Binder-free Fe₂O₃/CuO nanorod arrays for high-efficiency and stable photo-assisted lithium-oxygen batteries

Because of its extraordinarily high theoretical energy density, lithium-oxygen batteries (LOBs) have grown into an appropriate choice for next-generation energy storage devices. However, problems such as a large charge/discharge overpotential and a short cycle life restrict its advancement. Herein, we prepared self-supported p-n-type heterostructured Fe₂O₃/CuO nanorod arrays (Fe₂O₃/CuO NRA) on Cu foam and employed it for photo-assisted LOBs cathode. The heterostructure enhanced the ORR and OER performance by efficiently inhibiting the rate at which photogenerated electrons and holes recombine. The LOBs of Fe₂O₃/CuO NRA photocathodes showed good rate performance under the condition of illumination. When the capacity and current density were 0.25mAh cm⁻² and 0.5 mA cm⁻², respectively, the overpotential of LOBs decreased to 1.15 V, and the cycle stability was improved, which can reach 240 cycles. This material shows considerable potential as an electrode in photo-assisted LOBs.