Correlating Electrochemical Kinetic Parameters of Single LiNi1/3Mn1/3Co1/3O2 Particles with the Performance of Corresponding Porous Electrodes

Abstract

AbstractCharacterizing microscale single particles directly is requested for dissecting the performance‐limiting factors at the electrode scale. In this work, we build a single‐particle electrochemical setup and develop a physics‐based model for extracting the solid‐phase diffusion coefficient (Ds) and exchange current density (i0) from electrochemical impedance measurements. We find that the carbon coating on the LiNi1/3Mn1/3Co1/3O2 surface enhances i0. In addition, Ds and i0 decay irreversibly by ≈25 % and ≈10 %, respectively, when the cutoff charge voltage increases from 4.3 V to 4.4 V. Moreover, we correlate intrinsic parameters of single particles with the performance of porous electrodes. Porous electrodes assembled with active particles with higher i0 values deliver a greater capacity and faster capacity fade. The methods developed in this combined experimental and theoretical work can be useful in correlating the single‐particle scale and porous‐electrode scale for other similar systems.