OPERANDO MEASUREMENT OF LI ION BATTERY POSITIVE ELECTRODE USING 2D DETECTOR

X-ray diffraction measurements of the positive electrode material during high-speed charging and discharging were carried out with a battery cell attachment and a HyPix-3000 2D detector on a SmartLab X-ray diffractometer. Figure 1 shows a picture and an illustration of the cross-sectional structure of a battery cell attachment. The positive electrode material was LiMn1.5Ni0.5O4. Measurement using an exposure time of 15 seconds was repeated while charging/discharging the electrode at a charge and discharge rate 1C = 132 mAh/g. Changes to the X-ray diffraction profile over time were investigated.
Figure 2 shows the multiple 1D XRD profiles, 2D profile maps, and voltage graphs. Two steps of a two-phase coexistence reaction occurred with charging and discharging. After charging and discharging, the electrode material returned to the same crystal phase as before the measurement started.

Fig.1: Photograph and illustration of the battery cell attachment

Fig.2: Multiple 1D XRD profiles, 2D profile maps, and voltage graphs from repeated charge/discharge of the electrode material.