Carbon Electrodes for K-Ion Batteries
Carbon Electrodes for K-Ion Batteries
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DOI：
10.1021/jacs.5b06809
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发表时间：
2015-09-16
影响因子：
15
通讯作者：
Ji, Xiulei
中科院分区：
文献类型：
--
作者：
Jian, Zelang;Luo, Wei;Ji, Xiulei
我们首次报道了在非水电解液中电化学钾在石墨中的插入，其可逆容量高达273mAh/g.外场X射线衍射研究证实，KC36、KC24和KC8在钾化后依次形成，而沉淀通过相变以相反的顺序恢复石墨.石墨具有中等的倍率性能和较快的容量衰退。为了提高碳钾阳极的性能，我们合成了一种非石墨化软碳，其循环性能和倍率性能明显优于石墨。这项工作可能会为可充电的K离子电池开辟一种新的范式。
We for the first time report electrochemical potassium insertion in graphite in a nonaqueous electrolyte, which can exhibit a high reversible capacity of 273 mAh/g. Ex situ XRD studies confirm that KC36, KC24, and KC8 sequentially form upon potassiation, whereas depot-assiation recovers graphite through phase transformations in an opposite sequence. Graphite shows moderate rate capability and relatively fast capacity fading. To improve the performance of carbon K-ion anodes, we synthesized a nongraphitic soft carbon that exhibits cyclability and rate capability much superior to that of graphite. This work may open up a new paradigm toward rechargeable K-ion batteries.