利用MnO_2增强Ni-MH电池正极中CoOOH导电网络稳定性  

Stability enhancement of CoOOH conductive network in positive electrodes of Ni-MH batteries by MnO_2 doping

作　　者：王远乐 董云龙 张红明 宋洪军 赵泉 

机构地区：[1]吉林吉恩亚融科技有限公司,吉林132311

出　　处：《电源技术》2011年第6期681-682,732,共3页Chinese Journal of Power Sources

摘　　要：球形Ni(OH)2是制作Ni-MH电池的正极材料,在制备球形Ni(OH)2时掺杂一定比例的β-Co(OH)2,做电池时往正极中添加一定量的CoO,做成电池经化成后,β-Co(OH)2和CoO都会转变成导电性好的β-CoOOH,在球形Ni(OH)2内部和球镍之间形成一个能提高氢氧化镍利用率的立体导电网络。但是当电池在长时间高温搁置后,随着电池电压下降到某一值时β-CoOOH就会减少,变成溶解度低的β-Co(OH)2,这样第二级和第三级导电网络就会被破坏,从而使电池的容量出现永久性损失。阐述了往Ni-MH电池正极中添加1%MnO2就能确保电池在高温长时间搁置后电池仍能保持100%容量。Spherical nickel hydroxide is the electrochemically active material for the positive electrodes of MH-Ni batteries.Both the β-Co（OH）2 introduced in the preparation of nickel hydroxide and CoO added during the battery assembly would transform into β-CoOOH and become a three-dimensional conductive network among spherical nickel hydroxides after the battery formation was finished,which could improve the utility ratio of the active material.However,after the battery was shelved at high temperature for a long time,when its voltage declined to a certain point,some β-CoOOH was reduced into low-solubility β-Co（OH）2.As a result,the secondary and tertiary conductive networks were destroyed and the battery suffered a permanent capacity loss.In this paper,it is showed that adding only 1% MnO2 into the positive electrode can ensure 100% capacity retention even after the battery is stored at high temperature for quite some time.

关 键 词：球形NI(OH)2 β-Co(OH)2 β-CoOOH 

分 类 号：TM911[电气工程—电力电子与电力传动]