Reversibility of metal-hydride anodes in all-solid-state lithium secondary battery operating at room temperature

Abstract

The impact on the performance of conversion-type MgH2 anodes by using solid state electrolyte is reported. MgH2 anodes (~26 μm thick) made from homogenous slurries and subsequent drying, are used as model systems along with Li(BH4)0.75I0.25–0.8Li2S·0.2P2S5 as solid electrolyte in an “all-solid-state room-temperature secondary battery”. Electrochemical tests are carried out to investigate cycling properties and elucidate reversibility aspects during the conversion reaction. A major enhancement in performance is observed for the all-solid-state battery compared to MgH2 anodes using carbonate-based liquid electrolytes. This shows that good compatibility and improved reversibility can be obtained for hydride anodes when associated with borohydride-based electrolyte in a Li-ion cell operating at room temperature.