Structure and growth law of the battery solid-electrolyte interphase
In plain words
In lithium-ion batteries the electrolyte partly decomposes on the negative electrode and forms a thin film, the solid-electrolyte interphase, which passes lithium ions but blocks electrons. Its structure and why it keeps slowly thickening set battery lifetime but are known only roughly.
Precise statement
For graphite and lithium-metal anodes in carbonate electrolytes (for example 1 mol/L LiPF6 in ethylene carbonate and ethyl methyl carbonate), determine the nanoscale arrangement of inorganic (LiF, Li2CO3, Li2O) and organic phases in the solid-electrolyte interphase (SEI), the transport process that sustains its growth (electron tunneling, neutral lithium interstitial diffusion, solvent diffusion through pores), and the resulting thickness law $L(t)$, often reported near $t^{1/2}$. An answer is a model with first-principles rate parameters that predicts $L(t)$ and the measured calendar-aging capacity loss.
What would settle it
Cryogenic microscopy and depth-resolved spectroscopy of SEI composition over aging time, matched by a first-principles growth model.