High temperature resistant aqueous polyurethane solid electrolyte and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant water-based polyurethane solid electrolyte, which is composed of water-based polyurethane and lithium salt; the water-based polyurethane accounts for 70-90% of the mass fraction of the electrolyte polymer, and the lithium salt accounts for 10-30% of the mass fraction of the electrolyte polymer; synthesis The oligomer polyol raw material of waterborne polyurethane contains polyisosorbide terephthalate polyester diol. The invention also discloses a preparation method of the high-temperature-resistant water-based polyurethane solid electrolyte. The polymer solid electrolyte prepared by the invention has high ionic conductivity, high temperature resistance and excellent thermal stability, and also has good dimensional stability and high temperature ionic conductivity under the high temperature condition of 140°C, which can meet the high temperature conditions of lithium batteries. It meets the requirements of the following use, and the preparation method is simple.

Description

Technical field [0001] The invention relates to the technical field of polymer electrolytes, in particular to a high-temperature-resistant aqueous polyurethane solid electrolyte and a preparation method thereof. Background technique [0002] Lithium-ion batteries, as a new generation of green high-energy rechargeable batteries, have been widely used in commercialized electronic products, automotive power plants, and energy storage in power stations. Electrolyte material is one of the important factors that affect the overall battery safety and stability. Currently, the widely used liquid electrolyte corrodes the electrode sheets and causes irreversible loss of battery capacity, and the thermal safety of the organic electrolyte is insufficient, causing serious safety such as fires and explosions. problem. The use of solid electrolyte can avoid these drawbacks of liquid electrolyte, and its shape can be arbitrarily cut and changed, making the battery design lighter and more fashio...

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Problems solved by technology

However, polyethylene oxide has poor mechanical strength and is easy to crystallize, resulting in low electrical conductivity in the later stage, and limited operating temperature of the battery, which cannot be used at high temperatures.

Chinese patent CN102020780 A discloses an all-solid polymer electrolyte membrane, which is prepared by using polyethylene oxide and liquid crystal polymers containing sulfonate ions, etc., but the preparation process uses a large amount of toxic solvents such as acetonitrile, which is poor in environmental protection

Chinese patent CN101280104A discloses a polymer electrolyte material, polysiloxane is dispersed in water-based polyurethane by blending method, and conductive salt is directly dissolved in the mixed solution to prepare water-based polyurethane polysiloxane solid electrolyte, but the The electrolyte prepared by the method still needs to absorb 5-260% of the electrolyte to form a gel electrolyte before it can be used in batteries, and the long-term use of the gel electrolyte still has the problem of liquid precipitation, which is not a real all-solid electrolyte

Chinese patent CN 106532116 A discloses a high temperature resistant solid polymer electrolyte, which is obtained by ultraviolet light-induced free radical polymerization, but the solid polymer electrolyte obtained by this method has low ion conductivity, and will use Toxic solvents such as acetonitrile, not environmentally friendly

Chinese patent CN 102738426 A discloses a high-temperature-resistant lithium battery. The electrolyte membrane is prepared by thermosetting reaction of polyimide and polycarbosilane, which endows the battery with high-temperature resistance. However, the electrolyte membrane prepared by this method is brittle and poor in safety. , and still need to use a large amount of N-methylpyrrolidone, dimethylacetamide and dimethylformamide toxic solvents in the process, which is extremely harmful to the environment and construction personnel

Phthalic anhydride polyester is a material with good temperature resistance. At present, this type of material is mainly used in the field of plastic packaging materials. It has not been reported to prepare water-based polyurethane and use it as a solid electrolyte for lithium-ion batteries.

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