Negative electrode plate, method for preparing the same, secondary battery, battery module, battery pack and electrical device

Patent metadata

Field	Value
Publication number	US-2025046800-A1
Application number	US-202418918117-A
Country	US
Kind code	A1
Filing date	Oct 17, 2024
Priority date	Apr 20, 2022
Publication date	Feb 6, 2025
Grant date	—

Abstract

The present application provides a negative electrode plate for a secondary battery, a method for preparing the same, and a secondary battery including the negative electrode plate, a battery module, a battery pack, and an electrical device. The negative electrode plate in the present application includes a current collector and an active material layer disposed on at least one surface of the current collector, wherein the active material layer includes: a first graphite layer disposed on at least one surface of the current collector, a lithium titanate layer disposed on the surface of the first graphite layer, and a second graphite layer disposed on the surface of the lithium titanate layer; and the first graphite layer has an OI value of greater than or equal to 20.0, and the second graphite layer has an OI value of less than or equal to 15.0.

First claim

What is claimed is:

1 . A negative electrode plate, comprises a current collector and an active material layer disposed on at least one surface of the current collector, wherein
the active material layer comprises: a first graphite layer; a lithium titanate layer; and a second graphite layer, the first graphite layer is disposed on at least one surface of the current collector, the lithium titanate layer is disposed on a surface of the first graphite layer, and the second graphite layer is disposed on a surface of the lithium titanate layer, and the first graphite layer has an OI value of greater than or equal to 20.0, optionally from 30.0 to 40.0, and the second graphite layer has an OI value of less than or equal to 15.0, optionally from 8.0 to 12.0.

2 . The negative electrode plate according to claim 1 , wherein the first graphite layer has a thickness of less than or equal to 100 μm.

3 . The negative electrode plate according to claim 1 , wherein the lithium titanate layer has a thickness of from 25 μm to 50 μm.

4 . The negative electrode plate according to claim 1 , wherein the second graphite layer has a thickness of less than or equal to 100 μm.

5 . The negative electrode plate according to claim 1 , wherein the active material layer has a thickness of from 50 μm to 150 μm.

6 . The negative electrode plate according to claim 1 , wherein the negative electrode plate has a compacted density of from 0.9 to 1.8 g/cm 3 .

7 . A method for preparing a negative electrode plate, comprising
providing a current collector; forming a first graphite layer comprising first graphite on at least one surface of the current collector; forming a lithium titanate layer comprising lithium titanate on a surface of the first graphite layer; forming a second graphite layer comprising second graphite on a surface of the lithium titanate layer, to obtain a laminated body having an active material layer on at least one surface of the current collector, the active material layer comprising the first graphite layer, the lithium titanate layer, and the second graphite layer; and cold-pressing the laminated body to obtain the negative electrode plate; wherein the first graphite has an OI value of greater than 2.0 and less than or equal to 6.0, optionally from 3.0 to 5.0, and the second graphite has an OI value of greater than or equal to 0.5 and less than 2.0, and optionally from 1.0 to 1.5.

8 . The method according to claim 7 , wherein a pressure for the cold-pressing is from 15 T to 70 T.

9 . The method according to claim 7 , wherein after cold-pressing the laminated body, the first graphite layer as formed has an OI value of greater than or equal to 20.0, optionally from 30.0 to 40.0, and the second graphite layer as formed has an OI value of less than or equal to 15.0, optionally from 8.0 to 12.0.

10 . The method according to claim 7 , wherein after cold-pressing the laminated body, the negative electrode plate as formed has a compacted density of from 0.9 to 1.8 g/cm 3 .

11 . A secondary battery, comprising
a positive electrode plate; the negative electrode plate according to claim 1 ; an electrolyte; and a separator.

12 . A battery module comprising the secondary battery according to claim 11 .

13 . A battery pack comprising the battery module according to claim 12 .

14 . An electrical device comprising the secondary battery according to claim 11 .

Assignees

• Contemporary Amperex Technology Hong Kong Ltd

Inventors

• Chen Xiangbin
• Qu Denghong
• Gao Kai
• Lai Youlei

Classifications

• H01M4/366 Primary

  as layered products · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M2004/021

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

• H01M10/0525 Primary

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

• H01M4/587

  for inserting or intercalating light metals · CPC title