化学改性MnO_2的制备及可充性  

Preparation and rechargeability of chemical modified manganese dioxide

作　　者：郭炳焜[1] 杨子运[1] 李新海[1] 徐徽[1] 刘丽英[1] 

机构地区：[1]中南大学冶金物理化学与化学新材料研究所,湖南长沙410083

出　　处：《电源技术》2001年第2期65-68,90,共5页Chinese Journal of Power Sources

摘　　要：制备可充锌锰电池的关键技术之一是提高MnO2 的可逆性。采用化学沉淀氧化法制备改性MnO2 。研究了锰盐、掺杂物质、氧化剂、温度等对MnO2 可逆性的影响。采用模拟电池及微电极技术研究MnO2 的充放电性能 ,结合XRD、SEM检测改性MnO2 的晶形和形貌。实验结果表明 ,当以Bi(NO3) 3 为掺杂物质时 ,制备改性MnO2 的优化工艺条件是 :n(Mn) /n(Bi) (摩尔比 )为 6～ 10 ,氧化剂用NaClO ,锰盐可用Mn(NO3) 2 或MnSO4 ,2 5℃ ,反应时间 10～ 15h。所得改性MnO2 呈疏松微晶粒状 ,是以 β MnOOH为主的 β MnOOH与 β BiOOH的混合晶相。该样品经第 10次循环充放电后 ,其放电容量为初始放电容量的 12 1% ,10次累积放电容量是电解MnO2 (EMD)的 3倍。表明掺Bi3 +对改善MnO2 的可逆性和提高放电容量有重要作用。Enhancing the invertibility of MnO 2 was one of key technologies of preparing chargeable Zn-MnO 2 battery. Chemical deposition oxidation was adopted to prepare modified MnO 2 and manganic compounds, adulterants, oxidants, humidity effected to invertibility of MnO 2 were studied. Charge and discharge capability of MnO 2 was studied by adopting simulation cell and microelectrode. Crystal and shape of modified MnO 2 were detected by XRD and SEM. The results show that the optimal technological conditions for preparing modified MnO 2 by using Bi(NO 3) 3 as adulterant is as following: mole ratio of n(Mn)/n(Bi) is 6～10, oxidant is NaClO, manganic compound is Mn(NO 3) 3 or MnSO 4, temperature is 25 ℃, reaction time is 10～15 h. The modified MnO 2 is loosen micro-crystal powder, which is mixture of βMnOOH with a little βBiOOH. The powders discharge capability is 121% of initial discharge capability after the tenth charge and discharge cycle. The cumulate discharge capability of the tenth charge and discharge cycle is triple electrolyze MnO 2 (EMD). These show that it is important addition Bi 3+ to improve invertibility and to enhance discharge capability of MnO 2.

关 键 词：化学合成 改性 微电极 可充性 二氧化锰 可充碱锰电池 

分 类 号：TM911.14[电气工程—电力电子与电力传动]