Titanium Niobium Oxide Ti2Nb10O29/Carbon Hybrid Electrodes Derived by Mechanochemically Synthesized Carbide for High-Performance Lithium-Ion Batteries

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.

Automated summary

This work presents a facile and scalable two-step synthesis method for preparing Ti2Nb10O29 (TNO)/carbon hybrid material as a promising anode for lithium-ion batteries. The hybrid material exhibited high specific capacity, excellent cycling stability, and improved rate handling due to the addition of carbon.