Understanding the nature of the passivation layer enabling reversible calcium plating
; Energy Environ. Sci. 13, 3423–3431 (2020).
BibTeX
@article{Forerosaboya2020understanding,
author = {Forero-Saboya, J. and Davoisne, C. and Dedryvère, R. and Yousef, I. and Canepa, P. and Ponrouch, A.},
title = {{Understanding the nature of the passivation layer enabling reversible calcium plating}},
journal = {Energy & Environmental Science},
volume = {13},
pages = {3423--3431},
year = {2020},
doi = {10.1039/D0EE02347G}
}Brief summary
Calcium metal could make an energy-dense battery anode, but calcium plates reversibly only if the layer that forms on it lets calcium ions through. Combining experiments and theory, we identify borate polymers as the calcium-conducting part of this layer, show how to form it in advance, and speed calcium plating tenfold by tuning how the ions are solvated.
Full abstract
As for other multivalent systems, the interface between the calcium (Ca) metal anode and the electrolyte is of paramount importance for reversible plating/stripping. Here, we combined experimental and theoretical approaches to unveil the potential solid electrolyte interphase (SEI) components enabling facile Ca plating. Borates compounds, in the form of cross-linked polymers are suggested as divalent conducting component. A pre-passivation protocol with such SEI is demonstrated and allows to broaden the possibility for electrolyte formulation. We also demonstrated a 10-fold increase in Ca plating kinetics by tuning the cation solvation structure in the electrolyte limiting the degree of contact ion pair.