Operando micro-beam diffraction to monitor the phase transformation of individual cathode grains in all-solid-state batteries

All-solid-state Li-ion batteries are touted to be the battery of the future, providing higher energy densities while being intrinsically safe. However, one of the major challenges is to harvest the full capacity of the electrodes and to maintain this over many charge/discharge cycles. Although it is clear that degradation of the solid-solid interface is the starting point for the poor performance, the underlying degradation mechanism of a large ensemble of electrode crystallites, present in an realistic electrode remains elusive. We propose operando micro-beam diffraction experiments of state-of-the art all-solid-state batteries during repeated charge/discharge cycles. This will allow us to monitor the phase transformation of tens of electrode crystallites simultaneously, thus providing unique and direct insight to the transformation kinetics and degradation mechanisms.