The Current from Non-Disintegrable Suspended Particles at a Rotating Disk Electrode: A theoretical and Experimental Study.

Understanding the current response at an electrode from suspended solid particles in an electrolyte-liquid solution is crucial for developing materials to be used in semi-solid electrodes for energy storage applications. In this talk, an analytical model is presented to predict and understand the current response from non-disintegrable solid particles at a rotating disk electrode. The current is shown to be limited by a combination of ion diffusion within the solid particle and the mean residence time of the particle at the rotating disk electrode. This results in a relationship between current and angular frequency of I ∝ ω^3/4, instead of the classical Levich theory prediction I ∝ ω^1/2.. Specifically, the current response of LTO microparticles suspended in a non-aqueous electrolyte of lithium hexafluorophosphate (LiPF6) in ethylene carbonate:diethyl carbonate (EC:DEC) was determined experimentally and compared favorably with predictions from the proposed analytical model using fitting parameters consistent with the experimental conditions.