Battery and method for preparing the same

Patent metadata

Field	Value
Publication number	US-2019363391-A1
Application number	US-201916420773-A
Country	US
Kind code	A1
Filing date	May 23, 2019
Priority date	May 24, 2018
Publication date	Nov 28, 2019
Grant date	—

Abstract

The present disclosure provides a battery and method for preparing the same. The battery includes a cell and an electrolyte; the cell includes a positive electrode plate, a negative electrode plate and a separator. Wherein in the battery, at least one surface of the positive electrode film and/or the negative electrode film is provided with protrusions, with a proviso that: 0.3≤(T c +T a )/(H c +H a )≤1; wherein T c is a height of the protrusions provided on the at least one surface of the positive electrode film, T a is a height of the protrusions provided on the at least one surface of the negative electrode film, H c is a thickness increase of the positive electrode film when the battery has a 100% SOC, H a is a thickness increase of the negative electrode film when the battery has a 100% SOC.

First claim

What is claimed is:

1 . A battery, comprising a cell and an electrolyte, the cell comprising
a positive electrode plate, comprising
a positive electrode current collector and
a positive electrode film disposed on at least one surface of the positive electrode current collector and comprising a positive electrode active material;
a negative electrode plate, comprising
a negative electrode current collector and
a negative electrode film disposed on at least one surface of the negative electrode current collector and comprising a negative electrode active material;
and a separator, disposed between the positive electrode plate and the negative electrode plate; wherein in the battery, at least one surface of the positive electrode film and/or the negative electrode film is provided with protrusions, with a proviso that: 0.3≤(T c +T a )/(H c +H a )≤1, wherein T c is a height of the protrusions provided on the at least one surface of the positive electrode film; T a is a height of protrusions provided on the at least one surface of the negative electrode film; H c is a thickness increase of the positive electrode film when the battery has a 100% SOC; H a is a thickness increase of the negative electrode film when the battery has a 100% SOC.

2 . The battery according to claim 1 , wherein 0.4≤(T c +T a )/(H c +H a )≤0.8.

3 . The battery according to claim 1 , wherein 0.6≤(T c +T a )/(H c +H a )≤0.8.

4 . The battery according to claim 1 , wherein the protrusions are distributed in a form of an array on at least one surface of the positive electrode film and/or the negative electrode film.

5 . The battery according to claim 1 , wherein the protrusions are in a form of various regular or irregular shapes.

6 . The battery according to claim 1 , wherein the protrusions are in a form of a round, a semi-circular, a square, a rectangular or a trapezoidal shape.

7 . The battery according to claim 1 , wherein when the protrusions are disposed on the at least one surface of the positive electrode film, the projected area of the protrusions onto at least one surface of the positive electrode film is 10%-60% of total area of the positive electrode film.

8 . The battery according to claim 1 , wherein when the protrusions are disposed on at least one surface of the negative electrode film, the projected area of the protrusions onto at least one surface of the negative electrode film is 10%-60% of total area of the negative electrode film.

9 . The battery according to claim 1 , wherein the protrusions are only disposed on at least one surface of the positive electrode film.

10 . A method for preparing a battery, for preparing the battery according to claim 1 , comprising steps of:
step 1: coating a positive electrode slurry comprising a positive electrode active material onto a positive electrode current collector, drying and cold pressing, to obtain a positive electrode plate; coating a negative electrode slurry comprising a negative electrode active material onto a negative electrode current collector, drying and cold pressing, to obtain a negative electrode plat; and measuring an initial thickness of a positive electrode film of the positive electrode plate as H 1 , and measuring an initial thickness of a negative electrode film of the negative electrode plate as H 2 ; step 2: assembling the positive electrode plate and the negative electrode plate prepared in step 1, a separator and an electrolyte into a case to obtain a battery to be tested, charging the battery to be tested to 100% SOC, and disassembling the battery to be tested after being disconnected from a power supply; measuring a thickness of the positive electrode film as H 1 ′, the thickness of the negative electrode film as H 2 ′, and calculating a thickness increase of the positive electrode film as H c =H 1 ′−H 1 , and a thickness increase of the negative electrode film as H a =H 2 ′−H 2 ; and step 3: roll compacting the positive electrode plate and/or the negative electrode plate prepared in step 1 using a counter roller having a protrusion structure to form protrusions on at least one surface of the positive electrode film and/or the negative electrode film with a proviso that 0.3≤(T c +T a )/(H c +H a )≤1, wherein T c is a height of the protrusions on at least one surface of the positive electrode film, and T a is a height of the protrusions on at least one surface of the negative electrode film; and reassembling the obtained positive electrode plate and the negative electrode plate, the separator, and the electrolyte into a case, to obtain a battery.

11 . The method for preparing a battery according to claim 10 , wherein in step 1, the initial thickness H 1 of the positive electrode film is 0.1 mm-0.4 mm.

12 . The method for preparing a battery according to claim 10 , wherein in step 1, the initial thickness H 2 of the negative electrode film is 0.07 mm-0.3 mm.

Assignees

• Contemporary Amperex Technology Co Ltd

Inventors

• Yang Limei
• Liu Xiaomei

Classifications

• H01M10/04

  Construction or manufacture in general (H01M10/058, H01M10/12, H01M10/28, H01M10/38 take precedence) · CPC title

• H01M4/02

  Electrodes composed of, or comprising, active material · CPC title

• H01M10/0418 Primary

  with bipolar electrodes · CPC title

• H01M4/8828

  Coating with slurry or ink · CPC title

• H01M2004/021

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