Air-Stable and Dendrite-Free Lithium Metal Anodes Enabled by a Hybrid Interphase of C60 and Mg

Li metal is an ideal anode material for rechargeable high energy density batteries, but its sensitivity to humid air and uncontrolled dendrite growth limit its practical applications. A novel hybrid interphase is fabricated to address these issues. This interphase consists of dense fullerene (C-60) and magnesium metal bilayers, which are deposited successively on lithium foil by vacuum evaporation deposition and contribute to moisture resistance and lithium dendrite suppression. Thanks to this dual-functional feature, the assembled cells with the modified anodes and commercial LiFePO4 cathodes exhibit long cycle life (>200 cycles) with high capacity retention (>98.5%). Moreover, even the modified anodes that are exposed to humid air (30% relative humidity) for over 12 h; the cells still deliver excellent performance, comparable to those without exposure. Such a unique hybrid interphase provides a new promising method for fabricating air-stable and dendrite-free lithium metal batteries.