V_2O_5干凝胶薄膜电极电化学性能的研究

Electrochemical performance of V_2O_5 xerogel film electrodes for lithium rechargeable batteries

以晶态V2 O5(c V2 O5)为原料 ,采用熔融淬冷法成功制取了V2 O5干凝胶 (VXG)薄膜电极 ,以所制备的样品作为正极 ,金属锂为负极组装了纽扣电池。电化学阻抗谱 (EIS)分析表明 ,在放电过程中 ,几乎没有扩散阻抗的存在。循环伏安 (CV)、恒流放电 (CD)和充放电 (DC)结果显示该样品具有较好的综合性能 ,以 6 0mA/ g的质量电流密度充放电 ,其首次放电比容量高达 35 0mAh/ g ,充放电效率可达 98% ,循环 75次后 ,容量保持率仍可达 6 1%。

V 2O 5 xerogel (VXG) film electrodes were prepared by melting crystalline V 2O 5 (c-V 2O 5) at 700℃ for 3*!h followed by fast cooling to an ambient temperature. The coin type 2016 size secondary cells were manufactured and tested with the VXG film electrodes and lithium anodes. Analysis of the electrochemical impedance spectroscopy (EIS) analysis revealed the expected response for intercalation, except that there was almost no Warburg (diffusion) component. Analyses of the cyclic voltammetry (CV), constant discharge (CD) and the discharge/charge (DC) indicated the sample achieved a high initial discharge specific capacity of approximate 350mAh/g and a corresponding efficiency of 98% in the voltage diapason of 1.5～4.0V with a draining current 60mA/g. Its preservation rate of the capacity still kept as high as 61% even after 75 cycles.