Photo-enhanced lithium oxygen batteries with defective titanium oxide as both photo-anode and air electrode

The catalysts for lithium-oxygen batteries have been researched for decades due to the huge energy storage ability. However, the sluggish catalytic performance towards the decomposition of discharge products (Li2O2) inspires us to utilize the photo-generated holes to overcome the obstacle. As novel energy storage device, the TiO2 nanorod arrays on carbon textiles were well-designed and adopted as both air cathode and photo-anode for photo-assisted Li-O2 batteries. Electrochemical data strongly demonstrate that the abundant photo-generated holes on the TiO2 can efficiently oxidize the Li2O2 (the charge potential reduced from 4.31 V to 2.86 V vs Li/Li+). It is noted that the light illumination prompts the TiO2 to be more defective and the generated oxygen vacancies further enhance the electron and Li+ migration, leading to the improved ORR performance (discharge potential at 2.85 V vs Li/Li+). The batteries can charge/discharge for 30 cycles with no decay and deliver the excellent rate performance.