Negative pole piece, preparation method thereof and lithium secondary battery

A lithium secondary battery and negative pole piece technology, which is applied in the direction of secondary batteries, battery electrodes, non-aqueous electrolyte storage battery electrodes, etc., can solve the problems of poor fast charging performance of lithium secondary batteries, etc.

Active Publication Date: 2022-07-15
SUNWODA ELECTRIC VEHICLE BATTERY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The main purpose of this application is to provide a negative pole piece and its preparation method, lithium secondary battery, to solve the problem of poor fast charging performance of lithium secondary battery in the prior art

Method used

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  • Negative pole piece, preparation method thereof and lithium secondary battery
  • Negative pole piece, preparation method thereof and lithium secondary battery
  • Negative pole piece, preparation method thereof and lithium secondary battery

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preparation example Construction

[0064] In another embodiment of the present application, there is provided a method for preparing any of the foregoing negative electrode sheets, the preparation method comprising: preparing a negative electrode slurry; coating the negative electrode slurry on one side or both sides of a copper foil of a negative electrode current collector , obtain the negative pole piece after drying, cold pressing, slitting; Wherein, the process of preparing the negative electrode slurry includes: selecting porous graphite according to the following relational formula I, including the negative electrode active material of porous graphite and conductive agent, binder and Dispersing solvents are mixed to obtain negative electrode slurry;

[0065] 0.9≤A×Dv 50 / C≤4.3 Relationship I

[0066] Among them, the average pore diameter of the surface channels of porous graphite is A nm;

[0067] The volume median particle size of porous graphite is Dv 50 μm;

[0068] The gram capacity of porous gra...

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Abstract

The invention provides a negative pole piece, a preparation method thereof and a lithium secondary battery. The negative pole piece comprises a negative current collector and a negative diaphragm arranged on one surface or two surfaces of the negative current collector, the negative diaphragm comprises a negative active material, the negative active material comprises porous graphite, and the porous graphite meets the condition that A * Dv50 / C is larger than or equal to 0.9 and smaller than or equal to 4.3; wherein the average pore size of surface pore channels of the porous graphite is A nm; the volume median particle size of the porous graphite is Dv < 50 > [mu] m; and the gram volume of the porous graphite is C mAh / g. The lithium secondary battery has high energy density, long cycle life and rapid charging performance by reasonably adjusting the relationship among the average pore size of the porous graphite surface pore channels in the negative electrode active material, the gram volume of the porous graphite and the average particle size.

Description

technical field [0001] The present application relates to the field of lithium secondary batteries, and in particular, to a negative electrode pole piece and a preparation method thereof, and a lithium secondary battery. Background technique [0002] Lithium secondary batteries have outstanding characteristics such as light weight, high energy density, no pollution, no memory effect and long service life, and are widely used in portable electronic devices and new energy vehicles. However, a long charging time is one of the important factors limiting the rapid popularization of new energy vehicles. From a technical point of view, the negative pole piece has a great impact on the fast charging performance of lithium secondary batteries. If the charging and discharging current is too large, it will lead to Part of the lithium ions are directly reduced and precipitated on the surface of the negative electrode plate instead of being embedded in the negative electrode active mater...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/13H01M4/139H01M4/62H01M10/0525
CPCH01M4/13H01M4/625H01M10/0525H01M4/139Y02E60/10
Inventor 刘鹏罗汉卿陈云李嫚褚春波
Owner SUNWODA ELECTRIC VEHICLE BATTERY CO LTD
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