Scanning electrochemical cell microscopy for visualization and local electrochemical activities of lithium‐ion (de) intercalation process in lithium‐ion batteries electrodes

Abstract

Scanning electrochemical cell microscopy with a single barrel micro‐/nano‐pipette (SECCM) was applied to lithium iron phosphate (LiFePO 4 ) composite positive electrodes and an isolated LiFePO 4 secondary particle for lithium‐ion batteries. To analyze lithium‐ion (Li + ) charge or discharge process on the electrodes using local probe, a pipette filled with LiCl electrolyte solution and Ag/AgCl quasi‐reference counter electrode (QRCE) was used. Both the local electrochemical activities of LiFePO 4 on the composite electrodes and a single particle were revealed by SECCM as in‐situ direct measurement of current response‐related Li + transport from mapping and cyclic voltammogram at confined area by the pipette. The mapping has visualized Li + deintercalation process from LiFePO 4 at +0.65 V (applied between the sample‐QRCE). We show that the SECCM system is a strong analytical tool for a characterization of local Li + behavior of active electrode materials in lithium‐ion batteries.