Scalable Atomically Interfaced Heterostructure Photoelectrodes for Broadband Solar Energy Harvesting and Stable Li-Ion Storage

Photobatteries (PBs), which integrate photoactive materials into conventional battery architectures, offer an effective strategy to enhance battery performance by utilizing photogenerated charge carriers in the energy storage medium. Herein, we report scalable synthesis of WO 3– x -WS 2 nanosheet (NS)-based heterostructures for photoelectrodes in Li-ion PBs. These NS heterostructures enable broadband light harvesting (300–800 nm) and efficient separation of photocharge carriers. Atomically interfaced heterostructures of WO 3– x -WS 2 NSs have demonstrated stable electrochemical performance, retaining 80% of their capacity after 300 cycles with a specific capacity of 515.94 mAh g –1 (100–1000 mA g –1 ). Additionally, PBs exhibited enhanced kinetics under illumination (∼12 mW cm –2 ), resulting in a 35–59% increase in specific capacity. The dual-mesh current collector approach has been employed to increase the active mass loading, which further enhanced light–matter interaction and ultimately increased specific capacity. This work demonstrates a design framework for optimizing charge-carrier dynamics in PBs and establishes a viable pathway toward high-performance PBs for IoT applications.