Pulsed Current Constructs 3DM Cu/ZnO Current Collector Composite Anode for Free-Dendritic Lithium Metal Batteries

Abstract

Although lithium metal is an ideal anode material for achieving high-energy-density lithium-based batteries, the uneven deposition/exfoliation process of lithium during cycling easily triggers the formation of lithium dendrites and dead lithium, which leads to a low Coulombic efficiency and safety issues. In this paper, a lithiophilic 3D copper mesh current collector is designed by using lithiophilic ZnO and pulsed current plating and is applied to a lithium metal battery composite anode. Under the action of the pulsed current field, the novel lithium metal composite anode battery achieved the homogeneous deposition of lithium ions. The lithium-to-copper half cells assembled with the 3DM Cu/ZnO current collector from the pulsed current deposition presented a Coulombic efficiency as high as 97.8% after 1 min of activation at 3 mA cm−2 follow by 10 cycles at a stripping current of 0.5 mA cm−2. Moreover, the symmetric cell could be stable for 1500 h at 1 mA cm−2 with a limited capacity of 1 mAh cm−2, and the assembled full cell (LiFePO4 as the cathode) maintained a Coulombic efficiency of about 90% for the 30th cycle at 1 C. This novel mechanism is an advanced strategy to improve cyclic stability and is crucial for designing stable lithium metal batteries.

Keywords

• lithium metal battery
• composite anode
• pulsed current
• lithium deposition
• lithiophilic current collector