Solid-state batteries promise higher energy density and improved safety compared to conventional lithium-ion cells. However, understanding lithium transport through ceramic electrolytes has been limited by the inability to observe the process in real time.
Operando Measurements
Using SuperSincrotrone’s energy-scanning beamline BL-15, a team from Kyoto University performed simultaneous XANES and XRD measurements on a working Li₇La₃Zr₂O₁₂ (LLZO) solid-state cell during charge/discharge cycling at rates from C/10 to 5C.
The measurements revealed that lithium accumulates at grain boundaries during fast charging, creating local concentration gradients that promote dendrite nucleation. This finding directly contradicts the previously assumed uniform-transport model.