In Situ Supramolecular Self-Assembly Assisted Synthesis of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>–Carbon-Reduced Graphene Oxide Microspheres for Lithium-Ion Batteries

Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> (LTO)-carbon (C)-reduced graphene oxide (rGO) microspheres are synthesized via in situ supramolecular self-assembly, combined with spray drying and high-temperature calcination. Dopamine can polymerize on the surface of Ti­(OH)<sub>4</sub> and form polydopamine, through which graphene oxide­(GO) connects with Ti­(OH)<sub>4</sub> uniformly and tightly to form a homogeneous supramolecular sol system. During the high-temperature calcination, polydopamine is carbonized to carbon to connect LTO with rGO, so that the aggregation of rGO is inhibited, and small-sized LTO particles are obtained. The scanning electron microscopy (SEM) image shows that in the as-prepared LTO-C-rGO microspheres, LTO particles with diameters of ∼50 nm remained homogeneous and wrapped in a three-dimensional network built by the rGO nanosheets. Electrochemical measurements show that the LTO-C-rGO anode exhibits a high reversible capacity of 184 mAh g<sup>–1</sup> at 1 C and a high capacity retention of 94.5% after 500 cycles at 20 C. The above excellent electrochemical performance benefits from the unique structure of LTO-C-rGO, which enhances the ion diffusion and facilitates electron transport.