A kind of negative electrode of lithium ion battery and lithium ion battery

A lithium-ion battery and negative electrode technology, which is applied to battery electrodes, non-aqueous electrolyte battery electrodes, secondary batteries, etc., can solve the problems of reduced cycle life, poor rate performance, and reduced expansion, and achieve low expansion rate and low expansion rate Effect

Active Publication Date: 2017-12-08
NINGDE AMPEREX TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the non-covalent bond (Van der Waals effect) force provided by the binder in the negative pole piece system will be reduced due to the swelling of the polymer binder to varying degrees under the electrolyte immersion. When the thickness of the pole piece increases or the selection of When using active materials with greater expansion (silicon, silicon oxide, etc.), this will cause the loosening and falling off of the negative electrode active material layer, which will make it difficult to deintercalate lithium ions, increase polarization, and lithium precipitation during cycling. Serious problems such as poor performance and reduced cycle life

Method used

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  • A kind of negative electrode of lithium ion battery and lithium ion battery
  • A kind of negative electrode of lithium ion battery and lithium ion battery
  • A kind of negative electrode of lithium ion battery and lithium ion battery

Examples

Experimental program
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Embodiment 1

[0034] Embodiment 1, a lithium ion battery negative electrode, comprising a negative electrode current collector and a negative electrode active material layer coated on the negative electrode current collector, the negative electrode active material layer comprising a negative electrode active material, a conductive agent, a polymer thickener, and a water emulsion type polymer Material binder and water-soluble polymer binder, the water-soluble polymer binder is polyethyleneimine, and the weight ratio of the water-emulsion polymer binder and the water-soluble polymer binder is 10:90 ~90: 10.

[0035] The preparation of the negative electrode: The negative electrode slurry formula is based on the weight percentage of the dry material, consisting of 2% styrene butadiene rubber emulsion, 1.5% polyethyleneimine, 0.5% sodium carboxymethyl cellulose, 1% conductive carbon black, 95% negative electrode active material It is composed of five parts, in which the negative electrode active m...

Embodiment 2

[0047] The difference between Example 2 and Example 1 is that the preparation process of the negative electrode in this example is that the negative electrode slurry formula is based on the weight percentage of dry material, consisting of 2% nitrile rubber emulsion, 1.5% butadiene rubber emulsion, and 2% Polyethyleneimine, 0.5% carboxymethyl cellulose, 1% carbon fiber, 93% negative electrode active material consists of five parts, of which the negative electrode active material uses natural graphite and graphitized carbon fiber, the weight average molecular weight of polyethyleneimine is about 100,000g / mol, the pH value of the aqueous solution with a mass concentration of 5% is in the range of 9-12, the substitution degree of carboxymethyl cellulose is in the range of 0.8-1.0, and the aqueous solution with a mass concentration of 1% is at 25℃ The viscosity is in the range of 1000-3000mPa.s. In the slurry configuration process, the solvent is deionized water, and water accounts...

Embodiment 3

[0051] Example 3 is different from Example 2: The preparation process of the negative electrode in this example is that the negative electrode slurry formula is based on the weight percentage of the dry material, consisting of 2% butadiene rubber emulsion, 2% polyethyleneimine, and 1% It consists of five parts: hydroxyethyl cellulose, 1% carbon nanotubes, and 94% negative electrode active material. The negative electrode active material uses graphitized mesophase carbon beads and amorphous carbon. The weight average molecular weight of polyethyleneimine is about 5,000 g / mol, the pH value of an aqueous solution with a mass concentration of 5% is in the range of 9-12, the degree of substitution of hydroxyethylcellulose is in the range of 0.8-1.0, and an aqueous solution with a mass concentration of 1% is at 25°C The viscosity is in the range of 1000-3000mPa.s. In the slurry configuration process, the solvent is deionized water, and water accounts for 60% of the total slurry mass...

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Abstract

The invention discloses a lithium ion battery cathode. The lithium ion battery cathode comprises a cathode current collector and a cathode active-substance layer coated on the cathode current collector. The cathode active-substance layer comprises a cathode active-substance, a conductive agent, a polymer thickening agent, a water emulsion-type polymer binder and a water soluble polymer binder. The water soluble polymer binder is polyethyleneimine. A weight ratio of the water emulsion-type polymer binder to the water soluble polymer binder is in a range of (10: 90)-(90: 10). The lithium ion battery cathode can obviously improve the adhesion between the cathode active-substance layer and the cathode current collector and among particles in the cathode active-substance layer thereby improving structure stability of the cathode active-substance layer in long-term battery cycle and reducing a use amount of the polymer binders having electrochemical inertia, reducing a battery volume expansion ratio in cycle, and improving low temperature, multiplying power, cycle performances and energy density of a polymer lithium ion battery. The invention also discloses a lithium ion battery.

Description

Technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a lithium ion battery negative electrode and a lithium ion battery. Background technique [0002] Since the commercialization of lithium-ion batteries, they have been widely used as various portable electronics with many advantages such as high energy density, high working voltage, long cycle life, no memory effect, environmental protection, and flexible design according to actual needs. The power supply of electrical appliances, these broad application fields and various practical needs have greatly promoted the development of lithium-ion batteries. [0003] With the rapid development of mobile electronic and electrical equipment, lithium-ion batteries that provide power for these thin, portable and powerful devices are required to have higher capacity. Therefore, it is necessary to develop higher working voltage, higher energy density and higher energy densit...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/62H01M4/13H01M10/0525
CPCY02E60/10
Inventor 平翔梁如福陈永乐王景芳张柏清
Owner NINGDE AMPEREX TECH
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