C@TiO2/MoO3 Composite Nanofibers with 1T‐Phase MoS2 Nanograin Dopant and Stabilized Interfaces as Anodes for Li‐ and Na‐Ion Batteries

• Published in: ChemSusChem 2018-12, Vol.11 (23), p.4060-4070
• Main Authors: Zhou, Huimin, Xia, Xin, Lv, Pengfei, Zhang, Jin, Hou, Xuebin, Zhao, Min, Ao, Kelong, Wang, Di, Lu, Keyu, Qiao, Hui, Zimniewska, Malgorzata, Wei, Qufu
• Format: Article
• Language: English
• Subjects: Backbone; batteries; Carbon; Carbonization; electrochemistry; Electron transport; lithium; Lithium-ion batteries; Molybdenum disulfide; Molybdenum oxides; Molybdenum trioxide; Nanocomposites; Nanofibers; nanostructures; Organic chemistry; Polyvinylpyrrolidone; Prepolymers; Sodium; Sodium-ion batteries; Sulfidation; Titanium dioxide
• ISSN: 1864-5631; 1864-564X
• DOI: 10.1002/cssc.201801784

Integrating layered nanostructured MoS2 with a structurally stable TiO2 backbone to construct reciprocal MoS2/TiO2‐based nanocomposites is an effective strategy. C@TiO2/MoO3 composite nanofibers doped with 1T‐phase MoS2 nanograins were fabricated by partially sulfurizing MoOx/TiO2 precursors. By controlling a suitable preoxidation temperature before severe thermolysis of polyvinylpyrrolidone (PVP), the MoOx/TiO2 precursors formed a polymer‐embedded array through coordination of the Mo source and pyrrolidyl groups of PVP. Sulfidation under water/solvent hydrothermal conditions led to partial formation of metallic 1T‐phase MoS2 from the MoOx precursor with preoxidation at 200 °C. After carbonization, the TiO2/MoO3/MoS2 nanograins were encapsulated in a carbon backbone in a vertical pattern, providing both chemical contact for confined electron transport and sufficient space to adapt to volume changes. The obtained carbon‐based platform not only has the advantages of an integral structure, but also exhibited ultrastable specific capacities of 540 and 251 mAh g−1 for Li‐ion batteries and Na‐ion batteries, respectively, after 100 cycles. Better anode by design: A designed anode structure combining the metallic conductivity of 1T‐MoS2 with interconnected TiO2/MoO3 grains is beneficial for fast charge‐transfer reactions and reduced transmission losses. Moreover, a flexible carbon framework buffers swollen lithium compounds, such as LixMoO3 and LixMoS2, and supports the shrinking delithiated products, with potential for achieving high capacity stability in both Li‐ and Na‐ion batteries.