Preparation method of lithium ion battery porous silicon carbon composite negative material

A lithium-ion battery and silicon-carbon composite technology, applied in battery electrodes, circuits, electrical components, etc., can solve the problems of expensive nano-silicon raw materials, reduced capacity retention, and poor cycle performance, so as to reduce the initial irreversible capacity , Improve charge and discharge efficiency, improve the effect of cycle stability

Inactive Publication Date: 2012-10-03
力芯(青岛)新能源材料有限公司
View PDF1 Cites 36 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, silicon-based negative electrode materials are accompanied by large volume changes (>300%) during charge and discharge, and continuous volume changes can easily lead to material structure collapse and electrode material peeling, resulting in silicon particle breakage and pulverization, resulting in conductive network Separation occurs between silicon particles, the capacity drops rapidly, and the cycle performance deteriorates
In response to these problems, researchers have widely used the method of compounding silicon-based composite materials to improve their cycle performance. Using the synergistic effect between the components of the composite material, the purpose of complementary advantages can be achieved, such as with conductive polymers, metal nitrides, etc. , silicon oxide composites have been improved to a certain extent, but not ideal
It has been reported that using nano-silicon as the active material and coating it with amorphous carbon, the silicon-carbon composite material can have high lithium storage capacity and good cycle performance at the same time. For example, Magasinski et al. adopted a bottom-up self-assembly route, A silicon-carbon composite material with a hierarchical structure was prepared. The porosity of the particle itself can adjust the volume change of silicon during the intercalation / extraction process, and the reversible capacity reaches 1950 mAh / g (Nature materials. 2010, 9: 353-358), However, nano-silicon raw materials are expensive and the output is low, and the cost of the prepared silicon-carbon composite material is high and it is difficult to achieve the goal of industrialization and commercialization.
Kim et al prepared a silicon-carbon composite material with a reversible capacity of 613 mAh / g using cheap micron silicon powder as raw material by mechanical force-chemical ball milling (Journal of Power Sources. 2010, 195: 6031–6036), Li Hong et al. A silicon-carbon composite material with a "Yuanxiao" structure has been invented with commercial micro-silicon as raw material, which has high charging capacity and good safety (authorized announcement number CN 1328805C). There will be a serious volume effect during the discharge process, which will reduce the capacity retention rate during the cycle, and the prepared material will have poor cycle performance

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Nano-aluminum powder with a median diameter of 60 nm and commercial silicon powder (median diameter of 3 μm) are mixed in a mass ratio of 1:3, sealed in a ball mill jar in a high-purity nitrogen atmosphere, and placed in a vibrating ball mill. , set the milling speed to 300 r / min and mill for 12 h. Submerge the compound prepared by ball milling into 2.0 mol / L hydrochloric acid, add 30% more hydrochloric acid than the amount that completely reacts the aluminum, stir for 1.5 h, filter and wash with deionized water until the pH is greater than or equal to 5, at 110 °C The porous silicon material was prepared by drying, the measured pore diameter was 10-60 nm, the median diameter was 0.9 μm, and the particle surface pore size distribution number was 8.0×10 10 / cm 2 . Add 4.5 kg of asphalt into the mixed solution of tetrahydrofuran and acetone with a volume ratio of 1:1 until it is completely dissolved. In a high-purity nitrogen atmosphere, 16.5 kg of artificial spherical...

Embodiment 2

[0028] Nano-aluminum powder with a median diameter of 30 nm and commercial silicon powder (with a median diameter of 2 μm) in a mass ratio of 1:2 were sealed in a ball mill jar in an argon atmosphere, and prepared as described in Example 1 Methods Ball milled on a planetary ball mill at a speed of 500 r / min for 8 h, added 25% hydrochloric acid for 2.5 mol / L to completely react the aluminum, etched for 2 h, filtered, and washed with deionized water to pH Greater than or equal to 5, the porous silicon material was prepared by drying at 100 °C, the measured pore size was 10-50 nm, and the particle surface pore size distribution number was 1.1×10 11 / cm 2 , the number of pores per median diameter particle is 6000. 2.4 kg of porous silicon material, 15.6 kg of natural spherical graphite (median diameter of 6 μm) and 5.0 kg of citric acid dissolved in absolute ethanol were sealed in a vibrating ball mill jar in an argon atmosphere, and vibrated at 15Hz Frequency ball milling for 1...

Embodiment 3

[0031] Nano-aluminum powder with a median diameter of 30 nm and commercial silicon powder (with a median diameter of 2 μm) in a mass ratio of 1:2.5 were sealed in a ball mill jar in an argon atmosphere, and prepared as described in Example 1 Methods Ball milled on a bearing-type ball mill at a speed of 350 r / min for 10 h, added 20% hydrochloric acid for 3.0 mol / L to completely react the aluminum, etched for 2 h, filtered, and washed with deionized water until the pH was greater than Equal to 5, dry at 100 ℃ to prepare porous silicon materials, the pore diameter is 20~70 nm, the median diameter is 0.8 μm, and the particle surface pore size distribution number is 5.0×10 10 / cm 2 . 3.0 kg of porous silicon material, 15 kg of natural spherical graphite (median diameter of 12 μm) and 4.0 kg of PVA dissolved in deionized water were sealed in a ball mill jar in an argon atmosphere, and ball milled at a speed of 600 r / min 10 h. The prepared slurry was vacuum-dried and placed in a c...

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

PropertyMeasurementUnit
diameteraaaaaaaaaa
densityaaaaaaaaaa
specific surface areaaaaaaaaaaa
Login to view more

Abstract

The invention puts forwards a preparation method of a lithium ion battery porous silicon carbon composite negative material. The prepared porous silicon carbon composite material simultaneously has the characteristics of high capacity and excellent circulating stability. Micron silicon and nanometer aluminum powder are promoted to be compounded by utilizing a high-energy ball milling method, a porous silicon material can be formed through acid etching, and through a porous structure, the volume change of silicon in the discharging process is relieved to a great extent. Meanwhile, the stress generated by the volume change of the silicon can be effectively buffered through taking graphite as a dispersion matrix and in combination with a secondary surface amorphous carbon coating technology of the composite material, so that the circulating stability of the material is improved. The preparation method of the material has the advantages of simplicity, low cost and easiness in industrial production.

Description

[0001] technical field [0002] The invention relates to a preparation method of a lithium-ion battery negative electrode material, in particular to a preparation method of a lithium-ion battery silicon-carbon composite negative electrode material. [0003] technical background [0004] As a green, high-energy and environmentally friendly chemical power source, lithium-ion batteries have been widely used in portable devices such as mobile phones and notebooks. As a high-energy power source for the development of high-power batteries such as electric vehicles and motorcycles, it is urgent to increase the energy density of ion batteries. At present, graphite carbon has good cycle performance as the negative electrode material of lithium-ion secondary batteries, but the disadvantage is that the specific capacity is low, and the performance of carbon electrodes is greatly affected by the preparation process, which limits the application of high-energy lithium-ion batteries such...

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
Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/62H01M4/38
CPCY02E60/12Y02E60/10
Inventor 裴德成李博
Owner 力芯(青岛)新能源材料有限公司
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