Synthesis of ZIF-Derived CoS2 Nanocages Interconnected by CNTs for Rechargeable Li-O-2 Batteries
Synthesis of ZIF-Derived CoS2 Nanocages Interconnected by CNTs for Rechargeable Li-O-2 Batteries
复制标题
用于可充电 Li-O2 电池的由 CNT 互连的 ZIF 衍生 CoS2 纳米笼的合成
DOI：
10.1021/acssuschemeng.9b07714
复制
发表时间：
2020
影响因子：
8.4
通讯作者：
Ma Yanwen
中科院分区：
文献类型：
--
作者：
Lin Xiujing;Zhang Tingting;Chu Chengcheng;Li Zhuang;Liu Ruiqing;Li Pan;Li Yi;Huang Zhendong;Ma Yanwen
锂氧电池以其超高的理论能量密度和吸氧电极而受到广泛关注。合成高电导率、高循环稳定性的电极材料是锂氧电池的关键。本文制备了一种由ZIF-67衍生的CoS 2纳米笼和碳纳米管互连的杂化复合材料（CoS 2/CNTs），并将其用于Li-O2电池空气电极的制备。获得了2398.9mAh g-1的可逆容量，相当于放电容量的90%。当循环容量限制为500 mAh g-1时，电池循环稳定性为52次，截止电位保持在2.0 V以上。该材料的关键在于多孔CoS 2纳米笼的形成以及纳米笼与碳纳米管的插入，形成相互连接的导电网络。碳纳米管的掺入作为快速电子转移的通道，这克服了CoS 2的导电性差。此外，多孔CoS 2纳米笼可以为氧还原反应（ORR）和析氧反应（OER）提供丰富的活性位，有利于O2的扩散和电解质的渗透。高导电性碳纳米管和具有高效催化活性的CoS 2的结合提高了电池性能。
Lithium–oxygen (Li–O2) batteries, profiting by their super high theoretical energy density and oxygen-breathing electrodes, have attracted extensive concern. The synthesis of the electrode materials with high conductivity and promising cycling durability will be a critical aspect for Li–O2batteries. In this article, a hybrid composite of CoS2nanocages derived from ZIF-67 and interconnected by carbon nanotubes (CoS2/CNTs) is prepared and used in the air electrode fabrication for Li–O2batteries. A reversible capacity of 2398.9 mAh g–1is obtained, equivalent to 90% of the discharge capacity. When restricting the cycling capacity to 500 mAh g–1, the battery exhibits cycling stability for 52 cycles, with the cutoff potential keeping above 2.0 V. The key point of this material is the formation of porous CoS2nanocages and insertion of the nanocages with CNTs, forming interconnected electrically conducting networks. The incorporation of CNTs serves as channels for fast electron transfer, which overcomes the poor conductivity of CoS2. Furthermore, the porous CoS2nanocages could provide affluent active sites for an oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), which also facilitates the diffusion of O2and the infiltration of electrolytes. The combination of highly conductive CNTs and CoS2with efficient catalytic activity renders improvement in the battery performance.