公开(公告)号：US20230234852A1

公开(公告)日：2023-07-27

申请号：US17927644

申请日：2021-05-28

Applicant: SHOWA DENKO K.K.

Inventor： Masato FUJITA ,  Yuji ITO ,  Hirofumi INOUE

IPC: C01B32/372 ,  C01B33/029 ,  H01M10/0525

CPC classification number: C01B32/372 ,  C01B33/029 ,  H01M10/0525 ,  C01P2002/74 ,  C01P2004/51 ,  C01P2004/61 ,  C01P2006/12 ,  C01P2006/40

Abstract: An object of the present invention is to provide carbon-coated Si—C composite particles capable of maintaining a high Si utilization rate and suppressing deterioration of initial coulombic efficiency due to oxidation over time of a lithium-ion secondary battery.
The carbon-coated Si—C composite particles of the present invention includes Si—C composite particles containing a carbon material and silicon; and a carbonaceous layer present on surfaces of the Si—C composite particles,



wherein the carbon coverage thereof is 70% or more,
wherein the BET specific surface area is 200 m2/g or less; wherein R value (ID/IG) is 0.30 or more and 1.10 or less and ISi/IG is 0.15 or less, when the peak attributed to Si is present at 450 to 495 cm−1 and the intensity of the peak is defined as ISi, in Raman spectrum of the carbon-coated Si—C composite particles: and
wherein the full width at half maximum of the peak of a 111 plane of Si is 3.00 deg. or more, and (peak intensity of a 111 plane of SiC)/(peak intensity of the 111 plane of Si) is 0.01 or less, in the XRD pattern measured by powder XRD using a Cu-Kα ray of the carbon-coated Si—C composite particles.

公开(公告)号：US20230223537A1

公开(公告)日：2023-07-13

申请号：US17928195

申请日：2021-05-28

Applicant: SHOWA DENKO K.K.

Inventor： Naoto KAWAGUCHI ,  Yuji ITO ,  Masato FUJITA ,  Hirofumi INOUE

IPC: H01M4/587 ,  H01M4/36 ,  H01M4/38 ,  H01M4/62 ,  C01B32/342 ,  C01B32/318 ,  C01B32/372

CPC classification number: H01M4/587 ,  H01M4/366 ,  H01M4/386 ,  H01M4/622 ,  H01M4/625 ,  C01B32/342 ,  C01B32/318 ,  C01B32/372 ,  H01M2004/027

Abstract: The present invention relates to composite particles containing silicon and carbon, wherein a domain size region of vacancies of 2 nm or less is 44% by volume or more and 70% by volume or less when volume distribution information of domain sizes obtained by fitting a small-angle X-ray scattering spectrum of the composite particles with a spherical model in a carbon-vacancy binary system is accumulated in ascending order, and a true density calculated by dry density measurement by a constant volume expansion method using helium gas is 1.80 g/cm3 or more and 2.20 g/cm3 or less.

公开(公告)号：US20230216025A1

公开(公告)日：2023-07-06

申请号：US17927789

申请日：2021-05-28

Applicant: SHOWA DENKO K.K.

Inventor： Akifumi TAKEDA ,  Masato FUJITA ,  Yuji ITO ,  Hirofumi INOUE

IPC: H01M4/36 ,  H01M4/587 ,  H01M4/38 ,  H01M10/0525 ,  H01M4/133 ,  H01M4/134 ,  C01G23/00 ,  C01G33/00 ,  C01B32/25

CPC classification number: H01M4/364 ,  H01M4/587 ,  H01M4/386 ,  H01M10/0525 ,  H01M4/133 ,  H01M4/134 ,  C01G23/005 ,  C01G33/00 ,  C01B32/25

Abstract: An object of the present invention is to provide composite particles capable of suppressing oxidation over time of a Si—C composite material. Composite particles (B) of the present invention contains composite particles (A) containing carbon and silicon; and amorphous layers coating surfaces thereof, where the composite particles (B) have ISi/IG of 0.10 or more and 0.65 or less, and have R value (ID/IG) of 1.00 or more and 1.30 or less, when a peak due to silicon is present at 450 to 495 cm−1, an intensity of the peak is defined as ISi, an intensity of a G band (peak intensity in the vicinity of 1600 cm−1) is defined as IG, and an intensity of a D band (peak intensity in the vicinity of 1360 cm−1) is defined as ID in a Raman spectrum, and where the composite particles (B) have a full width at half maximum of a peak of a 111 plane of Si of 3.0 deg. or more using a Cu-Kα ray in an XRD pattern.