Realization of High Capacity and Cycling Stability in Pb‐Free A2CuBr4 (A=CH3NH3/Cs, 2 D/3 D) Perovskite‐Based Li‐Ion Battery Anodes

Lead‐free hybrid and inorganic perovskites (A2CuBr4; A=CH3NH3 or Cs, 2 D or3 D) are synthesized by a room‐temperature solid‐state reaction route and examined as anode materials in Li‐ion batteries. A remarkably high reversible capacity of 630 mAh g−1 is realized in the 2 D hybrid perovskite at 100 mA g−1 at the end of 140 cycles. A full cell with this anode is also tested and shows impressive cycling stability. A good reversible capacity of 420 mAh g−1 with excellent stability tested up to 1400 cycles is also obtained for the 3 D perovskites. Pb‐free hybrid/inorganic halide perovskites can thus be used as viable anode materials for battery applications. Lead it go: Lead‐free Cu‐based 2 D and 3 D hybrid and inorganic perovskites (A2CuBr4; A=CH3NH3 or Cs) are examined as anode materials in Li‐ion batteries. A high reversible capacity of 630 mAh g−1 is realized in the 2 D hybrid perovskite at 100 mA g−1, and a good reversible capacity of 420 mAh g−1 is also obtained for the 3 D perovskites case.