Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 14 of 14

Full-Text Articles in Engineering

A Custom Battery For Operando Neutron Powder Diffraction Studies Of Electrode Structure, Wei Kong Pang, Vanessa Peterson Jan 2015

A Custom Battery For Operando Neutron Powder Diffraction Studies Of Electrode Structure, Wei Kong Pang, Vanessa Peterson

Australian Institute for Innovative Materials - Papers

Structure-property relations are central to understanding functional materials, and for battery research the use of neutron powder diffraction to reveal the atomistic and molecular-scale origin of battery performance characteristics is often essential. Although operando experiments of this kind are increasingly common as neutron sources and instrumentation advance, these experiments are hindered by the often large barrier presented by the preparation of whole batteries that yield a neutron diffraction signal from the electrode of interest that is sufficient to extract detailed structural information. This article presents a custom battery that is specifically designed for operando neutron powder diffraction. The battery is …


Flexible Free-Standing Graphene Paper With Interconnected Porous Structure For Energy Storage, Kewei Shu, Caiyun Wang, Sha Li, Chen Zhao, Yang Yang, Hua-Kun Liu, Gordon G. Wallace Jan 2015

Flexible Free-Standing Graphene Paper With Interconnected Porous Structure For Energy Storage, Kewei Shu, Caiyun Wang, Sha Li, Chen Zhao, Yang Yang, Hua-Kun Liu, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

A novel porous graphene paper is prepared via freeze drying a wet graphene oxide gel, followed by thermal and chemical reduction. The macroscopic structure of the formed graphene paper can be tuned by the water content in the gel precursor. With 92% water content, an interconnected macroporous network can be formed. This porous graphene (PG) paper exhibits excellent electrochemical properties. It can deliver a high discharge capacity of 420 mA h g−1 at a current density of 2000 mA g−1 when used as binder-free lithium ion battery anode. PG paper exhibits a specific capacitance of 137 F g …


Enhanced Electron Lifetime Of Cdse/Cds Quantum Dot (Qd) Sensitized Solar Cells Using Znse Core-Shell Structure With Efficient Regeneration Of Quantum Dots, Rasin K. Ahmed, Long Zhao, Attila J. Mozer, Geoffrey D. Will, John M. Bell, Hongxia Wang Jan 2015

Enhanced Electron Lifetime Of Cdse/Cds Quantum Dot (Qd) Sensitized Solar Cells Using Znse Core-Shell Structure With Efficient Regeneration Of Quantum Dots, Rasin K. Ahmed, Long Zhao, Attila J. Mozer, Geoffrey D. Will, John M. Bell, Hongxia Wang

Australian Institute for Innovative Materials - Papers

Research on development of efficient passivation materials for high performance and stable quantum dot sensitized solar cells (QDSCs) is highly important. While ZnS is one of the most widely used passivation material in QDSCs, an alternative material based on ZnSe which was deposited on CdS/CdSe/TiO2 photoanode to form a semi-core/shell structure has been found to be more efficient in terms of reducing electron recombination in QDSCs in this work. It has been found that the solar cell efficiency was improved from 1.86% for ZnSe0 (without coating) to 3.99% using 2 layers of ZnSe coating (ZnSe2) deposited by successive ionic …


Dual Yolk-Shell Structure Of Carbon And Silica-Coated Silicon For High-Performance Lithium-Ion Batteries, L Y. Yang, H Z. Li, Jun Liu, Ziqi Sun, S S. Tang, M Lei Jan 2015

Dual Yolk-Shell Structure Of Carbon And Silica-Coated Silicon For High-Performance Lithium-Ion Batteries, L Y. Yang, H Z. Li, Jun Liu, Ziqi Sun, S S. Tang, M Lei

Australian Institute for Innovative Materials - Papers

Silicon batteries have attracted much attention in recent years due to their high theoretical capacity, although a rapid capacity fade is normally observed, attributed mainly to volume expansion during lithiation. Here, we report for the first time successful synthesis of Si/void/SiO2/void/C nanostructures. The synthesis strategy only involves selective etching of SiO2 in Si/SiO2/C structures with hydrofluoric acid solution. Compared with reported results, such novel structures include a hard SiO2-coated layer, a conductive carbon-coated layer, and two internal void spaces. In the structures, the carbon can enhance conductivity, the SiO2 layer has mechanically …


