Gel polymer lithium ion battery and preparation method thereof

Abstract

The invention discloses a gel polymer lithium ion battery and a preparation method thereof. The preparation method comprises the following steps: step (a), dissolving P (VDF-HFP) powder into an organic solvent to configure a P (VDF-HFP) solution; step (b), adding and dispersing inorganic micropowder into the P (VDF-HFP) solution; step (c), adding a non-solvent containing P (VDF-HFP) into the mixture obtained in the step (b), followed by fully mixing so as to make a diaphragm coating slurry; step (d), uniformly coating a substrate diaphragm with the diaphragm coating slurry, and performing drying so as to obtain a porous composite diaphragm; and step (e), assembling an electrical core with the porous composite diaphragm that is obtained in the step (d), a positive plate and a negative plate, and injecting a liquid electrolyte containing a lithium salt into the assembled electrical core; and then pressurizing, heating and baking the electrical core to obtain a gel polymer lithium ion battery. The gel polymer lithium ion battery provided in the invention has a simple preparation method and the process for making the gel polymer lithium ion battery is easy to control; besides, the battery has good performance.

Description

technical field [0001] The invention relates to the field of battery manufacturing, in particular to a gel polymer lithium ion battery and a preparation method thereof. Background technique [0002] Due to its high operating voltage, high energy density, and long cycle life, lithium-ion batteries have been widely used in various mobile digital products after nearly ten years of development, and have gradually developed into the field of electric vehicles, becoming HEV and EV one of the main power supplies. [0003] At present, most lithium-ion batteries are liquid lithium-ion batteries. The liquid electrolyte is composed of lithium salts dissolved in organic solvents such as carbonates, which may cause battery swelling, leakage, and thermal runaway, which may lead to safety accidents. Solid-state lithium-ion batteries can completely solve the above problems due to the use of solid-state electrolytes, but the conductivity of solid-state electrolytes is extremely low, making ...

AI Technical Summary

Problems solved by technology

However, the Bellcore technology is very complicated. It is necessary to dissolve polyvinylidene fluoride-hexafluoropropylene P (VDF-HFP), then add a large amount of plasticizer dibutyl phthalate (DBP) and silica particles, and then coat Make a P(VDF-HFP) film on the substrate, and then extract the plasticizer with a large amount of low-boiling point solvent (such as methanol) to obtain a microporous film, and finally roll the microporous film and the electrode layer and combine it in a drying room Inject a liquid electrolyte into the battery to activate it to obtain a polymer lithium-ion battery

The biggest disadvantage of this technology is that the process is too complicated, the production cost is extremely high, the extraction process of the plasticizer is complicated and difficult to control, and the thermal compounding process is prone to micro-short circuit, which leads to a decrease in the battery yield, so it is difficult to popularize and apply it on a large scale.

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