Surface Morphology Modifications for Improving the Performance and Stability of Lithium-Rich Lithium–Silver Alloy Anodes

Lithium–metal batteries (LMBs) are advantageous in that they offer high-energy-density energy storage. Unfortunately, their commercialization is hampered by the collapsing structure of the lithium–metal anode during cycling, their low cycling stability due to the formation of lithium dendrites, and their poor capacity retention. In this study, we developed a lithium–silver alloy, which contains 10 atom % silver (AL10) and has a redox potential similar to that of Li/Li + as a result of electrochemical alloying with silver. Furthermore, modification of AL10 by altering its surface morphology using an annealing process (AL10-A) can induce more homogeneous lithium electrodeposition, effectively suppress lithium dendrites, and increase the diffusion rate of lithium ions. As a result, a symmetric cell with AL10-A as the anode could operate stably for 1600 h of lithiation/delithiation with a small average overpotential (<133 mV) at a current density of 1 mA cm –2 and capacity of 2 mAh cm –2 . Moreover, the capacity retention of the full cell, with AL10-A as the anode paired with delithiated NCM as the cathode, remained high after 100 cycles (132.2 mAh g –1 ), even at high current densities, and the cell exhibited excellent rate capabilities. Our findings emphasize the important contribution of the surface morphology of metal anodes toward enhancing the electrochemical performance of lithium–metal batteries.