Negative Electrode Material and Preparation Method thereof and Lithium-ion Battery

Patent metadata

Field	Value
Publication number	US-2025087679-A1
Application number	US-202318284616-A
Country	US
Kind code	A1
Filing date	Apr 19, 2023
Priority date	Apr 21, 2022
Publication date	Mar 13, 2025
Grant date	—

Abstract

The present disclosure relates to the technical field of secondary batteries, and in particular to a negative electrode material and a preparation method thereof and a lithium-ion battery, wherein a crest factor A of particle size distribution of the negative electrode material satisfies: 0<A≤3, and wherein A=(D95−D5)/[2.5*(D75−D25)], and D95, D5, D75, and D25 respectively represent particle sizes of the negative electrode material when a volume percentage content on a cumulative curve reaches 95%, 5%, 75%, and 25%. The negative electrode material in the present disclosure has a suitable crest factor A, which can ensure consistency of particles of the negative electrode material, so that a coated electrode sheet has good consistency, further the performance consistency of the battery is high, and the battery performance is improved.

First claim

1 . A negative electrode material, wherein a crest factor A of particle size distribution of the negative electrode material satisfies: 0<A≤3, and wherein A=(D 95 −D 5 )/[2.5*(D 75 −D 25 )], and D 95 , D 5 , D 75 , and D 25 respectively represent particle sizes of the negative electrode material when a volume percentage content on a cumulative curve reaches 95%, 5%, 75%, and 25%; and
the negative electrode material comprises a silicon-based active material, the silicon-based active material comprises at least one of SiO x , SiO x /C, SiO x /M, Si, Si/C, and Si/M, wherein 0<x≤2, and the M comprises at least one of a metal, a nonmetal, a metal oxide, and a nonmetal oxide.

2 . The negative electrode material according to claim 1 , wherein the negative electrode material comprises at least one of following features (1)-(12):
(1) the particle size distribution of the negative electrode material is: 0<D 5 ≤65 μm, 0<D 25 ≤69 μm, 0<D 75 ≤75 μm, and 0<D 95 ≤79 μm; (2) an infrared spectrum of the negative electrode material tested in a range of wave number of 3200 cm −1 -3600 cm −1 has a bulge peak; (3) wadell degree of sphericity of the negative electrode material is greater than or equal to 0.8; (4) a particle size D50 of the silicon-based active material is greater than 0 μm, and equal to or less than 80 μm; (5) a specific surface area of the silicon-based active material is 0-10 m 2 /g, and is other than 0; (6) a tap density of the silicon-based active material is 0.5 g/m 3 ˜2 g/m 3 ; (7) the negative electrode material further comprises a doping material doped in the silicon-based active material; (8) the negative electrode material further comprises a doping material doped in the silicon-based active material, and the doping material comprises at least one of an alkali metal, an alkali-earth metal, an alkali metal oxide, and an alkali-earth metal oxide; (9) the negative electrode material further comprises a doping material doped in the silicon-based active material, and a weight percentage b of the doping material in the negative electrode material satisfies: 0<b≤20%; (10) a sorting coefficient B of the particle size distribution of the negative electrode material satisfies: 0<B≤3, wherein B=(D 84 −D 16 )/4+(D 95 −D 5 )/6.6, and D 84 , D 16 , D 95 , and D 5 respectively represent particle sizes of the negative electrode material when a volume percentage content on the cumulative curve reaches 84%, 16%, 95%, and 5%; (11) the particle size distribution of the negative electrode material is: 0<D 5 ≤65 μm, 0<D 16 ≤67 μm, 0<D 84 ≤77 μm, and 0<D 95379 μm; and (12) the sorting coefficient B and the crest factor A of the particle size distribution of the negative electrode material satisfy: 0<B/A≤5.

3 . The negative electrode material according to claim 1 , wherein the negative electrode material further comprises a coating layer located on a surface of the silicon-based active material, and the coating layer comprises at least one of a flexible polymer and a conductive material.

