Correlating the Solvating Power of Solvents with the Strength of Ion‐Dipole Interaction in Electrolytes of Lithium‐ion Batteries

Abstract

The solvation structure of Li+ plays a significant role in determining the physicochemical properties of electrolytes. However, to date, there is still no clear definition of the solvating power of different electrolyte solvents, and even the solvents that preferentially participate in the solvation structure remain controversial. In this study, we comprehensively discuss the solvating power and solvation process of Li+ ions using both experimental characterizations and computational calculations. Our findings reveal that the solvating power is dependent on the strength of the Li+‐solvent (ion‐dipole) interaction. Additionally, we uncover that anions tend to enter the solvation sheath in most electrolyte systems through Li+‐anion (ion‐ion) interaction, which is weakened by the shielding effect of solvents. The competition between the Li+‐solvent and Li+‐anion interactions ultimately determines the final solvation structures. This insight into the fundamental understanding of the solvation structure of Li+ ions provides inspiration for the design of multifunctional mixed‐solvent electrolytes for advanced batteries.

LiNO3‐Based Electrolytes via Electron‐Donation Modulation for Sustainable Nonaqueous Lithium Rechargeable Batteries

“…As NO 3 − has a weaker electron‐donation ability than DMSO, this leads to a deshielding effect of the electron cloud around Li + and the downfield shift in the 7 Li NMR spectra. For the LiNO 3 ‐DMSO@PC electrolyte, the 7 Li NMR signal further undergoes a downfield shift, suggesting that the interaction between Li + and DMSO is further weakened (corresponds to the Raman shift of DMSO, Figure 3b), and the AI‐ISC structure with more anionic contribution is formed in the LiNO 3 ‐DMSO@PC electrolyte [43,44] . It is rational to interpret the improved compatibility towards the graphite anode for the LiNO 3 ‐DMSO@PC electrolyte because the contribution of anions to Li + can usually stabilize the solvent molecules [37] .…”

LiNO3‐Based Electrolytes via Electron‐Donation Modulation for Sustainable Nonaqueous Lithium Rechargeable Batteries

“…For the LiNO 3 -DMSO@PC electrolyte, the 7 Li NMR signal further undergoes a downfield shift, suggesting that the interaction between Li + and DMSO is further weakened (corresponds to the Raman shift of DMSO, Figure 3b), and the AI-ISC structure with more anionic contribution is formed in the LiNO 3 -DMSO@PC electrolyte. [43,44] It is rational to interpret the improved compatibility towards the graphite anode for the LiNO 3 -DMSO@PC electrolyte because the contribution of anions to Li + can usually stabilize the solvent molecules. [37] The above spectroscopy analyses suggest that the addition of PC in the LiNO 3 -DMSO@PC electrolyte induced a change of ISC structure towards more anionic contribution, which is beneficial for the improved reduction stability of the electrolytes.…”

Molecular modulation strategies for two-dimensional transition metal dichalcogenide-based high-performance electrodes for metal-ion batteries

“…However, the low abundance of lithium resources may restrict large-scale LIB-based ESSs. 2,3 Therefore, alternate secondary metal-ion batteries with higher earth-abundance of the corresponding metals, such as sodium ion batteries (NIBs), 4–6 potassium ion batteries (PIBs), 7–10 and zinc ion batteries (ZIBs), 11–13 have been extensively studied. Among various battery systems, electrode materials play an important role in the battery's electrochemical performance.…”