Lithiophilic ZnCu alloy sites on copper current collector for high performance Li metal anode

Abstract

Lithium (Li) metal has been widely regarded as the optimal anode material for the high-energy density rechargeable batteries, due to its ultrahigh theoretical specific capacity and lowest electrochemical potential. However, the formation of Li dendrites presents a significant safety concern, which limits its practical application. In this paper, to address this issue, an efficient and cost-effective strategy was proposed to prepare a zinc-copper composite collector (ZCC) with outstanding electrochemical performance, which can effectively suppress the formation of lithium dendrites. The lithophilic surface with ZnCu alloy nanoparticles was achieved through physical vapor deposition followed by annealing treatment. The ZCC collector enables dendrite-free deposition of Li due to its negligible nucleation overpotential. Even at high area capacity of 3 mAh cm−2 at 1 mA cm−2 in half-cells, the ZCC exhibits exceptional cycling performance and high coulomb efficiency. Preloaded with Li, the composite electrode (Li/ZCC) delivers an enhanced lifespan with low overpotential evidently. Matched with LiFePO4 (LFP) cathode, LFP||Li/ZCC full cells reveal a superior cycling stability with enhanced capacity retention of 85 % (after 1000 cycles at 1 C) and 87 % (after 800 cycles at 3 C) respectively.