Lithium ion battery with graphene composite membrane as current collector and preparation method thereof

Abstract

The invention relates to a lithium ion battery with a graphene composite membrane as a current collector and a preparation method thereof. The lithium ion battery comprises a positive electrode, a negative electrode, a separator and an electrolyte, which are sealed in a packaging film. The positive electrode comprises a positive current collector and a positive active material coated on the current collector; the negative electrode comprises a negative current collector and a negative active material coated on the current collector; the positive current collector and the negative current collector are both graphene composite membrane; the graphene composite membrane is divided into three layers; a middle layer is a substrate; and both sides of the middle layer are conductive films mainly consisting of a graphene powder material. The preparation method comprises conductive film slurry preparation, conductive film slurry coating, drying and rolling. Compared with the prior art, the battery provided by the method can obtain better high temperature properties and safety performance, fundamentally eliminate electrochemical dissolution of a metal copper current collector caused by overdischarge of the battery, and improve safety of battery in the case of abuse usage.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries. More specifically, the invention relates to a lithium ion battery using a graphene composite film as a collector and a preparation method thereof. Background technique [0002] Traditional lithium-ion batteries usually use metal aluminum (Al) foil and metal copper (Cu) foil as the positive electrode current collector and negative electrode current collector, LiPF 6 carbonate solution as electrolyte. where LiPF 6 The thermal stability of LiPF is poor, and its decomposition temperature in organic solvents is about 80 ° C, which largely limits the use of LiPF 6 The application of traditional lithium-ion batteries as electrolytes in high-temperature environments. In addition, in traditional lithium-ion batteries, when the battery temperature rises, the electrolyte participates in almost all reactions that occur inside the battery, including not only the interaction between the electrolyte, the...

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Problems solved by technology

[0005] At present, there is no lithium-ion battery with a graphene composite film with good thermal stability, strong puncture resistance, and easy infiltration of electrolyte for both positive and negative electrodes.

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