Role of grain boundaries in sulfide solid electrolytes

Determine the role of grain boundaries in sulfide solid electrolytes by experimentally characterizing grain-boundary morphology and quantifying grain-boundary contributions to macroscopic ionic transport and resistance, which are difficult to isolate with current characterization methods.

Background

In oxide solid electrolytes, grain boundaries are known to increase resistance, but transferring that understanding to sulfide electrolytes has been challenging. The paper highlights that, in sulfides, grain-boundary morphology and contributions are hard to characterize and disentangle experimentally, leaving their overall effect on transport elusive.

The authors use multiscale simulations to probe grain-boundary effects in argyrodite sulfides, but explicitly note the experimental uncertainty surrounding the grain-boundary role, motivating targeted measurements to isolate and quantify these contributions.

References

Although GBs are known to increase resistance in oxide electrolytes [6-8], their role in sulfides remains elusive, as GB morphology and contribution are difficult to characterize and isolate experimentally.

— Non-Arrhenius Li-ion transport and grain-size effects in argyrodite solid electrolytes (2510.18630 - Ou et al., 20 Oct 2025) in Introduction