Preparation method of graphene-supported stannic oxide quantum dot negative electrode material for lithium ion battery

Abstract

The invention discloses a preparation method of a graphene/stannic oxide quantum dot composite electrode material for a lithium ion battery. In the sample preparation process, that graphene-supported stannic oxide quantum dots are synthesized under relatively mild experiment conditions by utilizing a wet chemical method, and urea is adopted as a reducing agent to reduce graphite oxide, so that the preparation method has the advantages of simple and controllable reaction conditions and low production cost; by introducing graphene, not only can the conductivity of the composite material be improved but also volume change in the stannic oxide charge-discharge process can be effectively buffered; therefore the composite material shows good cycling stability.

Description

technical field [0001] The invention relates to the field of preparation of negative electrode materials for lithium ion batteries, in particular to a preparation method of graphene and tin dioxide composite materials. Background technique [0002] At present, commercial lithium-ion batteries mostly use graphite materials as negative electrode active materials, but the theoretical capacity of graphite materials is only 372 mAh g -1 , which greatly limits the performance improvement and wide application of lithium-ion batteries. In recent years, the rapid development of electric vehicles has put forward higher requirements on the capacity and rate performance of lithium-ion batteries, which has forced researchers to try to find new lithium-ion anode materials with high capacity, excellent cycle performance and rate performance. Due to the high theoretical capacity (790 mAh g -1 ) has become a new research hotspot. A number of research results have shown that the conversio...

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Problems solved by technology

However, tin dioxide will produce a huge volume change during charging and discharging, which will cause the pulverization of the electrode material and lead to a sudden drop in its cycle performance. This defect greatly limits the use of tin dioxide as a negative electrode material in lithium-ion batteries. wide application of

[0003] In order to improve the cycle performance and rate performance of tin dioxide materials, researchers tried to prepare a composite material of tin dioxide and carbon materials. The introduction of carbon materials can not only significantly improve the electrical conductivity of tin dioxide materials, but also effectively buffer and charge The volume expansion of tin dioxide materials during the discharge process, but the synthesis process of such composite materials is usually complicated, the experimental conditions are harsh, and the production cost is high

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