The electrolyte plays an important role in governing the high-current performance of Li-ion batteries. Nonnally, battery electrolytes are optimized for maximum conductivity. In order to gain a more profound understanding of the role of the electrolyte, properties such as the Li salt diffusion coefficient, the Li + transference number, and the Li salt activity all need to be measured in addition to the conductivity. The situation is further complicated by the fact that high currents change the cell temperature and also create strong concentration gradients in the electrolyte. A full set of transport properties for LiPF 6 in a propylene carbonate/ ethylene carbonate/dimethyl/carbonate mixture were measured as a function of temperature and LiPF 6 concentration. The Li + transference number was found to be fairly constant with concentration. The activity and diffusion coefficient were both found to vary strongly with temperature and concentration. The temperature dependence of the transport properties is shown to be crucial for making predictions of cell performance at high currents.

https://iopscience.iop.org/article/10.1149/1.1872737/pdf

Transport Properties of LiPF6-Based Li-Ion Battery Electrolytes

http://depts.washington.edu/maple/pubs/4-EActa-GB-VS-RW-mathmodeling_sec_Lith_bat-2000.pdf

Mathematical modeling of secondary lithium batteries

Study of nanocrystalline TiO2 (anatase) electrode in the accumulation regime

Through coupled experimental analysis and computational techniques, we uncover the origin of anodic stability for a range of nonaqueous zinc electrolytes. By examination of electrochemical, structural, and transport properties of nonaqueous zinc electrolytes with varying concentrations, it is demonstrated that the acetonitrile-Zn(TFSI)2, acetonitrile-Zn(CF3SO3)2, and propylene carbonate-Zn(TFSI)2 electrolytes can not only support highly reversible Zn deposition behavior on a Zn metal anode (≥99% of Coulombic efficiency) but also provide high anodic stability (up to ∼3.8 V vs Zn/Zn(2+)). The predicted anodic stability from DFT calculations is well in accordance with experimental results, and elucidates that the solvents play an important role in anodic stability of most electrolytes. Molecular dynamics (MD) simulations were used to understand the solvation structure (e.g., ion solvation and ionic association) and its effect on dynamics and transport properties (e.g., diffusion coefficient and ionic conductivity) of the electrolytes. The combination of these techniques provides unprecedented insight into the origin of the electrochemical, structural, and transport properties in nonaqueous zinc electrolytes.

/pdf/origin-of-electrochemical-structural-and-transport-5g2sx1ezba.pdf

Origin of Electrochemical, Structural, and Transport Properties in Nonaqueous Zinc Electrolytes

Electrochemical lithium intercalation within carbonaceous materials has attracted much attention for use to produce anodes in rechargeable lithium batteries. Although small-size rechargeable lithium cells using carbon anodes have been already commercialized, there still remain a lot of problems to be solved. Furthermore, recent global environmental issues require carbon anodes with high energy densities for use in electric energy storage and electric vehicles in the near future. This review article covers recent topics of the lithium intercalation, focusing on three fundamental aspects: intercalation processes, surface film formation, and lithium diffusion within carbons.

Electrochemical Lithium Intercalation within Carbonaceous Materials : Intercalation Processes, Surface Film Formation, and Lithium Diffusion

Propylene carbonate, dimethyl formamide, acetonitrile and methyl formate diffusion coefficients measurement for estimating nonaqueous Li batteries transport limitations

D. C. Hanson

Papers

Diffusion Coefficients in Propylene Carbonate, Dimethyl Formamide, Acetonitrile, and Methyl Formate