Validated predictive computational methods for surface charge in heterogeneous functional materials: HeteroFoaM™

Kenneth L Reifsnider,Jon Michael Adkins,Jeffrey Baker,Dan G Cacuci,Fazle Rabbi

doi:10.1186/s40759-014-0001-y

Kenneth L Reifsnider, Jon Michael Adkins + Show 3 more

Open Access

https://doi.org/10.1186/s40759-014-0001-y

Copy DOI

Abstract

Abstract Background Essentially all heterogeneous materials are dielectric, i.e., they are imperfect conductors that generally display internal charge displacements that create dissipation and local charge accumulation at interfaces. Over the last few years, the authors have focused on the development of an understanding of such behaviour in heterogeneous functional materials for energy conversion and storage, called HeteroFoaM (www.HeteroFoaM.com). Using paradigm problems, this work will indicate major directions for developing generally applicable methods for the multiphysics, multi-scale design of heterogeneous functional materials. Methods The present paper outlines the foundation for developing validated predictive computational methods that can be used in the design of multi-phase heterogeneous functional materials, or HeteroFoaM, as a genre of materials. Such methods will be capable of designing not only the constituent materials and their interactions, but also the morphology of the shape, size, surfaces and interfaces that define the heterogeneity and the resulting functional response of the material system. Results Relationships to applications which drive this development are identified. A paradigm problem based on dielectric response is formulated and discussed in context. Conclusions We report an approach that defines a methodology for designing not only the constituent material properties and their interactions in a heterogeneous dielectric material system, but also the morphology of the shape, size, surface, and interfaces that defines the heterogeneity and the resulting functional response of that system.

Highlights

All heterogeneous materials are dielectric, i.e., they are imperfect conductors that generally display internal charge displacements that create dissipation and local charge accumulation at interfaces
Over the last few years, the authors have focused on the development of an understanding of such behaviour in heterogeneous functional materials for energy conversion and storage, called HeteroFoaM
Heterogeneous functional materials are widely used in our society as the materials systems that make batteries, fuel cells, separation membranes, and many electrochemical devices possible

Summary

Methods

We consider a simple two-phase material with morphology as shown in Figure 2 as a foundation for describing our approach. Cacuci and co-workers (Cacuci 2003; Cacuci et al 2005; Cacuci and Mihaela Ionescu-Bujor 2010; Cacuci et al 2014; Cacuci 2014a) have embarked on an effort to formulate a new conceptual framework that unifies the currently disparate fields of “inverse problems”, data assimilation, model calibration and validation, by developing a unified framework based on physics-driven mathematical procedures founded on the maximum entropy principle, dispensing with the need for “minimizing user-defined cost functionals” (which characterizes virtually all of the methods currently in use) This fairly self-explanatory framework is depicted, and aims at developing validated predictive computational methods that can be used in the design of multi-phase HeteroFoaM materials. The high efficiency of the second-order adjoint sensitivity analysis procedure (SO-ASAP) has been illustrated (Cacuci 2014b) via an application to a paradigm particle diffusion problem; a series of papers documenting the HO-ASAP are currently in preparation

Conclusions

Background