Super-three-dimensional lithiophilic Cu-based current collector for anode-free lithium metal battery

The formation of Li dendrites and dead Li, which causes short circuits, continuous side reactions, low Coulombic efficiency (CE) and thermal runaway, severely hinders the development of anode-free lithium metal batteries. Here, Cu-based current collector with super-three-dimensional lithiophilic modification layer is developed by the pyrolysis of resorcinol formaldehyde on 3D engineered copper mesh (a-RF@3D CM). The modification layer, consisting of highly dispersed CuOx sites in the O-containing defective carbon, together with the super-three-dimensional microstructure exhibits excellent lithiophilicity and capability to effectively reduce the nucleation overpotential, accommodate the uniform dendrite-free lithium deposition, promote stable and inorganic-rich solid electrolyte interphase formation, and improve the cycle stability. As a result, the a-RF@3D CM current collector exhibits reduced nucleation overpotential of 14.2 mV and prolonged cycling life over 400 cycles with average CE >98.5%. In the LiFePO4||a-RF@3D CM anode-free cell, average CE of 99.50% and capacity retention of 60.66% are successfully achieved after 100 cycles. Meanwhile, average CE 99.78% and capacity retention of 64.43% are successfully achieved in LiFePO4||Li@a-RF@3D CM cell (N/P = 1.6) after 200 cycles. The work provides feasible way to realize the fabrication of anode-free lithium metal batteries and also enhance the understanding of solid electrolyte interface evolution and regulation strategy of Li plating–stripping in advanced Li metal-based batteries.