Electrochemical device and electronic device including same

Patent metadata

Field	Value
Publication number	US-2023163311-A1
Application number	US-201917054207-A
Country	US
Kind code	A1
Filing date	Dec 25, 2019
Priority date	Dec 25, 2019
Publication date	May 25, 2023
Grant date	—

Abstract

An electrochemical device, including a cathode; an electrolyte; and an anode. The electrolyte includes a phosphorus and oxygen containing compound, and the anode includes an anode current collector and an anode mixture layer formed on the anode current collector, and after 100 charge and discharge cycles, an area of lithium precipitation of a surface of the anode mixture layer is 2% or below based on a total surface area of the anode mixture layer. The electrochemical device has improved cycle performance, storage performance and safety performance.

First claim

1 . An electrochemical device, comprising:
a cathode; an electrolyte; and an anode,
wherein,
the electrolyte comprises a phosphorus and oxygen containing compound, and
the anode comprises an anode current collector and an anode mixture layer formed on the anode current collector, and after 100 charge and discharge cycles, an area of lithium precipitation of a surface of the anode mixture layer is 2% or below based on a total surface area of the anode mixture layer.

2 . The electrochemical device according to claim 1 , wherein the electrolyte comprises at least one of the following compounds:
(a) lithium monofluorophosphate; (b) lithium difluorophosphate; (c) phosphate; (d) phosphocyclic anhydride; or (e) the compound of Formula 1: wherein R is substituted or unsubstituted C 1 -C 10 hydrocarbyl, wherein when substituted, the substituent is halo.

3 . The electrochemical device according to claim 2 , wherein the electrolyte comprises the compound of Formula 1, and the compound of Formula 1 comprises at least one of the following structural formulas:

or

4 . The electrochemical device according to claim 2 , wherein the electrolyte comprises the phosphate, and the phosphate has the structure of Formula 2:

wherein X is a linear or non-linear alkyl group having 1 to 5 carbon atoms or -SiR 2 R 3 R 4 ; wherein R 2 , R 3 , and R 4 are each independently an alkyl group having 1 to 5 carbon atoms, and
R 1 is an alkylene group having 2 to 3 carbon atoms and substituted with a substituent selected from the following: at least one fluorine atom or an alkyl group containing at least one fluorine atom and having 1 to 3 carbon atoms.

5 . The electrochemical device according to claim 1 , wherein a content of the phosphorus- and oxygen-containing compound is 0.001 wt% to 10 wt% based on a total weight of the electrolyte.

6 . The electrochemical device according to claim 1 , wherein the anode mixture layer comprises a carbon material, and 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.

7 . The electrochemical device according to claim 1 , wherein the anode mixture layer has at least one of the following characteristics:
(a) a thickness of not greater than 200 µm; (b) a porosity of 10% to 60%; or (c) 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 50 cm or above.

8 . The electrochemical device according to claim 1 , wherein the anode mixture layer comprises an auxiliary agent, and the auxiliary agent has at least one of the following characteristics:
(a) comprises polyether siloxane; (b) an oxidation potential of not less than 4.5 V and a reductive potential of not greater than 0.5 V; or (c) a surface tension of an aqueous solution containing 0.1 wt% of the auxiliary agent being not greater than 30 mN/m.

9 . The electrochemical device according to claim 1 , wherein based on a total weight of the anode mixture layer, a content of the auxiliary agent is 3000 ppm or below.

10 . An electronic device, comprising an electrochemical device , the electrochemical device comprising:
a cathode; an electrolyte; and an anode,
wherein
the electrolyte comprises a phosphorus- and oxygen-containing compound, and
the anode comprises an anode current collector and an anode mixture layer formed on the anode current collector, and after 100 charge and discharge cycles, an area of lithium precipitation of a surface of the anode mixture layer is 2% or below based on a total surface area of the anode mixture layer.

11 . The electronic device according to claim 11 , wherein the electrolyte comprises at least one of the following compounds:
(a) lithium monofluorophosphate; (b) lithium difluorophosphate; (c) phosphate; (d) phosphocyclic anhydride; or (e) a compound of Formula 1: wherein R is substituted or unsubstituted C 1 -C 10 hydrocarbyl, wherein when substituted, the substituent is halo.

12 . The electronic device according to claim 12 , wherein the electrolyte comprises the compound of Formula 1, and the compound of Formula 1 comprises at least one of the following structural formulas:

or

13 . The electronic device according to claim 12 , wherein the electrolyte comprises the phosphate, and the phosphate has a structure of Formula 2:

wherein X is a linear or non-linear alkyl group having 1 to 5 carbon atoms or -SiR 2 R 3 R 4 , wherein R 2 , R 3 , and R 4 are each independently an alkyl group having 1 to 5 carbon atoms, and
R 1 is an alkylene group having 2 to 3 carbon atoms and substituted with a substituent selected from the following: at least one fluorine atom or an alkyl group containing at least one fluorine atom and having 1 to 3 carbon atoms.

14 . The electronic device according to claim 14 , wherein the compound of Formula 2 includes at least one of the compounds of Formulas 2a to 2h:

15 . The electronic device according to claim 11 , wherein a content of the phosphorus-and oxygen-containing compound is 0.001 wt% to 10 wt% based on a total weight of the electrolyte.

16 . The electronic device according to claim 11 , wherein the anode mixture layer comprises a carbon material, and the carbon material has at least one of the following characteristics:
(a) having a specific surface area of less than 5 m 2 /g; (b) having a median particle size of 5 µm to 30 µm; (c) having amorphous carbon on a surface.

17 . The electronic device according to claim 11 , wherein the anode mixture layer has at least one of the following characteristics:
(a) having a thickness of not greater than 200 µm; (b) having a porosity of 10% to 60%; (c) a minimum height

Assignees

• Ningde Amperex Technology Ltd

Inventors

• Wang Kefei

Classifications

• H01M2004/021

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

• H01M4/133

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

• H01M10/0525

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

• H01M4/587 Primary

  for inserting or intercalating light metals · CPC title

• H01M10/0567 Primary

  characterised by the additives · CPC title