Air/Water Stability Problems and Solutions for Lithium Batteries

Recently, lithium-ion batteries (LIBs) have faced bottlenecks in terms of energy/power density and safety issues caused by flammable electrolytes. In this regard, all-solid-state batteries (ASSBs) may be one of the most promising solutions. However, many key battery materials (such as solid electrolytes (SEs), cathodes, and anodes) are unstable to air/water, which greatly limits their production, storage, transportation, practical applications, and the development of ASSBs. Herein, the research status on air/water stability of SEs, cathodes, and anodes is reviewed. The mechanisms for their air/water instability are revealed in details. The corresponding modification methods are also proposed, with emphasis on the construction strategies of air/water stable protective layers, including ex situ coatings and in situ reactions. Moreover, the application of air/water-stable protective layers in ASSBs is discussed correspondingly. Last but not least, the advantages and disadvantages of various protective layer construction strategies are analyzed, in which their applications in practical production are prospected.