Bismuth oxide self-standing anodes with concomitant carbon dots welded graphene layer for enhanced performance supercapacitor-battery hybrid devices

MOF-derived Bi2O3@C microrods as negative electrodes for advanced asymmetric supercapacitors

“…1f) indicates that the highly intensive peak ($284.9 eV) can be assigned to sp 2 hybridized carbon atoms, the other peak at $284.4 eV, $285.5 eV, and $288.7 eV are associated with C-O, C]O, and O-C]O, respectively. 9 The morphology of CAU-17 presents hexagonal microrods ( Fig. 2a).…”

“…3a) at different scan rates show a reversible charge-discharge response, and the distinct anodic and cathodic peaks are corresponding to the redox reactions of Bi 0+ , Bi 2+ and Bi 3+ . The possible faradaic reaction mechanism is described as the following equation: 9 Bi 2 O 3 + 3H 2 O +6e À 4 2Bi + 6OH À . Also, the current densities of redox peaks increase with the increased scan rates, indicating fast redox reactions at the electrode/electrolyte interface.…”

“…7 Recently, bismuth oxide (Bi 2 O 3 ) has been considered as a promising negative electrode material due to its cheaper, environmental friendliness, abundant resources and high theoretical specic capacities (1370 C g À1 at 1 A g À1 ). 8,9 For instance, Qiu et al 10 synthesized ultrathin Bi 2 O 3 nanowires by oxidative metal vapor transport deposition technique, which exhibited high specic capacity (576 C g À1 at 2 A g À1 ). Shinde et al 11 grew 3D Bi 2 O 3 by fast chemical method at room temperature, which demonstrated a specic capacity of 447 C g À1 at current density of 2 A g À1 .…”

High-performance Bi2O3-NC anodes through constructing carbon shells and oxygen vacancies for flexible battery-supercapacitor hybrid devices

“…The bad rate capability and low power density are mainly attributed to multielectron Faradic reactions of the unmatched Bi 2 O 3 electrodes for charge storage, which reflect relatively slower electrochemical kinetics than that of high-rate capacitive electrodes. To solve this, constructing composite structure has been considered as an effective strategy, resulting in the formation of Bi 2 O 3 /carbon composite electrodes, such as Bi 2 O 3 /activated carbon, 25,26 Bi 2 O 3 /carbon quantum dot, 27,28 Bi 2 O 3 /graphene. 28 For instance, a graphene/carbon dots encapsulation structure for the Bi 2 O 3 electrode supported by carbon nanotube films, has been reported to not only improve the conductivity but also inhibit the loss of capacity, which can account for the asymmetric supercapacitor with the energy density of 98.2 Wh kg -1 and the capacity retention of 80.1% after 8000 cycles.…”

“…To solve this, constructing composite structure has been considered as an effective strategy, resulting in the formation of Bi 2 O 3 /carbon composite electrodes, such as Bi 2 O 3 /activated carbon, 25,26 Bi 2 O 3 /carbon quantum dot, 27,28 Bi 2 O 3 /graphene. 28 For instance, a graphene/carbon dots encapsulation structure for the Bi 2 O 3 electrode supported by carbon nanotube films, has been reported to not only improve the conductivity but also inhibit the loss of capacity, which can account for the asymmetric supercapacitor with the energy density of 98.2 Wh kg -1 and the capacity retention of 80.1% after 8000 cycles. 28 Furthermore, the introduction of oxygen vacancies into crystal lattice of Bi 2 O 3 , has been considered as another effective route to the improvement of ion diffusion kinetics, 29 which is essential for reasonably matching the battery-type electrodes with the capacitive electrodes in BSH devices.…”