Lithiophilic V2O5 nanobelt arrays decorated 3D framework hosts for highly stable composite lithium metal anodes

Abstract

The lithium metal anode has been considered to be an optimal anode material for high-energy-density battery system due to its ultrahigh specific capacity. However, the sharp dendrite growth and infinite volume expansion have significantly impeded its commercial application. Herein, we propose that V2O5 as the lithiophilic substance can be decorated onto 3D stable frameworks to fabricate dendrite-suppressed composite Li metal anodes via a molten Li infusion method. It is demonstrated that the energetic chemical reaction between V2O5 and molten Li together with the capillary effect based on the nanostructure of interconnected V2O5 nanobelt arrays contributes synergistically to the great Li affinity of the V2O5-Ni foam (V2O5-NF) host and facilitate the efficient and uniform intake of molten Li into the 3D framework. Benefitting from the homogeneous Li distribution in the framework, the decreased local current density of the electrode and the stable property of the host, dendrite-free Li stripping/plating behavior and alleviated volume fluctuation have been achieved for the Li-V2O5-NF composite anode. Compared with the bare Li anode, the as-obtained Li-V2O5-NF composite anode exhibits much stable stripping/plating profiles with low overpotential (~18 mV) for ultralong lifespan (1600 h) at a current density of 1 mA cm−2 in symmetric Li/Li cell. Furthermore, outstanding rate capability and long-term cycling performance (78.8% capacity retention after 500 cycles under 2 C) are obtained in full cells when coupled with Li4Ti5O12 (LTO) cathodes, indicating a promising potential for practical application. Moreover, this work demonstrates that using a new lithiophilic material, V2O5, should be an effective method to construct high stable 3D Li metal anode for Li metal battery.