Ultrathin nanosheet-decorated honeycomb-like Co3O4 porous balls for high performance lithium-ion batteries

Abstract

Co₃O₄-based anodes are challenged by low rate capability and poor cycling stability, arising from the inherent structural instability of the electrode alongside difficulties for electrolyte penetration within the electrode interior. A potential solution to address this obstacle is through the meticulous design of electrode architecture. With this in mind, ultrathin nanosheets adorned with finely honeycomb-like Co₃O₄ porous balls featuring cavities were synthesized via in situ incorporation of a Co²⁺ source and SiO₂ precursor solution. The Co₃O₄ porous balls, with a honeycomb-like structure, yielded a consistent discharge capacity of 727 mA h g⁻¹ at 0.5 A g⁻¹ over 230 cycles, and an impressive 540 mA h g⁻¹ at 2 A g⁻¹ over 500 cycles, indicative of remarkable rate capabilities. This exceptional electrochemical performance is credited to the distinctive porous honeycomb-like structure and cavities among the balls. This structure acts as a buffer against volume change during charge–discharge processes, guaranteeing a well-maintained electrode structure and providing strong cycling stability. Furthermore, these ultrathin and intricately porous nanosheets minimize the transport distance of ions and charges, facilitating access to more active sites. These notable features have the ability to augment rate performance and lithium storage capabilities.