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CSCD
Recent researches in the development of in-plane micro-supercapacitor (MSC) have been dedicated to advancing its energy density in a finite storage area. However, the low ion-accessible surface area of plane electrode material has been the bottleneck limiting the energy output of MSC. Herein, we design a stable ionic liquid (IL)-MXene microemulsion system in virtue of tween-20 (TW20), gathering IL-TW20 microdroplets around MXene nanosheets. The microemulsion can adhere on the current collector and form the dense MXene-TW20-IL film. The IL as spacer and electrolyte is retained in the interlamination of MXene with the elimination of the TW20 during heat treatment, which enlarges the ion-accessible surface area of the MXene electrode. Thus, the MSC based on the flexible MXene-IL film exhibits a high areal capacitance (44.6 mF·cm−2), a high areal and volumetric energy density (50.7 μW·h·cm−2 and 39 mW·h·cm−3), surpassing most of the reported MXene-based MSCs. And the MSC unit can be arbitrarily integrated in terms of various energy and voltage requirements. For instance, the integrated array with thirty MSC units in series realizes a high voltage output of 90 V, widening the range of application in next-generation microelectronic devices.
We acknowledge the financial support from the National Natural Science Foundation of China (Nos. 22005168 and 21878063), the Taishan Scholars Program of Shandong Province (No. tsqn201909119), the Natural Science Foundation of Shandong Province (No. ZR2020QB118), the Key Program of Natural Science Foundation of Shandong Province (No. ZR2020KB011), and the Talent Foundation funded by Province and Ministry Co-construction Collaborative Innovation Center of Eco-chemical Engineering (No. STHGYX2219).