A Three-Dimensional Surface Layer and a Composite Aphroid Layer Constructed by a Facile Rolling Method for High-Performance Li Metal Anodes

The poor electrochemical performance and potential safety hazards caused by lithium dendrites have severely restricted the practical application of Li metal anodes, although they are one of the most promising anode candidates for future high-energy-density Li batteries. One key point for inhibiting Li dendrites is to optimize the uniform and stable interface between the electrode and electrolyte for homogeneous electric field distribution. Here, the composite Li metal anode consisting of the top three-dimensional (3D) surface layer, the middle aphroid layer, and the bottom metallic Li is fabricated by the rolling method. The 3D surface layer and composite aphroid layer based on lithiophilic Ag-decorated carbon fibers enhance the uniformity and stability of the interface between the electrode and electrolyte and facilitate fast ion diffusion and electron transfer, which promote stable nondendritic Li deposition. The composite Li anode exhibits a low overpotential of only ∼20 mV after cycling for over 400 h at 1 mA cm^–2. When paired with LiCoO₂, the full cell delivers excellent cycling performance of 500 cycles at 2C with a capacity retention of over 84%. The design of the 3D structure layer provides references for the industrial application of Li metals modified by low-cost raw materials and simple methods.