Carbon Quantum Dot-Anchored Bismuth Oxide Composites as Potential Electrode for Lithium-Ion Battery and Supercapacitor Applications

Abstract

The present investigation elucidates a simple hydrothermal method for preparing nanostructured bismuth oxide (Bi 2 O 3 ) and carbon quantum dot (CQD) composite using spoiled (denatured) milk-derived CQDs. The formation of the CQD–Bi 2 O 3 composite was confirmed by UV–vis absorption, steady-state emission, and time-resolved fluorescence spectroscopy studies. The crystal structure and chemical composition of the composite were examined by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and thermogravimetric analysis. The surface morphology and the particle size distribution of the CQD–Bi 2 O 3 were examined using field emission scanning electron microscope and high-resolution transmission electron microscope observations. As an anode material in lithium-ion battery, the CQD–Bi 2 O 3 composite exhibited good electrochemical activity and delivered a discharge capacity as high as 1500 mA h g –1 at 0.2C rate. The supercapacitor properties of the CQD–Bi 2 O 3 composite electrode revealed good reversibility and a high specific capacity of 343 C g –1 at 0.5 A g –1 in 3 M KOH. The asymmetric device constructed using the CQD–Bi 2 O 3 and reduced graphene oxide delivered a maximum energy density of 88 Wh kg –1 at a power density of 2799 W kg –1 , while the power density reached a highest value of 8400 W kg –1 at the energy density of 32 Wh kg –1 . The practical viability of the fabricated device is demonstrated by glowing light-emitting diodes. It is inferred that the presence of conductive carbon network has significantly increased the conductivity of the oxide matrix, thereby reducing the interfacial resistance that resulted in excellent electrochemical performances.

Carbon-Based Quantum Dots for Supercapacitors: Recent Advances and Future Challenges

“…C-QDs have been combined with many supercapacitor electrode materials to enhance their performances by modifying either their electrochemical properties or their surface properties. C-QDs have been reported to provide carbon matrices to improve their electrical conductivity and solid electrolyte interface stability [ 145 ]. Wei et al reported that a combination of NaOH treatment and the addition of C-QDs into carbon matrices would give a large hierarchical structure which provides ion-buffering reservoirs resulting in better electronic properties.…”

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

“…7b and listed in Table S5. BSH-1 provided an amazing energy density of 118 Wh kg -1 at the power density of 1.15 kW kg -1 , much higher than those of the reported symmetric device based on CQD-Bi 2 O 3 (88 Wh kg -1 ) 27 and asymmetric devices, such…”

“…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.…”

Bi‐Based Electrode Materials for Alkali Metal‐Ion Batteries

“…Besides, Fang et al [113] prepared polypyrrole-coated Bi 2 O 3 @CMK-3 nanocomposite, which exhibited enhanced performance of lithium storage due to the synergetic effect of nanosize Bi 2 O 3 , conductive CMK-3 and PPy layer (Figure 8e). Prasath et al [114] fabricated a novel carbon quantum dot (CQD)-anchored Bi 2 O 3 composite used as anode materials for LIBs, delivering a discharge capacity high up to 1500 mAh g −1 at 0.2 C.…”

“…Prasath et al. [ 114 ] fabricated a novel carbon quantum dot (CQD)‐anchored Bi 2 O 3 composite used as anode materials for LIBs, delivering a discharge capacity high up to 1500 mAh g −1 at 0.2 C.…”