Potassium鈥揝ulfur Batteries: A New Member of Room-Temperature Rechargeable Metal鈥揝ulfur Batteries

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• 作者：Qing Zhao ; Yuxiang Hu ; Kai Zhang ; Jun Chen
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：September 2, 2014
• 年：2014
• 卷：53
• 期：17
• 页码：9000-9005
• 全文大小：444K
• ISSN：1520-510X

文摘

We report room-temperature rechargeable potassium鈥搒ulfur (K-S) batteries using ordered mesoporous carbon (CMK-3)/sulfur and polyanilime (PANI) coated CMK-3/sulfur composites as the cathode and metallic potassium as the anode. The electrochemical reaction mechanism was investigated by electrochemical tests, TEM, XRD, and Raman spectra. It was found that K-S batteries delivered two reduction peaks located at about 2.1 and 1.8 V and one oxidation peak at about 2.2 V, respectively. Meanwhile, K₂S₃ was the major discharge product that could be charged to reversibly form S and K ion. Through optimization of sulfur content, the CMK-3/sulfur composite with 40.8 wt % S displayed an initial discharge capacity of 512.7 mAh g^鈥? and a capacity of 202.3 mAh g^鈥? after 50 cycles at a current density of 50 mA g^鈥?. A coating of conductive polyanilime (PANI) on the CMK-3/sulfur composite is effective in enhancing the cycling performance. In comparison, PANI@CMK-3/sulfur composite showed a capacity of 329.3 mAh g^鈥? after 50 cycles at 50 mA g^鈥?. The results shed light on the basic study of rechargeable K-S batteries.