Electrochemical device and electronic device including same

Patent metadata

Field	Value
Publication number	US-12160000-B2
Application number	US-201917056073-A
Country	US
Kind code	B2
Filing date	Dec 25, 2019
Priority date	Dec 25, 2019
Publication date	Dec 3, 2024
Grant date	Dec 3, 2024

Abstract

An electrochemical device, including a cathode; an anode; and an electrolyte. The anode has an anode mixture layer on an anode current collector, the anode mixture layer includes a carbon material as an anode active material, and at least a part of a surface of the anode mixture layer or a surface of the carbon material comprises a polymer compound having Si—C and Si—O bonds. The electrochemical device has improved cycle performance and storage performance.

First claim

What is claimed is:

1. An electrochemical device, comprising:
a cathode;
an anode; and
an electrolyte,
wherein the anode comprises an anode mixture layer disposed on an anode current collector, the anode mixture layer comprises a carbon material as an anode active material, at least a part of a surface of the anode mixture layer or a surface of the carbon material comprises a polymer compound having Si—C and Si—O bonds, and a surface tension of an aqueous solution containing 0.1 wt % of the polymer compound having Si—C and Si—O bonds being not greater than 30 mN/m,
wherein the polymer compound having Si—C and Si—O bonds has an oxidation potential of not less than 4.5 V and a reductive potential of not greater than 0.5 V;
wherein the carbon material has at least one of the following characteristics:
(a) a specific surface area of less than 5 m 2 /g,
(b) a median particle size of 5 μm to 30 μm, or
(c) amorphous carbon on a surface of the carbon material;
wherein the anode mixture layer has at least one of the following characteristics:
(i) a thickness of not greater than 200 μm,
(ii) a porosity of 10% to 60%, or
(iii) a minimum height from which a ball having a diameter of 15 mm and a weight of 12 g falls onto the anode mixture layer to cause formation of cracks on the anode mixture layer being at least 50 cm;
wherein the polymer compound having Si—C and Si—O bonds comprises at least one of trisiloxane surfactant, silicone surfactant, hydroxy-terminated polydimethylsiloxane, N-β-(aminoethyl)-γ-aminopropyl methyl dimethoxysilane, or dimethicone;
wherein the electrolyte comprises propionate, lithium difluorophosphate,
an organic compound having a cyano group, and a compound of Formula 1, the organic compound having the cyano group comprising 1,2,3-tris(2-cyanoethoxy)propane, the compound of Formula 1 is at least one selected from the group consisting of:

m is an integer from 1 to 4;
n is an integer from 0 to 2;
p is an integer from 0 to 6; and
wherein based on the total weight of the electrolyte, the content of the organic compound having the cyano group is 0.1 wt % to 15 wt %.

2. The electrochemical device according to claim 1 , wherein the polymer compound having Si—C and Si—O bonds comprises polyether siloxane.

3. The electrochemical device according to claim 1 , wherein based on a total weight of the anode mixture layer, a content of the polymer compound having Si—C and Si—O bonds is less than or equal to 3000 ppm.

4. The electrochemical device according to claim 1 , wherein the propionate has a structure of Formula 2:

wherein
R 1 is selected from ethyl or haloethyl, and
R 2 is selected from C 1 -C 6 alkyl or C 1 -C 6 haloalkyl; and
based on the weight of the electrolyte, a content of the propionate is 10 wt %- 65 wt %,
wherein the propionate is selected from at least one of: methyl propionate, ethyl propionate, propyl propionate, butyl propionate, or amyl propionate.

5. An electronic device, comprising an electrochemical device, the electrochemical device comprises:
a cathode;
an anode; and
an electrolyte,
wherein the anode comprises an anode mixture layer disposed on an anode current collector, the anode mixture layer comprises a carbon material as an anode active material, at least a part of a surface of the anode mixture layer or a surface of the carbon material comprises a polymer compound having Si—C and Si—O bonds, and a surface tension of an aqueous solution containing 0.1 wt % of the polymer compound having Si—C and Si—O bonds being not greater than 30 mN/m,
wherein the polymer compound having Si—C and Si—O bonds has an oxidation potential of not less than 4.5 V and a reductive potential of not greater than 0.5 V;
wherein the carbon material has at least one of the following characteristics:
(a) a specific surface area of less than 5 m 2 /g,
(b) a median particle size of 5 μm to 30 μm, or
(c) amorphous carbon on a surface;
wherein the anode mixture layer has at least one of the following characteristics:
(i) a thickness of not greater than 200 μm,
(ii) a porosity of 10% to 60%, or
(iii) a minimum height from which a ball having a diameter of 15 mm and a weight of 12 g falls onto the anode mixture layer to cause formation of cracks on the anode mixture layer being at least 50 cm;
wherein the polymer compound having Si—C and Si—O bonds comprises at least one of trisiloxane surfactant, silicone surfactant, hydroxy-terminated polydimethylsiloxane, N-β-(aminoethyl)-γ-aminopropyl methyl dimethoxysilane, or dimethicone;
wherein the electrolyte comprises propionate, lithium difluorophosphate, an organic compound having a cyano group, and a compound of Formula 1,
the organic compound having the cyano group comprising 1,2,3-tris (2-cyanoethoxy) propane, the compound of Formula 1 is at least one selected from the group consisting of:

m is an integer from 1 to 4;
n is an integer from 0 to 2; and
p is an integer from 0 to 6; and
wherein based on the total weight of the electrolyte, the content of the organic compound having the cyano group is 0.1 wt % to 15 wt %.

6. The electronic device according to claim 5 , wherein the polymer compound having Si—C and Si—O bonds comprises polyether siloxane.

7. The electronic device according to claim 5 , wherein based on a total weight of the anode mixture layer, a content of the polymer compound having Si—C and Si—O bonds is less than or equal to 3000 ppm.

8. The electronic device according to claim 5 , wherein the propionate has a structure of Formula 2:

wherein
R 1 is selected from ethyl or haloethyl, and
R 2 is selected from C 1 -C 6 alkyl or C 1 -C 6 haloalkyl; and
based on the weight of the electrolyte, a content of the propionate is 10 wt %- 65 wt %,
wherein the propionate is selected from at least one of: methyl propionate, ethyl propionate, propyl propionate, butyl propionate, or amyl propionate.

9. The electronic device according to claim 5 , wherein as measured using a contact angle measurement method, a contact angle of the anode mixture layer relative to a non-aqueous solvent is not greater than 60°.

10. The electrochemical device according to claim 1 , wherein as measured using a contact angle measurement method, a contact angle of the anode mixture layer relative to a non-aqueous solvent is not greater than 60°.

Assignees

• Ningde Amperex Technology Ltd

Inventors

• Wang Kefei
• Zhang Qingwen
• Dai Zhen
• Wang Yingying

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/364

  as mixtures · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title