A MnS/MnO-coated S,N-doped carbon anode obtained from a Mn(ii)-coordinated polymer for long-cycle life Li-ion batteries

Abstract

To address the limitations of the anodes used in current Li-ion batteries (LIBs), a MnS/MnO-decorated S,N-doped carbon (MSNC) electrode was designed by introducing a Mn²⁺-coordinated polymer (Mn-DTOGA) bonded to a sulfur atom with acetate counter ions through an imine formation reaction for advanced LIBs. The MSNC electrode was prepared and characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy, and transmission electron microscopy, which confirmed the ease of synthesis, superior controllability, and uniformity of the material. The electrochemical characteristics of the materials were assessed via cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge–discharge tests to determine their viability as anode materials in LIBs. The results demonstrate excellent cycling stability, with the material exhibiting superior performance for 500 cycles at a rate of 0.2 C. Furthermore, in situ XRD and XPS measurements provided a fundamental understanding of the material, confirming the redox reaction between the MnS/MnO complex and metallic Mn/Li₂S/Li₂O.