Topic 5 min read

Scanning probes & battery research

Latest updated: December 16, 2019

Overview

As demand for electric vehicles, portable electronics, and green energy storage grow, so too will the demand for better batteries. To improve on current battery technologies, researchers must intimately understand battery components. By employing scanning probe electrochemistry in the study of batteries, researchers can understand electrochemical processes as they occur locally. Scanning probe electrochemistry has already been used to help answer a number of questions about batteries as outlined in the table below.

 

 

Question Technique Information Measured Example
Is it possible to follow the formation of the Solid Electrolyte Interface (SEI)? dc-SECM Using dc-SECM it is possible to measure spatially resolved changes in the Faradaic current measured due to the interaction of the sample with a redox mediator of interest. These changes reflect local electrochemical activity with lower current due to decreased electrochemical activity. When investigating the SEI low current reflects the insulating SEI, while high current reflects exposed electrode regions. The effect of applying different voltages to the electrode on the SEI can be investigated. D. Liu et al., Journal of Physical Chemistry C 123 (2019) 12797-12806

 

S. Liu et al., Journal of Materials Chemistry A 7 (2019) 12993-12996

ac-SECM ac-SECM can investigate the heterogeneous kinetics across the surface of a sample. A sample with heterogeneous kinetics will lead to heterogeneous impedance measured by ac-SECM, which reflects the insulating SEI and exposed electrode regions. D. Liu et al., Journal of Physical Chemistry C 123 (2019) 12797-12806
Can changes in the SEI be detected? dc-SECM dc-SECM can be used to map local current changes over the same area of an electrode over time. How the current evolves reflects changes in the SEI layer during this period. This can indicate SEI instability, gas bubble formation, and local SEI damage. H. Bülter et al. Angewandte Chemie International Edition 53 (2014) 10531-10535
What is the distribution of the composite material on the electrode? ac-SECM ac-SECM signal reflects the local impedance directly under the probe. When an area map is measured this mirrors the local heterogeneity of the electrode. L. Wang et al., ACS Applied Material Interfaces 11 (2019) 19920-19932
How does the conductivity of solid-state electrolyte grains compare to grain boundaries? ac-SECM The local impedance measured by ac-SECM reflects the local conductivity of a sample. Comparison of the impedance of grains and grain boundaries provides information about their local conductivity, with more conductive regions showing lower impedance in ac-SECM. S. Catarelli et al., Frontiers in Energy Research 4 (2016) 14

T. Takami et al., ACS Applied Energy Materials 6 (2018) 2546-2554

How do different surface treatments affect an electrode? LEIS LEIS measures the local impedance of a sample. When the LEIS area maps of different samples, measured under the same conditions, are compared it is possible to compare the magnitude and heterogeneity of the impedance. X. Chang et al., Applied Surface Science 441 (2018) 105-112