Negative Electrode Material and Preparation Method thereof and Lithium Ion Battery

Patent metadata

Field	Value
Publication number	US-2024182314-A1
Application number	US-202218284875-A
Country	US
Kind code	A1
Filing date	Dec 20, 2022
Priority date	Dec 29, 2021
Publication date	Jun 6, 2024
Grant date	—

Abstract

The present disclosure relates to a negative electrode material and a preparation method thereof and a lithium ion battery, wherein the negative electrode material includes an active material, the active material includes a skeleton structure and a silicon oxygen material embedded on the skeleton structure; the skeleton structure includes a skeleton of lithium silicate located inside the active material and a skeleton of water-insoluble silicate located on a surface layer of the active material, and the skeleton of water-insoluble silicate is linked with the skeleton of lithium silicate, wherein in an XRD pattern of the negative electrode material, an intensity of a strongest diffraction characteristic peak of the lithium silicate is IA, and an intensity of a strongest diffraction characteristic peak of the water-insoluble silicate is IB, and 0.03≤IB/IA≤0.2.

First claim

1 . A negative electrode material, wherein the negative electrode material comprises an active material, the active material comprises a skeleton structure that runs throughout the active material and a silicon oxygen material embedded on the skeleton structure, wherein the skeleton structure comprises a skeleton of lithium silicate located inside the active material and a skeleton of water-insoluble silicate located on a surface layer of the active material, and the skeleton of water-insoluble silicate is linked with the skeleton of lithium silicate, wherein
in an XRD pattern of the negative electrode material, an intensity of a strongest diffraction characteristic peak of the lithium silicate is I A , and an intensity of a strongest diffraction characteristic peak of the water-insoluble silicate is I B , and 0.03≤I B /I A ≤0.2.

2 . A negative electrode material, wherein the negative electrode material comprises an active material;
the active material comprises lithium silicate, water-insoluble silicate, and a silicon oxygen material, wherein the water-insoluble silicate is coated on a surface of the lithium silicate; and the lithium silicate and/or the water-insoluble silicate contains the silicon oxygen material, wherein in an XRD pattern of the negative electrode material, an intensity of a strongest diffraction characteristic peak of the lithium silicate is I A , and an intensity of a strongest diffraction characteristic peak of the water-insoluble silicate is I B , and 0.03≤I B /I A ≤0.2.

3 . The negative electrode material according to claim 1 , satisfying at least one of conditions a˜g below:
a. the silicon oxygen material is SiO n , where 0.5≤n≤1.5;
b. the lithium silicate comprises at least one of Li 2 SiO 3 , Li 2 Si 2 O 5 , Li 4 SiO 4 , Li 2 Si 3 O 7 , Li 8 SiO 6 , Li 6 Si 2 O 7 , Li 4 Si 2 O 7 , Li 2 Si 4 O 7 , and LiSiO 3 ;
c. the water-insoluble silicate comprises zA 2 O·MO y ·xSiO 2 , where M comprises at least one of Mg, Al, Ca, Ge, Cr, V, Ti, Sc, Co, Ni, Cu, Sr, Zn, Zr, Fe, and Mn, A comprises at least one of Li, Na, and K, 0.2≤x≤10.0, 1.0≤y≤3.0, and 0≤z≤5.0;
d. the water-insoluble silicate further comprises A 2 O·nSiO 2 , wherein A comprises at least one of Li, Na, and K, and 1≤n≤10;
e. a work function range of the water-insoluble silicate is 2.5 eV≤η≤7.0 eV;
f. the water-insoluble silicate is located in a depth region of 20 nm˜50 nm of a surface of the active material; and
g. a mass content of Li element in the water-insoluble silicate is W 1 %, and a content of Li element in the lithium silicate is W 2 %, and W 2 >W 1 ≥0.

4 . The negative electrode material according to claim 1 , satisfying at least one of conditions a˜j below:
a. the negative electrode material further comprises a carbon layer existing on a surface of the active material;
b. an average thickness of the carbon layer is 30 nm˜500 nm;
c. a tap density of the negative electrode material is 0.6 g/cm 3 ˜1.2 g/cm 3 ;
d. a specific surface area of the negative electrode material is 1.0 m 2 /g˜12.0 m 2 /g;
e. an average particle size of the negative electrode material is 3.0 μm˜12.0 μm;
f. a mass percentage content of carbon in the negative electrode material is 1.5 wt %˜10.0 wt %;
g. a mass percentage content of lithium in the negative electrode material is 3 wt %˜15 wt %;
h. pH of the negative electrode material is 8.5˜12.0; and
i. in the XRD pattern of the negative electrode material, the intensity of the strongest diffraction characteristic peak of the lithium silicate is I A , and the intensity of the strongest diffraction characteristic peak of the water-insoluble silicate is I B , and 0.12≤I B /I A ≤0.18; and
j. a content of lithium element in the water-insoluble silicate of the negative electrode material is pm, and a total content of lithium element in the negative electrode material is p Li , where 0.01≤pm/p Li ≤0.6.

