Preparation method of polymer electrolyte membrane based on silicon-based negative electrode material

Abstract

The invention discloses a preparation method of a polymer electrolyte membrane based on a silicon-based negative electrode material. The method comprises the following steps: dissolving PPC and polymers (at least one of PPMMA, PAN, TPU and PVdF) with polar groups into an N,N-dimethyl acetamide and acetone mixed solution to prepare a uniform and semi-transparent spinning solution; injecting the semi-transparent spinning solution into an injection syringe, carrying out electrostatic spinning for 18 to 22 h with the injection volume of 0.3 to 0.7 ml / h at 15 to 17 kV, and then obtaining a nanometer fiber composite polymer membrane; carrying out vacuum drying on the polymer membrane, and obtaining a polymer electrolyte after electrolyte activation. In the preparation method, the PPC, PMA, PAN, TPU and PVdF serve as raw materials, the cost is low, the resources are wide, and the PPC is a completely degradable material, green and non-toxic. The method disclosed by the invention is simple, high in operability, good in repeatability and easy for industrial production, and has wide application prospect.

Description

technical field [0001] The invention belongs to the field of macromolecular materials, in particular relates to a lithium-ion battery separator material, in particular to a method for preparing a polymer electrolyte membrane based on a silicon-based negative electrode material. Background technique [0002] The Twelfth Five-Year Plan lists new energy vehicles as one of the seven strategic emerging industries. However, due to the urgent need for high-power power batteries required by new energy vehicles, and the current bottlenecks in lithium-ion power batteries such as price and safety, key materials for lithium-ion power batteries are facing new challenges. Among them, the SEI film formed by the commercialized graphite anode material of lithium-ion batteries during the charging and discharging process will cause irreversible capacity loss, and sometimes lead to changes in the internal structure of the carbon electrode and poor contact; at high temperatures, it may be due to...

AI Technical Summary

Problems solved by technology

However, during the charging and discharging process, the intercalation and extraction of lithium ions is accompanied by a volume change of more than 300%. With the volume change, it will cause the electrode material to pulverize and fall off, resulting in capacity loss. In addition, the exposed silicon surface will continue to be exposed to electrolysis. The liquid forms a new solid electrolyte interface film, which intensifies the corrosion and capacity fading of silicon, which greatly limits the application of silicon-based materials in lithium-ion batteries.

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