Preparation method of lithium-selenium battery positive electrode

Abstract

The invention discloses a preparation method of a lithium-selenium battery positive electrode. The preparation method of the lithium-selenium battery positive electrode comprises the following steps: depositing or growing a nitrogen-containing conductive polymer on the surface of a piece of paper, then carrying out alkaline activation and high-temperature carbonization to obtain a nitrogen-containing layered porous carbon compound current collector which takes a carbon fiber network structure as a self-supporting body, and further compounding the compound current collector with selenium to obtain the lithium-selenium battery positive electrode which is high in content of selenium, good in selenium fixation effect, high in mechanical performance and high in electrochemical performance. The preparation method of the lithium-selenium battery positive electrode is easy to operate, free from pollution and low in cost; the prepared lithium-selenium battery electrode is directly used for preparing a lithium-selenium battery with the high cycle performance and rate capability in the absence of an adhesive and a corresponding coating process.

Description

technical field [0001] The invention relates to a preparation method of a lithium-selenide battery, which belongs to the field of lithium batteries. Background technique [0002] Lithium-selenium battery refers to a type of metal lithium secondary battery that uses elemental selenium or selenium-containing compounds as the positive electrode and metallic lithium as the negative electrode, and realizes the mutual conversion between chemical energy and electrical energy through the chemical reaction between selenium and lithium. Lithium-selenium batteries have a similar volumetric capacity to lithium-sulfur batteries (3253mA h / cm 3 ), and the conductivity and electrochemical activity of selenium are much higher than that of sulfur, so it has high application potential and commercial value. However, there are still many problems in the practical application of lithium-selenium batteries, among which there are two prominent points: first, due to the phenomenon of active materia...

AI Technical Summary

Problems solved by technology

However, there are still many problems in the practical application of lithium-selenium batteries, among which there are two prominent points: first, due to the phenomenon of active material dissolution and shuttle effect in the electrodes of lithium-selenium batteries during charging and discharging, the capacity of the battery is attenuated faster

Second, although elemental selenium has a relatively high conductivity, it still needs to be effectively combined with a conductive agent to achieve high-rate charge and discharge.

This method of electrode preparation is relatively common, but there are some problems: 1) The additional conductive agent and binder increase the amount of inactive substances in the electrode, which play the role of bonding and conductivity, which is equivalent to reducing the active substance in the positive electrode The content of selenium is reduced, thereby reducing the energy density of the battery; 2) Since the composite materials and the current collector are adhered together by adhesives, the contact resistance between the two cannot be avoided, which will also lead to poor electrochemical performance of the battery. , especially the unsatisfactory rate performance

3) The adhesives used are expensive and these adhesives will dissolve and fail during the battery cycle, causing the active material particles to peel off, and the cycle performance of the electrode will deteriorate

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