High-capacity potassium ion storage mechanisms in a soft carbon revealed by solid-state NMR spectroscopy  

作　　者：Jing-Heng Han Jia He Qi-Yao Zou Jie Zhang Zhi Yang Zhi-Wei Zhao Hui-Xin Chen Hong-Jun Yue Da-Wei Wang Hai-Chen Lin Hao-Dong Liu Gui-Ming Zhong Zhang-Quan Peng 

机构地区：[1]College of Chemistry and Material Science,Fujian Normal University,Fuzhou,350000,China [2]CAS Key Laboratory of Design and Assembly of Functional Nanostructures,and Fujian Provincial Key Laboratory of Nanomaterials,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou,350002,China [3]Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials,Xiamen Institute of Rare-Earth Materials,Haixi Institutes,Chinese Academy of Sciences,Xiamen,361021,China [4]Laboratory of Advanced Spectro-Electrochemistry and Li-Ion Batteries,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian,116023,China [5]Key Laboratory of Automobile Materials of Ministry of Education&School of Materials Science and Engineering,Jilin University,Changchun,130025,China [6]Chemical Engineering,University of California San Diego,La Jolla,San Diego,CA,92093,USA

出　　处：《Rare Metals》2022年第11期3752-3761,共10页稀有金属（英文版）

基　　金：financially supported by the National Nature Science Foundation of China (Nos.21905314, 21825202,21733012,92045302 and 21603231);Newton Advanced Fellowships (No.NAF/R2/180603);"Scientist Studio Funding" from Tianmu Lake Institute of Advanced Energy Storage Technologies Co.,Ltd;the Science and Technology Service Network Initiative from Chinese Academy of Science (No.STS 2020T3022)。

摘　　要：Carbon materials are crucially important for the realization of potassium-ion batteries.However,the potassium storage mechanisms in various carbon materials are incompletely understood.Herein,solid-state ^(13)C nuclear magnetic resonance(NMR) spectroscopy coupled with Raman and X-ray diffraction(XRD) techniques are employed to study the reaction mechanism in a soft carbon quantitatively.It is revealed that the insertion of potassium ions into the soft carbon firstly induces a transformation of the disordered region to short-range ordered stacking,involving both the pristine local unorganized and organized carbon layers.Subsequently,potassium ions intercalate into the rearranged carbon structure,finally producing the nano-sized KC_(8).Moreover,a remarkable c apacity of 322 mAh·g^(-1) with a low mid potassiation voltage of <0.3 V is present for the prepared soft carbon,which is on account of the underlying potassium storage sites,including the disordered stacking carbon as a main component of the soft carbon.These results suggest that regulating the disordered stacking region in the turbostratic structure of soft carbon is a critical issue for further improving the potassium storage performance.

关 键 词：Reaction mechanism Soft carbon Solid-state nuclear magnetic resonance(NMR) Anode Potassium-ion batteries(PIBs) 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ127.11[化学工程—无机化工]