Cu3(1,3,5-benzenetricarboxylate)2 metal-organic framework: A promising anode material for lithium-ion battery

Abstract

Versatility and diversity in the nature of bonding between metal ions and polyfunctional organic molecules render metal organic frameworks (MOFs) as interesting materials for a variety of applications. In this work, we have examined the electrochemical properties of solvothermally synthesized Cu-1,3,5-benzenetricarboxylate MOF as a novel anode material for lithium-ion battery (LIB). At a current density of 96 mAg−1, reversible capacity of 740 mAhg−1 is achieved, the highest ever reported for a MOF. Even at a high current density of 383 mAg−1, specific capacity of 474 mAhg−1 is observed with no apparent fading up to 50 cycles. Ex-situ studies on the electrode material in the charged and discharged state by X-ray diffraction, Fourier transformed infra-red spectroscopy and X-ray photoelectron spectroscopy suggest that Li storage in Cu3(BTC)2 MOF might not be fully explained by the conventional conversion mechanism that involves reduction into corresponding metal and subsequent oxidation. Rather, redox participation of the organic moiety is indicated. The present results would help in designing new MOFs for LIB applications.