Ruddlesden–Popper 2D Perovskite‐MoS2 Hybrid Heterojunction Photocathodes for Efficient and Scalable Photo‐Rechargeable Li‐Ion Batteries

Abstract Photo‐rechargeable batteries (PRBs) can provide a compact solution to power autonomous smart devices located at remote sites that cannot be connected with the grid. The study reports the Ruddlesden–Popper (RP) metal halide perovskite (MHP) and molybdenum disulfide (MoS 2 ) hybrid heterojunction‐based photocathodes for Li‐ion photo‐rechargeable battery (Li‐PRB) applications. Hybrid Lithium‐ion batteries (LIBs) have demonstrated an average discharge specific capacity of 144.46 and 129.17 mAhg −1 for 50 cycles when operating at 176 and 294 mAg −1 , respectively compared to the pristine LIBs which have shown specific capacity of 37.48 and 25.60 mAhg −1 under similar conditions. Hybrid Li‐PRB has achieved an average dark discharge specific capacities of 128.66 mAhg −1 (capacity retention: 96.56%) which enhanced to 180.67 mAhg −1 under illumination (capacity retention: 97.39%; photo‐enhancement: 40.42%) at 64 mAg −1 . Excellent performance of hybrid Li‐PRB is attributed to the formation of type‐II heterojunction that leads to improved crystallinity and film morphology. The PRB has demonstrated a high photo conversion and storage efficiency (PC‐SE) of 0.52% under standard 1 Sun illumination, which outperforms other previously reported MHP based LIBs and PRBs. This work provides a novel approach of harnessing the potential of MHPs for PRBs and offers new avenues for MHP photocathodes for various applications beyond PRBs.