Lithium ion battery negative electrode material, negative plate and battery

A lithium-ion battery and negative electrode material technology, applied in battery electrodes, secondary batteries, circuits, etc., can solve the problems of reducing the effective active material content of the negative plate, high production cost, short cycle life, etc., to improve the cycle capacity retention rate , Improve wetting and holding capacity, reduce the effect of battery impedance

Inactive Publication Date: 2021-01-29
HEFEI GUOXUAN HIGH TECH POWER ENERGY
View PDF7 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when using PVDF as a binder, N-methylpyrrolidone (NMP) needs to be used as an organic solvent. NMP will pollute the environment and cause higher production costs
Therefore, commercial lithium-ion batteries usually use more environmentally friendly and low-cost aqueous systems to prepare negative electrodes. Due to the poor dispersion of common aqueous binders such as styrene-butadiene rubber (SBR), it is necessary to add sodium carboxymethyl cellulose Thickeners such as (CMC) are used to form a more stable slurry system, but the use of CMC / SBR combined system reduces the content of effective active materials in the negative plate on the one hand, and on the other hand, the CMC thickener has greater brittleness. After rolling, the structure will collapse due to excessive pressure, and problems such as powder drop and foil leakage will occur, and the volume expansion of the negative electrode material during the cycle cannot be effectively suppressed, resulting in a short cycle life.
[0004] Researchers have done more in-depth research on lithium-ion battery active materials, conductive agents and binders, but less research on thickeners. Therefore, how to choose a more effective thickener to combine with existing binders It is an important research direction in this field to further improve the electrochemical performance of lithium-ion batteries with better cooperation.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Lithium ion battery negative electrode material, negative plate and battery
  • Lithium ion battery negative electrode material, negative plate and battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] A preparation method of pseudo-physalis seed gum, comprising the steps:

[0024] Weigh 500g of impurity-removed false physalis seeds and soak them in 2500g of deionized water, heat in a water bath to control the water temperature to be 60°C, extract for 60 min, and remove the false physalis seeds with 100-mesh filter gauze to obtain the filtrate, which is the false physalis glue 50g concentrated liquid was obtained by concentrating the original solution of pseudo-physalis colloid in a rotary evaporator at 60 °C, adding isopropanol to precipitate the pseudo-physalis colloid from the concentrated solution, collecting the precipitate, vacuum drying, and pulverizing to obtain a pseudo-acid Pulp Seed Gum 3.4g.

Embodiment 2

[0026] A preparation method of pseudo-physalis seed gum, comprising the steps:

[0027] Weigh 500g of impurity-removed false physalis seeds and soak them in 5000g of deionized water, heat in a water bath to control the water temperature to 90°C, extract for 30 minutes, and remove the false physalis seeds with 100-mesh filter gauze to obtain the filtrate, which is the false physalis glue 500g of concentrated solution was obtained by concentrating the original solution of pseudo-physalis colloid in a rotary evaporator at 60°C, adding isopropanol to precipitate the pseudo-physalis colloid from the concentrated solution, collecting the precipitate, vacuum drying, and pulverizing to obtain a pseudo-acid Pulp Seed Gum 3.8g.

Embodiment 3

[0029] A lithium ion battery, the preparation method of which comprises the following steps:

[0030] a. Preparation of positive electrode sheet: Mix the positive active material NMC811 ternary material, the conductive agent acetylene black, and the binder polytetrafluoroethylene according to the weight ratio of 95:2.5:2.5, add N-methylpyrrolidone, and fully stir and mix A uniform positive electrode slurry is uniformly formed, uniformly coated on a 15 μm thick aluminum foil, and a positive electrode sheet is obtained after drying;

[0031] b, preparation of negative electrode sheet: the silicon carbon composite material (that is, the negative electrode active material), the conductive agent acetylene black, the pseudo-acid pulp seed colloid prepared in Example 1 and the binder SBR are 97.5:0.5:1 according to weight ratio: 1 Mix well, add deionized water, fully stir and mix to form a uniform negative electrode slurry, evenly coat it on 8μm thick copper foil, and dry to obtain a...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a lithium ion battery negative electrode material which comprises the following raw materials: a negative electrode active material, a conductive agent, a thickening agent anda binder, and the thickening agent is nicandra physaloides seed colloid. The invention also discloses a lithium ion battery negative plate which comprises a current collector and a negative electrodematerial layer coating the surface of the current collector, and the negative electrode material layer is formed by the lithium ion battery negative electrode material. The invention further disclosesa lithium ion battery. The lithium ion battery comprises the lithium ion battery negative plate. According to the invention, the nicandra physaloides seed colloid is selected as the thickening agent,so that the infiltration and retention capacity of the negative plate to electrolyte is improved, the impedance of the battery is reduced, the rate capability is obviously improved, and the nicandraphysaloides seed colloid is high in elasticity after crosslinking and can better adapt to volume expansion during the charging and discharging of a negative electrode, thereby effectively improving the retention rate of the cycle capacity.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a lithium ion battery negative electrode material, a negative electrode sheet and a battery. Background technique [0002] Due to the advantages of high energy density, excellent rate and power performance, long cycle life, safety and environmental protection, lithium-ion batteries are widely used in our daily life as an important chemical power source. In addition to long-term applications in traditional digital products such as mobile phones and portable computers, the application scope of lithium-ion batteries has gradually expanded to high-tech fields such as electric vehicles, aerospace and energy storage. [0003] Lithium-ion batteries are mainly composed of positive electrode sheets, negative electrode sheets, separators and electrolytes. The positive and negative electrode sheets are mainly composed of active materials, binders, thickeners, conductive agents...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): H01M4/131H01M4/133H01M4/134H01M4/62H01M10/0525
CPCH01M4/62H01M4/133H01M4/134H01M4/131H01M10/0525Y02E60/10
Inventor 梁大宇俞金萍沈剑赵坤王鹏
Owner HEFEI GUOXUAN HIGH TECH POWER ENERGY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap