Nanoflake arrays of lithiophilic metal oxides for the ultra-stable anodes of lithium-metal batteries

A molten lithium infusion strategy has been proposed to prepare stable Li-metal anodes to overcome the serious issues associated with dendrite formation and infinite volume change during cycling of lithium-metal batteries. Stable host materials with superior wettability of molten Li are the prerequisite. Here, it is demonstrated that a series of strong oxidizing metal oxides, including MnO2, Co3O4, and SnO2, show superior lithiophilicity due to their high chemical reactivity with Li. Composite lithium-metal anodes fabricated via melt infusion of lithium into graphene foams decorated by these metal oxide nanoflake arrays successfully control the formation and growth of Li dendrites and alleviate volume change during cycling. A resulting Li-Mn/graphene composite anode demonstrates a super-long and stable lifetime for repeated Li plating/stripping of 800 cycles at 1 mA cm−2without voltage fluctuation, which is eight times longer than the normal lifespan of a bare Li foil under the same conditions. Furthermore, excellent rate capability and cyclability are realized in full-cell batteries with Li-Mn/graphene composite anodes and LiCoO2cathodes. These results show a major advancement in developing a stable Li anode for lithium-metal batteries.