期刊
ADVANCED ENERGY MATERIALS
卷 9, 期 9, 页码 -出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/aenm.201803478
关键词
bridge-bond; covalent sulfur-carbon; electrochemistry; Na-S batteries
类别
资金
- National Key Research and Development Program of China [2018YFB0104200]
Room temperature sodium-sulfur batteries have emerged as promising candidate for application in energy storage. However, the electrodes are usually obtained through infusing elemental sulfur into various carbon sources, and the precipitation of insoluble and irreversible sulfide species on the surface of carbon and sodium readily leads to continuous capacity degradation. Here, a novel strategy is demonstrated to prepare a covalent sulfur-carbon complex (SC-BDSA) with high covalent-sulfur concentration (40.1%) that relies on -SO3H (Benzenedisulfonic acid, BDSA) and SO42- as the sulfur source rather than elemental sulfur. Most of the sulfur is exists in the form of O-S/C-S bridge-bonds (short/long-chain) whose features ensure sufficient interfacial contact and maintain high ionic/ electronic conductivities of the sulfur-carbon cathode. Meanwhile, the carbon mesopores resulting from the thermal-treated salt bath can confine a certain amount of sulfur and localize the diffluent polysulfides. Furthermore, the C-S-x-C bridges can be electrochemically broken at lower potential (<0.6 V vs Na/Na+) and then function as a capacity sponsor. And the R-SO units can anchor the initially generated S-x(2-) to form insoluble surface-bound intermediates. Thus SC-BDSA exhibits a specific capacity of 696 mAh g(-1) at 2500 mA g(-1) and excellent cycling stability for 1000 cycles with 0.035% capacity decay per cycle.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据