Multiscale Modelling of Electrolyte Materials for Energy Storage and Harvesting
Abstract
Energy is essential to human society to ensure our quality of life and to underpin all aspects of economy. Due to accelerated consumption of conventional energy sources (fossil fuels, coal, and natural gas, etc.), our world has reached a pivotal age of energy awareness. It is urgent to seek innovative sustainable energy supply and to develop advanced energy storage and conversion systems to alleviate energy crisis and environmental problems. Batteries and super-capacitors are key promising energy storage devices for load levelling and electric vehicles. In many cases, the concept is known, but the right materials solutions are lacking.
Ionic materials have been highlighted as electrolytes for energy storage devices due to their attractive properties and designable features. However, at the current stage, the utilization of ionic materials for energy storage and harvesting is significantly held back due to the versatility of ion structures and chemical compositions of ionic materials that restrict choices of ion species that must be tailor-made to force high ion conductivity and low viscosity at ambient conditions. This leads to a huge cost on materials synthesis and experimental characterizations to select promising candidates as an intrinsic connection between nanoscopic ion structures and macroscopic functionalities of ionic materials remains terra incognita. Additionally, there is a grand challenge to experimentally characterize specific binding structures of ion groups on electrodes, transport and electrochemical quantities of ionic materials in solid-electrolyte interphase (SEI), and more severely, their interfacial structural relaxations in SEI upon charging and discharging energy storage devices.
Molecular simulations are well positioned to provide state-of-art understanding of complicated phenomena on nano- and mesoscopic levels due to the boost of computer power and advent of computational algorithms. This is of particular significance for studying ionic materials because of their large diversities in ion structures and chemical compositions. As transport quantities of ionic materials and related charging/discharging phenomena happening at a wide spatiotemporal interval in energy storage devices, a multiscale modelling protocol unifying different methods and hierarchical models will be effective in describing intrinsic correlations between nanoscopic ion structures and macroscopic functionalities of ionic materials.
The goal of this project is to advance functionalities of ionic materials in energy storage devices via a multiscale modelling approach through 1) construction of hierarchical models for representative ionic materials; 2) optimization transport and electro-chemical stabilities of ionic materials via a systematic variation of chemical compositions of ionic materials; 3) investigation specific structural and dynamical correlations of ion structures in SEI to external stimuli to explore intrinsic charging and discharging mechanisms of ionic materials; and 4) development of an economical and robust modelling protocol connecting nanoscopic ion structures and macroscopic functional performance of ionic materials in energy storage devices.
Completing all these steps will allow us to construct a specific ontology relating nanoscopic ion structures to microstructures and dynamics, mesoscopic materials morphologies, and their macroscopic functionalities in confined environments to identify promising ionic materials and thereafter to optimize their functional performance as electrolytes for energy storage and harvesting.
