Synthesis, structures and electrochemical properties of lithium 1,3,5-benzenetricarboxylate complexes

Abstract

Four lithium coordination polymers, [Li 3 (BTC)(H 2 O) 6 ] (1), [Li 3 (BTC)(H 2 O) 5 ] (2), [Li 3 (BTC)(μ 2 -H 2 O)] (3), and [Li(H 2 BTC)(H 2 O)] (4) (H 3 BTC = 1,3,5-benzenetricarboxylatic acid), have been synthesized and characterized. All the structures have been determined using single crystal X-ray diffraction studies. Complexes 1 and 2 have two-dimensional (2-D) sheets, whereas complex 3 has three-dimensional (3-D) frameworks and complex 4 has one-dimensional (1-D) tubular chains. The crystal-to-crystal transformation was observed in 1-3 upon removal of water molecules, which accompanied the changes in structures and ligand bridging modes. Furthermore, the electrochemical properties of complexes 3 and 4 have been studied to evaluate these compounds as electrode materials in lithium ion batteries with the discharge capacities of 120 and 257 mAhg -1 in the first thirty cycles, respectively.