锂一次电池正极材料CFx-Cu的高倍率性能研究

CFx-Cu composites with excellent high rate performances as cathode materials for Lithium primary batteries

摘要:

本文采用一种简单新颖的原位化学改性方法制备了锂电池用CF_x-Cu复合正极材料。采用XRD、SEM、EDS、TGA、EIS、CV和恒电流放电对正极材料的结构、形貌、反应机理和电化学性能进行了表征。CuO与分布在CF_x边缘或表面的非活性基团反应原位生成纳米铜,有效地提高了材料的电子导电性和锂离子扩散率,从而使改性材料显示出优异的比容量、倍率性能及功率密度。CF_x-Cu复合材料在5 C的高倍率下,其放电比容量高达546 mAh/g,最大功率密度为8393 w/kg,放电电压平台为2.0 V。

Abstract:

In this work, we have successfully prepared CF_x-Cu cathode materials for primary lithium battery through a simple and novel in-situ chemical modification method with high-temperature calcination process. The structure, morphology, reaction mechanism and electrochemical performance of cathode materials were characterized by X-ray powder diffraction, high-resolution transmission electron microscopy, scanning electron microscope, energy dispersive X-ray spectroscopic, thermo gravimetric analysis, cyclic voltammetry and galvanostatic discharge. It can be inferred that copper oxide reacts with inert groups on the surface of CF_x to produce nano-copper particles, which increases the electronic conductivity and diffusion performance of lithium-ion in the CF_x-Cu cathode materials. Therefore, the composite exhibits excellent specific capacity, rate performance and power density. Specifically, the CF_x-Cu composites shows a high discharge specific capacity of 546 mAh/g, a maximum power density of 8393 W/kg, with a discharge voltage platform of 2.0 V at 5 C.