US 12,224,428 B2
Negative active material for rechargeable lithium battery and rechargeable lithium battery including the same
Dae-Hyeok Lee, Yongin-si (KR); Young-Min Kim, Yongin-si (KR); Jaemyung Kim, Yongin-si (KR); Jaehou Nah, Yongin-si (KR); Changsu Shin, Yongin-si (KR); and Jongmin Won, Yongin-si (KR)
Assigned to SAMSUNG SDI CO., LTD., Yongin-si (KR)
Filed by SAMSUNG SDI CO., LTD., Yongin-si (KR)
Filed on Oct. 30, 2020, as Appl. No. 17/085,007.
Claims priority of application No. 10-2019-0142041 (KR), filed on Nov. 7, 2019.
Prior Publication US 2021/0143411 A1, May 13, 2021
Int. Cl. H01M 4/36 (2006.01); H01M 4/38 (2006.01); H01M 4/587 (2010.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/366 (2013.01) [H01M 4/364 (2013.01); H01M 4/386 (2013.01); H01M 4/587 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/027 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A negative electrode for a rechargeable lithium battery, the negative electrode comprising:
a physical mixture of a first negative active material and a crystalline carbon as a second active material, the crystalline carbon including graphite,
wherein the first negative active material comprises secondary particles of agglomerated primary particles, the primary particles including Si particles with SiC on a surface of the Si particles; and
an amorphous carbon surrounding the secondary particles,
wherein the first negative active material has:
a peak intensity ratio (ISi(111)/ISiC(111) of a peak intensity (ISi(111)) at a Si (111) plane relative to a peak intensity (IISiC(111) at a SiC (111) plane of about 5 to about 20 measured by X-ray diffraction analysis using a CuKα ray,
wherein the crystalline carbon material has a peak intensity ratio (IGri(002)/ISiC(111)) of a peak intensity (IGr(002)) at a crystalline carbon (002) plane relative to a peak intensity (IISiC(111)) at a SiC (111) plane, measured by X-ray diffraction analysis using a CuKα ray of about 150 to about 1,500 in the negative electrode,
wherein a thickness of the SiC on the surface of the Si is about 5 nm or less,
wherein the negative active material includes:
about 5 wt % to about 20 wt % of SiC,
about 40 wt % to about 70 wt % of silicon, and
27 wt % to about 50 wt % of the amorphous carbon, all wt % being based on 100 wt % of the entire negative active material, and
wherein a full width at half maximum, FWHM (111), of a diffraction peak at a (111) plane found by X-ray diffraction of the Si particles using a CuKα ray is about 0.5 degrees (°) to about 7 degrees (°).