NH4+ Deprotonation at Interfaces Induced Reversible H3O+/NH4+Co-insertion/Extraction

作者：Huang, Meng; He, Qiu; Wang, Junjun; Liu, Xiong; Xiong, Fangyu; Liu, Yu; Guo, Ruiting; Zhao, Yan^*; Yang, Jinlong^*; Mai, Liqiang^*

来源：Angewandte Chemie - International Edition, 2023, 62(14): e202218922.

DOI：10.1002/anie.202218922

• Electrode-Electrolyte Interface
• Energy Storage Mechanism
• Proton Insertion
• Vanadium Dioxide
• In Situ Characterization

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 mAhg(-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.

• 单位
  y; 武汉理工大学; 武汉大学; 郑州大学; 四川大学