US 12,237,508 B2
Negative electrode active material for secondary battery, method of producing the same, and negative electrode for secondary battery and lithium secondary battery including the same
Hee Won Choi, Daejeon (KR); Je Young Kim, Daejeon (KR); Sang Wook Woo, Daejeon (KR); and Li Lin Piao, Daejeon (KR)
Assigned to LG ENERGY SOLUTION, LTD., Seoul (KR)
Appl. No. 17/292,200
Filed by LG ENERGY SOLUTION, LTD., Seoul (KR)
PCT Filed Jan. 16, 2020, PCT No. PCT/KR2020/000833
§ 371(c)(1), (2) Date May 7, 2021,
PCT Pub. No. WO2020/149683, PCT Pub. Date Jul. 23, 2020.
Claims priority of application No. 10-2019-0006527 (KR), filed on Jan. 18, 2019.
Prior Publication US 2021/0328220 A1, Oct. 21, 2021
Int. Cl. H01M 4/583 (2010.01); H01M 4/04 (2006.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/583 (2013.01) [H01M 4/0471 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/027 (2013.01)] 7 Claims
 
1. A method of producing the negative electrode active material for a secondary battery, the method comprising:
subjecting natural graphite particles to a first baking treatment at a temperature of 1,130° C. to 1,800° C.;
mixing the first baking-treated natural graphite particles and a liquid pitch to form a carbon coating layer,
wherein the carbon coating layer coats a surface and an inside of the natural graphite; and
subjecting the natural graphite particles having the carbon coating layer formed on the surface and in the inside of the natural graphite particles to a second baking treatment.