Self-assembled 3D Ni_xCo_3-xO₄ pseudocube superstructure as potential anode material for Li-Ion batteries

Self-assembled 3D Ni_xCo_3-xO₄ pseudocube superstructure was successfully synthesized through a facile solvothermal strategy followed by a calcination process. Structure analyses shows that the mesoscopic 3D pseudocube superstructures are stacked by mesoporous nanoflakes with tiny nanoparticles as basic unit, as an anode material for Li-Ion Batteries, such a hierarchical structure can greatly buffer the volume expansion and effectively shorten lithium ion diffusion distance. Comparing with the 1D NiCo₂O₄ nanorods and 2D Co₃O₄ nanoflakes synthesized via changing the synthesis parameters, it conclude that the nickel leach process plays a key role in formation of this unique morphology and a mechanism is proposed. As expected, the 3D Ni_xCo_3-xO₄ pseudocube exhibits the most impressive lithium storage performance, delivering a high reversible capacity of 1225 mA h g⁻¹ after 200 cycles at 200 mA g⁻¹, and even at high current of 4000 mA g⁻¹, it still delivers a specific capacity of 645 mA h g⁻¹. These results suggest a promising application for advanced energy storage units.