SnSe nano-particles as advanced positive electrode materials for rechargeable aluminum-ion batteries

Abstract

With the rapid consumption of fossil energy, the development of renewable energy storage technology has received much attention. Rechargeable aluminum-ion batteries (RAIBs) are expected to constitute large-scale energy storage systems because of the aluminum resources’richness and low cost. Therefore it is necessary to study the new type of RAIBs positive electrode material, but there is not a systematic design principle now. It is noted that SnSe, as a novel positive electrode material of aluminum-ion battery based on aluminium chloride/1-ethyl-3-methylimidazolium chloride (AlCl3/[EMIm]Cl) room temperature ionic liquid electrolyte for the first time, exhibits well-defined discharge voltage plateaus near 1.6 V and a high first cycle specific discharge capacity of 582 mAh g−1 (coulomb efficiency of 83.27%) at a current density of 0.3 A g−1. After 100 cycles, the specific discharge capacity can be maintained at 107 mAh g−1 (coulomb efficiency of 99.55%). X-ray photoelectron spectroscopy (XPS) and constant current Charge/Discharge results show that the mechanism of the cell is the reaction between AlCl4- and SnSe, and both Sn2+ and Se2– participate in the oxidation–reduction reaction. Just from the high capacity point of view, the novel Al-ion battery based on the AlCl4- reaction mechanism can be a multi-ion reaction.