Titanium Niobium Oxide Ti2 Nb10 O29 /Carbon Hybrid Electrodes Derived by Mechanochemically Synthesized Carbide for High-Performance Lithium-Ion Batteries

Abstract

This work introduces the facile and scalable two‐step synthesis of Ti2Nb10O29 (TNO)/carbon hybrid material as a promising anode for lithium‐ion batteries (LIBs). The first step consisted of a mechanically induced self‐sustaining reaction via ball‐milling at room temperature to produce titanium niobium carbide with a Ti and Nb stoichiometric ratio of 1 to 5. The second step involved the oxidation of as‐synthesized titanium niobium carbide to produce TNO. Synthetic air yielded fully oxidized TNO, while annealing in CO2 resulted in TNO/carbon hybrids. The electrochemical performance for the hybrid and non‐hybrid electrodes was surveyed in a narrow potential window (1.0–2.5 V vs. Li/Li+) and a large potential window (0.05–2.5 V vs. Li/Li+). The best hybrid material displayed a specific capacity of 350 mAh g−1 at a rate of 0.01 A g−1 (144 mAh g−1 at 1 A g−1) in the large potential window regime. The electrochemical performance of hybrid materials was superior compared to non‐hybrid materials for operation within the large potential window. Due to the advantage of carbon in hybrid material, the rate handling was faster than that of the non‐hybrid one. The hybrid materials displayed robust cycling stability and maintained ca. 70 % of their initial capacities after 500 cycles. In contrast, only ca. 26 % of the initial capacity was maintained after the first 40 cycles for non‐hybrid materials. We also applied our hybrid material as an anode in a full‐cell lithium‐ion battery by coupling it with commercial LiMn2O4.