US 11,670,770 B2
Method for manufacturing positive electrode active material, and secondary battery
Masahiro Takahashi, Kanagawa (JP); Mayumi Mikami, Kanagawa (JP); Yohei Momma, Kanagawa (JP); Teruaki Ochiai, Kanagawa (JP); and Jyo Saitou, Kanagawa (JP)
Assigned to Semiconductor Energy Laboratory Co., Ltd., Atsugi (JP)
Filed by SEMICONDUCTOR ENERGY LABORATORY CO., LTD., Atsugi (JP)
Filed on Sep. 29, 2020, as Appl. No. 17/36,740.
Application 17/036,740 is a continuation of application No. 16/624,319, previously published as PCT/IB2018/054351, filed on Jun. 14, 2018.
Claims priority of application No. 2017-124100 (JP), filed on Jun. 26, 2017; application No. 2017-199061 (JP), filed on Oct. 13, 2017; application No. 2018-007052 (JP), filed on Jan. 19, 2018; and application No. 2018-072924 (JP), filed on Apr. 5, 2018.
Prior Publication US 2021/0028456 A1, Jan. 28, 2021
Int. Cl. H01M 4/525 (2010.01); C01G 51/00 (2006.01); C01G 53/00 (2006.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/525 (2013.01) [C01G 51/66 (2013.01); C01G 53/66 (2013.01); H01M 10/0525 (2013.01); C01P 2002/32 (2013.01); C01P 2002/52 (2013.01); C01P 2002/72 (2013.01); C01P 2002/77 (2013.01); C01P 2002/85 (2013.01); C01P 2002/88 (2013.01); C01P 2004/04 (2013.01); C01P 2006/40 (2013.01); C01P 2006/42 (2013.01); H01M 2004/028 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A lithium ion secondary battery comprising:
a positive electrode active material comprising lithium cobalt oxide,
wherein a dQ/dV vs V curve in a range of greater than or equal to 4.0V and less than or equal to 4.8V is obtained by differentiating capacitance (Q) with respect to voltage (V) in a charge curve,
wherein the dQ/dV vs V curve comprises both a first peak and a second peak in a range of greater than or equal to 4.0V and less than or equal to 4.2V,
wherein the positive electrode active material has a crystal structure with a space group of P2/m between the first peak and the second peak,
wherein the dQ/dV vs V curve comprises a third peak in a range of greater than or equal to 4.5V and less than or equal to 4.7V, and
wherein a height of the third peak is less than a height of each of the first peak and the second peak.