US 11,990,606 B2
Negative electrode active material for non-aqueous electrolyte secondary batteries
Yohei Uchiyama, Hyogo (JP); Norihisa Yamamoto, Osaka (JP); and Tatsuya Akira, Osaka (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD., Osaka (JP)
Appl. No. 16/957,156
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
PCT Filed Oct. 29, 2018, PCT No. PCT/JP2018/040024
§ 371(c)(1), (2) Date Jun. 23, 2020,
PCT Pub. No. WO2019/130787, PCT Pub. Date Jul. 4, 2019.
Claims priority of application No. 2017-254952 (JP), filed on Dec. 28, 2017.
Prior Publication US 2020/0350563 A1, Nov. 5, 2020
This patent is subject to a terminal disclaimer.
Int. Cl. H01M 4/36 (2006.01); H01M 4/02 (2006.01); H01M 4/38 (2006.01); H01M 4/58 (2010.01); H01M 10/0525 (2010.01)
CPC H01M 4/362 (2013.01) [H01M 4/38 (2013.01); H01M 4/5825 (2013.01); H01M 10/0525 (2013.01); H01M 2004/027 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A negative electrode active material for non-aqueous electrolyte secondary batteries, comprising:
lithium silicate composite particles including a lithium silicate phase and silicon particles dispersed in the lithium silicate phase,
the lithium silicate phase being an oxide phase including Li, Si, O, and M, where
M is an element other than the following elements: Group 1 elements of alkali metals, Group 16 elements of oxygen group, Group 18 elements of rare gas, and Si, wherein
an amount of each element relative to a total amount of Li, Si and M in the lithium silicate phase is 3 mol % to 55 mol % for Li, 25 mol % or more for Si, and 3 mol % to 50 mol % for M;
a carbon material is present inside the lithium silicate composite particles;
an area ratio of the carbon material measured within an entire area excluding a peripheral region of 1 μm thick from a peripheral edge of a cross section of the lithium silicate composite particles is 0.008% to 6%, wherein the area ratio is an average of measurements of ten lithium silicate composite particles having a maximum diameter of 5 μm or more included in a cross-sectional image of an active material mixture layer containing the negative electrode active material;
the lithium silicate composite particles include an aggregate of a plurality of primary particles, the primary particles including the lithium silicate phase and the silicon particles;
the aggregate comprises a sintered body of the primary particles defining a linear continuous interface between said primary particles; and
the carbon material is present at at least part of the interface between the primary particles adjacent to each other, inside the lithium silicate composite particles.