Fabrication of flexible and highly performing graphene-based supercapacitors through spray coating process

Abstract

Energy storage devices serve as power banks for various electronic devices and can be utilized in all situations regardless of location and time. However, the existing power sources like conventional batteries have low output power, lack of portability, and hazardous explosives. In this respect, the researchers are actively focusing on flexible, wearable, cost-effective, safe, and eco-friendly energy storage devices with considerable features. In recent years, the supercapacitors, an electrochemical device stores electrical energy through electro chemical charge-discharge mechanism, have received great attention as suitable power storage devices. These supercapacitors possess high output power and long-life span since their functionalities depend on the physical adsorption-desorption of ions on the surface of electrodes. The usage of composites and tailoring of structural features prominently improving the performance of devices and thus, it is attracting more attention as a burning task. In order to increase the energy storage capacity of supercapacitors, the researchers have been adopted vari-ous methodologies and realized significant devices. However, the adopted methodologies so far not reached the expected goals due their limitations in terms of the complicated synTheses and structural improvements. Further, they also require expensive equipment or many processing steps. In this direction, we have developed efficient supercapacitors by designing a simple and cost-effective methodology. For this we have used a low-cost spray system and thermal evaporation technique. Using this scalable process, we are able to fabricate supercapacitors even on highly flexible surfaces. The supercapacitors developed on flexible substrates are tested to explore the mechanical impact on the charging and discharging performances. From this work, we are able to produce flexible, scalable supercapacitors with micro-level thickness. On the other hand, fabricated supercapacitors can be integrated with other electronic or biological devices due to their portability and compatibility along with low-temperature processability. Further, the outcomes of our work undoubtedly open new pathways in energy storage device technology and also provide solutions for various bottleneck problems in scientific technology. By taking all these points into account, we strongly believed that these flexible, high-performance supercapacitors can definitely contribute to the improvement of portability and wearability of sustainable devices in future industries.