Scientific Achievement
The high Li+ apparent transference number in the LiTFSI water-in-salt electrolyte was captured by MD simulations and the dominant Li+ conduction mechanism in the highly concentrated LiTFSI water-in-salt electrolyte was identified to be hopping between water and TFSI- anions.
Significance and Impact
The results show that water-rich and TFSI-rich nano-scale domains are not necessary for the high Li+ apparent transference number and therefore suggest a new mechanism to understand the electrochemical behavior in these highly concentrated water-in-salt electrolytes.
Research Details
- MD simulations were carried out using a force field validated previously for the liquid structure and further validated here against experimental transport properties.
- Calculated viscosity, self-diffusion coefficient, ionic conductivity, apparent transference number and inverse Haven ratio all agree with experimental results quantitatively.
- Transport and Li+ dynamics were studied in depth with the validated MD simulations.
