ABSTRACT

Carrageenan is an attractive bio-derived polymer electrolyte due to its high ionic conductivity, cyclic stability, and cost-effectiveness in copolymerizing with other biocompatible polymers such as polyvinyl alcohol (PVA). This paper discusses the physical and chemical characterizations of the bio-electrolyte(s): PVA, carrageenan, and PVA-carrageenan copolymer blend. We also describe a fabrication method to create a soft-printed, thin-film, bio-gel electrolytic double-layer capacitor (bio-EDLC) using a PVA-carrageenan polymer blend. The addition of PVA to carrageenan provided structural and mechanical stability to the biopolymer, as confirmed by the hydrogen bonds detected using attenuated Fourier-transform infrared spectroscopy analysis. The assembled bio-EDLCs were analyzed for their electrical properties including their internal charge transfer mechanism, electrical breakdown, specific capacitance, power density, and energy density. It was determined that the bio-EDLC offers specific capacitance of 84 F/g and power density of 4.15E-02 W/kg and has a breakdown voltage of ~1.1 V. Furthermore, preliminary optimization was performed on the bio-EDLC with a drop casting of reduced graphene oxide at the electrode/electrolyte interface to create surface micro-roughness resulting in a bio-EDLC system which demonstrated superior electrical characteristics with an overall specific capacitance of up to 118 F/g, breakdown voltage of ~1.3 V, and improved maximum charging capability to 80%.

摘要

角叉菜胶是一种极具吸引力的生物衍生聚合物电解质，因为它具有高离子电导率、循环稳定性以及与其他生物相容性聚合物（如聚乙烯醇 (PVA)）共聚的成本效益。本文讨论了生物电解质的物理和化学特性：PVA、角叉菜胶和 PVA-角叉菜胶共聚物混合物。我们还描述了一种使用 PVA-卡拉胶聚合物混合物制造软印刷薄膜生物凝胶电解双层电容器 (bio-EDLC) 的制造方法。向角叉菜胶中添加 PVA 为生物聚合物提供了结构和机械稳定性，正如使用衰减傅立叶变换红外光谱分析检测到的氢键所证实的那样。分析了组装的生物 EDLC 的电学特性，包括其内部电荷转移机制、电击穿、比电容、功率密度和能量密度。确定 bio-EDLC 的比电容为 84 F/g，功率密度为 4.15E-02 W/kg，击穿电压为 ~1.1 V。此外，对 bio-EDLC 进行了初步优化在电极/电解质界面滴铸还原氧化石墨烯以产生表面微粗糙度，从而形成生物 EDLC 系统，该系统表现出优异的电气特性，总比电容高达 118 F/g，击穿电压约为 1.3 V，并将最大充电能力提高到 80%。