Characterization of Lithium Ion Batteries with in Situ X Ray Tomography and Radiography

Rechargeable lithium ion batteries LIBs have penetrated ubiquitously into our daily lives from cell phones to laptops and recently, they are highly considered for powering electric vehicles EVs as well as for the storage and distribution of energy from sustainable sources, such as solar and wind energy. Nevertheless, the currently commercial LIBs still suffer from unsatisfied energy power density, unavoidable performance degradation, short life time and various safety concerns. In order to investigate the underlying operating mechanisms of LIBs and find out which factor dominates the inevitable performance decay during cycling, a variety of investigation tools such as scanning electron microscopy SEM , transmission electron microscopy TEM , X ray diffraction XRD and X ray tomography radiography have been employed. Unfortunately, a particular battery design such as an open structure and specialized electrolytes such as ionic and Li2O electrolyte that don t adequately simulate the real operating conditions of commercially available LIBs are adopted. This has, to some extent, prevented us from investigating the real operating mechanisms of LIBs and resultantly, the development of next generation energy storage technologies has been slowed down. In the present demonstration, we report the design and fabrication of two kinds of prototypes of LIBs for X ray Tomography and Radiography and the resultant results have been analyzed and discussed. The motivation of this work is to visually observe the underlying operating process of LIBs by synchrotron and or laboratory X rays to identify failure mechanisms during cycling. To this end, we have designed and fabricated a tomography cell tomo cell for three dimensional investigation and a radiography cell radio cell for two dimensional investigation, as shown in Fig. 1