Negative electrode material, preparation method therefor, and application thereof, and lithium ion battery comprising same

Patent metadata

Field	Value
Publication number	US-12519102-B2
Application number	US-202017754393-A
Country	US
Kind code	B2
Filing date	Sep 29, 2020
Priority date	Oct 9, 2019
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

A silicon-based negative electrode material, a preparation method therefor, and an application thereof in a lithium ion battery are provided. A lithium ion battery contains the silicon-based negative electrode material. The negative electrode material contains a silicon-containing material and a phosphorus-containing coating layer at the surface of the silicon-containing material. The phosphorus-containing coating layer contains a polymer that has polycyclic aromatic hydrocarbon structural segments. The negative electrode material exhibits improved initial coulombic efficiency, reversible charging specific capacity, cycle charging capacity retention and conductivity. When used in the lithium ion battery, the negative electrode material may improve the energy density of the battery.

First claim

The invention claimed is:

1 . A negative electrode material, comprising: a silicon-containing material having a phosphorus-containing coating layer at a surface of the silicon-containing material,
wherein the phosphorus-containing coating layer comprises a polymer having polycyclic aromatic hydrocarbon structural segments, wherein the negative electrode material further comprises a porous carbon layer disposed on a surface of the phosphorus-containing coating layer and a polymeric lithium salt intercalated in the porous carbon layer.

2 . The negative electrode material according to claim 1 , wherein the silicon-containing material is at least one selected from the group consisting of elemental silicon, SiOx wherein 0.6<x<1.5, and silicon-containing alloy.

3 . The negative electrode material according to claim 2 , wherein the elemental silicon is in a form of silicon powder having a median particle size of 0.05-10 μm.

4 . The negative electrode material according to claim 1 , wherein the 13C-NMR spectrum of the polymer having polycyclic aromatic hydrocarbon structural segments includes signals at 110 ppm-140 ppm; and/or
wherein phosphorus in the phosphorus-containing coating layer and silicon in the silicon-containing material are connected via P(O)—O—Si bond.

5 . The negative electrode material according to claim 1 , wherein the negative electrode material further comprises graphite; and/or wherein the negative electrode material further comprises a conductive agent.

6 . The negative electrode material according to claim 5 , wherein the conductive agent is at least one selected from the group consisting of carbon nanotubes, acetylene black, and conductive carbon black.

7 . The negative electrode material according to claim 5 , wherein the conductive agent is present in an amount of 1-10 wt % based on the total amount of the negative electrode material.

8 . The negative electrode material according to claim 1 , wherein the negative electrode material has a median particle size of 0.1-20 microns.

9 . The negative electrode material according to claim 1 , wherein the polymeric lithium salt is at least one selected from the group consisting of lithium polyacrylate, lithium polymethacrylate, lithium polymaleate, lithium polyfumarate, lithium carboxymethylcellulose, and lithium alginate.

10 . The negative electrode material according to claim 1 , wherein the polymeric lithium salt have a weight average molecular weight of 2000-5000000.

11 . The negative electrode material according to claim 1 , wherein based on the total amount of the negative electrode material, the polymeric lithium salt is present in an amount of 10-30 wt %.

12 . A lithium ion battery comprising a negative electrode comprising the negative electrode material according to claim 1 , a positive electrode, a separator and an electrolyte.

Assignees

• China Petroleum & Chem Corp
• Shanghai Res Inst Petrochemical Tech Sinopec

Inventors

• Sun Sai
• Zhang Siyu
• Gao Huanxin

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

• H01M4/587

  for inserting or intercalating light metals · CPC title