采用室温离子液体乙基三甲基咪唑双三氟甲磺酸亚胺盐(EMIMTFSI)替代原有钠/氯化金属电池(ZEBRA电池)的高熔点电解质氯铝酸钠(NaAlCl_4)来降低ZEBRA电池运行温度。利用循环伏安法、热分析法和交流阻抗法测试过渡金属Fe、Zn、Cu在离子液体中氧化还原可逆性、热稳定性以及电导率。结果表明:Cu和Zn电极在该离子液体中的可逆性良好,可组装中温ZEBRA电池,组装的Na/CuCl_2电池可在175℃下平稳运行,首次放电比容量达273 m A·h/g,库伦效率接近100%。
采用溶剂热法制备多壁碳纳米管(MWCNT)包覆沸石咪唑酯骨架(ZIF-8)而合成的MWCNT@ZIF-8复合材料,通过高温碳化此样品制备MWCNT包覆介孔碳(MWCNT@Meso-C)复合材料,再通过热熔融载硫(S),制得MWCNT@Meso-C/S复合材料。采用X线衍射分析(XRD)、拉曼光谱分析、比表面及孔容分析、热质量分析(TGA)、场发射扫描电子显微镜(FESEM)、能谱仪(EDS)以及电化学测试等手段对不同样品进行表征分析并测试其电化学性能。结果表明:在0.5C倍率下MWCNT@Meso-C/S半电池首次放电比容量为1 114 m A·h/g,100次循环后还有630 m A·h/g,库仑效率保持在99%以上。表明MWCNT@Meso-C/S复合材料有较高的活性物质利用率和良好的循环稳定性。
With on-line coupled thermo-gravimetric technique, the thermal decomposition of analyzer-Fourier transform infrared spectrometer lithium hexafluorophosphate （LiPF6） and its gas evolution at inert environment （H2O〈10 ppm） were studied under both non-isothermal and isothermal conditions. The results showed that the LiPF6 decomposition is a single-stage reaction with LiF as final residue and PF5 as gas product. In addition, its decomposi- tion kinetics was determined as 2D phase boundary movement （cylindrical symmetry） under both non-isothermal and isothermal conditions. Furthermore, the activation energy of LiPF6 decomposition was calculated as 104 and 92 kJ/mol for non-isothermal and isothermal con- ditions, respectively.
