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

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.

Automated summary

The introduction of TiO2-C matrix can improve the electrochemical performance of In2Te3-based active materials by enhancing Li-ion diffusion dynamics, reducing internal resistance, and volume change.