State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, P. R. China.
Institute for Superconducting and Electronic Materials, Australian Institute of Innovative Materials, University of Wollongong, Innovation Campus, Squires Way, North Wollongong, NSW, 2500, Australia.
Adv Mater. 2017 Dec;29(48). doi: 10.1002/adma.201700523. Epub 2017 Apr 4.
Smart surface coatings of silicon (Si) nanoparticles are shown to be good examples for dramatically improving the cyclability of lithium-ion batteries. Most coating materials, however, face significant challenges, including a low initial Coulombic efficiency, tedious processing, and safety assessment. In this study, a facile sol-gel strategy is demonstrated to synthesize commercial Si nanoparticles encapsulated by amorphous titanium oxide (TiO ), with core-shell structures, which show greatly superior electrochemical performance and high-safety lithium storage. The amorphous TiO shell (≈3 nm) shows elastic behavior during lithium discharging and charging processes, maintaining high structural integrity. Interestingly, it is found that the amorphous TiO shells offer superior buffering properties compared to crystalline TiO layers for unprecedented cycling stability. Moreover, accelerating rate calorimetry testing reveals that the TiO -encapsulated Si nanoparticles are safer than conventional carbon-coated Si-based anodes.
硅 (Si) 纳米粒子的智能表面涂层被证明是显著提高锂离子电池循环性能的良好范例。然而，大多数涂层材料面临着重大挑战，包括初始库仑效率低、繁琐的处理过程和安全评估。在这项研究中，展示了一种简便的溶胶-凝胶策略，用于合成由非晶态氧化钛 (TiO ) 封装的商业 Si 纳米粒子，具有核壳结构，表现出优异的电化学性能和高安全性的锂离子存储。非晶态 TiO 壳（≈3nm）在锂的放电和充电过程中表现出弹性行为，保持了高结构完整性。有趣的是，与晶态 TiO 层相比，发现非晶态 TiO 壳提供了卓越的缓冲性能，从而实现了前所未有的循环稳定性。此外，加速率量热测试表明，TiO 封装的 Si 纳米粒子比传统的碳涂层 Si 基阳极更安全。
