Synchotron Enabled Ex-Situ and in-Situ Mechanistic Interrogation of Energy Storage Systems

Introduction

Full understanding of the electrochemical processes taking place in batteries continues to be elusive due to the complex nature of the reactions associated with discharge and charge processes, and the difficulties of analytical interrogation of these reactions.  Ex-situ measurements at various states of electrochemical reduction and oxidation can provide mechanistic insight.  A direct approach to the interrogation of the reactions taking place inside batteries is to employ in-situ strategies.  Unfortunately, in-situ measurements are often hindered by diminution of signal due to the housing of an electrochemical cell or by the need to create special housings that enable the measurement. 

Results and Discussion

Strengths and limitations of diffraction and spectroscopy based approaches characterization of energy storage systems will be discussed, with an emphasis on the unique characterization opportunities provided by synchrotron radiation.  X-ray absorption spectroscopy (XAS) is sensitive to local structure within a few coordination shells around the absorbing atom, and can therefore characterize local structure even if long-range order is absent.^1,2  Energy dispersive x-ray diffraction (EDXRD) approaches allow in-situ measurement of an battery electrode in its native environment.³  Specifically, electrode interrogation as a function of depth by EDXRD will be presented, enabling identification of the chemical reaction front within the battery electrode.

 

References

1)      Patridge, C. J.; Jaye, C.; Tesfaye, A. A.; Ravel, B.; Fischer, D. A.; Marschilok, A. C.; Zhang, P.; Takeuchi, K. J.; Takeuchi, E. S.; Banerjee, S.  J. Phys. Chem. C, 2011, 115(29),14437–14447.

2)      Menard, M. C.; Takeuchi, K. J.; Marschilok, A. C.; Takeuchi, E. S., Physical Chemistry Chemical Physics. 2013, 15,18539-18548.

3)      Takeuchi, E. S.; Marschilok, A. C.; Takeuchi, K. J.; Ignatov, Alexander; Zhong, Zhong; Croft, Mark.  Energy and Environmental Science.  2013, 6, 1465-1470.