High specific power/energy, ultralong life supercapacitors enabled by cross-cutting bamboo-derived porous carbons

Ultralong-Life Supercapacitors Using Pyridine-Derived Porous Carbon Materials

“…It can be seen from the bode phase diagram (Figure S3) that the low-frequency phase angle of C-700 is −81°, which is close to the ideal angle (−90°), indicating that this is a capacitive behavior. When the characteristic frequency (f 0 ) is 0.67 Hz, the phase angle reaches −45° and the corresponding time constant (τ 0 ) is 1.49 s. The characteristic relaxation time constant (τ 0 ) represents the charge and reversible discharge rates of an electrode. , The quasi-linearity of the Nyquist curve in the low-frequency region shows that the C-700-based electrode exhibits a good capacitance behavior because of its low diffusion resistance. Additionally, W and CPE are the Warburg element and electrochemical double-layer capacitance, respectively.…”

Different pretreatment methods combined with subsequent activation to convert waste eucalyptus bark into porous carbon electrode materials for supercapacitors

“…At a current density of 0.5 A g À1 , the specific capacitance of PBPC-600, PBPC-700 and PBPC-800 was 349.4 F g À1 , 337.8 F g À1 and 305.6 F g À1 , which retained 257.0 F g À1 , 253.8 F g À1 and 238.0 F g À1 at a current density of 20 A g À1 , respectively. As listed in Table S1 (ESI †), compared with some reported porous carbon derived from waste biomass such as fallen leaves, 53 ginkgo leaves, 54 bamboo, 55,56 tea leaves, 57 rice straw, 58 withered rose 59 and lotus seedpod, 60 the PBPC-600 electrode possessed a marvelous specific capacitance, indicating that it had a great application potential as an electrode material for supercapacitors. The rate capability of each electrode is summarized in Fig.…”

High-performance supercapacitor electrode materials based on chemical co-precipitation synthesis of nickel oxide (NiO)/cobalt oxide (Co3O4)-intercalated graphene nanosheets binary nanocomposites

“…In general, organic electrolytes' electrochemical stability surpasses aqueous ones due to the absence of water and hence no trace of water splitting. Therefore, by taking benefit from this feature of organic electrolytes, the supercapacitor cells' voltage window was extended, and a higher energy density was obtained according to equation (5). However, organic electrolytes are composed of organic charge carriers with large ionic radius and lower electroconductivity.…”

“…Considering that renewable energy sources are not widely available, electrochemical energy storage devices such as fuel cells, rechargeable batteries, and supercapacitors are promising candidates to substitute the coal-powered supplies. Rechargeable batteries and supercapacitors can mostly play leading roles in portable electronic devices and the upcoming clean, zero-emission electric vehicles [1][2][3][4][5][6][7].…”