Pullulan-ionic liquid-based supercapacitor: A novel, smart combination of components for an easy-to-dispose device. (1st April 2020)

• Record Type: Journal Article
• Authors: Poli, Federico; Momodu, Damilola; Spina, Giovanni Emanuele; Terella, Antonio; Mutuma, Bridget. K.; Focarete, Maria Letizia; Manyala, Ncholu; Soavi, Francesca
• Is Part Of: Electrochimica acta. Volume 338(2020)
• Publication Date: 2020-04-01
• Subjects: Green supercapacitor -- Pullulan -- Electrospinning -- Ionic liquid -- Bio-char carbon; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2020.135872
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Strategies that simultaneously target energy/power performance, sustainable manufacturing processes, valorization of green raw materials, and easy recycling of supercapacitors are urgently needed. Today, efforts have to be devoted not only to improve system performance but also to address the sustainability of materials and devices manufacturing and recyclability. Specifically, pullulan is herein proposed as a novel bio-degradable binder and separator for green supercapacitors. It is processed by electrospinning from aqueous solutions, therefore overcoming issues related to conventional membrane processing by organic solvents. Furthermore, combining the water-soluble, biodegradable pullulan with a hydrophobic ionic liquid electrolyte brings about a novel approach for end-of-life management of devices. The use of pullulan is demonstrated in a supercapacitor with carbon electrodes obtained from pepper-seeds waste and 1-Ethyl-3-methylimidazoliumbis(trifluoromethylsulfonyl)imide as the electrolyte. The supercapacitor delivers up to 5 kW kg −1 specific power and 27.8 Wh kg −1 specific energy at 3.2 V, that well compare with conventional electrical double-layer capacitor performance with the added value of being eco-friendly and cheap. Graphical abstract: Image 1 Highligths: The use of pullulan to design major components (binder and separator) of supercapacitors is proposed. Combining hydrophilic and hydrophobic materials enables an easy-separation of end-of-life supercapacitor components. The pullulan-ionic liquid-based supercapacitor features up to 5 kW kg −1 and 27.8 Wh kg −1 at 3.2 V. The biochar carbon is prepared from a facile and environmentally safe technique with a mild activating agent. This work paves the way towards the design of biodegradable, easy-to-dispose supercapacitors.