Lithium ion supercapacitor negative electrode lithium pre-embedding method

Abstract

The invention discloses a novel negative electrode lithium pre-embedding method. In the process of preparing a porous carbon or conductive polymer and a composite positive electrode thereof, a lithium-carbon binary compound is added, wherein the lithium-carbon binary compound accounts for 10-30% of the mass of the positive electrode, after the electrode is prepared, the electrode can be assembledwith lithium-embeddable metallic oxide or carbon lithium-embedded negative electrode to form a lithium ion supercapacitor; the lithium carbide in the positive electrode is decomposed through a first-circle charging process to enable the metal lithium to enter the negative electrode, so that 50-85% of lithium pre-embedding treatment is performed on the negative electrode; and after a high-content lithium-source lithium-carbon compound is added into the positive electrode and is subjected to first-circle formation, the performance of the capacity of the positive electrode is influenced. The negative electrode is pre-embedded with lithium, so that the reduction of the concentration of body ions in the electrolyte and the irreversible adsorption of negative ions on the positive electrode in the charging and discharging process can be prevented to a certain extent, and the purpose of improving the charging and discharging performance of the lithium ion supercapacitor is achieved.

Description

technical field [0001] The invention relates to the technical field of lithium-ion supercapacitors, and belongs to the technical field of electrochemical energy storage. Background technique [0002] In recent years, an electrochemical hybrid supercapacitor composed of an electric double layer capacitor electrode and a secondary battery electrode has become a research and development hotspot. The positive electrode of the hybrid supercapacitor uses a carbon material based on the formation of an electric double layer based on interface charge adsorption and desorption. , the negative electrode uses metal oxides or carbonaceous materials that can intercalate lithium for energy storage based on lithium ion intercalation / extraction. Because the energy storage mechanism of the negative electrode is the same as that of the lithium-ion battery system, it is also called: lithium-ion supercapacitor. Generally, in the lithium-ion supercapacitor system, for the lithium-intercalation n...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a lithium-ion supercapacitor negative electrode pre-embedded lithium method, the purpose of which is to solve the problem of large attenuation of ion concentration in the electrolyte of lithium-ion supercapacitors, while further improving the lithium-ion supercapacitor Charge and discharge characteristics, such as efficiency, capacity, high current charge and discharge characteristics and cycle stability, etc.

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