Boron‐Based Functional Additives Enable Solid Electrolyte Interphase Engineering in Calcium Metal Battery

Abstract

Calcium-metal batteries have received growing attention recently after several studies reporting successful metal plating and stripping with organic electrolytes. Given the low redox potential of metallic calcium, its surface is commonly covered by a passivation layer grown by the accumulation of electrolyte decomposition products. The presence of borate species in this layer has been shown to be a key parameter allowing for Ca 2 + migration and favoring Ca electrodeposition. Here, boron-based additives are evaluated in order to tune the SEI composition, morphology, and properties. The decomposition of a BF 3 -based additive is studied at different potentiostatic steps and the resulting SEI layer was thoroughly characterized. SEI growth mechanism is proposed based on both experimental data and DFT calculations pointing at the formation of boron-crosslinked polymeric matrices. Several boron-based adducts are explored as SEI-forming additives for calcium-metal batteries paving the way to very rich chemistry leading to Ca 2 + conducting SEI.

A tris(2-aminoethyl)amine-based zinc complex as a highly water-soluble drug carrier for the anti-COVID-19 drug favipiravir: a joint experimental and theoretical study

“…Data collection for 2 was carried out on a Rigaku Oxford Diffraction SuperNova diffractometer using mirror monochromated Mo Kα radiation (λ = 0.71073 Å) at 100 K. Gaussian absorption corrections were applied to the data. 14 Systematic absences were consistent with the space groups C2/c or Cc; a satisfactory solution was obtained in the non-centrosymmetric space group Cc. Due to the crystals being small and poorly scattering on the synergy diffractometer, data for 1 and 3 were collected at 100 K at the MX1 beamline at the Australian synchrotron, fitted with a silicon double crystal monochromator, the wavelength being tuned to approximate Mo-Kα radiation (λ = 0.710917 Å or 0.71076 Å, respectively).…”

Two Layers of Computational Screening on Silaborane‐based Clusters Filter Ca(SiB11H11CH3)2 as the Promising Electrolyte for Calcium‐Ion Batteries

“…Also, the fluorine atoms are embedded into the Ca anode which hints at the formation of CaF 2 . Formation of CaF 2 passivation layer is a common experimental observation among the electrolytes containing F atoms in calcium‐ion batteries [63,64] . The corresponding dynamics is shown in the movie S2 of the SI (cf.…”

“…Furthermore, the BEs of Ca 2+ ion with TFSI − , $${{{\rm C}{\rm l}{\rm O}}_{4}^{-}}$$ , and $${{{\rm B}{\rm F}}_{4}^{-}}$$ were also calculated in gas phase as well as using implicit solvation model (THF). Calcium salts of these anions are already reported in previous works [32,63,64] . We calculated and compared the BEs of Ca 2+ /$${{{\rm S}{\rm i}{\rm B}}_{11}{{\rm H}}_{11}{{\rm C}{\rm H}}_{3}^{-}}$$ ion pair (found most suitable in our analysis) with Ca 2+ /$${{{\rm C}{\rm l}{\rm O}}_{4}^{-}}$$ , Ca 2+ /TFSI − , and Ca 2+ /$${{{\rm B}{\rm F}}_{4}^{-}}$$ ion pairs.…”

“…Calcium salts of these anions are already reported in previous works. [32,63,64] We calculated and compared the BEs of Ca 2 + /SiB 11 H 11 CH À 3 ion pair (found most suitable in our analysis) with Ca 2 + /ClO À 4 , Ca 2 + /TFSI À , and Ca 2 + /BF À 4 ion pairs. The calculated BEs are provided in Table S10 in the SI (Section S13).…”

Ca-dimers and solvent layering determine electrochemically active species in Ca(BH$_4$)$_2$ in THF

“…We study Ca(BH 4 ) 2 in THF as a promising electrolyte candidate, 18 spurred on by recent studies of the bulk electrolyte 19 and the anode interface. 6,20 We can also contrast its behavior with Mg(TFSI) 2 in THF, studied recently using free energy sampling. 21 Ref.…”