Positive electrode sheet capable of discharging at high rate, and lithium ion battery comprising positive electrode sheet

A technology of positive electrode sheet and positive electrode current collector, which is applied in the direction of electrode collector coating, positive electrode, electrode manufacturing, etc., can solve the problems of prone to side reactions, battery failure safety, and large contact area, so as to reduce gas production The risk of failure, the improvement of electrical conductivity and safety performance, and the effect of small specific surface area

Inactive Publication Date: 2020-12-29
ZHUHAI COSMX BATTERY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] But this brings a serious problem: the temperature of the battery core body is high during high-rate discharge, causing the low-boiling point solvent to decompose to produce gas, and the contact area between the ternary material with high specific surface area and the electrolyte is large, and side reactions are more likely to occur. Leading to the failure of the battery core will also bring safety hazards

Method used

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  • Positive electrode sheet capable of discharging at high rate, and lithium ion battery comprising positive electrode sheet
  • Positive electrode sheet capable of discharging at high rate, and lithium ion battery comprising positive electrode sheet
  • Positive electrode sheet capable of discharging at high rate, and lithium ion battery comprising positive electrode sheet

Examples

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Embodiment 1

[0055] Prepare the positive electrode active material slurry, and the positive electrode active material (the polycrystalline ternary 523 positive electrode material accounting for 70% and the single crystal ternary 622 positive electrode material accounting for 30% by mass) accounting for 94% by mass, the conductive material accounting for 3.5% by mass agent (conductive carbon black), a binder (polyvinylidene fluoride) with a mass proportion of 2.5% is mixed with NMP to prepare a slurry with a solid content of 65-70wt% and a viscosity of 5500-6000mPa·s. The slurry is coated on both sides of the positive electrode current collector, and after drying, it is rolled and die-cut to obtain the positive electrode sheet.

[0056] Prepare the negative electrode active material slurry, the negative electrode active material (artificial graphite) that the mass accounts for 95%, the conductive agent (conductive carbon black) that the mass accounts for 2.8%, the binding agent (polyvinylide...

Embodiment 2-5 and comparative example 1-3

[0059] Others are the same as in Example 1, except that the selection of the positive electrode active material is different, and the coating amount is different, as shown in Table 1 for details.

[0060] The composition of positive electrode active material in the lithium ion battery of table 1 embodiment and comparative example

[0061]

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Abstract

The invention provides a positive electrode sheet capable of realizing high-rate discharge, and a lithium ion battery comprising the positive electrode sheet. According to the invention, a positive active material layer is prepared by mixing a first positive active material (polycrystalline nickel-containing ternary material) and a second positive active material (monocrystalline or monocrystalline-like nickel-containing ternary material), and can reduce the coating amount and improve the rate capability of a lithium ion battery at the same time, or increase the energy density of the lithium ion battery while ensure the rate capability of the lithium ion battery; and by utilizing the characteristics that a second positive electrode active substance has good stability and the contact area with an electrolytic solution is small, the side reaction in the high-rate discharge process can be reduced, the risk of gas production failure is reduced, and the quick release performance of the system can be ensured.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a positive electrode sheet capable of high-rate discharge and a lithium ion battery including the positive electrode sheet. Background technique [0002] With the expansion of the demand for lithium-ion batteries in the consumer market, lithium-ion batteries are required to have higher power density and discharge rate, but the increase in discharge rate will inevitably increase the temperature rise of lithium-ion batteries during discharge, and in order to ensure electrolysis The liquid has a sufficiently high ionic conductivity, and lithium-ion batteries with high-rate discharge mostly use low-viscosity solvents, and low-viscosity solvents have relatively lower boiling points. [0003] At the same time, the positive plate in the lithium-ion battery with high rate discharge is also designed with low compaction and high residual liquid to ensure sufficien...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/525H01M4/36H01M4/131H01M4/04H01M10/0525H01M4/02
CPCH01M4/525H01M4/0404H01M4/131H01M4/366H01M10/0525H01M2004/028H01M2004/021Y02E60/10
Inventor 王洛彭冲许岩欧长志李俊义徐延铭
Owner ZHUHAI COSMX BATTERY CO LTD
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