Preparation method of silicon-graphene compound conductive paste

Abstract

The invention discloses a preparation method of silicon-graphene compound conductive paste. The preparation method comprises the following steps: (1) pre-treating graphite: putting the graphite into a mixed solution composed of an oxidant and an intercalation agent; carrying out ultrasonic stirring treatment to obtain a product; washing, filtering and drying the product and then putting the product into a muffle furnace; carrying out high-temperature treatment in nitrogen atmosphere to obtain a graphene dispersed solution for later use; (2) preparing the silicon-graphene compound conductive paste: putting micron-grade high-purity silicon powder and a grinding ball into a grinding pot at the mass ratio of (1-50) to 1; after vacuumizing the system by a vacuum pump, introducing protective atmosphere; driving a stirring rod by a motor and driving the grinding ball by the stirring rod to grind and crush raw material power; adding a carbon binding agent and the graphene dispersed solution; and further stirring and crushing for 0.1h-3h to finally obtain the silicon-graphene compound conductive paste. The conductive paste can be directly prepared into an electrode through forming a film on a current collector without the utilization of the binding agent and the electronic conduction of the electrode is greatly improved.

Description

technical field [0001] The invention relates to the technology in the field of electrodes, and in particular provides a method for preparing a silicon-graphene composite conductive paste. Background technique [0002] In the past ten years, with the wide application and rapid development of various portable electronic devices and electric vehicles, the demand and performance requirements for its power system—chemical power supply have increased dramatically. Lithium-ion batteries have been successfully and widely used due to their high power characteristics and other advantages. Applied in the field of mobile electronic terminal equipment. At present, commercial lithium battery anode materials generally use various carbon materials, which have disadvantages such as low specific capacity and easy occurrence of co-intercalation of organic solvents, which cannot meet the needs of high energy density batteries. [0003] Silicon-based composite materials have received widespread...

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Problems solved by technology

However, under the condition of deep lithium deintercalation, there is a large volume expansion and contraction (>300%), and the continuous volume change is easy to cause the cracking of the electrode and the shedding of the active material, which leads to the deterioration of the cycle performance of the electrode.

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