Electrochemical Measurements of Lithium-Ion Transports at Sulfide Solid | Solid Interfaces with Electrochemical Four-Electrode Cells

Electrochemical measurements of interfacial ion transports are important techniques for precisely investigate interfacial ion transfer behavior. Electrochemical four-electrode cells are essential for such measurements. This chapter begins by introducing the configuration, principles, and importance of the electrochemical four-electrode cell. Next, it presents examples of the development of reference electrodes applicable to lithium-ion conductive solid electrolytes, which are essential for constructing all-solid-state four-electrode cells. Specifically, developments of Li7Ti5O12|Li4Ti5O12, Li metal, In-Li alloy, and Au-Li alloy reference electrodes and applications of a mesh-shaped Li7Ti5O12|Li4Ti5O12 reference electrodes to all-solid-state electrochemical three-electrode cells are introduced. Finally, this chapter introduces a report of all-solid-state four-electrode cells for electrochemical measurements of lithium-ion transfers at the interfaces between lithium-ion conductive solid electrolytes. Specifically, analyses of lithium-ion transport resistances between two sulfide solid electrolytes using an all-solid-state four-electrode cell with the mesh-shaped Li7Ti5O12|Li4Ti5O12 reference electrode are presented.