Ultrathin Mesoporous NiCo₂ O₄ Nanosheet Networks as High-Performance Anodes for Lithium Storage

Ultrathin mesoporous NiCo₂ O₄ nanosheets were directly grown on Ni foams to form an efficient and reversible anode for lithium-ion half-cell batteries. Nanosheets with wrinkles, which were monolayers of 10 nm NiCo₂ O₄ nanoparticles, were interconnected to build up a honeycomb-like architecture that offered a large electrolyte contact area and good structural integrity. The firm attachment of the sheets on the foam endows the anode with good electrical conductivity and excellent mechanical stability. Electrochemical measurements confirm that the electrode has a better performance at reversible Li⁺ storage (specific capacity of 1170.1 mA h g^-1 in the 50th cycle at 0.2 C) than the pasted electrode made of NiCo₂ O₄ nanosheets powder.