Improving low-temperature performance of Li-alloy anodes by optimization of the electrolyte–electrode interface

The −20 °C performance of nano-tin-(lithium emeraldine base), i.e. nano-tin-(lithium hemi-oxidized polyaniline), abbreviated as nano-Sn-PAni, anodes was investigated. The rate-limiting process is slow charge-transfer kinetics, rather than poor electrolyte conductivity or a high solid electrolyte interface (SEI) film resistance. Two ionic conductors, i.e. Li+-doped polyethylene oxide (PEO) and 14Li2O–9Al2O3–38TiO2–39P2O5 ((LiAlTiP)xOy) ceramic powders were incorporated into the anode material to accelerate the interfacial charge-transfer process. The (LiAlTiP)xOy ceramic proved to be much better than doped PEO in improving the low-temperature performance. One nano-Sn-PAni anode material containing 15 wt.% (LiAlTiP)xOy gave particularly high initial charge and discharge capacities (795 and 545 mAh g−1, respectively) at −20 °C.