Do imaging techniques add real value to the development of better post-Li-ion batteries?

Imaging techniques are increasingly used to study Li-ion batteries and, in particular, post-Li-ion batteries such as Li–S batteries, Na-ion batteries, and all-solid-state batteries. Results that appear impressive owing to good image design and reconstruction are frequently published in high-impact-factor journals; however, questions have arisen about the added value of such results and the information they reveal about reaction mechanisms occurring in batteries during operation and/or degradation. We present here a review of imaging techniques and the knowledge acquired from these techniques for three systems: Li–S batteries, Na-ion batteries, and all-solid-state batteries. There are always advantages and disadvantages associated with these techniques, but beam damage remains the bottleneck to characterization. This factor needs to be considered seriously in order to obtain valuable outcomes that will enable improvements of battery performance and lifetime.