Cobalt selenide and carbon composite material for negative electrode of high-performance potassium ion battery, preparation method of cobalt selenide and carbon composite material and matched electrolyte

Abstract

The invention provides a cobalt selenide and carbon composite material for a negative electrode of a high-performance potassium ion battery, a preparation method of the cobalt selenide and carbon composite material and a matched electrolyte. The mass content of cobalt selenide in the composite material is 50-80%, and the mass content of carbon in the composite material is 20-50%. The microstructure of the cobalt selenide and carbon composite material is that cobalt selenide nanoparticles are uniformly distributed in a carbon skeleton of a cubic block structure, and the carbon skeleton of the cubic block structure is uniformly coated with an additional carbon layer. The invention also provides a preparation method of the composite material and an electrolyte matched with the composite material. The unique cubic carbon skeleton structure of the composite material can enhance charge transfer in the embedding / de-embedding process of potassium ions, and volume change in the discharging / charging process can be buffered to the maximum extent. By optimizing the electrolyte, the cycling stability of the composite material applied to the potassium ion battery is further improved. The preparation method of the cobalt selenide and carbon composite material is simple in synthesis process and easy to operate.

Description

technical field

[0001] The invention relates to a high-performance cobalt selenide@carbon composite material for negative electrodes of potassium-ion batteries, its preparation method and matching electrolyte, especially the improvement of its electrochemical performance through optimization of the electrolyte, which belongs to the field of electrochemical technology. Background technique

[0002] In the past two decades, with the rapid development of electrochemical energy storage, the market demand for renewable and efficient energy storage devices has increased, and rechargeable lithium-ion batteries currently dominate the electrochemical energy storage market. However, the further application of lithium-ion batteries in the field of large-scale energy storage has been constrained by problems such as high cost, limited reserves (0.0017wt.% of the earth's crust), and uneven distribution of lithium resources. Therefore, it is of great practical significance to explore alter...

Images