Edge‐Dislocated WO ₃ Photocathode Toward Efficient Photo‐Assisted Li‐O ₂ Batteries

Abstract

Abstract The operation of rechargeable Li‐O 2 batteries critically depends on the highly reversible formation and decomposition of Li 2 O 2 at the cathode. However, the intrinsic insulating nature of Li 2 O 2 fundamentally restricts reaction kinetics, posing a core challenge to practical applications. Here, it is demonstrate that the insulating properties of Li 2 O 2 can be effectively improved by photoexcitation, attributed to the generation of photo‐induced charge carriers. It is inspired to develop photo‐assisted Li‐O 2 batteries featuring Z‐type photocathode@Li 2 O 2 heterojunction, which serves as a charge modulation channel to regulate carrier dynamics through photocathode modifications. By employing edge‐dislocated WO 3 as the photocathode, sustained growth of Li 2 O 2 films is observed with a thickness >18 µm, which is 2–3 orders of magnitude higher than typically reported values. Benefiting from the enhanced exciton dissociation of Li 2 O 2 and improved oxidative capability of photocathode, the battery delivers an ultra‐high discharge capacity of 31 800 mAh g −1 under a current density of 100 mA g −1 and a light‐induced temperature of ≈60 °C. In addition, a low polarization overpotential of 0.04 V is achieved with high reversibility over 1 000 h. The grasp of photoexcited Li 2 O 2 within Li‐O 2 batteries can drive solutions beyond state‐of‐the‐art metal‐air batteries.