Chen Renpeng, Xue Xiaolan, Lu Jingyu, Chen Tao, Hu Yi, Ma Lianbo, Zhu Guoyin, Jin Zhong
Key Laboratory of Mesoscopic Chemistry of MOE, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Nanoscale. 2019 May 9;11(18):8803-8811. doi: 10.1039/c9nr00159j.
Antimony (Sb) based anodes with high conductivity and capability have shown great promise for applications in lithium ion batteries (LIBs). However, they often suffer from poor cycling stability because of the drastic volume variation and structural degradation on undergoing lithiation-delithiation processes. Here we demonstrate a novel Sb-based anode with a free-standing structure realized by uniformly implanting intermetallic compound breithauptite (nickel antimonide, NiSb) nanocrystals into nitrogen-doped carbon nanofibers (NiSb@NCNFs). The discharge/charge behavior of NiSb@NCNFs was systematically investigated by ex situ characterization, which revealed a special "dealloying-lithiation/delithiation-realloying" cycling mechanism. The NiSb nanocrystals possess high lithium storage capacity, and the interconnected network of NCNFs can accommodate the volume variation of encapsulated NiSb nanoparticles, while also providing smooth pathways for charge transport. Compared to other Sb-based anodes, the NiSb@NCNF anode presents exceptional reversible capacity (720 mA h g-1 at a current density of 100 mA g-1) and greatly enhanced cycling life at high rates (510 mA h g-1 after 2000 cycles at 2000 mA g-1). Furthermore, the free-standing NiSb@NCNF anode is free of binders, conductive additives and metal current collectors, exhibiting high flexibility and remarkable performances for the construction of flexible and bendable soft-packed full Li-ion pouch cells.
具有高导电性和性能的锑基阳极在锂离子电池（LIBs）应用中显示出巨大潜力。然而，由于在锂化-脱锂过程中体积剧烈变化和结构退化，它们往往循环稳定性较差。在此，我们展示了一种新型的具有自立结构的锑基阳极，通过将金属间化合物辉锑镍矿（镍锑化物，NiSb）纳米晶体均匀植入氮掺杂碳纳米纤维（NiSb@NCNFs）中来实现。通过非原位表征系统研究了NiSb@NCNFs的充放电行为，揭示了一种特殊的“脱合金化-锂化/脱锂-再合金化”循环机制。NiSb纳米晶体具有高储锂容量，NCNFs的互连网络可以适应封装的NiSb纳米颗粒的体积变化，同时也为电荷传输提供了顺畅的途径。与其他锑基阳极相比，NiSb@NCNF阳极具有出色的可逆容量（在100 mA g-1电流密度下为720 mA h g-1），并且在高倍率下循环寿命大大提高（在2000 mA g-1下经过2000次循环后为510 mA h g-1）。此外，自立式NiSb@NCNF阳极不含粘结剂、导电添加剂和金属集流体，在构建柔性可弯曲软包全锂离子软包电池方面表现出高柔韧性和卓越性能。
