87 research outputs found
Free-standing and bendable carbon nanotubes/TiO(2) nanofibres composite electrodes for flexible lithium ion batteries
No full textAbstract not availablePeng Zhang, Jingxia Qiu, Zhanfeng Zheng, Gao Liu, Min Ling, Wayde Martens, Haihui Wang, Huijun Zhao, Shanqing Zhan
SnO₂ decorated graphene nanocomposite anode materials prepared via an up-scalable wet-mechanochemical process for sodium ion batteries
No full textA facile and up-scalable wet-mechanochemical process is designed for fabricating ultra-fine SnO2 nanoparticles anchored on graphene networks for use as anode materials for sodium ion batteries. A hierarchical structure of the SnO2@graphene composite is obtained from the process. The resultant rechargeable SIBs achieved high rate capability and good cycling stability.Sheng Li, Yazhou Wang, Jingxia Qiu, Min Ling, Haihui Wang, Wayde Martens and Shanqing Zhan
Microporous bamboo biochar for lithium−sulfur batteries
No full textBeing simple, inexpensive, scalable and environmentally friendly, microporous biomass biochars have been attracting enthusiastic attention for application in lithium-sulfur (Li-S) batteries. Herein, porous bamboo biochar is activated via a KOH/annealing process that creates a microporous structure, boosts surface area and enhances electronic conductivity. The treated sample is used to encapsulate sulfur to prepare a microporous bamboo carbon-sulfur (BC-S) nanocomposite for use as the cathode for Li-S batteries for the first time. The BC-S nanocomposite with 50 wt.% sulfur content delivers a high initial capacity of 1,295 mA·h/g at a low discharge rate of 160 mA/g and high capacity retention of 550 mA·h/g after 150 cycles at a high discharge rate of 800 mA/g with excellent coulombic efficiency (=95%). This suggests that the BC-S nanocomposite could be a promising cathode material for Li-S batteriesGriffith Sciences, Griffith School of EnvironmentFull Tex
Carbonaceous and Hydrogenated Nanostructured Materials for Energy Storage Devices
No full textMaterials engineering and nano-manipulation play a key role in the development of advanced Lithium-ion batteries (LIBs) in terms of energy and power density (both gravimetric and volumetric), stability, rate capability, safety and the cost of production. In this thesis, two strategies are used to address the demands, i.e., the use of low cost and environmentally benign carbonaceous nanostructured materials (CNMs) and the use of hydrogenation technology.
In the first strategy, CNMs including carbon nanotubes (CNTs) and graphene are incorporated with anode materials (such as metal oxide and carbon) to synthesize corresponding CNM composites that possess improved electrochemical performance because it can not only provide highly conductive matrix but also prevent the aggregation of the nanostructured electrode materials and the CNMs.
TiO2-reduced graphene oxide (TiO2-RGO) was prepared for LIBs using photocatalysis method. TiO2 nanoparticles can be anchored on the GO sheets via the abundant oxygen-containing functional groups. Using the TiO2 photocatalyst, the GO was photocatalytically reduced under UV illumination, leading to the production of TiO2-RGO nanocomposite. The resultant LIBs of the TiO2-RGO nanocomposite possess more stable cyclic performances, larger reversible capacities, and better rate capability, compared with those of the pure TiO2 and TiO2-GO samples.Thesis (PhD Doctorate)Doctor of Philosophy (PhD)Griffith School of EnvironmentScience, Environment, Engineering and TechnologyFull Tex
Rational design of sustainable transition metal-based bifunctional electrocatalysts for oxygen reduction and evolution reactions
No full textOxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are two critical processes for metal-air batteries (MABs) that afford large energy capacity and high power density. However, both reactions suffer from sluggish kinetics. The availability of efficient electrocatalysts that could conquer activation energy barriers and accelerate reaction rates is crucial to tackling this issue. The noble metal-based electrocatalysts (e.g., Pt/C and Ru/IrO2) cannot meet the requirement for large-scale applications due to their scarce abundance, high cost, and insufficient stability. Transition metal-based materials can be a sustainable and promising candidate to replace the noble metal-based electrocatalysts for this purpose. This review intends to review the most recent, high performance, and sustainable strategies on tuning the catalytic activity of the transition metal-based materials toward ORR and OER. We also propose perspectives on remaining challenges and future research directions of transition metal-based bifunctional electrocatalysts toward practical applications. These fundamental design principles and strategies are crucial to guide and accelerate the design of the ideal catalysts and make possible the practical applications of MABs.No Full Tex
Multifunctional SA-PProDOT binder for lithium ion batteries
No full textAn environmentally benign, highly conductive,\ud
and mechanically strong binder system can overcome the\ud
dilemma of low conductivity and insufficient mechanical\ud
stability of the electrodes to achieve high performance lithium ion batteries (LIBs) at a low cost and in a sustainable way. In this work, the naturally occurring binder sodium alginate (SA) is functionalized with 3,4-propylenedioxythiophene-2,5-dicarboxylic acid (ProDOT) via a one-step esterification reaction in a cyclohexane/dodecyl benzenesulfonic acid (DBSA)/water\ud
microemulsion system, resulting in a multifunctional polymer\ud
