Preparation method of v2o5/graphene composite material and battery cathode

Abstract

The invention discloses a preparation method of a V2O5 / graphene composite material. The preparation method comprises the following steps: step I, weighing V2O5 powder and graphene powder according toa weight ratio of (80:1) to (100:1), and adding the V2O5 powder and graphene powder into the deionized water in different batches under a constant-temperature condition, and obtaining black brown liquid; step II, adding H2O2 with the concentration of 35 percent under a stirring condition, continuously reacting for 10 to 60min, then adding the deionized water, continuously performing ultrasonic reaction for 45 to 120mins, and obtaining a viscous gel liquid; step III, enabling thick liquid to stand for 6 to 24h under 10 to 40 DEG C, and forming jelly-like jel; step IV, diluting the gel for 2 to5 times by adopting the deionized water, uniformly stirring, placing into an ultralow-temperature refrigerator, and freezing for 6 to 24 h; step V, placing the completely frozen sample into a frozen drying machine, freeze-drying for 12 to 48h, and obtaining a V2O5 / graphene precursor; and step VI, sintering the freeze-dried V2O5 / graphene precursor in the air for 1 to 4h at 300 to 450 DEG C, and obtaining the V2O5 / graphene composite material.

Description

technical field [0001] The invention relates to the technical field of battery electrode materials and preparation thereof, in particular to a method for preparing v2o5 / graphene composite materials suitable for battery electrode materials. Background technique [0002] At present, energy shortage has become an issue of increasing concern to governments at all levels, and the use of clean, renewable, safe and reliable energy is imminent. Lithium-ion batteries are one of the renewable chemical energy sources with excellent performance due to their high energy density, good cycle stability and low self-discharge rate. Among many cathode materials for lithium-ion batteries, the orthorhombic V2O5 with layered structure has attracted extensive attention due to its wide source of raw materials, relatively low price, easy preparation, and good safety, and is considered to be very promising. A new generation of cathode materials for lithium-ion batteries. However, poor cycle stabil...

AI Technical Summary

Problems solved by technology

However, poor cycle stability, low lithium-ion diffusion coefficient and poor electronic conductivity have been the key issues restricting the practical application of V2O5 as a cathode material for lithium-ion batteries.

[0003] V2O5 can be used as an electrode material due to its intercalation structure and high energy density. However, V2O5 is limited by the large electron transport resistance, which leads to its low specific capacity and poor cycle performance at high rates.

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