Silicon anode electrode plate for lithium ion battery and preparation method of electrode plate

Abstract

The invention discloses a silicon anode electrode plate for a lithium ion battery and a preparation method of the electrode plate. Silicon materials and organic matters are mixed and dissolved in solvents to obtain mixture, the mixture is spray-dried to obtain organic matter coated silicon composite materials, the materials are sequentially treated at three temperature sections in an inert gas environment: the materials are placed for 0.5-1 hour at normal temperature, heated to reach 150-250 DEG C and placed for 0.5-1 hour, heated again to reach 450-750 DEG C and placed for 2-4 hours, the coated organic matters are cracked into carbon to obtain carbon-coated silicon composite materials, the carbon-coated silicon composite materials are sufficiently mixed with conductive agents, adhesives, dispersing agents and the solvents to obtain electrode slurry, the surface of a current collector is uniformly coated with the electrode slurry, and the current collector is dried to obtain the electrode plate. The electrode plate comprises the current collector and a negative active layer, the surface of the current collector is coated with the negative active layer, the negative active layer comprises the carbon-coated silicon composite materials, the conductive agents, the adhesives and the dispersing agents, the carbon-coated silicon composite materials are silicon materials with surfaces coated with carbon and comprise, by weight, 0.1-99 parts of carbon, the thickness of the carbon-coated silicon composite materials ranges from 1 nanometer to 100 micrometers, and the internal silicon materials are metal-containing micro-nanostructure silicon or silicon micro-powder.

Description

technical field [0001] The invention relates to a silicon negative electrode sheet for a lithium ion battery and a preparation method thereof. Background technique [0002] With people's continuous pursuit of energy technology, the demand and performance requirements for the power supply of various electrical products are also getting higher and higher. Lithium-ion batteries with high energy density and long cycle life have become the first choice for power supply equipment in various application fields. To improve the energy density of lithium-ion batteries, the development of active materials with high lithium intercalation capacity is essential. Silicon has become one of the main anode materials for current research and development due to its ultra-high theoretical lithium intercalation capacity. [0003] However, due to the huge volume change of the silicon anode material during the charging and discharging process, the internal stress causes the material to pulverize a...

AI Technical Summary

Problems solved by technology

These methods have certain effects, but due to the complex process, difficult control, high cost, and inability to adapt to production, it is impossible to fundamentally improve the energy density and cycle life of the battery and improve the performance of the battery.

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