Dynamics of Solid-Electrolyte Interphase Formation on Silicon Electrodes Revealed by Combinatorial Electrochemical Screening

Revealing how formation protocols influence the properties of the solid-electrolyte interphase (SEI) on Si electrodes is key to developing the next generation of Li-ion batteries. SEI understanding is, however, limited by the low-throughput nature of conventional characterisation techniques. Herein, correlative scanning electrochemical cell microscopy (SECCM) and shell-isolated nanoparticles for enhanced Raman spectroscopy (SHINERS) are used for combinatorial screening of the SEI formation under a broad experimental space (20 sets of different conditions with several repeats). This novel approach reveals the heterogeneous nature and dynamics of the SEI electrochemical properties and chemical composition on Si electrodes, which evolve in a characteristic manner as a function of cycle number. Correlative SECCM/SHINERS has the potential to screen thousands of candidate experiments on a variety of battery materials to accelerate the optimization of SEI formation methods, a key bottleneck in battery manufacturing.

Automated summary

In this study, correlative scanning electrochemical cell microscopy (SECCM) and shell-isolated nanoparticles for enhanced Raman spectroscopy (SHINERS) were used to screen the formation of solid-electrolyte interphase (SEI) on Si electrodes. The results revealed the heterogeneous and dynamic nature of SEI, showing characteristic evolution as a function of cycle number. This correlative technique has the potential to accelerate the optimization of SEI formation methods in lithium-ion batteries.