Synergistic Performance Boosts of Dopamine-Derived Carbon Shell Over Bi-metallic Sulfide: A Promising Advancement for High-Performance Lithium-Ion Battery Anodes.

ABSTRACT

A CoMoS composite is synthesized to combine the benefits of cobalt and molybdenum sulfides as an anodic material for advanced lithium-ion batteries (LIBs). The synthesis is accomplished using a simple two-step hydrothermal method and the resulting CoMoS nanocomposites are subsequently encapsulated in a carbonized polydopamine shell. The synthesis procedure exploited the self-polymerization ability of dopamine to create nitrogen-doped carbon-coated cobalt molybdenum sulfide, denoted as CoMoS@NC. Notably, the de-lithiation capacity of CoMoS and CoMoS@NC is 420 and 709 mAh g⁻1, respectively, even after 100 lithiation/de-lithiation cycles at a current density of 200 mA g⁻1. Furthermore, excellent capacity retention ability is observed for CoMoS@NC as it withstood 600 consecutive lithiation/de-lithiation cycles with 94% capacity retention. Moreover, a LIB full-cell assembly incorporating the CoMoS@NC anode and an NMC-532 cathode is subjected to comprehensive electrochemical and practical tests to evaluate the performance of the anode. In addition, the density functional theory showcases the increased lithium adsorption for CoMoS@NC, supporting the experimental findings. Hence, the use of dopamine as a nitrogen-doped carbon shell enhanced the performance of the CoMoS nanocomposites in experimental and theoretical tests, positioning the material as a strong candidate for LIB anode.