In situ anomalous small angle X-ray scattering and absorption on an operating rechargeable lithium ion battery cell

We have employed anomalous small angle X-ray scattering (ASAXS) and X-ray absorption in situ on an operating lithium ion battery cell with LiMn₂O₄ as the positive electrode material. Manganese K-edge absorption spectra and scattering patterns were recorded at various stages of charge between 3.8 and 4.5 V. The shift of the manganese absorption K-edge was observed as a function of the charge of the electrode. Clear changes in the microstructure of the spinel at the 4 V plateau was observed even during the first charging cycle.