Highly reversible alloying/dealloying behavior of SnSb nanoparticles incorporated into N-rich porous carbon nanowires for ultra-stable Na storage
Highly reversible alloying/dealloying behavior of SnSb nanoparticles incorporated into N-rich porous carbon nanowires for ultra-stable Na storage
复制标题
将 SnSb 纳米粒子掺入富氮多孔碳纳米线中实现超稳定 Na 存储的高度可逆合金化/脱合金行为
DOI：
10.1016/j.ensm.2018.12.015
复制
发表时间：
2019-09-01
影响因子：
20.4
通讯作者：
Zhou, Zhen
中科院分区：
文献类型：
--
作者：
Gu, Haichen;Yang, Leping;Zhou, Zhen
合金型钠离子电池负极材料具有理论容量高、利用率高、不需要任何绝缘产品等优点。然而，缓慢的离子扩散动力学和严重的体积变化会导致不可修复的颗粒粉碎和再团聚，从而导致电极劣化。更严重的是，电化学反应过程中的不可逆相变对快速和长周期的Na+储存是有害的。本论文通过静电纺丝和连续煅烧的方法制备了超小尺寸的SnSb纳米晶与富氮多孔碳纳米线（SnSb/N-PCNWs）。富氮多孔碳纳米线不仅能均匀地分散SnSb颗粒，而且能优化SnSb颗粒的电学性质，为Na+吸附提供大量的边缘/缺陷，从而促进表面或近表面反应的超快赝电容行为。SnSb/N-PCNWs在2A g（-1）下具有180 mA h g（-1）的超长循环寿命，高达10，000次循环，容量保持率接近100%。独特的纳米结构使SnSb具有高度可逆的合金化/去合金化行为，即使在10，000次循环后也能保留明显的晶相，这保证了Na+存储的超长循环寿命。这些结果为实现实用钠离子电池的合金型负极材料提供了新的见解。
Alloying-type anode materials for sodium ion batteries have high theoretical capacity and efficient utilization without any insulating products. However, sluggish ion diffusion kinetics and severe volume changes induce irreparable particle pulverization and re-agglomeration, and accordingly electrode degradation. More seriously, irreversible phase transition during electrochemical reactions is harmful for fast and long-cycle Na+ storage. In this work, ultra-small SnSb nanocrystallites incorporated into N-rich porous carbon nanowires (SnSb/N-PCNWs) are prepared via electrospinning and sequential calcination. N-rich porous carbon nanowires not only disperse SnSb particles homogeneously in nanoscale, but also optimize the electronic properties and provide numerous edges/defects for Na+ adsorption, which would promote surface or near-surface reactions of ultrafast pseudocapacitance behaviors. SnSb/N-PCNWs sustain a ultralong cycle life of similar to 180 mA h g(-1) at 2 A g(-1) up to 10,000 robust cycles with superb capacity retention ratio of almost 100%. The distinctive nanostructure enables highly reversible alloying/dealloying behavior and conspicuous crystalline-phase reservation of SnSb even after 10,000 cycles, which guarantees the ultralong cycle life for Na+ storage. These results shed new insight to achieve alloying-type anode materials for practical sodium ion batteries.