Sulfur-based solid electrolyte coated silicon negative electrode and preparation method thereof

Abstract

The invention discloses a silicon / sulfur-based solid electrolyte composite negative electrode material with high cycle property and a preparation method thereof. The silicon / sulfur-based solid electrolyte composite negative electrode material is prepared by in-situ synthesis one-step method of a solution. The method is simple and convenient to operate, the mechanical property and the electrochemical performance stability of silicon are improved by coating of a sulfur-based solid electrolyte, and the composite negative electrode has favorable electrochemical cycle property. The composite material has the following advantages that the volume expansion of a silicon negative electrode during the charge-discharge process can be effectively reduced by the sulfur-based solid electrode, meanwhile, the sulfur-based solid electrolyte has relatively high ion conductivity compared with a primary solid electrolyte membrane, the diffusion of Li ions can be effectively improved, the internal resistance of a battery is effectively reduced, and the rate performance of the battery is improved.

Description

technical field [0001] The invention relates to the field of preparation of lithium-ion battery sulfur-based solid-state electrolyte-coated silicon negative electrode materials, in particular to the preparation of a composite electrode material with good performance in the charging and discharging process. Background technique [0002] In order to meet the needs of grid energy storage, electric vehicles and consumer electronics products for energy storage devices, electrode materials with long cycle life, high energy density and power density are currently research hotspots. Due to its abundant natural reserves, low discharge platform and large specific capacity (4200mAh / g), silicon is considered to be the most potential anode material for lithium batteries in the future. However, there are certain problems in the application of the silicon negative electrode, for example, the volume expands by more than 300% during the charging and discharging process, resulting in continuo...

AI Technical Summary

Problems solved by technology

However, the above-mentioned technology has the following disadvantages: First, the drying and spraying equipment is complicated and the energy consumption is high, which will greatly increase the cost of materials

The materials prepared by this technology have the following disadvantages: alumina has poor electronic conductivity and ionic conductivity, resulting in relatively low cycle performance and rate performance of the coated silicon anode

At present, there are no relevant reports in the market or patents about sulfur-based solid electrolyte coated silicon as the negative electrode of lithium-ion batteries.

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