An electrochemical cell for operando bench-top X-ray diffraction

An X-ray transparent electrochemical cell for operando bench-top X-ray diffraction in reflection geometry is presented. Dense glassy carbon (Sigradur-G) is used as an X-ray transparent window. The cell and dedicated sample holder are easy to handle and cost efficient thanks to their simple designs. To demonstrate the performance of this new Swagelok-type operando cell, diffractograms were collected during cycling of the cathode material Li_xMn₂O₄ (x ≤ 1) in a lithium-ion battery. During charging/deli­thia­tion, three spinel phases with evolving lattice parameters were found. This observation confirms the expected mixed two-phase and solid-solution behaviour and thereby validates our experimental setup. The presented low-cost setup may enable further battery research units to access operando X-ray diffraction data for characterization of structural phenomena during battery cycling and degradation mechanisms during prolonged cycling, which will lead to improvement of the battery technology.