Direct Laser Etching Free‐Standing MXene‐MoS₂ Film for Highly Flexible Micro‐Supercapacitor

Abstract

Micro‐supercapacitors (MSCs) with excellent flexibility and high electrochemical performance are essential for portable and miniaturized electronics. In this paper, a laser etching technology with advantages of simple process, low cost, and high machining accuracy is used to directly etch the free‐standing MXene‐molybdenum disulfide (MoS2) film for MSC. As adding MoS2 in MXene effectively improves the electrochemical performance, such as a higher specific capacitance (about 60% higher than pure MXene). Eventually, the maximum specific capacitance of this MSC (based on the total volume of positive and negative electrodes) is 173.6 F cm−3 (1 mV s−1), and the maximum energy density and maximum power density are 15.5 mWh cm−3 and 0.97 W cm−3, respectively. In addition, the MSC also shows the excellent cycle stability and flexibility, e.g., after 6000 charge–discharge cycles and bending up to 150°, the capacitances of the MSC still retain about 98% and 89% of its initial capacitance, respectively. The laser‐etched MSC based on MXene‐MoS2 offers a new idea for future high‐performance micro energy storage devices.

Highly Flexible and Self‐Healable Zinc‐Ion Hybrid Supercapacitors Based on MWCNTs‐RGO Fibers

“…The slope of the EIS curve in the low‐frequency range represents the diffusion resistance of zinc‐ions in the electrolyte solution. [ 39,40 ] The larger slope means the smaller resistance. It can be seen that the MWCNTs‐RGO hybrid fiber (1:4) has the lowest ESR (4.5 Ω cm 2 ) and R ct (18.5 Ω cm 2 ), and also has the maximum slope of the EIS curve in the low‐frequency range.…”

Two-Dimensional MXene Based Materials for Micro-Supercapacitors

“…i.e., the fabricated device displays a high specific capacitance of 173.6 F/cm 3 at the scan rate of 1 mV/s, MSC shows around 98% of capacitance retention with 89% of coulombic efficiency even after 6000 cycles along with several bending angle of device upto 150 . The above study demonstrated huge potential of TMDs which can be introduced with MXenes to make high performing MSC devices [67]. Li et al demonstrated a strategy to mitigate the self-restacking of MXene layers by introducing RuO 2 nanoparticles by simple wet chemical phase reaction to improve the ion exchange rate.…”

Recent developments of advanced micro-supercapacitors: design, fabrication and applications

“…Similarly, Chen et al 114 introduced MoS 2 into MXene and assembled them into symmetrical MSCs. It should be pointed out that the adoption of MoS 2 could not only inhibit the restacking of MXene sheets but also contribute extra pseudocapacitance by virtue of its pseudocapacitive nature.…”