Li–air Battery with a Superhydrophobic Li-Protective Layer
Chao Li, Jishi Wei, Ke Qiu, Yonggang Wang
Abstract
Li–air batteries operated in ambient air are imperative toward real practical applications. However, the passivation of lithium metal anodes induced by attacking air hinders their long-term running, accelerating the degradation of Li–air batteries. Herein, a hydrogel-derived hierarchical porous carbon (HDHPC) layer with superhydrophobicity is proved as an effective Li-protective layer for a Li–air battery that suppresses the H2O attack and lithium dendrite formation during cycling. Accordingly, the HDHPC protective layer-based Li–air cell exhibits eminent cycling stability in ambient air [relative humidity (RH) of ∼40%], which is far better than that of the Li–air cell without the HDHPC protective layer. It is also demonstrated that the conversion of O2/Li2O2 in Li–air batteries adversely affects the decomposition of the byproduct and electrolyte. The usage of the HDHPC protective layer pioneers a new avenue of developing high-performance Li–air batteries in ambient air.