Realization of high capacity and cycling stability in Pb‐free A2CuBr4 (A = CH3NH3/Cs, 2D/3D) perovskite based Li‐ion battery anodes

: Lead-free hybrid and inorganic perovskites (A2 CuBr4 ; A=CH3 NH3 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.