US 11,837,728 B2
Anode active material and lithium secondary battery including the same
Hae Suk Hwang, Daejeon (KR); Hee Gyoung Kang, Daejeon (KR); Hyo Sang Kim, Daejeon (KR); So Hyun Park, Daejeon (KR); and Jong Hyuk Lee, Daejeon (KR)
Assigned to SK ON CO., LTD., Seoul (KR)
Filed by SK Innovation Co., Ltd., Seoul (KR)
Filed on Aug. 5, 2021, as Appl. No. 17/394,679.
Claims priority of application No. 10-2020-0098124 (KR), filed on Aug. 5, 2020.
Prior Publication US 2022/0045327 A1, Feb. 10, 2022
Int. Cl. H01M 4/00 (2006.01); H01M 4/583 (2010.01); H01M 4/133 (2010.01); H01M 4/66 (2006.01); H01M 4/62 (2006.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/583 (2013.01) [H01M 4/133 (2013.01); H01M 4/623 (2013.01); H01M 4/662 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An anode active material, comprising:
a first artificial graphite particle; and
a second artificial graphite particle having a different particle diameter from that of the first graphite particle and a hardness higher than that of the first graphite particle, wherein a pellet density and a tap density of the anode active material satisfy a relation of Equation 1:
1.3≤DP/DT≤1.45   [Equation 1]
wherein, in Equation 1, DP is the pellet density (g/cm3) of the anode active material, and DT is the tap density (g/cm3) of the anode active material,
wherein, the pellet density is calculated using a height difference measured after putting 1 g of the anode active material into a cylindrical pelletizer with a diameter of 13 mm and pressurizing the pelletizer with 3 metric ton for 10 seconds,
wherein the tap density is measured from a volume and a weight of a sample obtained after filling the sample of 10 g of the anode active material in 25 ml measuring cylinder, and then tapping with a stroke length of 10 mm 3,000 times.