Supporting data for "Fundamental Investigations on the Ionic Transport and Thermodynamic Properties of Non-aqueous Potassium-Ion Electrolytes"

This is the dataset of the electrochemical, densitometry and XPS data for our publication "Fundamental Investigations on the Ionic Transport and Thermodynamic Properties of Non-aqueous Potassium-Ion Electrolytes". This archive contains the raw data and python scripts used in the analysis and modelling for the presentation of the results in this manuscript. Abstract of manuscript: Non-aqueous potassium-ion batteries (KIBs) represent a promising complementary technology to lithium-ion batteries due to the availability and low cost of potassium. Moreover, the lower charge density of K⁺ compared to Li⁺ favour the ion-transport properties in the liquid electrolyte solutions, thus, making KIBs potentially capable of improved rate capability and low-temperature performance. However, a comprehensive study of the ionic transport and thermodynamic properties of non-aqueous K-ion electrolyte solutions is not available. Here we report the full characterisation of the ionic transport and thermodynamic properties of a model non-aqueous K-ion electrolyte solution system comprising potassium bis(fluorosulfonyl)imide (KFSI) salt and 1,2-dimethoxyethane (DME) solvent and compare it with its Li-ion equivalent (i.e., LiFSI:DME), over the concentration range 0.25–2 molal. Using tailored K metal electrodes, we demonstrate that KFSI:DME electrolyte solutions show higher salt diffusion coefficients and cation transference numbers than LiFSI:DME solutions. Finally, via Doyle-Fuller-Newman (DFN) simulations, we investigate the K-ion and Li-ion storage properties for K||graphite and Li||graphite cells.本数据集支撑我们发表于论文《非水钾离子电解质的离子传输与热力学性质基础研究》（*Fundamental Investigations on the Ionic Transport and Thermodynamic Properties of Non-aqueous Potassium-Ion Electrolytes*）的相关研究内容，涵盖电化学、密度测定及X射线光电子能谱（XPS）相关数据。本存档包包含该论文中用于结果呈现、分析与建模的原始数据及Python脚本。 论文摘要：由于钾资源储量丰富且成本低廉，非水钾离子电池（KIBs）有望成为锂离子电池的互补性技术。此外，相较于锂离子（Li⁺），钾离子（K⁺）的电荷密度更低，有助于提升液态电解质溶液中的离子传输性能，进而使KIBs有望具备更优异的倍率性能与低温表现。然而，目前尚无针对非水钾离子电解质溶液的离子传输与热力学性质的系统性研究。本研究针对由双氟磺酰亚胺钾（KFSI）盐与1,2-二甲氧基乙烷（DME）溶剂构成的典型非水钾离子电解质模型体系，在0.25~2质量摩尔浓度的范围内，完成了其离子传输与热力学性质的完整表征，并将其与对应锂离子体系（即LiFSI:DME）进行对比。采用定制化钾金属电极，本研究证实KFSI:DME电解质溶液的盐扩散系数与阳离子迁移数均高于LiFSI:DME体系。最后，本研究通过多伊尔-富勒-纽曼（DFN）模拟，探究了钾||石墨与锂||石墨半电池的离子存储性能。