摘要
The shuttle effect of lithium polysulfides and the uncontrollable deposition of lithium sulfides(Li_(2)S)severely hinder the realization of high-performance lithium-sulfur(Li-S)batteries.Herein,we fabricated a carbon cloth(CC)-based self-supported interlayer(denoted as Co_(4)S_(3)/C@CC),which is covered with Co_(4)S_(3)-embedded porous carbon nanoarrays through a facile two-step method with cobalt-based metal-organic framework(Co-MOF)nanosheets as the template.The interconnected carbon network and the polar Co_(4)S_(3) nanoparticles in the Co_(4)S_(3)/C@CC interlayer not only effectively suppress the polysulfide shuttle,but also significantly facilitate the lithium ion(Li^(+))conduction with a considerable Li^(+)transference number of 0.86.Besides,the rich interfaces between the polar Co_(4)S_(3) nanoparticles and the conductive carbon substrate serve as reaction sites to accelerate the polysulfide conversion and guide the flower-like growth of Li_(2)S,which ultimately mitigates the interlayer surface passivation and improves the sulfur utilization.Therefore,the Li-S batteries with the Co_(4)S_(3)/C@CC interlayer deliver an excellent rate capacity(368.7 mA h g^(−1) at 10 C),a stable cycling performance(a low fading rate of 0.045%per cycle over 1400 cycles at 2.0 C),and a high initial areal capacity(4.83 mA h cm^(−2) at 0.2 C under a sulfur loading of 4.6 mg cm^(−2)).This work provides a perspective on the self-supported catalytic interlayer for the selective Li^(+)conduction and Li_(2)S regulation toward high-performance Li-S batteries.
多硫化锂的飞梭效应与不可控硫化锂(Li_(2)S)的沉积现象严重阻碍了高性能锂硫电池的实现.在本研究中,我们制备了一种负载有Co_(4)S_(3)/C多孔纳米阵列的自支撑碳布(CC)基夹层(Co_(4)S_(3)/C@CC),其中Co_(4)S_(3)/C多孔纳米阵列是以钴基金属-有机框架(Co-MOF)纳米片为模板制备而成的.Co_(4)S_(3)/C@CC夹层中相互连接的碳网络和极性Co_(4)S_(3)纳米粒子不仅能有效地抑制多硫化物飞梭,而且能显著地促进锂离子(Li^(+))的传导,其Li^(+)迁移数高达0.86.此外,极性Co_(4)S_(3)纳米粒子与导电碳基底之间丰富的界面能够作为反应中心以加速多硫化物的转化与引导Li_(2)S的花状生长,最终减轻Li_(2)S对夹层表面的钝化以及提高硫的利用率.因此,载有Co_(4)S_(3)/C@CC夹层的锂硫电池可以提供出色的倍率容量(在10 C时比容量为368.7 mA h g^(−1))、稳定的循环性能(在2.0 C下1400周循环过程中衰减率为0.045%)以及高初始面容量(在0.2 C且硫含量为4.6 mg cm^(−2)时面容量达到4.83 mA h cm^(−2)).这项工作展现了自支撑催化夹层对高性能锂硫电池中选择性Li^(+)传导和Li_(2)S沉积的调控能力.
作者
Jianbin Liu
Yifan Song
Cunjian Lin
Qingshui Xie
Dong-Liang Peng
Rong-Jun Xie
刘剑斌;宋一凡;林存键;谢清水;彭栋梁;解荣军(College of Materials,Xiamen University,Xiamen,36005,China;Fujian Provincial Key Laboratory of Materials Genome,Xiamen University,Xiamen,361005,China;State Key Laboratory of Physical Chemistry of Solid Surfaces,Xiamen University,Xiamen,61005,China)
基金
financially supported by the National Natural Science Foundation of China(51871188,51931006)。
