Unravelling the performance of lead-free perovskite cathodes for rechargeable aqueous zinc-ion batteries

The quest for efficient and sustainable energy storage solutions has led to the emergence of zinc-ion batteries (ZIBs) as a promising candidate, offering numerous advantages in terms of cost-effectiveness, safety, and performance. The key to commercialising ZIBs lies in developing cathode materials that offer high specific capacity and prolonged cycle performance. The present study demonstrates the capability of environmentally friendly, lead-free inorganic perovskites for high-rate rechargeable aqueous zinc-ion batteries with enhanced stability and excellent rate performance. The battery exhibits a high specific capacity of 220 mAh/g at a current density of 1000 mA/g and a quite stable capacity of 50 mAh/g and a good cycling stability of 20000 cycles at a very high rate of 20 A/g. The caesium bismuth iodide perovskite emerges as a promising candidate for cathode material in Zn-ion batteries, exhibiting high specific capacity and superior rate cyclability. Furthermore, incorporation of Ag in CsBi 3 I 10 is found to enhance the specific capacity and exhibits superior cycling stability. This study marks a significant advancement in the utilisation of perovskite materials as new cathodes for high-rate ZIBs. • Lead-free, non-toxic, inorganic perovskites have been explored as cathode materials. • Ag-doped CsBi 3 I 10 exhibits a high specific capacity of 220 mAh/g at a rate of 1A/g. • A capacity retention of 72 % after 1000 cycles has been achieved. • Good long-term cycling stability along with excellent rate capability is observed. • Mechanistic insights have been investigated using In-situ and ex-situ studies.