Investigating the Complex Chemistry of Functional Energy Storage Systems: The Need for an Integrative, Multiscale (Molecular to Mesoscale) Perspective

Abstract

Electric energy storage systems such as batteries can significantly impact society in a variety of ways, including facilitating the widespread deployment of portable electronic devices, enabling the use of renewable energy generation for local off grid situations and providing the basis of highly efficient power grids integrated with energy production, large stationary batteries, and the excess capacity from electric vehicles. A critical challenge for electric energy storage is understanding the basic science associated with the gap between the usable output of energy storage systems and their theoretical energy contents. The goal of overcoming this inefficiency is to achieve more useful work (w) and minimize the generation of waste heat (q). Minimization of inefficiency can be approached at the macro level, where bulk parameters are identified and manipulated, with optimization as an ultimate goal. However, such a strategy may not provide insight toward the complexities of electric energy storage, especially the inherent heterogeneity of ion and electron flux contributing to the local resistances at numerous interfaces found at several scale lengths within a battery. Thus, the ability to predict and ultimately tune these complex systems to specific applications, both current and future, demands not just parametrization at the bulk scale but rather specific experimentation and understanding over multiple length scales within the same battery system, from the molecular scale to the mesoscale. Herein, we provide a case study examining the insights and implications from multiscale investigations of a prospective battery material, Fe3O4.

Boosting Rechargeable Batteries R&D by Multiscale Modeling: Myth or Reality?

“…Within the realm of battery modeling, some of these models have already been the subject of numerous comprehensive review papers. − …”

Multi-electron transfer enabled by topotactic reaction in magnetite

“…And due to its high capacity, low cost, and natural abundance, Fe 3 O 4 is of great interest for battery application 12,15–19 . The recent mechanistic studies on electrochemical reaction in Fe 3 O 4 provided insights into the structure-determined ionic transport and high cyclability in this material 12,16,24–26 . Particularly, a combination of synchrotron X-ray and electron microscopy measurements revealed preferential orientation of the formed Fe nanoparticles 12 .…”

Atomic Structure of 2 nm Size Metallic Cobalt Prepared by Electrochemical Conversion: An in Situ Pair Distribution Function Study

“…13,22 Much progresses have been made toward the fundamental understanding of the conversion-based mechanisms. [22][23][24][25][26][27][28] Moreover, these reactions provide also unique opportunities to design ultra-small objects with unique structural and physico-chemical properties. 29 In the present work, we investigated the lithium electrochemical conversion reaction occurring in CoF2, a potential high capacity electrode.…”