Deciphering Interfacial Phenomena in Hybrid Electrolytes: Pioneering Solid-State Battery Progress

ChemRxiv

Abstract

Understanding the interfacial behavior at the interface within solid hybrid polymer/ceramic electrolytes is crucial for advancing solid state battery technology. In this study, we investigate the effect of grafting various polymer monomers onto the surface of a lithium-ion conducting material, lithium aluminum titanium phosphate (LATP), through density functional theory (DFT) calculations. Specifically, we examine the adsorption and grafting of polycaprolactone (PCL), propionate, pentyl carbonate, and polyoxyethylene monomers onto the LATP surface. Grafting PCL onto LATP enhances interfacial stability by promoting stronger chemisorptive interactions compared to physisorption observed during simple adsorption. We explore the impact of monomer size and functional group on the adsorption energy and shifting of nearby lithium ions from the LATP surface. We find that smaller monomers with similar functional groups exhibit stronger bonding to the LATP surface. The influence of grafting density on interfacial lithium-ion energetics is also examined. While complete Li extraction from a perfect LATP surface remains energetically unfavorable, grafted monomers reduce the relative energy differences associated with lithium-ion positioning near the interface, suggesting a modified local environment that may facilitate interfacial ion transport. Electronic structure analysis reveals hybridization between grafted monomers and the LATP surface and indicates that the grafted species retain sizable band gaps, supporting their electrochemical stability. Overall, our study provides valuable insights into the design of polymer-solid electrolyte interfaces for advanced hybrid solid-state batteries.

Authors 3

1. Kazem Zhour Aachen Junior Professorship of Multiscale Modeling of Heterogeneous Catalysis in Energy Systems

   RWTH Aachen University

   Affiliation as printed

   Junior Professorship of Multiscale Modeling of Heterogeneous Catalysis in Energy Systems, RWTH Aachen University

2. Andreas Heuer

   University of Münster

   Affiliation as printed

   Institut für Physikalische Chemie, Universität Münster, Corrensstaße 28, Münster, Germany, 48149

3. Diddo Diddens

   Forschungszentrum Jülich

   Affiliation as printed

   Forschungszentrum Jülich GmbH, Corrensstraße 46, Münster, Germany, 148159