(558az) Formulation of Complex Ionic-Liquids Electrolytes for High-Voltage Nanohybrid Supercapacitors

Supercapacitors are being considered as the most promising energy storage devices for the efficient utilization of clean and renewable energy due to their high power density and ultralong cycle life. However, their broad applications are still being hindered by the lower energy density. Recent studies indicate that the energy density can be elevated by combining ionic liquids (ILs) and pseudocapacitive materials ^[1]. Nevertheless, there are some challenges awaiting for solution when combining pseudocapacitive materials and ILs. Adding organic solvents to ILs, functionalizing ILs with specific moieties, and modifying electrodes with nanocarbons are some effective strategies to overcome the above limitations.Our recent works indicate that some pseudocapacitive electrodes modified with carbon materials, including NiO/rGO, TiO₂(B)@C/rGO, and T-Nb₂O₅/rGO, would exhibit enhanced performances when using ionogel electrolytes. Here we are going to present our findings related to the materials design principles and energy storage mechanisms ^[2-4]. The systematic modulation and optimization of the porous microstructures, nanocarbons, and combination types are critical for boosting the specific capacitance and rate capability. In addition, the formulation of lithium salts and ionic liquids play important role for the complete utilization of Faradaic and non-Faradaic contributions.

References

1. Eléonore Mourad, Laura Coustan, Pierre Lannelongue, Dodzi Zigah, Ahmad Mehdi, André Vioux, Stefan A, Freunberger, Frédéric Favier, Olivier Fontaine. Biredox ionic liquids with solid-like redox density in the liquid state for high-energy supercapacitors. Nature Materials., 2017, 16: 446-453.
2. Ao Liu, Haitao Zhang, Jiahe Zhang, Suojiang Zhang. Sandwich-like NiO/rGO nanoarchitectures for 4 V solid-state asymmetric-supercapacitors with high energy density. Electrochimica Acta, 2018, 283: 1401-1410.
3. Yuzhi Jiao, Haitao Zhang, Hailang Zhang, Ao Liu, Yanxia Liu, Suojiang Zhang. Highly-bonded T-Nb₂O₅/rGO Nanohybrids for 4 V Quasi-solid State Asymmetric Supercapacitors with Improved Electrochemical Performance. Nano Research, 2018, 11: 4673-4685.
4. Yongfeng Zhao, Haitao Zhang, Ao Liu, Yuzhi Jiao, Jae-Jin Shim, Suojiang Zhang. Fabrication of nanoarchitectured TiO₂(B)@C/rGO electrode for 4 V quasi-solid-state nanohybrid supercapacitors. Electrochimica Acta, 2017, 258: 343-352.