MXene-Integrated Porous Carbon–Silicon Composite as a Stable and High-Capacity Anode for Lithium-Ion Batteries
Abstract
In this work, a novel composite anode material combining activated carbon, MXene, and nanosized silicon was developed for high-performance lithium-ion batteries. Unlike previously known MXene/Si or Si/C systems, our work is the first to implement a three-component AC/Si/MXene architecture, where biomass activated carbon provides a highly developed porous structure and additional conductivity, MXene stabilizes and enhances electron transport, and nano-Si contributes high capacitance. The composite design integrates the advantages of each component: silicon for its high theoretical capacity, MXene for its excellent electrical conductivity and layered structure, and biomass-derived activated carbon for its high surface area and structural integrity. A sequential synthesis strategy was employed, where nanosilicon was first intercalated into MXene layers, followed by mixing with porous activated carbon to form a homogeneous and stable hybrid structure. Here, the synthesized MXene material acts as a matrix for nanosilicon to restrain volume expansion during charge/discharge, and the synthesized activated carbon acts as a conductor for structural stability and also has additional capacity. Electrochemical analysis of the AC/Si/MXene composite demonstrated a high initial discharge capacity exceeding 2000 mAh/g at a current density of 200 mA/g. Subsequent capacity studies at different current densities showed that the material is stable. The composite material also showed higher capacity compared to individual nano-Si, MXene, and AC.