Conducting Salts Govern Thermal Boundary Conductance across Solid Electrode/Organic Liquid Electrolyte Interfaces in Lithium-Ion Batteries
Document Type
Article
Date of Original Version
12-16-2025
Abstract
Thermal boundary resistance at material interfaces poses a major challenge to effective heat dissipation in lithium-ion batteries, particularly at the interface between solid electrodes and organic liquid-based electrolytes. Despite its critical role in thermal management, the nanoscale mechanisms governing interfacial heat transfer in these systems remain poorly understood. Here, we employ all-atom molecular dynamics simulations to investigate heat transport across the interface between lithium cobalt oxide (LCO) electrodes and a liquid electrolyte mixture of ethylene carbonate and ethyl methyl carbonate (3:7 mass ratio) containing either LiPF or LiTFSI salts at concentrations ranging from 0.05 to 2 M. Our results show that thermal boundary conductance is highly sensitive to both the identity of the conducting salt and the degree of lithium-ion adsorption on the LCO surface. While thermal boundary conductance can be as low as 20 MW m K at room temperature─comparable to the resistance of a ∼2 μm silicon layer─increased lithium surface coverage enhances vibrational coupling and significantly increases thermal boundary conductance. We also find that larger anions such as TFSI enable better interfacial heat transfer than smaller PF anions, which disrupt vibrational bridging at high lithium densities. Spectral analyses reveal that adsorbed lithium ions facilitate low-frequency vibrational coupling, especially in the LiTFSI system where the contributions from the transverse phonon modes in the solid are crucial. These findings underscore the critical role of salt-specific interfacial structuring and vibrational dynamics in modulating heat transfer, offering key design insights for thermally optimized, high-performance lithium-ion batteries.
Publication Title, e.g., Journal
ACS nano
Volume
19
Issue
49
Citation/Publisher Attribution
Dionne, C J., Patrick E. Hopkins, Arijit Bose, and Ashutosh Giri. "Conducting Salts Govern Thermal Boundary Conductance across Solid Electrode/Organic Liquid Electrolyte Interfaces in Lithium-Ion Batteries." ACS nano 19, 49 (2025). doi: 10.1021/acsnano.5c13221.