Factors Influencing Preferential Anion Interactions during Solvation of Multivalent Cations in Ether-based Solvents

Specific anion coordination is more strongly controlled by solvent structure and second-shell interactions (i.e., solvent separated ion pairs are shown to be critical for controlling inter-ionic interactions).

Scientific Achievement

Discovered and described how solvent structure and cation size influence cation−anion interactions, suggesting that they drive the formation of free ions in ethereal multivalent electrolytes.

Significance and Impact

These results provide a fundamental understanding of the physical chemistry in multivalent battery electrolytes and can be used as guidelines for the design of future secondary batteries.

Research Details

  • Pulsed field gradient nuclear magnetic resonance and Raman spectroscopy experiments show that specific solvent−cation interactions are stronger for glymes than for cyclic ethers.
  • Despite having a lower charge density, the larger-sized Ca2+ generally interacts more strongly with anions than Zn2+.
  • Ionic conductivity, ΛM, and dielectric relaxation spectroscopy measurements reveal that second-shell ion correlations are prevalent in these solvents as are dipolar ion pairs, suggesting a general mechanism for de-correlating ion motion in relatively
    well-dissociated multivalent electrolytes.

Download this highlight 

DOI: 10.1021/acs.jpcc.0c09830

Latest Updates

See All