TY - JOUR
T1 - Understanding the Strength of the Selenium-Graphene Interfaces for Energy Storage Systems
AU - Sharma, Vidushi
AU - Mitlin, David
AU - Datta, Dibakar
N1 - Funding Information:
D.M. (co-conception and guidance of research, preparation of the manuscript) was supported by the National Science Foundation, Civil, Mechanical and Manufacturing Innovation (CMMI), Award Number 1911905. V.S. (computation, manuscript preparation) and D.D. (co-conception and guidance of research, preparation of the manuscript) were supported by NSF (Award Number 1911900). D.D. acknowledges the Extreme Science and Engineering Discovery Environment (XSEDE) for the computational facilities (Award Number – DMR180013). V.S. acknowledges Dr. Kamalika Ghatak for the fruitful discussion during the project.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/2/16
Y1 - 2021/2/16
N2 - 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.
AB - 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.
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U2 - 10.1021/acs.langmuir.0c02893
DO - 10.1021/acs.langmuir.0c02893
M3 - Article
C2 - 33524260
AN - SCOPUS:85100770973
SN - 0743-7463
VL - 37
SP - 2029
EP - 2039
JO - Langmuir
JF - Langmuir
IS - 6
ER -