Self‐Charging Power System Empowered by Bismuth Halide Perovskite‐Based Hybrid Nanogenerator and Lithium‐ion Battery

Abstract Halide perovskite, renowned for its multifunctional properties, shows considerable promise for realizing self‐charging power systems. In this study, a lead‐free methylammonium bismuth iodide (MA 3 Bi 2 I 9 ) perovskite is used to create a self‐charging power unit (SPU). This involves constructing a hybrid piezoelectric‐triboelectric nanogenerator (Hybrid‐TENG) and utilizing MA 3 Bi 2 I 9 for energy storage as an anode in a lithium‐ion battery (LIB). Initially, MA 3 Bi 2 I 9 nanorods are synthesized and composited with a polystyrene‐block‐poly(ethylene‐ran‐butylene)‐block‐polystyrene polymer. The dielectric and mechanical properties of composite films having perovskite loading content are investigated. The optimized Hybrid‐TENG exhibits superior performance, generating a voltage of 537 V, current density of 13.2 µA cm − 2 , and maximum power density of 3.04 mW cm −2 , which can be attributed to the high piezoelectric coefficient of MA 3 Bi 2 I 9 nanorods (≈20.6 pm V −1 ). A MA 3 Bi 2 I 9 thin film, serving as an electrode in LIB, demonstrates a high specific capacity of 2378.9 mAh cm −3 (578.8 mAh g −1 ) with a capacity retention of ≈87.5% over 100 cycles, underscoring its stable performance. Furthermore, a Hybrid‐TENG is employed to charge the MA 3 Bi 2 I 9 ‐based LIB, thus realizing an SPU for driving portable electronics. This study highlights the promising potential of perovskites for developing efficient nanogenerators and LIBs, paving the way for sustainable energy solutions in small‐scale electronics.