An overview of the unstable and irreversible lithium metal anode-related issues in nonaqueous Li–O2/air batteries
Abstract
Towards the practical application of nonaqueous Li–O2/air batteries (LOBs/LABs) with high theoretical energy density (3500 W h kg−1), they should work stably, effectively, and safely in an open-air environment and not be trapped in the closed-O2 atmosphere. In these systems, Li-metal is the direct ion supply source, and thus the stability of Li-anode determines the lifetime and safety of LOBs/LABs. In this review, we firstly summarize the severe shuttle effect originating from a practical working environment (O2, N2, CO2, H2O, etc.) and operation process (electro-reduced oxygen species, redox mediators) towards Li-anode, which is fatal for inherently unhealthy Li-anode. Moreover, several concerns affecting the rechargeability of LOBs/LABs are also discussed, including factors affecting the mass transfer of O2 (O2 selective membrane, gas diffusion layer, and solubility of oxygen species), battery components controlling the transportation of Li ions (cathode, separator, liquid/solid/gel electrolytes, and Li-surface coating), reshaping of 3D structure/composition of the SEI of Li-surface, and irreversible electrolyte decomposition. Finally, four development directions (open gas environment, wide temperature range, evaluation standards, and practical pouch cell assembly) of LOBs/LABs on real applications are mentioned. This review emphasizes the importance of Li-metal anode-related issues in LOBs/LABs and also reveals development directions from scientific and engineering perspectives.
- This article is part of the themed collection: Journal of Materials Chemistry A Recent Review Articles