Mesoporous carbon matrix confinement synthesis of ultrasmall WO3 nanocrystals for lithium ion batteries

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2018, Vol.6 (43), p.21550-21557
• Main Authors: Wang, Changyao, Zhao, Yujuan, Zhou, Lili, Liu, Yang, Zhang, Wei, Zhao, Zaiwang, Hozzein, Wael N, Alharbi, Hind M S, Li, Wei, Zhao, Dongyuan
• Format: Article
• Language: English
• Subjects: Anodes; Carbon; Chemical synthesis; Confinement; Crystals; Electrode materials; Evaporation; Lithium; Lithium-ion batteries; Nanocomposites; Nanocrystals; Oxides; Phenolic compounds; Phenolic resins; Phenols; Pore size; Porosity; Pyrolysis; Rechargeable batteries; Resins; Self-assembly; Specific capacity; Strategy; Transition metal oxides; Transition metals; Tungsten oxides
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c8ta07145d

Transition metal oxides (TMOs)/carbon nanocomposites are promising for high capacity long life lithium ion batteries (LIBs). Herein, we report a mesoporous carbon matrix confinement growth strategy to synthesize ultrasmall WO3 nanocrystals for lithium storage. In this strategy, WCl6 and phenolic resins (resol) are co-assembled with amphiphilic diblock copolymer PEO-b-PS into ordered mesostructures through an evaporation induced self-assembly (EISA) process. During the pyrolysis process, the resol molecules can be polymerized and carbonized into amorphous mesoporous carbon matrices, which lock the amorphous W species well. Then, WO3 nanocrystals are formed and are uniformly distributed in the ordered mesoporous carbon matrix with the increased pyrolysis temperature; moreover, the particle size is well controlled to ∼3 nm under the confinement effect of the carbon matrices. The resultant ordered mesoporous carbon/WO3 composites show very large pore size (∼11.3 nm), high surface area (∼157 m2 g−1), high pore volume (∼0.25 cm3 g−1), and WO3 content of 84%. As an anode material for LIBs, the obtained composites show excellent cycling stability and rate performance. A high specific capacity of 440 mA h g−1 can be achieved after 100 cycles at a current density of 0.1 A g−1. We believe that such a confinement synthesis strategy is versatile to create TMO-based nanocomposites for outstanding LIBs.