Raw research data to the article entitled "Redox-active low transition temperature mixtures of propylene glycol and iodide salts as electrolytes for hybrid electrochemical capacitors"

This dataset contains Raw Data from Publication entitled: “Redox-active low transition temperature mixtures of propylene glycol and iodide salts as electrolytes for hybrid electrochemical capacitors” by Aleksandra A. Mroziewicz, Rafał Jurczkowski, Jerzy Antonowicz, Grażyna Zofia Żukowska, Magdalena Skunik-Nuckowska published in Electrochimica Acta. The data are provided in Excel files and correspond to all figures presented in the article and a Read Me file with detailed description. Abstract: This work reports the first synthesis and systematic investigation of redox-active low-transition-temperature mixtures based on propylene glycol and iodide salts containing different monovalent cations (Li⁺, Na⁺, K⁺, NH4⁺), and evaluates their application as electrolytes for hybrid electrochemical capacitors. It is shown that unlike iodide–ethylene glycol systems classified as deep eutectic solvents, these liquids undergo vitrification rather than classical crystallization. Extensive hydrogen-bonding interactions enable them to remain liquid down to −90 °C while providing efficient ion transport and electroactive iodide species. Comprehensive spectroscopic, thermal, and ionic transport characterization reveals a strong dependence of these properties on the cation type. Mixtures containing larger, weakly solvated cations exhibit the highest ionic conductivity (1.2 mS cm⁻¹) and the lowest viscosity (51.6 mPa s), following the trend K⁺ > NH4⁺ > Na⁺ > Li⁺. Electrochemical evaluation over 0–80 °C showed that the KI:propylene glycol-based capacitor exhibits the most balanced performance, delivering a room-temperature capacitance and specific energy of 40.9 F g⁻¹ and 12.8 Wh kg⁻¹, respectively, and 6.0 Wh kg⁻¹ during a 60 s discharge at 0 °C, outperforming Li⁺- and Na⁺-based analogues (2.7–3.3 Wh kg⁻¹). Long-term cycling tests showed good stability for all alkali metal-based electrolytes, exemplified by the K⁺-based system (78 % capacitance retention, ~84 % coulombic efficiency over 10,000 cycles at 1.5 V), while NH₄⁺-containing mixtures degraded due to ammonium ion decomposition.These results establish these mixtures as a new, sustainable class of redox-active electrolytes and provide quantitative guidelines本数据集收录了发表于《Electrochimica Acta（电化学学报）》、题为《Redox-active low transition temperature mixtures of propylene glycol and iodide salts as electrolytes for hybrid electrochemical capacitors（氧化还原活性低转变温度混合物：丙二醇与碘盐用作混合电化学电容器电解质）》的研究论文的原始数据，作者为Aleksandra A. Mroziewicz、Rafał Jurczkowski、Jerzy Antonowicz、Grażyna Zofia Żukowska、Magdalena Skunik-Nuckowska。数据以Excel文件形式提供，涵盖论文中所有图表的对应数据，以及一份包含详细说明的Read Me文件。 摘要： 本工作首次报道了基于丙二醇与含不同一价阳离子（Li⁺、Na⁺、K⁺、NH₄⁺）的碘盐的氧化还原活性低转变温度混合物（redox-active low-transition-temperature mixtures）的合成与系统研究，并评估了其作为混合电化学电容器（hybrid electrochemical capacitors）用电解质的应用潜力。 研究表明，与被归类为低共熔溶剂（deep eutectic solvents）的碘化物-乙二醇体系不同，此类液体发生玻璃化转变而非传统结晶过程。广泛的氢键相互作用使其可在低至-90℃的温度下保持液态，同时实现高效的离子传输与电活性碘化物物种。 全面的光谱学、热学与离子传输特性表征显示，这些物性强烈依赖于阳离子种类。含更大尺寸、弱溶剂化阳离子的混合物展现出最高的离子电导率（1.2 mS·cm⁻¹）与最低的黏度（51.6 mPa·s），其变化趋势遵循K⁺ > NH₄⁺ > Na⁺ > Li⁺。 在0~80℃范围内开展的电化学评估结果表明，基于碘化钾与丙二醇的电容器性能最为均衡：其室温电容与比能量分别可达40.9 F·g⁻¹与12.8 Wh·kg⁻¹，在0℃下60秒放电时的比能量为6.0 Wh·kg⁻¹，性能优于基于Li⁺与Na⁺的同类器件（2.7~3.3 Wh·kg⁻¹）。 长期循环测试表明，所有碱金属基电解质均表现出良好的稳定性，其中基于K⁺的体系表现尤为突出（在1.5 V下10000次循环后电容保持率为78%，库仑效率（coulombic efficiency）约为84%）；而含NH₄⁺的混合物则因铵离子分解发生性能衰减。 上述研究结果将此类混合物确立为一类新型、可持续的氧化还原活性电解质，并提供了量化的设计指导原则。