US 11,811,060 B2
Positive electrode active material and lithium secondary battery comprising the same
Jung Bae Park, Cheongju-si (KR); Hyun Jong Yu, Cheongju-si (KR); and Moon Ho Choi, Cheongju-si (KR)
Assigned to ECOPRO BM CO., LTD., Cheongju-si (KR)
Filed by ECOPRO BM CO., LTD., Cheongju-si (KR)
Filed on Jul. 20, 2021, as Appl. No. 17/380,664.
Claims priority of application No. 10-2020-0132472 (KR), filed on Oct. 14, 2020.
Prior Publication US 2022/0115658 A1, Apr. 14, 2022
Int. Cl. H01M 4/525 (2010.01); H01M 4/505 (2010.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/525 (2013.01) [H01M 4/505 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A positive electrode active material comprising a lithium composite oxide enabling lithium intercalation/deintercalation,
wherein the positive electrode active material comprises a first lithium composite oxide, and a second lithium composite oxide that has a larger average particle diameter than the first lithium composite oxide,
wherein when a lithium secondary battery using the positive electrode active material as a positive electrode and a lithium foil as a negative electrode is charged/discharged under the following charging/discharging conditions,
[Charging/discharging conditions]
1st cycle:
Cut off voltage 3.0V˜4.3V
charging: 0.1 C (CCCV)/discharging: 0.1 C (CC)
2nd cycle:
Cut off voltage 3.0V˜4.3V
charging: 0.1 C (CCCV)/discharging: 0.1 C (CC)
3rd cycle:
Cut off voltage 3.0V˜4.4V
charging: 1 C (CCCV)/discharging: 1 C (CC)
in a graph illustrating the voltage (V) and the battery capacity (Q) at the 3rd cycle and having an X axis indicating the voltage (V) and a Y axis indicating a value (dQ/dV) obtained by differentiating the battery capacity (Q) with respect to the voltage (V),
a peak intensity ratio (A) defined in Equation 1 below is satisfied:
I1/I2≥1.4  [Equation 1]
(In Equation 1,
I1 is a y axis value (dQ/dV) for a peak shown between 3.0V and 3.8V in a charging region, and
I2 is a y axis value (dQ/dV) for a peak shown between 3.8V and 4.1V in a charging region).