Long-life manganese-based water system mixed zinc ion capacitor and preparation method thereof

Abstract

The invention discloses a long-life manganese-based water system mixed zinc ion capacitor and a preparation method thereof, and belongs to the technical field of electrochemical energy storage devices. The capacitor comprises a manganese-based positive electrode, an electrolyte, a zinc sheet negative electrode, a diaphragm arranged between the positive electrode and the negative electrode and a shell, and the manganese-based positive electrode is of a Mn3O4 / C nanosheet array composite structure; the electrolyte is composed of soluble zinc salt, soluble sodium salt and deionized water; the Mn3O4 / C nanosheet array composite structure is obtained by taking carbon cloth as a matrix and uniformly depositing a Mn3O4 nanosheet array on the carbon cloth by utilizing an electro-deposition method. The capacitor prepared by the invention can provide specific capacity of 200mAh / g when working in a voltage range of 0-1.8 V, and the manganese-based water system mixed zinc ion capacitor disclosed bythe invention shows excellent cycling stability, has a capacity retention ratio of 81% in 1500 cycles, and is low in cost and simple in preparation process.

Description

technical field [0001] The invention belongs to the technical field of electrochemical energy storage devices, and in particular relates to a long-life manganese-based water system mixed zinc ion capacitor and a preparation method thereof. Background technique [0002] As we all know, energy storage is an important issue facing human society. In recent years, with the rapid development of electric vehicles and portable electronic products, energy storage devices with high energy density, high power output, long service life and high safety have become an urgent need for people. Currently existing energy storage devices include batteries (such as lithium-ion batteries, alkaline zinc-manganese oxide batteries), supercapacitors, etc. However, the safety risks of lithium-ion batteries and limited lithium resources, the cycle of alkaline zinc-manganese oxide batteries Problems such as poor stability have prompted researchers to search for cheap alternative energy storage systems...

AI Technical Summary

Problems solved by technology

However, zinc-ion batteries have the problem of poor power density. Based on the advantages of high energy density and high power density of lithium-ion capacitors and avoiding the problem of limited lithium resources, a water-based zinc ion battery with high energy density and high power density is designed. Hybrid capacitors have important application value

[0003] Manganese-based oxides are the most promising cathode materials for aqueous zinc-ion batteries due to their high energy density, but their structural instability leads to poor cycle stability.

For example, in the process of charging and discharging, the dissolution of the cathode, irreversible lattice distortion and electrostatic interaction make the battery capacity decay seriously and the cycle stability is poor. These have seriously restricted the development and promotion of zinc-ion batteries, and have not been effectively solved at present.

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