Solid polymer lithium ion battery positive electrode and preparation method and application thereof

Abstract

The invention relates to a solid polymer lithium ion battery, in particular to a solid polymer lithium ion battery positive electrode and a preparation method and application thereof. The positive electrode of the solid polymer lithium ion battery comprises an active material, a binder and conductive carbon, the active material is lithium cobalt oxide or high-nickel cobalt lithium manganate, and the binder is selected from one or a mixture of more of sodium carboxymethyl cellulose, lithium carboxymethyl cellulose, sodium alginate and lithium alginate, wherein the positive electrode comprises the following components in percentage by mass of 70-95% of an active material, 2-15% of the binder and 3-15% of conductive carbon. The positive electrode material disclosed by the invention is betterin cycling stability, longer in service life and higher in energy density under the voltage of 4V or above. Moreover, the preparation process of the solid polymer lithium ion battery is simple, is easy to amplify and is environment-friendly, and facilitates the development of the solid-state high-energy-density lithium batteries.

Description

technical field [0001] The invention relates to a solid polymer lithium ion battery, in particular to a positive electrode of a solid polymer lithium ion battery and a preparation method and application thereof. Background technique [0002] As a rechargeable energy storage device, lithium-ion batteries have the advantages of being green and pollution-free, high energy density, and can be charged and discharged repeatedly. The above advantages make lithium-ion batteries have the prospect of replacing fossil fuels in the transportation industry. However, at present, lithium-ion batteries are mainly used in small devices such as mobile phones, cameras, and laptop computers, as well as in small electric vehicles; to further apply lithium-ion batteries to the field of electric transportation and replace fuel vehicles, the safety of lithium-ion batteries needs to be solved Problems of sex and energy density. Compared with traditional liquid batteries, solid-state lithium-ion bat...

AI Technical Summary

Problems solved by technology

Although the above-mentioned coating technical scheme can significantly improve the cycle stability of solid polymer lithium-ion batteries, the improvement range is limited, and it is far from meeting the requirements of practical applications.

In addition, in the prior art, there is also a method of using a double-layer electrolyte to improve the stability of a solid-state polymer lithium-ion battery at a voltage of 4 volts and above. The method is specifically to use a PEO polymer electrolyte with a stable negative electrode. On the positive side, a layer of high-voltage stable poly-N-methylmalonamide (PMA)-based polymer electrolyte (Adv. Mater. 2019, 31, 1805574); the above-mentioned double-layer solid-state polymer lithium-ion battery It exhibits excellent cycle performance when matched with lithium cobalt oxide cathode, but this double-layer electrolyte method increases the mass of the electrolyte layer and reduces the energy density of solid-state batteries

Images