Nile
Blue Functionalized Graphene Aerogel as a Pseudocapacitive
Negative Electrode Material across the Full pH Range
Yasin Shabangoli
Mohammad S. Rahmanifar
Abolhassan Noori
Maher F. El-Kady
Richard B. Kaner
Mir F. Mousavi
10.1021/acsnano.9b03351.s002
https://acs.figshare.com/articles/media/Nile_Blue_Functionalized_Graphene_Aerogel_as_a_Pseudocapacitive_Negative_Electrode_Material_across_the_Full_pH_Range/10060145
The
pursuit of new negative electrode materials for redox supercapacitors
with a high capacitance, boosted energy, and high rate capability
is still a tremendous challenge. Herein, we report a Nile Blue conjugated
graphene aerogel (NB–GA) as a negative electrode material with
excellent pseudocapacitive performance (with specific capacitance
of up to 483 F g<sup>–1</sup> at 1 A g<sup>–1</sup>)
in all acidic, neutral, and alkaline aqueous electrolytes. The contribution
from capacitive charge storage represents 93.4% of the total charge,
surpassing the best pseudocapacitors known. To assess the feasibility
of NB–GA as a negative electrode material across the full pH
range, we fabricated three devices, namely, a symmetric NB–GA||NB–GA
device in an acidic (1.0 M H<sub>2</sub>SO<sub>4</sub>) electrolyte,
an NB–GA||MnO<sub>2</sub> device in a pH-neutral (1.0 M Na<sub>2</sub>SO<sub>4</sub>) electrolyte, and an NB–GA||LDH (LDH
= Ni–Co–Fe layered double hydroxide) device in an alkaline
(1.0 M KOH) electrolyte. The NB–GA||NB–GA device exhibits
a maximum specific energy of 22.1 Wh kg<sup>–1</sup> and a
specific power of up to 8.1 kW kg<sup>–1</sup>; the NB–GA||MnO<sub>2</sub> device displays a maximum specific energy of 55.5 Wh kg<sup>–1</sup> and a specific power of up to 14.9 kW kg<sup>–1</sup>, and the NB–GA||LDH device shows a maximum specific energy
of 108.5 Wh kg<sup>–1</sup> and a specific power of up to 25.1
kW kg<sup>–1</sup>. All the devices maintain excellent stability
over 5000 charge–discharge cycles. The outstanding pseudocapacitive
performances of the NB–GA nanocomposites render them a highly
promising negative electrode material across the entire pH range.
2019-10-28 15:36:16
electrolyte
pH range
Nile Blue Functionalized Graphene Aerogel
electrode material
LDH
NB
capacitive charge storage
KOH
device
kg
Full pH Range