Laboratory-based X-ray diffractometer with fast time resolution for <i>operando</i> battery studies

O<i>perando</i> X-ray diffraction (XRD) is an important characterization tool for real-time monitoring of structural changes in materials under different reaction conditions. In this study, we developed a laboratory-based diffractometer that could capture a full XRD spectrum within 10 s. The instrument has several advanced features. First, it uses a Ga–In alloy metal-jet X-ray source, thereby achieving high X-ray flux with a brightness of up to 3.0 × 10¹⁰ photons/(s·mm²·mrad²). Second, it employs an ellipsoidal mirror with a multilayer coating to produce quasi-parallel monochromatic light characterized by a divergence of 0.6 mrad and an energy resolution of 5.9 × 10⁻³. Third, it is equipped with a high-efficiency, high-signal-to-noise-ratio Pilatus 3R 1M detector for collecting diffraction signals. These features make the developed instrument applicable in studying rapid phase transitions in lithium-ion batteries, especially under extremely fast charge–discharge conditions. The data quality was comparable to that of synchrotron radiation XRD.