锂/二氧化锰电池用高电导率正极

High electrical conductivity positive electrode for Li/MnO2 battery

选择不同碳材料导电剂制备单一和多元导电剂正极,并测试电导率。将超导炭黑Super-P、石墨烯浆料和碳纳米管(CNT)作为三元导电剂(质量比50∶30∶12)添加到正极中,制得的正极粉末电导率最高,可达4.545S/cm,与电解二氧化锰(EMD)相比,提高了94倍。采用此正极的锂(Li)/二氧化锰(MnO2)电池,单体电池内阻(90~120mΩ)低,在-40℃下,对5串的电池组进行3A脉冲放电,电压平台高(>9.7V)且平稳。球磨工艺的不当使用,会破坏正极导电结构,降低正极材料的导电率。

Different conductive agents consisting of single carbon material component or their mixture were selected to prepare cathode.The cathode with the mixture of superconductive carbon black Super-P,grapheme paste and carbon nano tube(CNT)as conductive agents(mass ratio 50∶30∶12)possessed the highest electrical conductivity(4.545 S/cm),which was about 94 time higher than that of electrolytic manganese dioxide(EMD).For the corresponding lithium(Li)/manganese dioxide(MnO2)battery,a single cell had low internal resistance(90-120 mΩ),a battery pack with 5 cells in series exhibited stable and high(>9.7 V)voltage plateau employing pulse discharge at 3 A at-40℃.The improper use of ball-milling technology could destroy the conductive structure,reduce the electrical conductivity during the fabrication of positive electrodes.