Polyaniline/Small‐Sized MXene/Carbon Cloth Electrodes with 3D Hierarchical Porous Structure for All‐Solid‐State Flexible Supercapacitors

Abstract

The porous structure of electrodes can exert a significant impact on electrochemical performances of supercapacitors. Herein, the polyaniline/small‐sized MXene/carbon cloth (PANI/S‐MXene/CC) electrodes with 3D hierarchical porous structure are fabricated by a facile single‐step pulsed electrodeposition. First, the PANI/S‐MXene nanowires closely overlap each other and form a nanosized pore structure, which provides large specific surface area and abundant ion diffusion channels. Second, the CC with a large pore structure can facilitate permeation of gel electrolyte. S‐MXene with small lateral size not only decreases charge transfer resistance of electrodes, but also ensures an interconnected porous framework. Consequently, the assembled all‐solid‐state flexible device delivers a high areal capacitance (478.4 mF cm−2 at 0.5 mA cm−2), a superior rate capability (307.5 mF cm−2 at 10 mA cm−2), a remarkable energy density (42.5 μWh cm−2), favorable cycle stability (75.4% capacitance retention after 4000 cycles), as well as 93.2% capacitance retention after 180° mechanical bending with 1000 cycles. Herein, it is revealed that size selection of nanomaterials is a priority when the porous structure is designed.

Exploring the Potential of MBenes Supercapacitors: Fluorine-Free Synthesized MoAl1–xB with Ultrahigh Conductivity and Open Space

“…The high performance could be attributed to its good ion diffusion and ultralow resistance as shown in Figure c: the intercept on the horizontal axis and the semicircular arc at the high frequency is related to the solution resistance for the formation of electrode–electrolyte interaction ( R S ) and the charge transfer resistance ( R ct ), respectively, which are calculated to be equal to 0.0037 and 0.0023 Ω cm –2 based on the equivalent circuit fitting shown in the inset of Figure c. These results are much lower than those of MXene-based electrodes (3.0 and 6.5 Ω cm –2 for bimetallic-sulfide@layered Ti 3 C 2 Tx-MXene, 1.109 and 0.0075 Ω cm –2 for Ti 3 C 2 Tx@Al, and 0.392 and 0.164 Ω cm –2 for PANI/small-sized MXene). The complex model of capacitance was utilized to further confirm the impedance behavior (eqs S13 and S14).…”

Prestretching‐Enhanced Conductive Hydrogel Electrode for Supercapacitors with High Areal Capacitance and Excellent Stretching Stability

“…The equivalent series resistance (ESR) is available by the intercept of Nyquist plot on the x ‐axis. [ 34 ] The ESR of PPCH 5 (13.38 Ω)‐based supercapacitor was obviously lower than that of PCH (39.95 Ω). Meanwhile, compared with PCH‐based supercapacitor, the PPCH 5 ‐based supercapacitor showed a lower voltage drop (Figure 5e), also illustrating low internal resistance.…”