Facile Solid-State Synthesis of Prelithiated LiTiO2 With Nitrogen-Doped Carbon for Lithium-Ion Battery Anodes

초록

Although Ti-based oxides are attractive anode materials for Li-ion batteries (LIBs) owing to their inherent stability and enhanced safety, their electrochemical performance is severely limited by low conductivity and slow Li-ion diffusion. Conventional LiTiO2 synthesis methods are not cost-effective because they rely on high-purity precursors and energy-intensive procedures. To address these limitations, in this study, prelithiated LiTiO2 with nitrogen-doped carbon (NC-LiTiO2) was synthesized via a solid-state reaction using TiO2 hollow spheres (HSs) derived from ammonium hexafluorotitanate (AHFT[(NH4)2TiF6]). The NC-LiTiO2 exhibited a highly crystalline structure with a homogeneous elemental distribution, and the nitrogen-doped carbon enhanced its electronic conductivity and facilitated Li-ion diffusion, thereby improving the overall performance of the LiTiO2 anodes. The electrochemical testing results indicated a high discharge capacity (170 mA h g-1), excellent rate performance, and good cycling stability over 1000 cycles at 2 C. The improved performance was attributed to the nitrogen-doped carbon, robust structure, and progressive activation of Li-ion pathways. Morphological and impedance analyses after cycling revealed minimal volume expansion and a significant reduction in the interfacial resistance. The strategy proposed herein offers a facile, cost-effective route for fabricating prelithiated oxide anodes and is effective for enhancing their electrochemical performance through improved structural and interfacial design.

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