehicle electrical system) may be performed before all the internal contactors 502 are closed, for example with the aid of the pre-charge contactor 506. Pre-charging of a high voltage direct current system is known to the person skilled in the art and is thus not discussed in further detail.

With reference to figure 9, the electric battery pack 500 may comprises an electric battery pack fuse 508, which, for example, may be a melt fuse, or a pyrotechnic fuse (or pyro fuse), for protection. It is to be understood that the electric battery pack 500 may include additional electrical components or equipment known to the person skilled in the art, such as sensors, but these are left out for illustrative purposes.

With reference to figure 10, an embodiment of the vehicle 600 according to the fourth aspect of the invention is schematically illustrated. The vehicle 600 includes one or more of the group of: an electric battery cell unit 100; 200 according to any one of the embodiments disclosed above or below; and an electric battery arrangement 400 according to any one of the embodiments disclosed above or below.

With reference to figure 10, the vehicle 600 is illustrated as a tractor vehicle. However, in other embodiments, the vehicle 600 may, for example, be a bus, a truck, a heavy truck or a car. Other types of vehicles are also possible. The vehicle 600 may be an electric vehicle, EV, for example a hybrid vehicle or a hybrid electric vehicle, HEV, or a battery electric vehicle, BEV.

With reference to figure 10, the vehicle 600 may be a wheeled vehicle, i.e. a vehicle 600 having wheels 604. Only the wheels 604 on the left-hand side of the vehicle 600 are visible in figure 10. It is to be understood that the vehicle 600 may have fewer or more wheels than what is shown in figure 10. The vehicle 600 may comprise a powertrain 606, for example configured for one of an EV, HEV and BEV. The vehicle 600 may be configured to hold or carry, or may include, one or more electric battery cell units 100; 200 according to any one of the embodiments disclosed above, an electrical battery arrangement 400 according to the embodiment disclosed above, for example as illustrated in figures 8, and/or an electric battery pack 500 as illustrated in figure 9. The electrical battery arrangement 400 and/or the electric battery pack 500 may, for example, be attachable to a chassis 607 of the vehicle 600. It is to be understood that the vehicle 600 may include further unites, components, such as electrical and/or mechanical components, one or more electric motors 602, a combustion engine 608 and other devices required for a vehicle 600, such as for an EV, HEV or BEV.

With reference to figure 10, it may be defined that the powertrain 606 and/or the one or more electric motors 602 is/are configured to propel, or drive, the vehicle 600. It may be defined that the powertrain 606 includes the one or more electric battery cell units 100; 200, the electrical battery arrangement 400 and/or the electric battery pack 500.

With reference to figure 10, the vehicle 600 may include a vehicle electrical system 610. It may be defined that the vehicle electrical system 610 is configured for direct current. It may be defined that vehicle electrical system 610 is a vehicle high voltage system 610. It may be defined that the vehicle high voltage system 610 is configured for a high voltage, such as a voltage above 60 V, for example above 400 V, or above 450 V, such as above 650 V. For example, the vehicle high voltage system 610 may be configured for a voltage up to 1500 V and/or for a voltage above 1500 V. The electric power, or the electric current, for example the direct current, of the vehicle electrical system 610 may be transferred at a high voltage, for example at one or more of the voltages levels mentioned above. The vehicle electrical system 610 may be configured to transfer the electric power, or the electric current, at a high voltage, for example at one or more of the voltages levels mentioned above. The vehicle electrical system 610 may be configured to transfer direct current.

With reference to Figure 10, the vehicle electrical system 610 may be electrically connected, or connectable, to the one or more electric battery cell units 100; 200, the electrical battery arrangement 400 and/or the electric battery pack 500. The one or more electric battery cell units 100; 200 may be one or more high voltage battery cell units 100; 200. It may be defined that the one or more electric battery cell units 100; 200, the electrical battery arrangement 400 and/or the electric battery pack 500 is/are configured for high voltage, for example for one or more of the voltages levels mentioned above. The vehicle electrical system 610 may be configured to electrically connect the one or more electric battery cell units 100; 200, the electrical battery arrangement 400 and/or the electric battery pack 500 to the powertrain 606 of the vehicle 600. The vehicle electrical system 610 may be configured to electrically connect the one or more electric battery cell units 100; 200, the electrical battery arrangement 400 and/or the electric battery pack 500 to the one or more electric motors 602 of the vehicle 600. It may be defined that the vehicle electrical system 610 is configured to transfer the electric power, or the electric current, for example between the one or more electric motors 602 (and/or the powertrain 606) and the one or more electric battery cell units 100; 200, the electrical battery arrangement 400 and/or the electric battery pack 500.

It is to be understood that embodiments of the electric battery cell unit 100; 200, the method and the electrical battery arrangement 400; 500 may be applied to configurations, structures, or apparatuses, different from a vehicle 600. The present invention is not limited to the above-described embodiments. Instead, the present invention relates to, and encompasses all different embodiments being included within the scope of the independent claims.