Understanding the Strength of the Selenium-Graphene Interfaces for Energy Storage Systems

Document Type

Article

Publication Date

2-16-2021

Abstract

We present comprehensive first-principles density functional theory (DFT) analyses of the interfacial strength and bonding mechanisms between crystalline and amorphous selenium (Se) with graphene (Gr), a promising duo for energy storage applications. Comparative interface analyses are presented on amorphous silicon (Si) with graphene and crystalline Se with a conventional aluminum (Al) current collector. The interface strengths of monoclinic Se (0.43 J m-2) and amorphous Si with graphene (0.41 J m-2) are similar in magnitude. While both materials (c-Se, a-Si) are bonded loosely by van der Waals (vdW) forces over graphene, interfacial electron exchange is higher for a-Si/graphene. This is further elaborated by comparing the potential energy step and charge transfer (Δq) across the graphene interfaces. The interface strength of c-Se on a 3D Al current collector is higher (0.99 J m-2), suggesting a stronger adhesion. Amorphous Se with graphene has comparable interface strength (0.34 J m-2), but electron exchange in this system is slightly distinct from monoclinic Se. The electronic characteristics and bonding mechanisms are different for monoclinic and amorphous Se with graphene as they activate graphene via surface charge doping divergently. The implications of these interfacial physicochemical attributes on electrode performance have been discussed. Our findings highlight the complex electrochemical phenomena in Se interfaced with graphene, which may profoundly differ from their "free"counterparts.

Identifier

85100770973 (Scopus)

Publication Title

Langmuir

External Full Text Location

https://doi.org/10.1021/acs.langmuir.0c02893

e-ISSN

15205827

ISSN

07437463

PubMed ID

33524260

First Page

2029

Last Page

2039

Issue

6

Volume

37

Grant

1911900

Fund Ref

National Science Foundation

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