binder, that is, SA-PProDOT. With the synergetic effects of the functional groups (e.g., carboxyl, hydroxyl, and ester groups), the resultant SA-PProDOT polymer not only maintains the outstanding binding capabilities of sodium alginate but also enhances the mechanical integrity and lithium ion diffusion coefficient in the LiFePO4 (LFP) electrode during the operation of the batteries. Because of the conjugated network of the PProDOT and the lithium doping under the battery environment, the SA-PProDOT becomes conductive and matches the conductivity needed for LiFePO4 LIBs. Without the need of conductive additives such as carbon black, the resultant batteries have achieved the theoretical specific capacity of LiFePO4 cathode (ca. 170 mAh/g) at C/10 and ca. 120 mAh/g at 1C for more than 400 cycles
Low cost and green preparation process for α-Fe2O3@gum arabic electrode for high performance sodium ion batteries
No full textConventional electrode manufacturing processes for lithium ion batteries involve the use of toxic organic solvents (such as N-methyl-2-pyrrolidone, NMP). A low cost and green preparation process for high performance electrodes for sodium ion batteries (SIBs) is important to address simultaneously the environmental and health risks of production processes and the shortage of lithium metal. Herein, gum arabic (GA), which is a non-toxic biodegradable biopolymer, is used as a water soluble binder to design a water-based electrode preparation process to fabricate α-Fe2O3 electrodes (i.e., α-Fe2O3@GA electrode). The α-Fe2O3@GA electrode demonstrates better mechanical properties and binding capability than that of the α-Fe2O3 electrode with poly(vinylidene fluoride) (PVDF) as the binder (α-Fe2O3@PVDF electrode). Due to these merits, a higher rate and cycling performance of the α-Fe2O3@GA electrode are achieved compared with the α-Fe2O3@PVDF electrode when both electrodes are used for SIBs' application. The α-Fe2O3@GA electrode demonstrates high initial discharge and charge capacities of 2437 and 1102 mA h g−1 at the current density of 0.2 A g−1. The α-Fe2O3@GA electrode maintains a high reversible discharge capacity of 492 mA h g−1 at the current density of 5 A g−1 after 500 cycles with a fading rate of 0.08% per cycle after the first cycle, which indicates a superior cycling performance. The outstanding performance of the resultant SIBs suggests that the green fabrication process of the α-Fe2O3@GA electrode would play a critical role in the future battery industry.Griffith Sciences, Environmental Futures Research InstituteNo Full Tex
Directional synthesis of tin oxide@graphene nanocomposites via a one-step up-scalable wet-mechanochemical route for lithium ion batteries
No full textDirectional synthesis of SnO2@graphene nanocomposites via a one-step, low-cost, and up-scalable wet-mechanochemical method is achieved using graphene oxide and SnCl2 as precursors. The graphene oxides are reduced to graphene while the SnCl2 is oxidized to SnO2 nanoparticles that are in situ anchored onto the graphene sheets evenly and densely, resulting in uniform SnO2@graphene nanocomposites. The prepared nanocomposites possess excellent electrochemical performance and outstanding cycling in Li-ion batteries.Griffith Sciences, School of Environment and ScienceFull Tex
Dual-functional gum arabic binder for silicon anodes in lithium ion batteries
No full textSi has attracted enormous research and manufacturing attention as an anode material for lithium ion batteries (LIBs) because of its high specifi c capacity. The lack of a low cost and effective mechanism to prevent the pulverization of Si electrodes during the lithiation/ delithiation process has been a major barrier in the mass production of Si anodes. Naturally abundant gum arabic (GA), composed of polysaccharides and glycoproteins, is applied as a dualfunction binder to address this dilemma. Firstly, the hydroxyl groups of the polysaccharide in GA are crucial in ensuring strong binding to Si. Secondly, similar to the function of fi ber in fi berreinforced concrete (FRC), the long chain glycoproteins provide further mechanical tolerance to dramatic volume expansion by Si nanoparticles. The resultant Si anodes present an outstanding capacity of ca. 2000 mAh/g at a 1 C rate and 1000 mAh/g at 2 C rate, respectively, throughout 500 cycles. Excellent long-term stability is demonstrated by the maintenance of 1000 mAh/g specifi c capacity at 1 C rate for over 1000 cycles. This low cost, naturally abundant and environmentally benign polymer is a promising binder for LIBs in the future.Griffith Sciences, Griffith School of EnvironmentNo Full Tex
Recent applications of TiO2 nanomaterials in chemical sensing in aqueous media
No full textA review. TiO2 is n-type, wide band-gap and environmentally friendly semiconductor with good biocompatibility and stability. On the one hand, owing to the large surface area, TiO2 nanomaterials possess unique chem., phys., optical, electronic, and photocatalytic properties. On the other hand, a large amt. of the TiO2 nanostructures were prepd., characterized and available for construction of sensor due to the tremendous efforts from scientists and materials engineers. These bestow the TiO2 nanomaterials be used as an extremely versatile component to construct a wide range of sensing devices for detn. of chems. in aq. media. This work aims to review the recent applications of the TiO2 nanomaterials for fabrication of electrochem. sensors, electrochem. biosensors, photocatalytic sensors and photoelectrocatalytic sensors.Griffith Sciences, Griffith School of EnvironmentNo Full Tex
- …
