School of Chemical Science and Engineering, Tongji University, Shanghai, 200092, China.
Research Center for Translational Medicine and Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, No. 150 Jimo Road, Shanghai, 200120, P. R. China.
Adv Mater. 2017 Sep;29(34). doi: 10.1002/adma.201701494. Epub 2017 Jun 21.
The realization of antipulverization electrode structures, especially using low-carbon-content anode materials, is crucial for developing high-energy and long-life lithium-ion batteries (LIBs); however, this technology remains challenging. This study shows that SnO triple-shelled hollow superstructures (TSHSs) with a low carbon content (4.83%) constructed by layer-by-layer assembly of various nanostructure units can withstand a huge volume expansion of ≈231.8% and deliver a high reversible capacity of 1099 mAh g even after 1450 cycles. These values represent the best comprehensive performance in SnO -based anodes to date. Mechanics simulations and in situ transmission electron microscopy suggest that the TSHSs enable a self-synergistic structure-preservation behavior upon lithiation/delithiation, protecting the superstructures from collapse and guaranteeing the electrode structural integrity during long-term cycling. Specifically, the outer shells during lithiation processes are fully lithiated, preventing the overlithiation and the collapse of the inner shells; in turn, in delithiation processes, the underlithiated inner shells work as robust cores to support the huge volume contraction of the outer shells; meanwhile, the middle shells with abundant pores offer sufficient space to accommodate the volume change from the outer shell during both lithiation and delithiation. This study opens a new avenue in the development of high-performance LIBs for practical energy applications.
实现抗粉碎电极结构,特别是使用低碳含量的阳极材料,对于开发高能量和长寿命的锂离子电池(LIBs)至关重要;然而,这项技术仍然具有挑战性。本研究表明,通过逐层组装各种纳米结构单元构建的具有低碳含量(4.83%)的 SnO 三层壳空心超结构(TSHS)可以承受 ≈231.8%的巨大体积膨胀,并在 1450 次循环后提供高达 1099 mAh g 的高可逆容量。这些值代表了迄今为止基于 SnO 的阳极的最佳综合性能。力学模拟和原位透射电子显微镜表明,TSHS 在锂化/脱锂过程中实现了自协同结构保持行为,防止超结构崩溃并保证电极结构完整性在长期循环过程中。具体来说,在锂化过程中外壳完全锂化,防止了内部壳层的过度锂化和崩溃;相反,在脱锂过程中,富含孔的内部壳层作为坚固的核,支撑外壳的巨大体积收缩;同时,中层壳具有足够的空间来容纳外壳在锂化和脱锂过程中的体积变化。这项研究为实际能源应用中高性能 LIBs 的开发开辟了新途径。