Matthew W Thompson

Vanderbilt University | Vander Bilt · Department of Chemical and Biomolecular Engineering

Significance Water organization at solid–liquid interfaces plays a critical role in a range of applications related to adsorption, membrane separations, energy storage, and catalysis. Currently, our understanding of molecular water at solid interfaces is limited to macroscopic and bulk measurement approaches. These interrogation techniques lack the...

We present molecular-simulation-based calculations of the Van Hove correlation function (VHF) of water using multiple modeling approaches: classical molecular dynamics with simple three-site nonpolarizable models, with a polarizable model, and with a reactive force field; density functional tight-binding molecular dynamics; and ab initio molecular...

Systems composed of soft matter (e.g. liquids, polymers, foams, gels, colloids, and most biological materials) are ubiquitous in science and engineering, but molecular simulations of such systems pose particular computational challenges, requiring time and/or ensemble-averaged data to be collected over long simulation trajectories for property eval...

Most polar solvent molecules are unstable toward electrode materials used in Li-based batteries. Solid electrolytes and ionic liquids are far more stable, however, they have relatively low conductivity, and therefore electrical energy storage devices based on them would suffer from low power. Solvent-in-Salt (SIS) systems combine chemical stability...

Systems composed of soft matter (e.g., liquids, polymers, foams, gels, colloids, and most biological materials) are ubiquitous in science and engineering, but molecular simulations of such systems pose particular computational challenges, requiring time and/or ensemble-averaged data to be collected over long simulation trajectories for property eva...

Electrolyte solutions are ubiquitous in materials in daily use and in biological systems. However, the understanding of their molecular and ionic dynamics, particularly those of their correlated motions, are elusive despite extensive experimental, theoretical, and numerical studies. Here we report the real-space observations of the molecular/ionic-...

The dissolution of room temperature ionic liquids (RTILs) in organic solvents has been shown to enhance ion dynamics. We previously used molecular dynamics (MD) simulations to study the ionic liquid ([BMIM+][Tf2N−]) in 22 unique solvents over a wide range of concentrations. By screening over a large parameter space, we reached several conclusions:...

A key component to enhancing reproducibility in the molecular simulation community is reducing ambiguity in the parameterization of molecular models used to perform a study. Ambiguity in molecular models often stems from inadequate usage documentation of molecular force fields and the fact that force fields are not typically disseminated in a forma...

We present the complex microscopic dynamics of 1-butyl-3-methyl-imidazolium bis(trifluromethylsulfonyl)imide, [Bmim+][TFSI-], ionic liquid mixed with organic solvents to improve its properties for energy storage applications. To probe the microscopic dynamics on different length and time scales, we have employed different neutron scattering spectro...

Room temperature ionic liquids (RTILs) are a class of organic salts that are liquid at room temperature. Their physiochemical properties, including low vapor pressure and wide electrochemical stability window, have driven their use as electrolytes in many electrochemical applications, however, their slow transport properties can hinder their perfor...

A key component to enhancing reproducibility in the molecular simulation community is reducing ambiguity in the parameterization of molecular models. Ambiguity in molecular models often stems from the dissemination of molecular force fields in a format that is not directly usable or is ambiguously documented via a non-machine readable mechanism. Sp...

Present and future electrochemical devices employing advanced electrode and electrolyte materials are expected to operate in diverse environments, where they are exposed to variable conditions, such as changing humidity levels. Such conditions can possibly alter the microscopic mechanisms that influence the electrochemical performance. Here, using...

Given that the kinetics of ion insertion into and adsorption within micropores are two foundational phenomena in charging and discharging of electrochemical double layer capacitors, methods must be developed to characterize ions within micropores of charged porous materials. Here we will discuss the use of electrochemical small angle neutron scatte...

We investigated the influence of water molecules on the diffusion, dynamics, and electrosorption of a room temperature ionic liquid (RTIL), [BMIm+][Tf2N−], confined in carbide-derived carbon with a bimodal nanoporosity. Water molecules in pores improved power densities and rate handling abilities of these materials in supercapacitor electrode confi...

We report a novel atomistic model of carbide-derived carbons (CDCs), which are nanoporous carbons with high specific surface areas, synthesis-dependent degrees of graphitization, and well-ordered, tunable porosities. These properties make CDCs viable substrates in several energy-relevant applications, such as gas storage media, electrochemical capa...

Supercapacitors such as electric double-layer capacitors (EDLCs) and pseudocapacitors are becoming increasingly important in the field of electrical energy storage. Theoretical study of energy storage in EDLCs focuses on solving for the electric double-layer structure in different electrode geometries and electrolyte components, which can be achiev...

We explore the influence of the solvent dipole moment on the cation-anion interactions and transport in 1-butyl-3-methyl-imidazolium bis(trifluromethylsulfonyl), [BMIM+] [Tf2N-]. Free energy profiles derived from atomistic molecular dynamics (MD) simulations show a correlation of the cation-anion separation and the equilibrium depth of the potentia...

Transport of electrolytes in nanoporous carbon-based electrodes largely defines the function and performance of energy storage devices. Using molecular dynamics simulation and quasielastic neutron scattering, we investigate the microscopic dynamics of a prototypical ionic liquid electrolyte, [emim][Tf2N], under applied electric potential in carbon...