Effect of 3D lithiophilic current collector for anode-free Li ion batteries

The realization of anode-free lithium metal batteries (AFMBs) is limited owing to low Coulombic efficiency derived from the formation of uneven lithium plating at the anode side. Here, we induce the uniform deposition of lithium by an Au predeposited three-dimensional (3D) anodic current collector with an ether-based electrolyte. At the modified anodic current collector, the over-potential generated during the initial deposition of lithium converged to 6 mV, and stable cycling was achieved with an extremely high Coulombic efficiency of 99 % over 100 cycles. Furthermore, when compared to two-dimensional (2D) bare copper foil (LiFePO4/2D Cu), AFMBs using LiFePO4 cathode with Au predeposited 3D anodic current collector (LiFePO4/Au-3D Cu) show better rate performance and longer cycle life. This improvement in electrochemical performance is derived from the regulation of lithium deposition and inhibition of electrolyte decomposition due to the local current density through the predeposition of Au and 3D structure. This study provides a new path to realizing AFMBs.