【摘要】 为了提高MnO2对氧还原的催化活性,将稀土硝酸盐(硝酸镧)和碱土硝酸盐(硝酸锶)同硝酸锰一起浸渍到碳粉中,并在270℃下煅烧,制得空气电极催化剂,通过冷压方法制成空气电极.用稳态极化和交流阻抗测试了各个空气电极的电化学性能.稳态极化测试结果表明,当催化层中金属元素Mn、La、Sr的摩尔比为1∶0.4∶0.6时,空气电极极化最小.交流阻抗分析表明,镧氧化物和锶氧化物的加入,减小了电化学反应动力学阻抗和氧的扩散阻抗.为考察电池的放电性能,装配了AA型锌空气电池进行放电测试,结果表明,加入镧氧化物和锶氧化物能大幅度提高电池的工作电压和电池容量.更多还原

【Abstract】 In order to improve the electrocatalytic activity of MnO2,catalysts were prepared from the carbon powder impregnated with Mn(NO3)2 and rare-earth nitrate(La(NO3)3·6H2O) and alkaline-earth nitrate(Sr(NO3)2),and heated at 270℃.The air electrode was obtained by cold-pressing.Electrochemical performance of the electrodes was studied by current-potential polarization curves and AC impedance test.The current-potential polarization result shows that the air electrode has exhibited the best performance when stoichiometric ratio of Mn∶La∶Sr was 1∶0.4∶0.6,and its polarization is the smallest.The analysis of AC impedance spectra shows that added rare-earth oxide and alkaline-earth oxide to the system can decrease the charge-transfer resistance and oxygen diffusion resistance.Another experiment was made to find the performance of AA size zinc-air battery using this type of catalyst.The discharge results show that the rare-earth oxide and alkaline-earth oxide can significantly enhance the zinc-air battery’s capacity and operating voltage.更多还原