摘要
用X射线衍射仪检测不同锂含量的二氧化锰高温化学及随后的电化学锂化过程中的晶体结构的变化;模拟锂硼合金阳极的热电池分析其阴极放电性能,410℃化学锂化时,随Li/Mn原子比的提高,β相结构的二氧化锰经片层状的锂化二氧化锰结构,转向尖晶石型结构;750℃长时间保温,锂化二氧化锰转变成LiMn_2O_4尖晶石和Mn_2O_3.500℃电化学嵌锂时,也生成过渡相Li_xMnO_2和最终相LiMn_2O_2尖晶石,其阴极放电电压与锰的初始价态不敏感,过电位主要取决于晶体结构中锂离子的扩散通道。
Crystal-structural changes of manganese dioxide during chemically and afterwards electrochemically lithiated at high temperatures were determined using X-ray diffractometer, and the cathodical discharge properties of the compounds were analysed by simulating thermal batteries with a Lithium-Boron alloy anode. After chemically lithiated at 410℃, with Li/Mn molar ratio increasing, β-MnO_2 turn to spinelstructure compounds through layered lithiated manganese dioxide which can change to spinel compounds and Mn_2O_3 if long-time exposed at 750℃. Intermediate phase Li_xMnO_2 and final spinel phase LiMn_2O_4 also occurred if MnO2 or Li, MnO_2 was electrochemically lithiated at 500℃. The voltage of chemically lithiated compounds was not sensitive to Mn's initial valence when they were cathedically discharged, Over-potential was dependent mainly on the channels in which lithium-ion can diffuse inside the crystals.
出处
《粉末冶金材料科学与工程》
EI
1999年第4期243-250,共8页
Materials Science and Engineering of Powder Metallurgy
基金
国家教育部博士点基金
关键词
二氧化锰
锂化
热电池
manganese dioxide
lithiation
thermal battery
