US 11,791,467 B2
Nonaqueous electrolyte secondary battery
Hajime Nishino, Nara (JP); Satoko Motomatsu, Osaka (JP); Kazuhiro Yoshii, Osaka (JP); Takao Sato, Osaka (JP); and Tomoki Shiozaki, Osaka (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD., Osaka (JP)
Appl. No. 16/636,818
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
PCT Filed Jul. 5, 2018, PCT No. PCT/JP2018/025525
§ 371(c)(1), (2) Date Feb. 5, 2020,
PCT Pub. No. WO2019/044168, PCT Pub. Date Mar. 7, 2019.
Claims priority of application No. 2017-167583 (JP), filed on Aug. 31, 2017.
Prior Publication US 2020/0373582 A1, Nov. 26, 2020
Int. Cl. H01M 4/62 (2006.01); H01M 4/36 (2006.01); H01M 4/66 (2006.01); H01M 10/0525 (2010.01); H01M 50/46 (2021.01); H01M 50/531 (2021.01); H01M 50/595 (2021.01); H01M 50/534 (2021.01); H01M 4/02 (2006.01)
CPC H01M 4/626 (2013.01) [H01M 4/366 (2013.01); H01M 4/662 (2013.01); H01M 10/0525 (2013.01); H01M 50/46 (2021.01); H01M 50/531 (2021.01); H01M 50/534 (2021.01); H01M 50/595 (2021.01); H01M 2004/027 (2013.01); H01M 2004/028 (2013.01)] 9 Claims
 
1. A nonaqueous electrolyte secondary battery comprising:
a coiled electrode assembly and a nonaqueous electrolyte,
wherein the coiled electrode assembly includes
a positive electrode,
a negative electrode,
a separator interposed between the positive electrode and the negative electrode,
a positive electrode lead electrically connected to the positive electrode, and
a positive electrode insulating tape that covers a portion of the positive electrode, and
the coiled electrode assembly is formed by coiling the positive electrode and the negative electrode with the separator interposed therebetween;
the positive electrode includes
a positive electrode current collector that includes a first main surface and a second main surface that is opposed to the first main surface and
a positive electrode active material layer that is supported by the first main surface and the second main surface;
the first main surface includes a first exposed section which faces the negative electrode and on which the positive electrode active material layer is not arranged;
the positive electrode lead is connected to the first exposed section and includes an extension section that protrudes from the first exposed section and an overlapping section that overlaps the first exposed section;
at least a portion of the first exposed section, along with at least a portion of the overlapping section, is covered with the positive electrode insulating tape;
the positive electrode insulating tape includes a base, a first layer that adheres to the first exposed section and to the overlapping section, and a second layer interposed between the base and the first layer; and
the second layer expands when heated above a threshold,
wherein the second layer includes a foaming filler that is in an unexpanded state and is configured to expand when heated above the threshold;
wherein the second main surface includes a second exposed section which is disposed so as to correspond to the first exposed section and on which the positive electrode active material layer is not arranged, and
at least a portion of the second main surface is covered with the positive electrode insulating tape.