酸处理对天然二氧化锰电性能的影响

Influence of acid treated natural MnO 2 on its performance

用稀硫酸和盐酸处理天然二氧化锰制备活化二氧化锰。经XRD分析,确定了活化二氧化锰的晶型与天然二氧化锰相同,仍为β型,从等离子体光谱(ICP)分析得知二氧化锰和锰的含量增加。经恒电流放电和线性电位扫描测试,发现活化二氧化锰的电性能较天然二氧化锰有所改善,如开路电压提高50～70mV,工作电压提高10～20mV,放电容量增加47%～75%,而放电曲线形状相似。线性电位扫描曲线两者相似,但两个还原峰电位均比天然二氧化锰的峰电位要正些。这些性能的变化是与经酸处理后的活化二氧化锰提高了活性物质的含量与颗粒度小有关。实验还表明。

Active manganese dioxide (AMD) was prepared from nature manganese dioxide (NMD) which was treated by diluted sulfuric acid and diluted hydrochloric acid.The XRD determination displays that the crystal structure of AMD is the same as NMD,i.e.the β type.The ICP determination reveals that the contents of MnO 2 and Mn increase.By means of the constant discharge test and linear potential scan test,we find that the property of AMD is better than NMD.For example,the open circuit voltage and the discharge voltage of AMD raise 50～70 mV and 10～20 mV respectively as well as its capacity improves 47%～75%.However,the discharge curves of AMD are the same as that of NMD.Their linear potential scan curves are similar except two reducing peak potentials of AMD are shifted to positive direction vs.NMD.The performance alteration of AMD is due to the acid treated AMD,which increases the content of active material and reduces the granula size.The experiments also indicate that the property of AMD treated by diluted hydrochloric acid is better than that treated by diluted sulfuric aicd.