Composite conductive agent preparation method, lithium battery positive plate preparation method and lithium battery preparation method

Abstract

The invention discloses a composite conductive agent preparation method which includes the steps: firstly, respectively weighing carbon nano-tubes, graphene and acetylene black according to the weight ratio of 5:5:90, adding the carbon nano-tubes, the graphene and the acetylene black into 15% of ethanol solution, adjusting a pH (potential of hydrogen) value of the solution, and enabling the pH value to be 6; secondly, enabling the carbon nano-tubes, the graphene and the acetylene black to organically combine by the aid of assist vibration process of high-speed dispersion and intense ultrasound, and synthesizing mixture by the aid of action of pi-pi bonds between material molecules and Vander Wale force to obtain uniformly-dispersed three-dimensional hybridization conductive agent solution of the carbon nano-tubes, the graphene and the acetylene black; thirdly, drying the hybridization conductive agent solution obtained in the step 2 for 24 hours in a vacuum drying oven at the temperature of 85 DEG C, and sufficiently grinding dried solid matters into powder to form the composite conductive agent. The invention further provides a lithium battery positive plate and a lithium battery preparation method.

Description

[0001] 【Technical field】 [0002] The invention relates to the technical field of lithium batteries, in particular to a preparation method of a composite conductive agent, a preparation method of a positive plate of a lithium battery and a preparation method of a lithium battery. [0003] 【Background technique】 [0004] At present, electric vehicles are gradually being promoted and will have broad prospects in the future. Lithium batteries are one of the most critical technologies for electric vehicles, and their performance has a great impact on the entire vehicle. LiFePO 4 The material has become an important commercial power battery positive electrode material for industrial production at present, but due to the low electrical conductivity of the material itself (the electronic conductivity is 10 -10 ~10 -9 S / cm), the theoretical capacity of the material cannot be maximized. Large rate charge and discharge characteristics, long service life, LiFePO 4 The huge challenge t...

AI Technical Summary

Problems solved by technology

At present, the commonly used conductive agent acetylene black is granular, which is not conducive to the formation of a conductive network, and the polarization of the electrode is serious, which is still limited to improve the utilization rate of active materials and the energy density of lithium-ion secondary batteries.

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