Safety lithium-supplementing composite negative pole piece and preparation method thereof

A negative pole piece and lithium replenishment technology, which is applied in the field of safe lithium supplementary composite negative pole piece and its preparation, can solve problems affecting battery safety performance, battery short circuit, and easy pulverization of lithium slices, so as to improve the first charge and discharge efficiency, Prevents the effect of puncturing the diaphragm and avoiding direct contact

Inactive Publication Date: 2018-11-23
桑顿新能源科技(长沙)有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, although this method can achieve the effect of lithium supplementation, the lithium sheet is easily pulverized or lithium dendrites exist during the cycle, and it is easy to pierce the separator and cause a short circuit of the battery, thereby affecting the safety performance of the battery.

Method used

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  • Safety lithium-supplementing composite negative pole piece and preparation method thereof
  • Safety lithium-supplementing composite negative pole piece and preparation method thereof
  • Safety lithium-supplementing composite negative pole piece and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0090] Such as figure 1 As shown, the present embodiment provides a safe lithium-supplementing composite negative electrode sheet 1 comprising: a foamed copper current collector 11, which is a three-dimensional network structure with a thickness of 20 μm; the first negative electrode active material disposed on the front of the foamed copper current collector 11 Layer 121 and the second negative electrode active material layer 122 on the opposite side have a thickness of 165 μm, and the copper foam current collector 11, the first negative electrode active material layer 121, and the second negative electrode active material layer 122 constitute the negative electrode sheet body;

[0091] On the front of the negative electrode sheet body, there are first lithium supplementary layer 131 and first ceramic layer 141 sequentially from inside to outside, and the second lithium supplementary layer 132 and second ceramic layer 142 are sequentially arranged on the reverse side from insi...

Embodiment 2

[0105] The difference between this embodiment and embodiment 1 is:

[0106] The thickness of the copper foam collector is: 10μm;

[0107] The coating thicknesses of the first negative electrode active material layer and the second negative electrode active material layer are both: 180 μm;

[0108] The coating thicknesses of the first lithium supplementary layer and the second lithium supplementary layer are both: 0.5 μm;

[0109] The coating thicknesses of the first ceramic layer and the second ceramic layer are both: 8 μm;

[0110] Ceramic powder: silicon dioxide powder; particle size: 30nm;

[0111] Adhesive B and adhesive C are all made of polyvinyl ester;

[0112] The particle size of metal lithium powder is: 5μm;

[0113] In the negative electrode slurry, the weight percentage of artificial graphite: KS-6: PVDF is 97%: 1.5%: 1.5%;

[0114] In the lithium supplement slurry, the weight percentage of inactive lithium metal powder: CMC is 60%: 40%;

[0115] In the ceram...

Embodiment 3

[0118] The difference between this embodiment and embodiment 1 is:

[0119] The thickness of the copper foam collector is: 20μm;

[0120] The thicknesses of the first negative electrode active material layer and the second negative electrode active material layer are both: 150 μm;

[0121] The coating thicknesses of the first lithium supplementary layer and the second lithium supplementary layer are both: 2 μm;

[0122] The coating thicknesses of the first ceramic layer and the second ceramic layer are both: 3 μm;

[0123] Ceramic powder: silicon nitride powder; particle size: 100nm;

[0124] The particle size of the inactive lithium metal powder is: 5 μm;

[0125] In the negative electrode slurry, the weight percentage of natural graphite: Ketjen black: PVDF is 96%: 2%: 2%;

[0126] In the lithium supplement slurry, the weight percentage of inactive lithium metal powder: CMC is 80%: 20%;

[0127] In the ceramic slurry, the weight percentage of ceramic powder: polyvinyl e...

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Abstract

The invention relates to a safety lithium-supplementing composite negative pole piece and a preparation method thereof. The safe lithium-supplementing composite negative pole piece comprises a negative pole piece body, a first lithium-supplementing layer, a first ceramic layer, a second lithium-supplementing layer and a second ceramic layer, wherein the first lithium-supplementing layer and the first ceramic layer are sequentially arranged on the front side of the negative pole piece body from inside to outside, and the second lithium-supplementing layer and the second ceramic layer are sequentially arranged on the reverse side of the negative pole piece body from inside to outside. The invention further provides the preparation method of the negative pole piece. According to the safety lithium-supplementing composite negative pole piece, the front side and the back side of the negative pole piece body coated with negative active materials are coated with the lithium-supplementing layers separately, and then the surfaces of the lithium-supplementing layers on both sides are coated with the ceramic layers separately, so that lithium ions consumed in the first charging process can besupplemented by the lithium-supplementing layers to improve the capacity of a battery and the first charging and discharging efficiency on one hand; and on the other hand, direct contact between thelithium supplementing layers and separators are avoided through the ceramic layers, lithium dendrites are prevented from piercing the separators, and the safety performance of the battery is improved.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a negative pole piece and a preparation method thereof, in particular to a safe lithium supplement composite negative pole piece and a preparation method thereof. technical background [0002] As an environmentally friendly lithium secondary battery, lithium-ion batteries have been widely used in various electronic fields such as 3C and EV fields due to their high specific energy, high specific power, long cycle life, and good high and low temperature performance. Wait. With the continuous expansion of application fields, there are occasional reports of lithium-ion battery explosions and insufficient battery life. Therefore, the improvement of safety performance and energy density of lithium batteries has always been an issue of extreme concern in the industry. [0003] For graphite or silicon carbon negative electrode sheets, part of the lithium will be consumed d...

Claims

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Application Information

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IPC IPC(8): H01M4/133H01M4/1393H01M10/0525H01M10/42
CPCH01M4/133H01M4/1393H01M10/0525H01M10/4235Y02E60/10
Inventor伍成徐海平刘学良刘昆武媛王耐清李小兵陈小平
Owner桑顿新能源科技(长沙)有限公司