Graphical abstract

Exploration of NaSICON Frameworks as Calcium-Ion Battery Electrodes

D. B. Tekliye, A. Kumar, W. Xie, T. D. Mercy, P. Canepa, and G. S. Gautam; Chem. Mater. 34, 10133 (2022).

BibTeX 
@article{Tekliye2022exploration,
  author  = {Tekliye, D. B. and Kumar, A. and Xie, W. and Mercy, T. D. and Canepa, P. and Gautam, G. S.},
  title   = {{Exploration of NaSICON Frameworks as Calcium-Ion Battery Electrodes}},
  journal = {Chemistry of Materials},
  volume  = {34},
  pages   = {10133},
  year    = {2022},
  doi     = {10.1021/acs.chemmater.2c02841}
}
PDF
tekliye-chem-mater-2022.pdf
DOI
10.1021/acs.chemmater.2c02841
GitHub
https://github.com/sai-mat-group/ca-nasicon-electrodes
Topics
Batteries Multivalent Electrochemistry

Brief summary

Calcium batteries could be cheaper and safer than lithium-ion if good electrodes are found. Screening NaSICON frameworks CaxM2(ZO4)3 with calculations, we identify CaxV2(PO4)3, CaxMn2(SO4)3 and CaxFe2(SO4)3 as promising positive electrodes, and find the silicate versions unstable.

Full abstract

The development of energy storage technologies that are alternative to state-of-the-art lithium-ion batteries but exhibit similar energy densities, lower cost, and better safety is an important step in ensuring a sustainable energy future. Electrochemical systems based on calcium (Ca)-intercalation or deintercalation form such an alternative energy storage technology but require the development of intercalation electrode materials that exhibit reversible Ca-exchange with reasonable energy density and power density performance. To address this issue, we use first-principles calculations to screen over the wide chemical space of sodium superionic conductor (NaSICON) frameworks, with a chemical formula of CaxM2(ZO4)3 (where M = Ti, V, Cr, Mn, Fe, Co, or Ni and Z = Si, P, or S) for Ca electrode materials. We calculate the average Ca2+ intercalation voltage, the thermodynamic stability (at 0 K) of charged and discharged Ca-NaSICON, and the migration barriers of (meta)stable Ca-NaSICON compositions. Importantly, our calculations indicate CaxV2(PO4)3, CaxMn2(SO4)3, and CaxFe2(SO4)3 Ca-NaSICONs to be promising as Ca-cathodes. We find all silicate Ca-NaSICONs to be thermodynamically unstable and hence unsuitable as Ca-cathodes. We report the overall trends in the ground state Ca-vacancy configurations, besides voltages, stabilities, and migration barriers. Our work contributes to unearthing strategies for developing practical calcium-ion batteries, involving polyanionic intercalation frameworks.