(中南工业大学粉末冶金国家重点实验室，长沙410083)
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Li Mn2O4尖晶石和Mn2O3。500℃电化学嵌锂时，也生成过渡相LixMnO2和最终相LiMn2O4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。
关键字: 二氧化锰; 含锂合金; 热电池
（State Key Laboratory for Powder Metallurgy, Central South University of Technology, Changsha, 410083, P.R.China）
Abstract:Changes of crystal structure of manganese dioxide during chemical and following electrochemical lithiation 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 the increase of Li/M n molar ratio, β-MnO2 turns to spinel-structure compounds through layered lithiated manganese dioxide which can change to spinel compounds and Mn2O3 if long-time exposed at 750℃. Intermediate phase LixMnO2 and final spinel phase LiMn2O4 also occurred if MnO2 or LixMnO2 were electrochemically lithiated at 500℃. The voltage of chemically lithiated compounds was not sensitive to Mn's initial valence when they were cathodically discharged, while over-potential was dependent mainly on the channels in which lithium-ions can diffuse inside the crystals.
Key words: manganese dioxide; lithium alloys; thermal battery
