Understanding Interfaces at the Positive and Negative Electrodes on Sulfide-Based Solid-State Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Sulfide solid-state batteries offer high ionic conductivity and good mechanical properties.
• Complex solid-solid interfaces hinder fast rate and long cycling performance in these batteries.

Purpose of the Study:

• To comprehensively assess factors determining cell performance in sulfide-based solid-state batteries.
• To disentangle interfacial processes affecting battery components: high-voltage cathode, sulfide separator, and lithium metal anode.

Main Methods:

• Utilized a multiconfigurational approach.
• Applied advanced deconvolution of electrochemical impedance signals using distribution of relaxation times.

Main Results:

• Identified multiple impedance sources from cathode, separator, and anode interfaces.
• Found cycling performance is sensitive to cathode chemomechanics, SEI formation, and Li diffusion.

Conclusions:

• Interfacial processes significantly impact overall performance of lithium metal solid-state batteries.
• Results aid in designing improved sulfide solid-state batteries and assessing battery aging.