【摘要】 用偏钒酸铵和二氧化锰为原料,合成了V₂O₅—MnO₂作为二次电池阴极材料。实验电池用饱和的LiOH水溶液为电解质,在电流密度为2mA/cm²下充放电,结果表明,电池的比容量与V₂O₅—MnO₂的合成条件密切相关。当V/Mn摩尔比为1时,在空气中350℃下,灼烧8h,所得样品的比容量最高,第一次放电时可达133mAh/g阴极活性物质。而在同样条件下,在400℃时所得样品的循环性能最好,在第10次放电后,其比容量为初始容量的90％。XRD和电镜的研究显示样品的主要组成为V₂O₅和β—MnO₂,另外还有Mn₂O₃和Mn₂V₂O₇,随着体系中Mn₂O₃和MnV₂O₇含量的增加,电池的比容量降低。更多还原

【Abstract】 V2O5 - MnO2 mixtures synthesized from NH4VO3 and MnO2 under various conditions were used as the cathode materials of aqueous solution secondary batteries. The test cells used saturated LiOH aqueous solution electrolyte were charged/discharged at 2mA/cm:. The results indicated that electrochemical performances were closely depended on the V/Mn mole ratio or heat-treatment temperature and the atmosphere during baking. A mixture (V/Mn mole ratio=1:1) obtained under 350℃ for 8 hrs in air,gave the highest specific capacity of 133mAh/g cathode activity material in first discharge. The product of the same condition at 400℃ heating temperature showed the best cycling characteristics. Its capacity only decresed 10% of initial value after 10 cycles. The XRD and SEM analysis indicated that the products were mainly composed of V2O5 and beta-MnO2.The electrochemical behaviors of products would deteriorate by forming Mn2O3 and Mn2V2O7 in these systems.更多还原