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NH4+ Deprotonation at Interfaces Induced Reversible H3O+/NH4+ Co-insertion/Extraction |
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| Authors: | Meng Huang Qiu He Junjun Wang Xiong Liu Fangyu Xiong Yu Liu Ruiting Guo Yan Zhao Jinlong Yang Liqiang Mai |
| Institution: | 1. Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060 China
College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070 China These authors contributed equally to this work.;2. College of Materials Science and Engineering, Sichuan University, Chengdu, 610065 China These authors contributed equally to this work.;3. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070 China;4. School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001 China;5. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070 China Department of Physics, City University of Hong Kong, Tat Chee Avenue, Kowloon, 999077 Hong Kong, China;6. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070 China Department of Materials Science and Engineering, National University of Singapore, Singapore, 117574 Singapore;7. College of Materials Science and Engineering, Sichuan University, Chengdu, 610065 China;8. Guangdong Research Center for Interfacial Engineering of Functional Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060 China |
| Abstract: | Ion insertions always involve electrode-electrolyte interface process, desolvation for instance, which determines the electrochemical kinetics. However, it′s still a challenge to achieve fast ion insertion and investigate ion transformation at interface. Herein, the interface deprotonation of NH4+ and the introduced dissociation of H2O molecules to provide sufficient H3O+ to insert into materials′ structure for fast energy storages are revealed. Lewis acidic ion-NH4+ can, on one hand provide H3O+ itself via deprotonation, and on the other hand hydrolyze with H2O molecules to produce H3O+. In situ attenuated total reflection-Fourier transform infrared ray method probed the interface accumulation and deprotonation of NH4+, and density functional theory calculations manifested that NH4+ tend to thermodynamically adsorb on the surface of monoclinic VO2, and deprotonate to provide H3O+. In addition, the inserted NH4+ has a positive effect for stabilizing the VO2(B) structure. Therefore, high specific capacity (>300 mAh g?1) and fast ionic insertion/extraction (<20 s) can be realized in VO2(B) anode. This interface derivation proposes a new path for designing proton ion insertion/extraction in mild electrolyte. |
| Keywords: | Electrode-Electrolyte Interface Energy Storage Mechanism Proton Insertion Vanadium Dioxide In Situ Characterization |