In-Situ Annealed Ti3C2Tx MXene Based All-Solid-State Flexible Zn-Ion Hybrid Micro Supercapacitor Array with Enhanced Stability

Abstract

Zn-ion hybrid supercapacitors (SCs) are considered as promising energy storage owing to their high energy density compared to traditional SCs. How to realize the miniaturization, patterning, and flexibility of the Zn-ion SCs without affecting the electrochemical performances has special meanings for expanding their applications in wearable integrated electronics. Ti3C2Tx cathode with outstanding conductivity, unique lamellar structure and good mechanical flexibility has been demonstrated tremendous potential in the design of Zn-ion SCs, but achieving long cycling stability and high rate stability is still big challenges. Here, we proposed a facile laser writing approach to fabricate patterned Ti3C2Tx-based Zn-ion micro-supercapacitors (MSCs), followed by the in-situ anneal treatment of the assembled MSCs to improve the long-term stability, which exhibits 80% of the capacitance retention even after 50,000 charge/discharge cycles and superior rate stability. The influence of the cathode thickness on the electrochemical performance of the MSCs is also studied. When the thickness reaches 0.851 µm the maximum areal capacitance of 72.02 mF cm−2 at scan rate of 10 mV s−1, which is 1.77 times higher than that with a thickness of 0.329 µm (35.6 mF cm−2). Moreover, the fabricated Ti3C2Tx based Zn-ion MSCs have excellent flexibility, a digital timer can be driven by the single device even under bending state, a flexible LED displayer of “TiC” logo also can be easily lighted by the MSC arrays under twisting, crimping, and winding conditions, demonstrating the scalable fabrication and application of the fabricated MSCs in portable electronics.

Progress and Perspectives in Designing Flexible Microsupercapacitors

“…In situ treatment is also an effective method for improving the electrochemical performance of the electrode materials [90][91][92][93][94]. Our group reported an in situ annealed flexible Ti 3 C 2 T x cathode based Zn-ion hybrid MSCs with enhanced rate and cycle stability [62]. After annealed treatment, the assembled flexible Zn-ion hybrid MSCs exhibit the maximum areal capacitance of 72.02 mF/cm 2 (662.53 F/cm 3 ) at a scan rate of 10 mV/s and provide a power density of 0.50 mW/cm 2 at an area energy density of 0.02 mWh/cm 2 .…”

“…The laser direct writing method has demonstrated the universal adaptability, facility, and variable-area patterns with high-resolution, which have no requirement for the solvents, the utilization of binder, additives, and the adjustment of the viscosity, surface tension, and wettability of the materials to be processed [100][101][102][103][104]. Our group reported on a Ti 3 C 2 T x MXene based Zn-ion hybrid MSCs employing the laser direct writing approach [62]. Figure 8a displays the laser scribing process of the Ti 3 C 2 T x MXene based Zn-ion hybrid MSCs on the flexible substrate.…”

“…In this review, we systematically summarize the recent efforts to promote the development of the flexible on-chip MSC and its applications in smart, integrated, and wearable electronics. Targeting the aforementioned problems of the electrochemical performance improvements for a certain electrode material via structural design, we proposed three solutions that contain composites synthesis, 3D architecture build, and in situ modification materials, as shown in Figure 1 [56][57][58][59][60][61][62][63][64][65][66]. In each solution, detailed examples are given to discuss the mechanism of the electro-chemical performance enhancements.…”

“…At the end of this review, the challenges and future perspectives are proposed for high-performance on-chip MSC and the smart integrated system. [59]; Screen printing-the figure has been reproduced with permission from The Royal Society of Chemistry [60]; Cut, Mechanical scribing-the figure has been reproduced with permission from Wiley [61]; Laser scribing-the figure has been reproduced with permission from Springer Nature [62]; Print, Ink printing-the figure has been reproduced with permission from Springer Nature [63] and Wiley [64]; Integration and application: Self-charged MSC-the figure has been reproduced with permission from Wiley [65]; Integrated system-the figure has been reproduced with permission from Wiley [66]. [56]; 3D architecture-the figure has been reproduced with permission from Wiley [57]; In situ treatment-the figure has been reproduced with permission from Springer Nature [58]; Device fabrication technology: Mask, Photolithography-the figure has been reproduced with permission from The Royal Society of Chemistry [59]; Screen printing-the figure has been reproduced with permission from The Royal Society of Chemistry [60]; Cut, Mechanical scribing-the figure has been reproduced with permission from Wiley [61]; Laser scribing-the figure has been reproduced with permission from Springer Nature [62]; Print, Ink printing-the figure has been reproduced with permission from Springer Nature [63] and Wiley [64]; Integration and application: Self-charged MSC-the figure has been reproduced with permission from Wiley [65]; Integrated system-the figure has been reproduced with permission from Wiley [66].…”

“…An overview of the flexible on-chip MSCs and their application in smart integrated system. Electrode materials design: Composites-the figure has been reproduced with permission from Springer Nature [56]; 3D architecture-the figure has been reproduced with permission from Wiley [57]; In situ treatment-the figure has been reproduced with permission from Springer Nature [58]; Device fabrication technology: Mask, Photolithography-the figure has been reproducedwith permission from The Royal Society of Chemistry[59]; Screen printing-the figure has been reproduced with permission from The Royal Society of Chemistry[60]; Cut, Mechanical scribing-the figure has been reproduced with permission from Wiley[61]; Laser scribing-the figure has been reproduced with permission from Springer Nature[62]; Print, Ink printing-the figure has been reproduced with permission from Springer Nature[63] and Wiley[64]; Integration and application: Self-charged MSC-the figure has been reproduced with permission from Wiley[65]; Integrated system-the figure has been reproduced with permission from Wiley[66].…”