An interconnected silver coated carbon cloth framework as a host to reduce lithium nucleation over-potential for dendrite-free lithium metal anodes

Lithium metal is considered as a potential anode for lithium batteries, but its commercialization process is hindered by several problems, including uncontrollable lithium dendrite growth, large volume expansion, low utilization of lithium and so on. To address these issues, in this work, lithiophilic silver layers with 80 nm thickness are coated on the commercial carbon cloth (CC) using thermal evaporation method to regulate Li growth during lithium plating process. We find that the uniformly distributed silver layers can successfully reduce lithium nucleation over-potential, thus inducing the homogeneous deposition of metal Li, supported by density functional theory calculation. Benefited from the as-prepared lithiophilic Ag layers, the CC/Ag/Li anode with an ultrahigh areal capacity of 16 mAh cm−2 is achieved adopting electrochemical deposition at 0.2 mA cm−2 without the formation of lithium dendrites, which is confirmed by continuous detection using visual discrimination and scanning electron microscope observation. As a result, a stable dendrite-free CC/Ag/Li anode exhibits excellent electrochemical properties: (1) the assembled CC/Ag/Li symmetrical cell maintains a stable voltage hysteresis within 25 mV after cycling 750 h at a current density of 1 mA cm−2; (2) The assembled CC/Ag/Li-LiFePO4 cell also demonstrates enhanced electrochemical behaviors in terms of rate performance and capacity retention; (3) When coupled with a carbon/sulfur cathode, the CC/Ag/Li anode also demonstrates excellent compatibility. The initial discharge capacity of the CC/Ag/Li-S cell is 899.3 mAh g−1 at 0.2C, the reversible capacity retains a value of 587.7 mAh g−1 after 400 cycles, corresponding to a capacity attenuation rate of 0.075% per cycle.