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

Abstract

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.