TY - JOUR
T1 - Three-dimensional modeling of mediator-enhanced solid-state supercapacitors
AU - Wang, Yuchen
AU - Zhang, Chen
AU - Qiao, Xiaoyao
AU - Mansour, Azzam N.
AU - Zhou, Xiangyang
N1 - Funding Information:
The authors thank the US Office of Naval Research (Grant number: N00014-17-1-2362) and Emil Buehler Foundation for partial financial support.
Funding Information:
The authors thank the US Office of Naval Research (Grant number: N00014-17-1-2362 ) and Emil Buehler Foundation for partial financial support.
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/5/31
Y1 - 2019/5/31
N2 - A three-dimension model is set up to simulate the transport and electrochemical processes in mediator-enhanced solid-state supercapacitors. The roles of mediators are studied in wide ranges of mediator parameters, including concentration, conductivity, and diffusivity. The simulation results are validated using experimental data previously published. The simulation results show that with a concentration of mediators greater than 0.2 mol L−1 and diffusivity of mediators greater than 3 × 10−12 m2 s−1 in electrodes, the charge/discharge behaviours are generally battery-like. The simulation results clearly reveal that if free ions are given off by mediators during the charging process, the specific capacity of the supercapacitors can be increased. The simulation results also indicate that if the diffusivity of mediators in the separator membrane is below 10−12 m2 s−1, the self-discharge of the supercapacitor due to shuttling of the redox species between the electrodes is negligible. Thus, an operational mediator supercapacitor relies on a selective separator membrane and a high diffusivity of mediators in the composite electrodes.
AB - A three-dimension model is set up to simulate the transport and electrochemical processes in mediator-enhanced solid-state supercapacitors. The roles of mediators are studied in wide ranges of mediator parameters, including concentration, conductivity, and diffusivity. The simulation results are validated using experimental data previously published. The simulation results show that with a concentration of mediators greater than 0.2 mol L−1 and diffusivity of mediators greater than 3 × 10−12 m2 s−1 in electrodes, the charge/discharge behaviours are generally battery-like. The simulation results clearly reveal that if free ions are given off by mediators during the charging process, the specific capacity of the supercapacitors can be increased. The simulation results also indicate that if the diffusivity of mediators in the separator membrane is below 10−12 m2 s−1, the self-discharge of the supercapacitor due to shuttling of the redox species between the electrodes is negligible. Thus, an operational mediator supercapacitor relies on a selective separator membrane and a high diffusivity of mediators in the composite electrodes.
KW - Crossover
KW - Ion supply
KW - Mediator
KW - Solid-state supercapacitor
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U2 - 10.1016/j.jpowsour.2019.03.012
DO - 10.1016/j.jpowsour.2019.03.012
M3 - Article
AN - SCOPUS:85063049208
VL - 423
SP - 18
EP - 25
JO - Journal of Power Sources
JF - Journal of Power Sources
SN - 0378-7753
ER -