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