Bipolar sodium ion battery and preparation method thereof

Abstract

The invention relates to a bipolar sodium ion battery and a preparation method thereof, the bipolar sodium ion battery comprises a plurality of bipolar pole pieces, a diaphragm and an electrolyte, the plurality of bipolar pole pieces are sequentially stacked, each bipolar pole piece comprises an aluminum foil, an insulating strip and an insulating layer, the aluminum foil is provided with a first surface and a second surface which are oppositely arranged, each of the first surface and the second surface comprises a positive electrode region, a bending region and a negative electrode region which are sequentially arranged, the positive electrode region is coated with a positive electrode active layer, and the negative electrode region is coated with hard carbon; the positive electrode active layer comprises a transition metal oxide, a Prussian blue material, a polyanion compound or an amorphous material; the aluminum foils can be folded along the bending area, so that the positive electrode region and the negative electrode region are arranged oppositely; the insulating strip is arranged in the bending region; the insulating layer is clamped between the positive active layer and the hard carbon; a diaphragm is arranged between every two adjacent bipolar pole pieces; and the electrolyte is used for conducting electricity for the positive electrode active layer and the hard carbon and comprises sodium hexafluorophosphate. The bipolar sodium ion battery is high in energy density and long in service life.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a bipolar sodium ion battery and a preparation method thereof. Background technique [0002] A sodium-ion battery is a rechargeable electrochemical sodium-ion battery that mainly relies on the movement of sodium ions between the positive and negative electrodes, and uses sodium ion intercalation compounds as the positive electrode material. The material cost of sodium-ion batteries is low, and the price is more advantageous. Due to the increasing demand for energy storage, the demand for low-cost energy storage battery technology is becoming more and more urgent. The research on sodium-ion batteries has advanced by leaps and bounds in the past ten years, but the main changes in the current sodium battery industry chain In terms of positive electrode materials, the energy density and service life of sodium-ion batteries can be improved through positive electrode materials, negat...

AI Technical Summary

Problems solved by technology

However, the effect of improving the energy density and service life of sodium-ion batteries through materials is limited. Therefore, there is an urgent need for a bipolar sodium-ion battery and a preparation method thereof to improve the structure of the sodium-ion battery and combine the positive electrode material of the sodium-ion battery. , negative electrode materials and electrolyte materials to improve the energy density and service life of sodium-ion batteries

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