Disorder Dynamics in Battery Nanoparticles During Phase Transitions Revealed by Operando Single‐Particle Diffraction

Structural and ion-ordering phase transitions limit the viability of sodium-ion intercalation materials in grid scale battery storage by reducing their lifetime. However, combination phenomena nanoparticulate electrodes creates complex behavior that is difficult to investigate, especially on single-nanoparticle under operating conditions. In this work, operando single-particle X-ray diffraction (oSP-XRD) used observe rotation, interlayer spacing, layer misorientation a functional battery. oSP-XRD applied Na2/3[Ni1/3Mn2/3]O2, an archetypal P2-type sodium-ion-positive electrode material with notorious P2-O2 transition induced sodium (de)intercalation. It found during extraction, crystalline layers inside individual particles increases before suddenly align just prior transition. The increase long-range order coincides additional voltage plateau signifying To explain alignment, model for evolution proposed includes from localized correlated Jahn–Teller distortions. anticipated guide further characterization engineering type transitions. oSP-XRD, therefore, opens powerful avenue revealing heterogeneous systems.