Designed inorganics doped gel electrolyte with enhancing ion transfer and diffusion effects for flexible interdigitated supercapacitors

• Published in: Journal of power sources 2024-10, Vol.616, p.235139, Article 235139
• Main Authors: Jin, Kaili, Sun, Jiafeng, Li, Chengcheng, Su, Xing, Chen, Anqi, Han, Qing, Zhang, Zhaotong, Fu, Yani, Zhao, Yaping, Cai, Zaisheng
• Format: Article
• Language: English
• Subjects: Conductivity; Energy storage; Flexible interdigitated miniaturized supercapacitors; Gel electrolyte; Polydopamine modified boron nitride nanosheets
• ISSN: 0378-7753
• DOI: 10.1016/j.jpowsour.2024.235139

Electrolyte enhancement strategy becomes a promising route to improve flexible interdigitated miniaturized supercapacitors (IMSCs) performance due to the less mass loading of electrode materials on interdigitated electrodes. Herein, we develop a flexible polyvinyl alcohol/KOH (PVA/KOH) gel electrolyte with homogeneous BN-PDA (polydopamine modified boron nitride nanosheets) doping for enhancing energy storage of IMSCs, in which the conductivity is up to 112.1 mS cm−1 with excellent mechanical strength and heat stability. The ionicity of BN-PDA caused by electronegativity difference between B and N atoms significantly facilitates KOH transfer in PVA gel and diffusion in electrode diffuse layer by rapping-pairing effect. Furthermore, the different phase transition behavior of BN-PDA and PVA in water provides additional ions transmission pathways and effectively disperses external forces. With such excellent electrolytes, ultra-high energy density (14.7 μWh cm−2) at a high power density (420 μW cm−2) has been achieved for IMSCs. Moreover, the capacitance of IMSCs can always be maintained at a very high level during the long-term charge and discharge process. Our work suggests a feasible pathway to design inorganic fillers uniformly modified gel electrolyte with high conductivity and increased energy storage capacity of IMSCs as well as other flexible energy storage devices. The designed PVA/KOH/BN-PDA gel electrolyte has excellent conductivity, which can greatly improve the energy storage performance of interdigitated micro-supercapacitors. [Display omitted] •The BN-PDA can be uniformly distributed in the PVA-based gel electrolyte.•The contribution of BN-PDA to improve the electrolyte conductivity is investigated.•A valid improvement in conductivity from 20 to 112 mS cm−1 by the effect of BN-PDA.•The energy density of supercapacitor is10 μWh cm−2 at power density of 699 μW cm−2.