Abstract: The present invention provides a preparation method of polyimide, comprising the following steps: a) carrying out a dehydration polymerization reaction on a diamine and an anhydride of an organic acid in a non-polar solvent to obtain a mixture, the non-polar solvent being one or more of arene, aliphatic hydrocarbon, halogenated arene and halogenated aliphatic hydrocarbon, and the anhydride of the organic acid being one or more of dianhydride and single anhydride: and b) filtering the mixture obtained in step a) and drying to obtain the polyimide. In the present invention, the dehydration polymerization reaction between the diamine and the anhydride of the organic acid can be carried out directly in the non-polar solvent to obtain the polyimide which cannot be dissolved in the non-polar solvent. Therefore, polyimide powder with fine particles can be obtained by directly filtering and drying the reaction mixture without washing.

Abstract: A polyimide blend nanofiber and its use in battery separator are disclosed. The polyimide blend nanofiber is made of two kinds of polyimide precursors by high pressure electrostatic spinning and then high temperature imidization processing, wherein one of the polyimide precursor does not melt under high temperature, and the other is meltable at a temperature of 300-400° C. The polyimide blend nanofiber of present invention has high temperature-resistance, high chemical stability, high porosity, good mechanical strength and good permeability, and can be applied as battery separator.

Abstract: The present invention provides a preparation method of polyimide, comprising the following steps: a) carrying out a dehydration polymerization reaction on a diamine and an anhydride of an organic acid in a non-polar solvent to obtain a mixture, the non-polar solvent being one or more of arene, aliphatic hydrocarbon, halogenated arene and halogenated aliphatic hydrocarbon, and the anhydride of the organic acid being one or more of dianhydride and single anhydride: and b) filtering the mixture obtained in step a) and drying to obtain the polyimide. In the present invention, the dehydration polymerization reaction between the diamine and the anhydride of the organic acid can be carried out directly in the non-polar solvent to obtain the polyimide which cannot be dissolved in the non-polar solvent. Therefore, polyimide powder with fine particles can be obtained by directly filtering and drying the reaction mixture without washing.

Abstract: The present invention specifically relates to a polyimide capacitance battery and a manufacturing method thereof. The polyimide capacitance battery of the present invention is obtained by manufacturing a positive electrode and a negative electrode, and then combining the positive and negative electrodes into the capacitance battery, which consists of the positive electrode, the negative electrode, a polymer membrane therebetween, and an electrolyte, wherein the positive electrode material is a mixture of a lithium-ion insertion compound and a porous carbon material, the negative electrode material is a mixture of modified graphite and a porous activated carbon material, the polymer membrane is a polyimide membrane, and the electrolyte is an electrolyte containing a lithium ion compound and an organic solvent.

Abstract: A copolyimide nano-fiber non-woven fabric, a process for producing the same and the use thereof. The process comprises the following steps: tetracid dianhydride monomer and diamine monomer are polycondensated in the reaction medium of a high polar solvent under mechanical agitation to form a solution of a copolyamic acid; the copolyamic acid solution is electrostatically spinned under a high voltage electric field to give a non-woven fabric of a nano-fiber of the copolyamic acid; and then the non-woven fabric is imidized. The copolyimide nano-fiber non-woven fabric has features of a strong tear resistance, a high porosity, high/low-temperature resistances and excellent mechanical properties, etc., and can be used in battery membrane and capacitor membrane.

Abstract: A polyimide blend nanofiber and its use in battery separator are disclosed. The polyimide blend nanofiber is made of two kinds of polyimide precursors by high pressure electrostatic spinning and then high temperature imidization processing, wherein one of the polyimide precursor does not melt under high temperature ,and the other is meltable at a temperature of 300-400° C. The polyimide blend nanofiber of present invention has high temperature-resistance, high chemical stability, high porosity, good mechanical strength and good permeability, and can be applied as battery separator.