Three-Dimensional Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene-Prussian Blue Hybrid Microsupercapacitors by Water Lift-Off Lithography.

Lei, Yongjiu; Zhao, Wenli; Zhu, Yunpei; Buttner, Ulrich; Dong, Xiaochen; Alshareef, Husam N · ACS Nano · 2022

basic_science · Level V

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Abstract

The construction of electrochemical energy-storage devices by scalable thin-film microfabrication methods with high energy and power density is urgently needed for many emerging applications. Herein, we demonstrate an in-plane hybrid microsupercapacitor with a high areal energy density by employing a battery-type CuFe-Prussian blue analogue (CuFe-PBA) as the positive electrode and pseudocapacitive titanium carbide MXene (Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub>) as the negative electrode. A three-dimensional lignin-derived laser-induced graphene electrode was prepared as the substrate by laser exposure combined with an environmentally friendly water lift-off lithography. The designed hybrid device achieved enhanced electrochemical performance thanks to the ideal match of the two types of high-rate performance materials in proton-based electrolytes and the numerous electrochemically active sites. In particular, the device delivers a high areal capacitance of 198 mF cm<sup>-2</sup>, a wide potential window (1.6 V), an ultrahigh rate performance (75.8 mF cm<sup>-2</sup> retained even at a practical/high current density of 100 mA cm<sup>-2</sup>), and a competitive energy density of 70.5 and 27.6 μWh cm<sup>-2</sup> at the power densities 0.74 and 52 mW cm<sup>-2</sup>, respectively. These results show that the Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub>/CuFe-PBA hybrid microsupercapacitors are promising energy storage devices in miniaturized portable and wireless applications.