Lattice-dependent activation of highly efficient SnTe cathode catalyst for Li–air batteries

Lithium–air batteries (LABs) have attracted considerable interest in research in recent years owing to their ultrahigh energy density. However, almost all highly active cathode catalysts considered for them exhibit excellent performance only when operating in a pure O2 environment, because of which such batteries are classified as Li–O2 batteries (LOBs). Activating the capability of the cathodic catalyst in ambient air for LOBs is thus important. In this study, we use a lattice-dependent activation strategy to enhance the capability of the cathodic catalyst of LOBs in ambient air. It is demonstrated that the LABs performance of SnTe cathode catalyst applied in LOBs can be achieved through selected exposing crystal plane. The SnTe cathode with its (100) plane exposed exhibited a high specific capacity of over 9000 mAh g−1 and a long cycle performance of over 170 cycles at 500 mA g−1, about three times longer than that of the SnTe cathode with the (111) plane exposed. However, these two cathodes achieved similar cycle performance in the LOBs. The results of experimental and theoretical calculations revealed that the (111) plane of the catalyst yielded the best catalytic capability for the formation/decomposition of Li2O2, whereas the (100) plane could capture an adequate amount of oxygen while repelling CO2 and H2O. This enabled it to efficiently avoid the formation of side-products, such LiOH and Li2CO3, in ambient air and yield a high-performance LAB. This work provides practical design guidance for advanced catalysts assembled in LABs.