Strategies to Optimize the Lithium Storage Capability of the Metal-Organic Framework Copper-1,3,5-Trimesic Acid (Cu-BTC)

Metal-organic frameworks (MOFs) have recently been considered as potential electrodes for lithium-ion batteries. However, there are only a few reports of pristine MOFs as high-performance electrode materials; whereas, in other cases, their overall specific capacities and cycle stabilities are insufficient. In this work, Cu-BTC (BTC=1,3,5-trimesic acid) is taken as an example to systematically explore the effects of polymer binder, activation temperature, and synthesis method on the electrochemical properties of MOFs. Through the optimization of these conditions, the electrochemical properties of Cu-BTC can be significantly improved. With carboxymethyl cellulose (CMC) as the binder, the activated Cu-BTC (synthesized with the pre-cooling method) displays a stable specific capacity of 626.4 mAh g(-1)after 100 cycles of charge and discharge at a current density of 100 mA g(-1). Besides, the mechanism study shows that both the copper species and organic ligands of Cu-BTC take part in the redox chemistry contributing to the lithium storage capability.