Zn/Co-ZIF-Derived Composites as High-Performance Anode Materials for Sodium-Ion Batteries

Composite materials derived from zeolite imidazolate frameworks (Zn/Co-ZIFs) have a unique porous structure, which has been used in the field of energy storage and catalysis. In this work, by direct heat treatment of Zn/Co-ZIFs, composite materials (Zn/Co-NPC (N-doped porous carbon) composites) of Zn and Co distributed uniformly in NPC were obtained. The pore structure and specific surface area of the composites were tuned by adjusting the heat-treatment temperature. Testing results show that the specific surface area and average pore size of the composites (at 700 degrees C) are 272.3 m2 g-1 and 8.4 nm, respectively. When used as anode material for sodium-ion batteries, the composites have a high reversible specific capacity of 269.1 mAh g-1 (100 mA g-1 current density) after 100 cycles, and also have excellent rate capability. Therefore, this work provides new insights for the future synthesis of anode materials for sodium-ion batteries with unique structure and high capacity.