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Strain‐Based In Situ Study of Anion and Cation Insertion into Porous Carbon Electrodes with Different Pore Sizes
Author(s) -
Black Jennifer M.,
Feng Guang,
Fulvio Pasquale F.,
Hillesheim Patrick C.,
Dai Sheng,
Gogotsi Yury,
Cummings Peter T.,
Kalinin Sergei V.,
Balke Nina
Publication year - 2014
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201300683
Subject(s) - materials science , electrolyte , molecular dynamics , microporous material , carbon fibers , horizontal scan rate , electrode , porosity , ion , kinetics , in situ , strain (injury) , chemical physics , analytical chemistry (journal) , chemical engineering , composite material , electrochemistry , cyclic voltammetry , chemistry , chromatography , organic chemistry , computational chemistry , medicine , physics , quantum mechanics , composite number , engineering
The expansion of porous carbon electrodes in a room temperature ionic liquid (RTIL) is studied using in situ atomic force microscopy (AFM). The effect of carbon surface area and pore size/pore size distribution on the observed strain profile and ion kinetics is examined. Additionally, the influence of the potential scan rate on the strain response is investigated. By analyzing the strain data at various potential scan rates, information on ion kinetics in the different carbon materials is obtained. Molecular dynamics (MD) simulations are performed to compare with and provide molecular insights into the experimental results; this is the first MD work investigating the pressure exerted on porous electrodes under applied potential in a RTIL electrolyte. Using MD, the pressure exerted on the pore wall is calculated as a function of potential/charge for both a micropore (1.2 nm) and a mesopore (7.0 nm). The shape of the calculated pressure profile matches closely with the strain profiles observed experimentally.