Facile synthesis of bimetallic zeolite imidazolate framework with enhanced lithium storage performance

Zeolitic imidazolate framework ZIF-67 and a bimetallic CoCu-ZIF were synthesized via a simple chemical precipitation method and applied as anode materials in lithium-ion batteries. The as-prepared CoCu-ZIF delivers a reversible capacity of 883.74 mAh g−1 after 200 cycles at a current density of 200 mA g−1 and 339 mAh g−1 after 200 cycles at 2 A g−1, which is higher than the performance of single metal ZIF-67. The better electrochemical performance of CoCu-ZIF than ZIF-67 could be mainly attributed to the synergy of copper and cobalt which can increase the contact area between the active material and the electrolyte, and it also can reduce the transmission distance between ions and electrons.