Hierarchical NiCoO₂ Nanosheets Anchored on Hollow Carbon Spheres for High-Performance Lithium-Ion Battery Anodes

This study reports the synthesis of hierarchical NiCoO₂ nanosheets growing on hollow carbon spheres (denoted as NiCoO₂ NSs@HCS) via a facile and low-cost process. When evaluated as anode materials for lithium-ion batteries, the as-prepared NiCoO₂ NSs@HCS exhibits high specific capacity, enhanced cycling stability, and good rate capability. A high discharge capacity of 631.7 mA h g⁻¹ is delivered even after 200 cycles at a current density of 400 mA g⁻¹, corresponding to approximately 92 % of the second reversible discharge capacity. The hierarchical and hollow structure of NiCoO₂ NSs@HCS plays a role in its excellent performance.