Parallelepipedally shaped ZnCo2O4 particles with a hierarchical porous structure as an anode for lithium-ion batteries

The micrometer-sized ZnCo2O4 parallelepipeds with a hierarchical porous structure have been fabricated by a simple two-step procedure, i.e., the synthesis of the Zn1/3Co2/3CO3 parallelepipeds and the subsequent calcination. When tested in lithium-ion batteries (LIBs), the hierarchical porous ZnCo2O4 parallelepipeds could exhibit a reversible capacity of > 860 mAh g(-1) at a current density of 0.1 C. This clearly demonstrates the potential use of the hierarchical porous ZnCo2O4 parallelepipeds in LIBs. The high electrochemical performance of the hierarchical porous ZnCo2O4 parallelepipeds might originate from the unique porous structure which consists of the secondary ZnCo2O4 particles. First, the porous structure allows for a better accessibility of the active material to the Li+ ion storage, favoring easier diffusion of electrolyte in and out of electrode material. Second, the presence of the secondary particles shortens a pathway of Li+ diffusion in ZnCo2O4, facilitating the better utilization of the active material.