Design Principles for High-Performance Electrolytes—Overcoming Low-Temperature Challenges in Lithium-Ion Batteries

Current commercial lithium-ion batteries (LIBs) struggle with low-temperature performance, posing challenges for applications in electric vehicles, grid operations, defense systems, space exploration, and subsea operations. Understanding the atomistic origins that hinders Li-ion transport in bulk electrolyte as well as its interfaces with the electrodes are crucial towards rational design of high-performing LIBs under extreme conditions. In this work, we employ classical molecular dynamics simulations to elucidate the effects of temperature and concentration on the ionic conductivity of a prototypical battery electrolyte. More specifically, we deconvolute the temperature and concentration dependent ionic conductivity into local speciation. Based on this, two fundamental design principles that governs the overall electrolyte performance are formulated—one for ambient temperatures and the other for low-temperature conditions. We further extend these design principles to interfacial processes, focusing on addressing the competing effects of ion desolvation and ion-pairing in the electrolyte and at the interface. Ultimately, the fundamental knowledge we obtained on the prototype system and the workflow established will allow us to identify key features that dictates the low-temperature performance of LIBs and provide design strategies for improvements.


This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344 and was supported by Laboratory Directed Research and Development funding under project number 23-SI-002.