title: Constructing Novel Si@SnO2 Core-Shell Heterostructures by Facile Self-Assembly of SnO2 Nanowires on Silicon Hollow Nanospheres for Large, Reversible Lithium Storage.
abstract: Developing an industrially viable silicon anode, featured by the highest theoretical capacity (4200 mA h g(-1)) among common electrode materials, is still a huge challenge because of its large volume expansion during repeated lithiation-delithiation as well as low intrinsic conductivity. Here, we expect to address these inherent deficiencies simultaneously with an interesting hybridization design. A facile self-assembly approach is proposed to decorate silicon hollow nanospheres with SnO2 nanowires. The two building blocks, hand in hand, play a wonderful duet by bridging their appealing functionalities in a complementary way: (1) The silicon hollow nanospheres, in addition to the major role as a superior capacity contributor, also act as a host material (core) to partially accommodate the volume expansion, thus alleviating the capacity fading by providing abundant hollow interiors, void spaces, and surface areas. (2) The SnO2 nanowires serve as a conductive coating (shell) to enable efficient electron transport due to a relatively high conductivity, thereby improving the cyclability of silicon. Compared to other conductive dopants, the SnO2 nanowires with a high theoretical capacity (790 mA h g(-1)) can contribute outstanding electrochemical reaction kinetics, further adding value to the ultimate electrochemical performances. The resulting novel Si@SnO2 core-shell heterostructures exhibit remarkable synergy in large, reversible lithium storage, delivering a reversible capacity as high as 1869 mA h g(-1)@500 mA g(-1) after 100 charging-discharging cycles.
authors.affiliation: Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Zheng-Wei
authors.initials: ZW
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.|State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University , Beijing 100084, China.
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Liu
authors.affiliation: Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Xu-Ming
authors.initials: XM
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University , Beijing 100084, China.
authors.forename: Xiong-Ying
authors.initials: XY
authors.lastname: Ye
keywords: SnO2; core−shell heterostructures; lithium-ion batteries; self-assembly; silicon