Polymer Electrolyte Based Flexible Micro-Supercapacitors for Future Aerospace and Smart e-Textile Applications

Kurzfassung

Abstract Introduction Advancements of ultra-thin, lightweight microelectronics, portable/wearable technologies and next-generation energy-autonomous systems have significantly increased the development for high-power energy storage systems [1]. Similarly, future aerospace and aviation systems are looking for clean and decentralized power supplies for various quality, safety, low cost and system monitoring requirements. Among various energy storage systems, electrochemical energy storage (EES) devices such as batteries and supercapacitors are being widely used in various sectors. However, in most cases, the battery cannot meet the requirements due to its high charging time, low power density, safety concern and limited cycle life [2]. In last few years, micro-supercapacitors (MSCs) have attracted considerable attention to be applied as flexible on-chip and microscale devices for peak power energy storage due to several excellent advantages such as fast charge–discharge rate, light weight, high power density and long cycle-life. On the other hand, solid/gel polymer electrolytes, as an important component of a supercapacitors play a promising role for electrochemical performance. This research work reports the fabrication and test results of MSC devices with CO2-laser-induced interdigital graphene electrodes (LIG) based MSCs and polymer gel electrolyte (PGE) that are developed by polypropylene carbonate (PPC) and polycarbonates (PC) embedded ionic liquid of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][TFSI]. This novel [EMIM][TFSI]/PPC/PC polymer electrolyte integrated MSC shows excellent energy storage performance delivering high capacitance of 0.91 mF/cm2 at 0.01 mA/cm2 with over 90% capacitance retention after 20000 cycles in a voltage 1.6 V. Moreover, our research results obtained with this novel interdigital graphene electrode based MSC show better performance comparing to the recent reported work of Xu Z. et al. [3]. Thus, this research work aims to emphasize the use of CO2-laser-induced graphene (LIG)- electrodes based flexible and scalable micro-supercapacitors for future application where flexibility must meet robustness. Results and discussion In this context, several optimizations have been done to achieve the best quality interdigital graphene electrodes (Fig. 1a) by CO2-laser structuring of polyimide-based Kapton ® HN foils. This synthesis process is cost effective, highly efficient, rapid and scalable which can also improve the thermal and electrical conductivity of the graphene electrodes. Various material characterizations such as structural, morphological and compositional studies have been performed using SEM, XRD and EDX analysis. The porous structure of graphene electrodes significantly enhances the electrochemical charge storage performance by improving the infiltration of electrolyte ions through the pores and providing short charge transfer paths. Details electrochemical studies by means of cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), electrochemical impedance spectroscopy (EIS) and cyclic charge-discharge (CCD) demonstrated excellent EDLC-type supercapacitive performance compared to reported laser-induced graphene and gel polymer electrolytes based MSC. Polymer electrolytes containing different ionic liquids integrated are tested applying different voltage windows and the [EMIM][TFSI]/PPC/PC polymer electrolyte integrated MSC shows excellent cyclic performance over 20000 cycles @100 µA (Fig. 1b). Overall electrochemical studies demonstrate that this leakage free, interfacial compatible, high flexibile and nonflammable novel polymer electrolyte integrated solid-state micro-flexible supercapacitors can be easily coupled to various energy harvester such as triboelectric nanogenerators (TENGs) via innovative power management circuits, acting as energy reservoirs to provide on-demand batteryless charging to wearable devices and sensors for future maintenance-free aerospace and smart e-textiles applications. All-in-one, self-charging smart e-textiles with integrated electronic systems can provide a human-body-centric technology and interface of the user to the IoT by wireless transmission of sensors’ signals [4]. Conclusion These studies highlight that this one step, cost effective and rapid CO2-laser structuring synthesis process is superior for large scale conductive graphene production. Combination of the LIG interdigital electrodes with the [EMIM][TFSI]/PPC/PC polymer electrolyte to yield MSCs shows excellent supercapacitive performance. Further research under the GRAPHERGIA project will enable the integration of the MSCs with polymer electrolytes onto e-textile, nano-/micro satellites and turbine components. It is expected that this development of efficient materials and device architectures for structural energy storage devices will become imperative to meet the needs of new emerging markets. Acknowledgement The authors would like to thank GRAPHERGIA, supported by the European Union’s Horizon Europe research and innovation programme under grant agreement No. 101120832, for financial support for conducting this research. References Tawiah et al. Journal of Power Sources 595 (2024) 234069. Saruhan and A. Ray Materials Research Bulletin 180 (2024) 113052. Xu et al. Journal of Energy Storage 105 (2025) 114797. GRAPHERGIA – Powering the Future with Graphene