High-performance ZnTe-TiO2-C nanocomposite with half-cell and full-cell applications as promising anode material for Li-Ion batteries

초록

C-coated ZnTe-TiO2 nanocomposite is successfully synthesized via annealing followed by high-energy mechanical milling. ZnTe-TiO2-C nanocomposite is comprised of intermetallic ZnTe nanoalloy homogeneously distributed in a hybrid matrix of ruffle TiO2 and conducive amorphous C. The presence of rutie TiO2 and C significantly improves the electrochemical performance of ZnTe; that is, highly stable cyclic performance (611 mAh g(-1) at 0.1 A g(-1) with similar to 95% capacity retention over 300 cycles and 492 mAh g(-1) at 0.5 A g(-1) after 500 cycles) and good rate capability (76% capacity retention at 10 A g -1 compared with the capacity at 0.1 A g(-1)). The improved electrochemical performance is primarily associated with the TiO2 -C hybrid matrix that efficiently surrounds the ZnTe nanocrystallites, thereby providing high electric conductivity and at the same time functioning as a buffering medium that alleviates the large volume change during extended cycling. Furthemore, the practical application of ZnTe-TiO2-C as an anode is investigated with full cell consisting of a ZnTe-TiO2-C anode and a LiFePO4-graphite (LFP@G) cathode. The ZnTe-TiO2-C//LFP@G full cell exhibits good cyclic stability with 79% capacity retention at 0.1 A g(-1) after 200 cycles. These results suggest the ZnTe-TiO2-C nanocomposite is a promising candidate for a high-performance anode in next-generation LIBs.

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