Strategies of promotion solution growth mechanism in Aprotic Li-O2 batteries

Owing to the high theoretical specific energy, lithium-O₂ batteries have been considered as promising new energy sources beyond conventional Li-ion batteries. One of the challenges of a Li-O₂ battery is that the desired discharge product Li₂O₂ forms as a thin and insulating film on the electrode surface, which leads to large overpotential, low discharge capacity, and early cell death. Here, I summarize the strategies of promoting the solution growth of toroidal Li₂O₂ particles: high donor number electrolyte solvents and electrolyte salts have been shown to ensure the growth of toroidal Li₂O₂ particles in solution; additives such as derivatives based on anthraquinones with electron-withdrawing groups and water have also been suggested. Each strategy has its benefits and drawbacks, which needs a further understanding of the individual system. Until now, the methods of promoting solution growth of Li₂O₂ toroids in Li-O₂ batteries are still in research.