Double-Network Nanostructured Hydrogel-Derived Ultrafine Sn-Fe Alloy in Three-Dimensional Carbon Framework for Enhanced Lithium Storage

作者：Shi, Hongxia; Fang, Zhiwei; Zhang, Xiao; Li, Feng; Tang, Yawen; Zhou, Yiming; Wu, Ping^*; Yu, Guihua^*

来源：Nano Letters, 2018, 18(5): 3193-3198.

DOI：10.1021/acs.nanolett.8b00898

• Tin anode
• ultrafine alloy
• carbon framework
• Li-ion battery
• double-network hydrogel

Tin-based alloys (Sn-M, M = Fe, Co, Ni, and Cu) have been considered as promising alternatives for graphite anode in advanced Li-ion batteries, but their practical application is hindered by huge volume change-induced poor cycle life. We propose here a facile inorganic-organic double-network nanostructured hydrogel-enabled methodology for uniformly immobilizing ultrafine Sn-M alloys in hierarchical carbon frameworks. The double-network nanostructured gel, consisting of three-dimensional (3D) intertwined cyano-bridged Sn(IV)-Fe(II) inorganic gel and chitosan-glutaraldehyde organic polymer gel, can realize 3D space confinement in molecular scale and thus obtain ultrafine Sn-Fe alloy particles (average size similar to 2.7 nm) uniformly embedded in hierarchical 1D to 3D carbon framework. These unique structural features enable the Sn-Fe@C framework electrodes to exhibit long cycle life (516 mA h g(-1) after 500 cycles at 0.1 A g(-1)) and high rate capability (491 and 270 mA h g(-1) at 1 and 10 A g(-1), respectively). This work provides new insight into controlled synthesis of ultrafine alloys in hierarchical 3D carbon frameworks for improving energy storage properties.

• 出版日期2018-5
• 单位南京师范大学