UNI-MB - logo
UMNIK - logo
 
E-viri
Celotno besedilo
Recenzirano
  • Intercalation of Metal Ions...
    Li, Shuo; Shi, Qi; Li, Yang; Yang, Jie; Chang, Ting‐Hsiang; Jiang, Jianwen; Chen, Po‐Yen

    Advanced functional materials, October 1, 2020, Letnik: 30, Številka: 40
    Journal Article

    Microsupercapacitors (MSCs) with neutral multivalent electrolytes are safer, cheaper, and exhibit higher theoretical energy densities compared with the MSCs with acidic and alkaline electrolytes. Multivalent charge carriers (e.g., Mg2+, Zn2+) in the MSCs with Ti3C2Tx MXene electrodes have not been demonstrated, which could theoretically achieve higher specific capacitances and energy densities. However, because of the larger size of multivalent charge carriers, the MXene electrodes require further modifications to facilitate reversible electrochemical reactions. Herein, through spontaneous intercalation of various metal ions into MXene multilayers, twelve metal ion intercalated MXene electrodes (Mn+‐MXene) are fabricated and demonstrate improved electrochemical performance. Different nanopillar effects are observed between divalent Be2+ and trivalent Al3+ intercalants, which are systematically investigated by electrochemical impedance spectroscopy and molecular dynamics simulation. Among all Mn+‐MXene electrodes, the Be2+‐MXene electrode largely facilitates the charge‐transfer process with minimal disturbance of electrolyte diffusion rates, showing improved specific capacitances and high rate performance in univalent (Li2SO4, Na2SO4, K2SO4) and multivalent electrolytes (BeSO4, MgSO4, ZnSO4). Finally, flexible Be2+‐MXene MSCs with neural ZnSO4 gel electrolytes are fabricated, demonstrating superior areal capacitances (77.2 mF cm−2) and high energy density (3.86 μWh cm−2 at 0.12 mW cm−2) together with high user safety. A facile metal‐ion intercalation technology is developed to enhance the electrochemical performance of Ti3C2Tx MXene in various neutral multivalent electrolytes. Twelve metal ions are intercalated into MXene electrodes. The Be2+‐intercalated MXene electrode facilitates the charge‐transfer process with minimal disturbance of electrolyte diffusion rates. Finally, Be2+‐MXene microsupercapacitors with neural ZnSO4 gel electrolytes demonstrate superior areal capacitances together with high user safety.