A\nHighly Immobilized Organic Anode Material for High\nPerformance Rechargeable Lithium Batteries

Abstract

Organic conjugated\ncarbonyl materials have attracted considerable\nattention in the field of high-capacity and green energy storage technologies.\nHowever, the high solubility in organic electrolyte restrains their\nfurther application. In this work, an organic terephthalate compound\n(Li₂M) with propargyl groups is synthesized innovatively\nand then used to prepare a highly cross-linked anode material (X-Li₂M) by simple hydrothermal treatment for rechargeable lithium\nbatteries. The electrochemical properties are enhanced significantly\nby in situ constructing an interpenetrating network of X-Li₂M and the conductive carbon nanotubes (CNTs). The as-synthesized\nX-Li₂M@CNTs composite anode delivers a reversible capacity\nof ∼200 mAh g^–1 at 0.1 C after 200 cycles\nand exhibits excellent cycle stability at a high rate of 1 C with\n∼150 mAh g^–1 retention capacity after 1000\ncycles and nearly 100% average Coulombic efficiency. Additionally,\nthe superior rate capability is obtained at the high rate of 2 and\n10 C and with specific discharge capacities of 140 and 100 mAh g^–1, respectively. Highly reversible redox reaction of\nthe electrochemical active site carbonyl group (CO) is ascertained\nby ex-situ infrared spectroscopy and X-ray photoelectron spectroscopy.\nThe described approach provides a novel direction for the immobilization\nof organic electrode molecules and is intended to serve as a universal\nguide for the research and fabrication of high-performance organic\nbatteries.