A Highly Immobilized Organic Anode Material for High Performance Rechargeable Lithium Batteries.

Organic conjugated carbonyl materials have attracted considerable attention in the field of high-capacity and green energy storage technologies. However, the high solubility in organic electrolyte restrains their further application. In this work, an organic terephthalate compound (Li2M) with propargyl groups is synthesized innovatively and then used to prepare a highly cross-linked anode material (X-Li2M) by simple hydrothermal treatment for rechargeable lithium batteries. The electrochemical properties are enhanced significantly by in situ constructing an interpenetrating network of X-Li2M and the conductive carbon nanotubes (CNTs). The as-synthesized X-Li2M@CNTs composite anode delivers a reversible capacity of ∼200 mAh g-1 at 0.1 C after 200 cycles and exhibits excellent cycle stability at a high rate of 1 C with ∼150 mAh g-1 retention capacity after 1000 cycles and nearly 100% average Coulombic efficiency. Additionally, the superior rate capability is obtained at the high rate of 2 and 10 C and with specific discharge capacities of 140 and 100 mAh g-1, respectively. Highly reversible redox reaction of the electrochemical active site carbonyl group (C═O) is ascertained by ex-situ infrared spectroscopy and X-ray photoelectron spectroscopy. The described approach provides a novel direction for the immobilization of organic electrode molecules and is intended to serve as a universal guide for the research and fabrication of high-performance organic batteries.