On the Role of Reaction Current Distribution to Attain Competitive Solid-State Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Solid-state batteries require high areal loadings and fast charging rates for practical applications.
• Current research often focuses on lower loadings and C-rates, hindering scalability.
• Charge transport limitations emerge with increased active material content and charging speeds.

Purpose of the Study:

• To investigate the role of reaction current distribution in composite electrodes for advanced solid-state batteries.
• To rationalize composite electrode cycling performance using Newman's porous electrode theory.
• To identify strategies for improving electrode composition and ionic/electronic transport.

Main Methods:

• Utilized NCM-argyrodite composites as a case study.
• Applied Newman's porous electrode theory to solid-state battery context.
• Employed operando high-energy X-ray diffraction to monitor lithiation states.

Main Results:

• Demonstrated significant improvements in reaction current distribution with faster conducting Li5.5PS4.5Cl1.5 compared to Li6PS5Cl.
• Highlighted the critical need for fast lithium-ion conductors in solid-state batteries.
• Showcased the importance of balanced ionic and electronic transport for homogeneous active material utilization.

Conclusions:

• Optimizing electrode composition is crucial for balancing ionic and electronic transport.
• Faster conducting solid electrolytes are essential for enabling competitive solid-state batteries.
• Homogeneous utilization of active materials and mitigation of local strain are key for battery longevity.