Experimental data of "Analysis of battery-like and pseudocapacitive ion intercalation kinetics via distribution of relaxation times"

Improving the kinetics of electrochemical ion intercalation processes is of interest for realizing high-power electrochemical energy storage. This includes classical battery-like intercalation and pseudocapacitive intercalation processes with a capacitor-like electrochemical signature. Electrochemical methods are needed to probe the kinetics of such complex multistep processes in detail. Here, we present the use of the Distribution of Relaxation Times (DRT) analysis of electrochemical impedance data to identify the kinetic limits of intercalation reactions. We study the lithium intercalation reaction in TiS2 from organic and aqueous electrolytes as a model system. The material can exhibit both battery-like and pseudocapacitive intercalation regimes depending on the potential range, variable diffusion lengths by adjusting its particle size, and a tunable degree of solvent cointercalation by choosing the electrolyte solvent. Using DRT, we can distinguish between the kinetic limitations imposed by solid-state ion diffusion, interfacial ion adsorption and transport, and ion desolvation processes. Thus, DRT analysis can complement existing methods, such as voltammetry or 3D-Bode analysis, to better understand the kinetics of intercalation reactions.优化电化学离子插层过程的动力学性能，对于实现高功率电化学储能系统具有关键意义。此类过程既包含经典的类电池插层机制，也涵盖具有类电容电化学特征的赝电容插层过程。为详尽解析这类复杂多步过程的动力学特性，亟需专用的电化学分析手段。本研究提出利用电化学阻抗数据的弛豫时间分布（Distribution of Relaxation Times, DRT）分析方法，来甄别插层反应的动力学限制因素。我们以有机电解液与水系电解液中的二硫化钛（TiS₂）锂插层反应作为模型体系展开研究。该材料的插层机制可在类电池与赝电容模式间切换，具体取决于电势区间；通过调控颗粒尺寸可精准改变离子扩散长度，而选择不同的电解液溶剂则可调节溶剂共插层的程度。借助弛豫时间分布分析，我们能够区分固态离子扩散、界面离子吸附与传输，以及离子脱溶剂过程各自带来的动力学限制。由此可见，弛豫时间分布分析可作为伏安法、3D博德（3D-Bode）分析等现有技术的补充手段，帮助我们更深入地理解插层反应的动力学特性。