Electrolyte effect on electrochemical behaviors of manganese fluoride material for aqueous asymmetric and symmetric supercapacitors
Zheng‐Hua He, Jian‐Fei Gao, Ling‐Bin Kong
Abstract
Abstract Exploring wide voltage window materials is not only an available measure to enhance the energy density of hybrid supercapacitor (HSCs), but also avoids the dynamic mismatch caused by different energy storage mechanisms of two electrodes in assembled symmetrical HSC. However, there are few reports about the wide potential window materials except Bi 2 O 3 and VO 2 . Therefore, the MnF 2 synthesized by solvothermal reaction was served as the electrode for HSC. The MnF 2 exhibited electrochemical activity in alkaline solution in three‐electrode system, especially with a wide potential window from −0.8 to + 0.5 V in 2 mol·L −1 NaOH. Furthermore, the assembled MnF 2 //MnF 2 symmetrical HSC had a potential window of 1.5 V, and it exhibited outstanding long‐cycle capability. Meanwhile, when MnF 2 was taken as the negative and positive respectively, the potential windows of asymmetric devices CoMoO 4 //MnF 2 and MnF 2 //Activated Carbon (AC) could reach 1.3 and 1.45 V, respectively, showing excellent cycle stability. This work shows that MnF 2 material has great research value in HSC, and provides a new research direction for developing high‐performance devices.