Parallelepipedally shaped ZnCo 2 O 4 particles with a hierarchical porous structure as an anode for lithium-ion batteries

The micrometer-sized ZnCo 2 O 4 parallelepipeds with a hierarchical porous structure have been fabricated by a simple two-step procedure, i.e., the synthesis of the Zn 1/3 Co 2/3 CO 3 parallelepipeds and the subsequent calcination. When tested in lithium-ion batteries (LIBs), the hierarchical porous ZnCo 2 O 4 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 ZnCo 2 O 4 parallelepipeds in LIBs. The high electrochemical performance of the hierarchical porous ZnCo 2 O 4 parallelepipeds might originate from the unique porous structure which consists of the secondary ZnCo 2 O 4 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 ZnCo 2 O 4 , facilitating the better utilization of the active material.