Unraveling improved electrochemical kinetics of In2Te3-based anodes embedded in hybrid matrix for Li-ion batteries

Abstract

Although the introduction of hybrid matrices (e.g., metal oxide–carbon (e.g., TiO2–C) and metal carbide–carbon (e.g., TiC–C)) has shown to be effective for enhancing the electrochemical performance of alloy-based active materials, reliable evidence that verifies these favorable effects remain ambiguous. Herein, we propose a simple and effective strategy that can effectively resolve these issues and significantly extend the battery lifespan. To elucidate this phenomenon more clearly, In2Te3-based active materials with/without a TiO2–C matrix were prepared via simple two-step high-energy ball milling. To precisely elucidate the dynamics of Li-ion diffusion, various electrochemical techniques, including electrochemical impedance spectroscopy, cyclic voltammetry, and the galvanostatic intermittent titration technique, were used. The results indicate the synergetic roles of TiO2 and C; whereas the TiO2 phase improves the Li-ion diffusion dynamics, amorphous carbon reduces the internal resistance and volume change of the active In2Te3 material. Consequently, the In2Te3 embedded in the TiO2–C matrix (In2Te3–TiO2–C) exhibits good electrochemical performance for Li-ion storage, i.e., high specific capacity (∼846 mAh g−1 at 100 mA g−1 after 200 cycles and ∼704 mAh g−1 at 200 mA g−1 after 300 cycles), high rate capability (∼450 mAh g−1 at 10 A g−1 and ∼99% capacity recovery after a series of different current densities), and good long-term cycling performance (∼435 mAh g−1 of specific capacity after 500 cycles at a high current density of 500 mA g−1), compared with three control counterpart electrodes. Therefore, the In2Te3–TiO2–C composite developed in this study is a promising anode material for next-generation LIBs. © 2021 Elsevier B.V.