(中南工業(yè)大學(xué)粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙410083)
摘 要: 用X射線衍射儀檢測(cè)不同鋰含量的二氧化錳高溫化學(xué)及隨后的電化學(xué)鋰化過程中的晶體結(jié)構(gòu)的變化；模擬鋰硼合金陽極的熱電池分析其陰極放電性能。 410℃化學(xué)鋰化時(shí)，隨Li, Mn原子比的提高， β相結(jié)構(gòu)的二氧化錳經(jīng)層狀的鋰化二氧化錳結(jié)構(gòu)，轉(zhuǎn)向尖晶石型結(jié)構(gòu)；750℃長(zhǎng)時(shí)間保溫，鋰化二氧化錳轉(zhuǎn)變成Li Mn2O4尖晶石和Mn2O3。500℃電化學(xué)嵌鋰時(shí)，也生成過渡相LixMnO2和最終相LiMn2O4尖晶石，其陰極放電電壓與錳的初始價(jià)態(tài)不敏感，過電位主要取決于晶體結(jié)構(gòu)中鋰離子的擴(kuò)散通道。
關(guān)鍵字: 二氧化錳; 含鋰合金; 熱電池
（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
