Space charge effects in mixed ionic–electronic conducting electrodes for solid-state batteries
Journal
Physical Chemistry Chemical Physics
Journal Volume
26
Journal Issue
37
Start Page
24689
End Page
24698
ISSN
1463-9076
1463-9084
Date Issued
2024
Author(s)
Shu-Han Chen
DOI
10.1039/d4cp02727b
Abstract
Mixed ionic-electronic conductors are widely used as electroactive materials in energy applications. The contact of a mixed conductor with another phase plays a crucial role in charge storage and transport in energy devices. However, the interfacial chemistry at the heterojunctions comprising mixed conductors and its interplay with the bulk chemistry remains imperative yet inadequately understood. This study addresses the fundamentals of space charge effects by exploring the equilibrium situations for contacts consisting of mixed conductors. From the perspective of defect chemistry, and by unifying the bulk and interfacial conditions with the electrochemical potential, our treatment allows for predicting the built-in potential at heterojunctions, profiling the space charge distributions, and evaluating the resulting interfacial charge storage and transport. The treatment can be related to experimental characterization, including coulometric titration, conductivity, and capacitance measurements at electrochemical interfaces in all-solid-state batteries. Besides, our treatment also highlights the significance of size and doping effects in nanocrystalline electrodes. This work provides a comprehensive framework for understanding and engineering the heterojunctions in electrochemical devices.
Publisher
Royal Society of Chemistry (RSC)
Type
journal article