Uniform Li deposition assisted by dual carbon-confined CoO-NiO nanoparticles for dendrite-free Li metal anode

Li metal has been considered as one of the most promising anodes for next-generation rechargeable batteries. However, the growth of Li dendrites and the huge volume change limit its practical application. Herein, we have developed a CoO-NiO nanoparticles embedded in carbon polyhedral matrix (CPM) and reduced graphene oxide (rGO) sheets electrode with lithiophilic properties for a Li metal anode via a simple hydrothermal method followed by freeze-drying process and subsequent thermal annealing. The homogeneously distributed CoO-NiO nanoparticles serve as nucleation sites to effectively reduce the overpotential for Li nucleation. Moreover, CPM and rGO sheets lead to the double carbon-confined hierarchical composites with strong coupling effect, providing sufficient void space to withstand the volume expansion during Li deposition. As a result, the as-obtained composite delivers enhanced Columbic efficiency (similar to 98.7% after 300 cycles) along with negligible nucleation overpotential. The symmetric cell can operate stably over 800 hat 1 mA cm(-2) and even 120 h under 3 mA cm(-2) with a fixed capacity of 1 mAh cm(-2). Moreover, remarkable rate capability and long-term cycling stability (92.6% capacity retention after 300 cycles at 1 C) are obtained in full cells paired with a LiFePO4 cathode.