A simple electrochemical cell for in-situ fundamental structural analysis using synchrotron X-ray powder diffraction
A simple in-situ cell design is formulated based on the various in-situ electrochemical cells developed over the last three decades. The cell is targeted at those researchers who are not necessarily in the field of lithium ion battery research but are interested in synthesising and performing fundamental structural analyses of compounds that cannot be made via any other route. Therefore, this design uses only components that are routinely available and can be machined in-house. The effectiveness of the initial cell design is demonstrated through kinetic analysis of the lithium insertion reaction for the Li0.18Sr0.66Ti0.5Nb0.5O3 defect perovskite using data obtained from hundreds of diffraction patterns. Within the first discharge it has been possible to identify three regions with different rates of crystal lattice expansion. These regions extend from 1.01 to 1.47 V, 1.47–1.58 V and 1.58–2.07 V with rates of crystal lattice expansion determined to be 1.765(6) × 10−5 Å min−1, 1.44(5) × 10−5 Å min−1 and 2.47(1) × 10−5 Å min−1, respectively. These three regions correlate with three distinct regions in the electrochemical profile, between 1.00 and 1.36 V, 1.36–1.55 V and 1.55–1.80 V.