Investigating the NH 4 + Preintercalation and Surface Coordination Effects on MnO 2 for Ammonium-Ion Supercapacitors

• Published in: Inorganic chemistry 2024-09, Vol.63 (38), p.17714-17726
• Main Authors: Xiao, Ting, Tang, Can, Lin, Hongxiang, Li, Xiuru, Mei, Yuting, Xu, Can, Gao, Lin, Jiang, Lihua, Xiang, Peng, Ni, Shibing, Xiao, Yequan, Tan, Xinyu
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.4c02554

Ion preintercalation is an effective method for fine-tuning the electrochemical characteristics of electrode materials, thereby enhancing the performance of aqueous ammonium-ion hybrid supercapacitors (A-HSCs). However, much of the current research on ion preintercalation lacks controllability, and the underlying mechanisms remain unclear. In this study, we employ a two-step electrochemical activation approach, involving galvanostatic charge-discharge and cyclic voltammetry, to modulate the preintercalation of NH in MnO . An in-depth analysis of the electrochemical activation mechanism is presented. This two-step electrochemical activation approach endows the final MnO /AC electrode with a high capacitance of 917.4 F g , approximately 2.4 times higher than that of original MnO . Furthermore, the MnO /AC electrode retains approximately 93.4% of its capacitance after 10 000 cycles at a current density of 25 mA cm . Additionally, aqueous A-HSC, comprising MnO /AC and P-MoO , achieves a maximum energy density of 87.6 Wh kg . This study offers novel insights into the controllable ion preintercalation approach via electrochemical activation.