Title:
SECONDARY BATTERY, BATTERY MODULE, AND VEHICLE
Document Type and Number:
Japanese Patent JP2023042962
Kind Code:
A
Abstract:
To provide a secondary battery having excellent lifetime characteristics and low resistance.SOLUTION: A secondary battery is provided according to an embodiment. The secondary battery includes: a wound electrode group including a positive electrode, a negative electrode containing a negative electrode active material, and a separator; and an exterior member accommodating the wound electrode group. The negative electrode active material contains a niobium-titanium composite oxide. A proportion (Rblack) determined by the following method is within the range of more than 2.0% and 20.0% or less. The proportion (Rblack) is determined by a method including the steps of: obtaining, by X-ray CT, 800 cross-sectional images orthogonal to a winding axis of the wound electrode group; binarizing each of the cross-sectional images; determining, as a percentage, a proportion of an area (Sb) of a black portion to an area (St) of the wound electrode group defined by an outer periphery of the wound electrode group in each of the binarized cross-sectional images; and simply averaging a plurality of the proportions obtained in each of the cross-sectional images.SELECTED DRAWING: Figure 6
Inventors:
YOSHIMA KAZUOMI
YANAGI ITSUHITO
NAMIKI YUSUKE
ISHIBASHI MITSURU
HOSHINA KEIGO
HARADA YASUHIRO
TAKAMI NORIO
WATANABE HIDETOSHI
YASUDA KAZUHIRO
YANAGI ITSUHITO
NAMIKI YUSUKE
ISHIBASHI MITSURU
HOSHINA KEIGO
HARADA YASUHIRO
TAKAMI NORIO
WATANABE HIDETOSHI
YASUDA KAZUHIRO
Application Number:
JP2021150404A
Publication Date:
March 28, 2023
Filing Date:
September 15, 2021
Export Citation:
Assignee:
TOSHIBA CORP
International Classes:
H01M10/0587; H01M4/485; H01M10/0525; H01M50/103; H01M50/209; H01M50/249
Attorney, Agent or Firm:
Patent Attorney Corporation Suzue Patent General Office