Preparation method of graphene-sulfide composite negative material

Abstract

The invention relates to a preparation method of a graphene-sulfide composite negative material. The preparation method comprises the following steps of: (1) preparing a transition metal tin compound / graphene composite material; (2) dissolving manganese chloride in deionized water, adding transition metal tin compound / graphene composite material to the solution, and fully stirring and dispersing the mixture to obtain a mixed solution; and (3) adding sodium sulfide into the mixed solution, sealing and heating, reacting and cooling to room temperature, collecting a solid product, alternately and repeatedly washing the product with deionized water and ethanol, and drying the washed product to obtain the nickel-based graphene-manganese sulfide composite negative material. According to the nickel-based graphene-manganese sulfide composite negative material for a lithium-ion battery, the manganese sulfide with high specific capacity and the nickel and copper modified graphene material are combined together, so that the negative material has the characteristics of high capacity, high conductivity and high cycle stability.

Description

Technical field [0001] The invention relates to a preparation method of a graphene-sulfide composite negative electrode material. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, high energy density, and good safety performance. Therefore, they are widely used in portable electronic products such as digital cameras, mobile phones, and notebook computers. They also have application prospects for electric bicycles and electric vehicles. The anode materials of current commercial lithium-ion batteries are graphite and other forms of carbon materials. Since the theoretical capacity of graphite is only 372mAh g -1 , and the lithium intercalation potential is low, which limits its application range. [0003] Compared with carbon materials, some transition metal sulfides have higher theoretical capacity, such as NiS with a theoretical capacity of up to 589mAh g -1 . This type of transition metal sulfide has one thing in common: the...

AI Technical Summary

Problems solved by technology

This type of transition metal sulfide has one thing in common: the contained sulfur can undergo a reversible reaction with lithium metal, which provides a reversible capacity, and the transition metal formed by lithium intercalation for the first time does not undergo alloying / dealloying reactions with lithium, although This reaction can provide a higher capacity, but due to the large volume change during the lithium-deintercalation process, the capacity rapidly decays.