Three-dimensional flower-like NiO on Cu foam as a lithiophilic current collector for high-performance lithium metal batteries

With the development of energy storage devices, the lithium metal anode has been explored in depth because of its excellent theoretical specific capacity. However, some fatal defects such as uncontrollable volume expansion, random growth of lithium dendrites and successive consumption of lithium restrict its development, especially at large current densities and deposition capacities. In this study, flower-like NiO grown on Cu foam (CF) was developed via a hydrothermal and post-annealing method. Lithiophilic NiO with a large surface area provides abundant sites for lithium deposition, which is beneficial to obtain a dendrite-free deposition process. Moreover, the combination of lithiophilic NiO and three-dimensional Cu foam can alleviate the volume change of lithium, suppress the generation of dead lithium and improve the utilization ratio of lithium metal, which is beneficial to obtain excellent electrochemical performance. As a result, the designed NiO@CF host can achieve a long-stable lifespan of 1200 h and a voltage hysteresis of 93 mV in a symmetrical cell at 10 mA cm-2. Furthermore, the capacity retention rate of the full cell can be maintained at 85% after 500 cycles at 3C. Generally, this study provides a feasible exploration for the suppression of dendrites in high performance lithium metal batteries at large current density. Lithiophilic NiO with large surface area was grown on 3D copper foam by hydrothermal and post-annealing method. Flower-like NiO provides abundant active sites, which facilitates uniform deposition of lithium and effectively inhibit the growth of lithium dendrites.