Optimizing deposition behavior by hollow carbon sphere with lithiophilic cobalt oxide core for dendrite-free lithium metal anode

lithium (Li) metal has emerged as one of the most promising anode materials for next-generation batteries, attracting considerable interest owing to its exceptional high energy density and specific capacity. However, severe volume expansion and dendritic growth during cycling critically hinder the practical application of Li metal anodes. Herein, a hollow carbon sphere-encapsulating cobalt oxide (CoO) core (CoO/CS) framework was fabricated through a layer-by-layer assembly and controlled etching approach, which effectively suppresses dendrite formation in Li metal anodes. Density functional theory (DFT) calculations reveal that the CoO core exhibits significantly higher Li adsorption energy compared to the graphite shell, demonstrating its preferential role in guiding Li deposition. COMSOL Multiphysics simulations demonstrate that the CoO core effectively optimizes the local current density distribution. Consequently, the Li + preferentially nucleates at the CoO core due to its lithiophilic character, sequentially filling the hollow carbon sphere's interior volume. The hollow architecture provides abundant nucleation sites and sufficient void space to accommodate deposited Li metal, effectively mitigating volume changes during cycling. The synergistic combination of the hollow carbon structure and lithiophilic CoO core enables exceptional stability (operation exceeding 1700 h). Finally, the full cell capacity of CoO/CS electrode shows significant improvement across various current densities.