Revealing the influence of conversion-type Co₃O₄ dimensionality on cyclic and rate performance for lithium storage

Cobalt tetraoxide (Co₃O₄) is regarded as a promising anode material for Li-ion batteries owing to its high theoretical capacity (890 mAh g^-1), simple preparation, and controllable morphology. Nanoengineering has been proven to be an effective method for producing high-performance electrode materials. However, systematic research on the influence of material dimensionality on battery performance is lacking. Herein, we prepared Co₃O₄ with various dimensionalities (one-dimensional (1D) Co₃O₄ nanorod (NR), two-dimensional (2D) Co₃O₄ nanosheet (NS), three-dimensional (3D) Co₃O₄ nanocluster (NC), and 3D Co₃O₄ nanoflower (NF)) using a simple solvothermal heat treatment method, and their morphologies were controlled by varying the precipitator type and solvent composition. The 1D Co₃O₄ NR and 3D samples (3D Co₃O₄ NC and 3D Co₃O₄ NF) exhibited poor cyclic and rate performances, respectively, while the 2D Co₃O₄ NS exhibited the best electrochemical performance. The mechanism analysis revealed that the cyclic stability and rate performance of the Co₃O₄ nanostructures are closely related to their intrinsic stability and interfacial contact performance, respectively, and the 2D thin-sheet structure can achieve an optimal balance between the two, resulting in the best performance. This work presents a comprehensive study on the effect of dimensionality on the electrochemical performance of Co₃O₄ anodes, providing a new concept for the nanostructure design of conversion-type materials.