Silicon-containing electrodes including cross-linked polymeric binders and methods for preparing the same

Patent metadata

Field	Value
Publication number	US-2024204192-A1
Application number	US-202318131187-A
Country	US
Kind code	A1
Filing date	Apr 5, 2023
Priority date	Dec 20, 2022
Publication date	Jun 20, 2024
Grant date	—

Abstract

An electrode for an electrochemical cell includes a silicon-containing electroactive material that includes a plurality of silicon-containing electroactive material particles and a polymeric network that forms polymeric cages around each of the silicon-containing electroactive material particles of the plurality. The polymeric cages include polyacrylic acid (PAA), lithiated polyacrylic acid (PAALi), or a combination of polyacrylic acid (PAA) and lithiated polyacrylic acid (PAALi) covalently bonded with poly(2-hydroxyethyl acrylate) (PHEA). The polymeric network has a mass ratio of the polyacrylic acid (PAA), the lithiated polyacrylic acid (PAALi), or the combination of the polyacrylic acid (PAA) and the lithiated polyacrylic acid (PAALi) to the poly(2-hydroxyethyl acrylate) (PHEA) of greater than or equal to about 0.5 to less than or equal to about 10.

First claim

What is claimed is:

1 . An electrode for an electrochemical cell that cycles lithium ions, the electrode comprising:
a silicon-containing electroactive material; and a polymeric network in contact with the silicon-containing electroactive material, the polymeric network comprising polyacrylic acid (PAA) cross-linked with poly(2-hydroxyethyl acrylate) (PHEA).

2 . The electrode of claim 1 , wherein the silicon-containing electroactive material comprises Li y SiO x , where 0<y<1 and 0<x<2.

3 . The electrode of claim 1 , wherein the electrode further comprises a carbonaceous electroactive material.

4 . The electrode of claim 3 , wherein the electrode comprises greater than or equal to about 80 wt. % to less than or equal to about 98 wt. % of the silicon-containing electroactive material and greater than or equal to about 85 wt. % to less than or equal to about 95 wt. % of the carbonaceous electroactive material.

5 . The electrode of claim 1 , wherein the silicon-containing electroactive material comprises a plurality of silicon-containing electroactive material particles, and the polymeric network defines a plurality of polymeric cages, wherein each polymeric cage of the plurality of polymeric cages at least partially surrounds one or more silicon-containing electroactive material particles of the plurality of silicon-containing electroactive material particles.

6 . The electrode of claim 1 , wherein a mass ratio of the polyacrylic acid (PAA) to the poly(2-hydroxyethyl acrylate) (PHEA) is greater than or equal to about 0.5 to less than or equal to about 10.

7 . The electrode of claim 1 , wherein the electrode comprises greater than or equal to about 1 wt. % to less than or equal to about 15 wt. % of the polymeric network.

8 . The electrode of claim 1 , wherein the polyacrylic acid (PAA) is lithiated polyacrylic acid (PAALi).

9 . The electrode of claim 1 , wherein the electrode further comprises greater than or equal to about 0.5 wt. % to less than or equal to about 15 wt. % of a conductive additive.

10 . The electrode of claim 1 , wherein the polyacrylic acid (PAA) cross-linked with poly(2-hydroxyethyl acrylate) (PHEA) defines a first binder and the electrode further comprises greater than 0 wt. % to less than or equal to about 10 wt. % of a second polymeric binder.

11 . The electrode of claim 10 , wherein the second polymeric binder is selected from the group consisting of: polyimide (PI), polyamic acid, polyamide, polysulfone, polyvinylidene difluoride (PVdF), polytetrafluoroethylene (PTFE), polyhexafluoropropene, polychlorotrifluoroethylene, ethylene propylene diene monomer (EPDM) rubber, carboxymethyl cellulose (CMC), nitrile butadiene rubber (NBR), styrene-butadiene rubber (SBR), sodium alginate, lithium alginate, polyacrylonitrile (PAn), and combinations thereof.

12 . An electrode for an electrochemical cell that cycles lithium ions, the electrode comprising:
a silicon-containing electroactive material comprising a plurality of silicon-containing electroactive material particles; and a polymeric network forming polymeric cages around each of the silicon-containing electroactive material particles of the plurality, the polymeric cages comprising polyacrylic acid (PAA), lithiated polyacrylic acid (PAALi), or a combination of polyacrylic acid (PAA) and lithiated polyacrylic acid (PAALi) covalently bonded with poly(2-hydroxyethyl acrylate) (PHEA), and the polymeric network having a mass ratio of the polyacrylic acid (PAA), the lithiated polyacrylic acid (PAALi), or the combination of the polyacrylic acid (PAA) and the lithiated polyacrylic acid (PAALi) to the poly(2-hydroxyethyl acrylate) (PHEA) is greater than or equal to about 0.5 to less than or equal to about 10.

13 . The electrode of claim 12 , wherein the silicon-containing electroactive material comprises Li y SiO x , where 0<y<1 and 0<x<2.

14 . A method for preparing a silicon-containing electrode, the method comprising:
heating an electroactive material slurry disposed adjacent to one or more surfaces of a current collector to a temperature greater than or equal to about 120° ° C. to less than or equal to about 180° ° C. to form the silicon-containing electrode, wherein the electroactive material slurry comprises a plurality of silicon-containing electroactive material particles and polymeric binders comprising polyacrylic acid (PAA) and poly(2-hydroxyethyl acrylate) (PHEA), wherein after the heating, the silicon-containing electrode comprises a polymeric network that contacts each of the silicon-containing electroactive material particles of the plurality of silicon-containing electroactive material particles, the polymeric network comprising the polyacrylic acid (PAA) cross-linked with the poly(2-hydroxyethyl acrylate) (PHEA).

15 . The method of claim 14 , wherein the temperature is held for a period greater than or equal to about 30 minutes to less than or equal to about 5 hours.

16 . The method of claim 14 , wherein the temperature is a first temperature and the method further comprises preparing the poly(2-hydroxyethyl acrylate) (PHEA), wherein the preparing of the poly(2-hydroxyethyl acrylate) (PHEA) comprises:
contacting 2-hydroxyethyl acrylate (HEA) and an initiator to form an admixture; heating the admixture to a second temperature greater than or equal to about 130° ° C. to less than or equal to about 180° C.; and precipitating poly(2-hydroxyethyl acrylate) from the admixture.

17 . The method of claim 14 , wherein the method further comprises:
disposing the electroactive material slurry on the one or more surfaces of the current collector.

18 . The method of claim 14 , wherein the method further comprises:
preparing the electroactive material slurry by contacting the silicon-containing electroactive material, the polyacrylic acid (PAA), and the poly(2-hydroxyethyl acrylate) (PHEA).

19 . The method of claim 14 , wherein the polyacrylic acid (PAA) is lithiated polyacrylic acid (PAALi).

20 . The method of claim 14 , wherein the silicon-containing electroactive material comprises Li y SiO x , where 0<y<1 and 0<x<2.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Kong Dewen
• Liu Haijing
• Hou Mengyan
• Chen Si
• Xu Zhixin
• Yang Jun

Classifications

• H01M10/0525

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

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title