Process for improving roll sticking and powder falling during rolling of negative plate

A negative electrode sheet and roll pressing technology, which is applied to battery electrodes, electrical components, circuits, etc., can solve the problems of negative electrode falling off, sticking to rolls, powder falling, etc., and achieve the effects of solving sticking rolls, improving yield and performance, and relieving stress

Pending Publication Date: 2022-04-12
山东天瀚新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the existing actual production, the sticky roll is generally caused by excessive water content. The positive electrode sheet is made of oil-based NMP to make the moisture easy to bake. In actual rolling, the roll is sticky and the phenomenon of powder dropping is less, while the negative electrode sheet is configured by water-based slurry. , there will be excessive moisture in some parts, which will often cause sticking and powder dropping during actual rolling. In severe cases, the negative electrode will fall off in a large area, which seriously affects the product quality of lithium-ion batteries.

Method used

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  • Process for improving roll sticking and powder falling during rolling of negative plate
  • Process for improving roll sticking and powder falling during rolling of negative plate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] (1) Put the coated negative plate at room temperature and vacuum for 12H, preferably at room temperature of 25°C;

[0018] (2) Perform a high-temperature heat treatment at 100° C. for 0.5 hours on the negative electrode sheet after standing in an oven;

[0019] (3) Put the heat-treated negative electrode sheet into a low-temperature box for 0.5H at a low temperature, preferably at a low temperature of -15°C;

[0020] (4) Alternate (2) and (3) for N times, preferably N≥3;

[0021] (5) The negative electrode sheet treated at low temperature after circulation is rolled once, and the rolling method uses a large gap and high pressure method for rolling. Example 2

Embodiment 2

[0022] (1) Put the coated negative plate at room temperature and vacuum for 12H, preferably at room temperature of 25°C;

[0023] (2) Perform a high-temperature heat treatment at 110° C. for 0.5 hours on the negative electrode sheet after standing in an oven;

[0024] (3) Put the heat-treated negative electrode sheet into a low-temperature box for 0.5-1H at a low temperature, preferably at a low temperature of -20°C;

[0025] (4) Alternate (2) and (3) for N times, preferably N≥3;

[0026] (5) The negative electrode sheet treated at low temperature after circulation is rolled once, and the rolling method uses a large gap and high pressure method for rolling.

Embodiment 3

[0028] (1) Put the coated negative plate at room temperature and vacuum for 24H, preferably at room temperature of 25°C;

[0029] (2) Perform a high-temperature heat treatment at 120° C. for 1 hour on the negative electrode sheet after standing in an oven;

[0030] (3) Put the heat-treated negative electrode sheet into a low-temperature box for 1H at a low temperature, preferably at a low temperature of -20°C;

[0031] (4) Alternate (2) and (3) for N times, preferably, N≥3;

[0032] (5) The negative electrode sheet treated at low temperature after circulation is rolled once, and the rolling method uses a large gap and high pressure method for rolling.

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Abstract

The invention discloses a process for improving roll sticking and powder falling during rolling of a negative electrode plate. The process comprises the following steps: (1) putting the coated negative electrode plate into an oven, and carrying out normal-temperature vacuum standing for 12-24H; (2) carrying out high-temperature heat treatment on the standing negative electrode plate in the oven at 100-120 DEG C for 0.5-1H; (3) placing the negative plate subjected to heat treatment in a low-temperature box for 0.5-1H at a low temperature; (4) alternately carrying out N cycles on the steps (2) and (3), wherein N is greater than or equal to 3; and (5) directly rolling the negative electrode plate which is placed at low temperature after circulation for one time. By means of a cold and heat alternating mode, stress borne during rolling can be effectively relieved, the phenomena of roll sticking, powder falling and the like during negative plate rolling are avoided, the lithium battery yield is increased, and the lithium ion battery performance is improved.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to an improved process for rolling, sticking, and powder dropping of negative electrode sheets. Background technique [0002] Lithium-ion batteries have the advantages of large specific capacity, high working voltage, long cycle life, high energy density, and low environmental pollution. They have been widely used in low-speed vehicles, electric tools, and energy storage. [0003] Among them, the battery pole piece is the main component of the lithium-ion battery. The quality of the battery pole piece directly affects the performance and yield of the battery. The lithium-ion battery pole piece is based on aluminum foil and copper foil. The production is completed after the rolling and cutting process. Rolling is to improve the battery energy density, electronic conductivity and improve bonding. It is the most important process before the battery pole piece is formed. In t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/139
CPCY02E60/10
Inventor 张朋赵美菊
Owner 山东天瀚新能源科技有限公司
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