4 . The negative electrode material according to claim 3 , wherein the negative electrode material further comprises at least one of following features (1)-(13):
(1) the conductive material comprises flake graphite and a nanocarbon material; (2) the flexible polymer comprises a natural flexible polymer and/or a synthetic flexible polymer; (3) the flexible polymer comprises at least one of polyolefin and derivatives thereof, polyvinyl alcohol and derivatives thereof, polyacrylic acid and derivatives thereof, polyamide and derivatives thereof, carboxymethyl cellulose and derivatives thereof, alginic acid and derivatives thereof, and polycarbonate and derivatives thereof; (4) the flexible polymer has a weight-average molecular weight of 2000-1000000; (5) the flexible polymer contains a thermally crosslinked functional group, and the thermally crosslinked functional group comprises at least one of an epoxy group, a carboxyl group, a hydroxyl group, an amino group, a double bond, and a triple bond; (6) the flake graphite comprises natural flake graphite and/or artificial flake graphite; (7) the nanocarbon material comprises at least one of conductive graphite, graphene, carbon nanotube, and carbon nanofiber; (8) based on a total mass of the negative electrode material being 100%, a mass percentage of the flexible polymer is 0-10%, excluding 0; (9) based on the total mass of the negative electrode material being 100%, a mass percentage of the flake graphite is 0-20%, excluding 0; (10) based on the total mass of the negative electrode material being 100%, a mass percentage of the nanocarbon material is 0-5%, excluding 0; (11) the coating layer has a thickness of 10 nm˜5000 nm; (12) a mass proportion of the coating layer in the negative electrode material is 0-20%, excluding 0; and (13) the mass proportion of the coating layer in the negative electrode material is 2%˜10%.

5 . A preparation method of a negative electrode material, comprising following step:
preparing a powdered negative electrode material; adjusting a particle size of the prepared powdered negative electrode material to obtain the negative electrode material, wherein a crest factor A of a particle size distribution of the negative electrode material satisfies: 0<A≤3, and wherein A=(D 95 −D 5 )/[2.5*(D 75 −D 25 )], and D 95 , D 5 , D 75 , and D 25 respectively represent particle sizes of the negative electrode material when a volume percentage content on a cumulative curve reaches 95%, 5%, 75%, and 25%; and the negative electrode material comprises a silicon-based active material, and the silicon-based active material comprises at least one of SiO x , SiO x /C, SiO x /M, Si, Si/C, and Si/M, wherein 0<x≤2, and the M comprises at least one of a metal, a nonmetal, a metal oxide, and a nonmetal oxide.

6 . The preparation method according to claim 5 , wherein a sorting coefficient B of the particle size distribution of the negative electrode material satisfies: 0<B≤3, wherein B=(D 84 −D 16 )/4+(D 95 −D 5 )/6.6, and D 84 , D 16 , D 95 , and D 5 respectively represent particle sizes when a volume percentage content on the cumulative curve reaches 84%, 16%, 95%, and 5%.

7 . The preparation method according to claim 6 , wherein a method of preparing the powdered negative electrode material comprises: pulverizing the silicon-based active material to obtain the powdered negative electrode material.

8 . The preparation method according to claim 7 , wherein the preparation method at least satisfies one of following features (1)˜(6):
(1) a method of the pulverizing comprises crushing and ball milling;
(2) an apparatus used for the crushing comprises a crusher, and a crushing power p of the crusher satisfies: 0<p≤300 kW;
(3) an apparatus used for the ball milling comprises a ball mill, and a rotational speed v1 of the ball mill satisfies: 0<v1≤1500 rpm;
(4) an apparatus used for adjusting the particle size comprises a classifier; and a frequency f of an induced draft fan of the classifier satisfies: 0<f≤100 Hz;
(5) the sorting coefficient B and the crest factor A satisfy: 0<B/A≤5; and
(6) a particle size D50 of the silicon-based active material is greater than 0 μm, and less than or equal to 80 μm.

9 . The preparation method according to claim 8 , wherein the method of preparing the powdered negative electrode material further comprises: carbon-coating the pulverized silicon-based active material with a carbon material to obtain the powdered negative electrode material, wherein a weight percentage a of the carbon material in the negative electrode material satisfies: 0<a≤15%.

10 . The preparation method according to claim 8 , wherein the method of preparing th

Assignees

• Btr New Mat Group Co Ltd
• Huizhou Btr New Material Tech Co Ltd
• Dingyuan New Energy Tech Co Ltd

Inventors

• Deng Zhiqiang
• Xie Wei
• Pang Chunlei
• Ren Jianguo
• He Xueqin

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title