5 . (canceled)

6 . (canceled)

7 . A preparation method of a negative electrode material, comprising steps of:
performing a surface etching treatment on a pre-lithiated silicon oxygen material; and mixing the silicon oxygen material having undergone the surface etching treatment with a metal M-containing compound, and performing a solid-phase thermal reaction under a protective atmosphere, to obtain the negative electrode material.

8 . The method according to claim 7 , satisfying at least one of conditions a˜d below:
a. the metal M-containing compound comprises at least one of a carbonate of metal M, an oxide of metal M, and a hydroxide of metal M, where M comprises at least one of Mg, Al, Ca, Ge, Cr, Pb, Sr, Zn, Zr, Fe, and Mn;
b. a mass ratio of the silicon oxygen material having undergone the surface etching treatment to the metal M-containing compound is 1:(0.01˜0.1);
c. a mass ratio of the silicon oxygen material having undergone the surface etching treatment to the metal M-containing compound is 1:(0.075˜0.1); and
d. the metal M-containing compound is an oxide of metal M.

9 . The method according to claim 7 , satisfying at least one of conditions a˜f below:
a. the mixing comprises at least one of mechanical stirring, ultrasonic dispersion, and grinding dispersion;
b. the mixing is ball milling and mixing, and a ball milling time is 3 h˜24 h;
c. a gas of the protective atmosphere comprises at least one of nitrogen gas, helium gas, neon gas, argon gas, krypton gas, and xenon gas;
d. a temperature of the solid-phase thermal reaction is 600° C.˜1200° C.;
e. a time of the solid-phase thermal reaction is 3 h˜12; and
f. a heating rate of the solid-phase thermal reaction is 1° C./min˜5° C./min.

10 . The method according to claim 7 , satisfying at least one of conditions a˜k below:
a. the pre-lithiated silicon oxygen material is a pre-lithiated carbon-coated silicon oxygen material;
b. the pre-lithiated carbon-coated silicon oxygen material is obtained by reaction of the carbon-coated silicon oxygen material with a lithium source;
c. the silicon oxygen material is SiO n , where 0.5≤n≤1.5;
d. an average particle size (D 50 ) of the silicon oxygen material is 2.0 μm-15.0 μm;
e. a thickness of a carbon layer on a surface of the carbon-coated silicon oxygen material is 30 nm˜500 nm;
f. the lithium source comprises at least one of elemental lithium or a lithium-containing compound;
g. the lithium source comprises at least one of lithium hydride, lithium alkyl, lithium metal, lithium aluminum hydride, lithium amide, and lithium borohydride;
h. a reaction temperature of the carbon-coated silicon oxygen material and the lithium source is 150° C.˜300° C.;
i. a reaction time of the carbon-coated silicon oxygen material and the lithium source is 2.0 h˜6.0 h;
j. a mass ratio of the carbon-coated silicon oxygen material to the lithium source is 1:(0.01˜0.20); and
k. a mass percentage content of lithium in the pre-lithiated carbon-coated silicon oxygen material is 3 wt %˜20 wt %.

11 . The method according to claim 7 , wherein before performing the surface etching treatment on the pre-lithiated silicon oxygen material, the method further comprises:
making the silicon oxygen material react with a lithium source to obtain the pre-lithiated silicon oxygen material; or making a carbon-coated silicon oxygen material react with a lithium source to obtain a pre-lithiated carbon-coated silicon oxygen material.

12 . The method according to claim 7 , satisfying at least one of conditions a˜c below:
a. an acid solution used in the surface etching treatment has a following characteristic: when the pre-lithiated silicon oxygen material is subjected to the surface etching treatment, pH of a reaction system for surface etching is mai

Assignees

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

Inventors

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

Classifications

• C01B33/325 Primary

  After-treatment, e.g. purification or stabilisation of solutions, granulation; Dissolution; Obtaining solid silicate, e.g. from a solution by spray-drying, flashing off water or adding a coagulant · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M4/583

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• C01P2002/08

  Intercalated structures, i.e. with atoms or molecules intercalated in their structure · CPC title