A Fe/Fe3o4/N-Carbon Composite With Hierarchical Porous Structure And In Situ Formed N-Doped Graphene-Like Layers For High-Performance Lithium Ion Batteries, Yao Li, Qing Meng, Shenmin Zhu, Zeng-Hui Sun, Hao Yang, Zhixin Chen, Chengling Zhu, Zaiping Guo, Di Zhang Jan 2015

A Fe/Fe3o4/N-Carbon Composite With Hierarchical Porous Structure And In Situ Formed N-Doped Graphene-Like Layers For High-Performance Lithium Ion Batteries, Yao Li, Qing Meng, Shenmin Zhu, Zeng-Hui Sun, Hao Yang, Zhixin Chen, Chengling Zhu, Zaiping Guo, Di Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

Fe/Fe3O4/N-carbon composite consisting of a porous carbon matrix containing a highly conductive N-doped graphene-like network and Fe/Fe3O4 nanoparticles was prepared. The porous carbon has a hierarchical structure which is inherited from rice husk and the N-doped graphene-like network formed in situ. When used as an anode material for lithium batteries, the composite delivered a reversible capacity of approximately 610 mA h g(-1) at a current density of 200 mA g(-1) even after 100 cycles, due to the synergism between the unique hierarchical porous structures, highly electrically conductive N-doped graphene- like networks and nanosized particles of Fe/Fe3O4. This work provides a …


Thin Film Lubrication Of Hexadecane Confined By Iron And Iron Oxide Surfaces: A Crucial Role Of Surface Structure, Thi Dinh Ta, A Kiet Tieu, Hongtao Zhu, Buyung Kosasih Jan 2015

Thin Film Lubrication Of Hexadecane Confined By Iron And Iron Oxide Surfaces: A Crucial Role Of Surface Structure, Thi Dinh Ta, A Kiet Tieu, Hongtao Zhu, Buyung Kosasih

Faculty of Engineering and Information Sciences - Papers: Part A

A comparative analysis of thin film lubrication of hexadecane between different iron and its oxide surfaces has been carried out using classical molecular dynamic simulation. An ab initio force-field, COMPASS, was applied for n-hexadecane using explicit atom model. An effective potential derived from density functional theory calculation was utilized for the interfacial interaction between hexadecane and the tribo-surfaces. A quantitative surface parameterization was introduced to investigate the influence of surface properties on the structure, rheological properties, and tribological performance of the lubricant. The results show that although the wall-fluid attraction of hexadecane on pure iron surfaces is significantly stronger than …


Simple Structure For Reactive Power Control Of Ac Photovoltaic Modules, Viet Thang Tran, Danny Sutanto, Kashem M. Muttaqi Jan 2015

Simple Structure For Reactive Power Control Of Ac Photovoltaic Modules, Viet Thang Tran, Danny Sutanto, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

The objective of this paper is to propose a simple structure for reactive power control (RPC) of AC Photovoltaic (AC PV) modules. With the proposed structure, a cost-effective microcontroller can be adopted to achieve an effective reactive power control in order to support the grid voltage within acceptable bounds by absorbing or supplying reactive power. Moreover, the sliding mode control (SMC) is adopted to enhance the current control's dynamic response and reduce the current harmonic distortion. Comprehensive simulation of an AC PV module connected to grid using PSIM software with different operation modes are used to demonstrate the control strategy. …


Macrostrength And Pore Structure Of Coke Subjected To Gasification And Annealing Under Blast Furnace Conditions, Xing Xing, Harold P. Rogers, Guangqing Zhang, Paul Zulli, Oleg Ostrovski Jan 2015

Macrostrength And Pore Structure Of Coke Subjected To Gasification And Annealing Under Blast Furnace Conditions, Xing Xing, Harold P. Rogers, Guangqing Zhang, Paul Zulli, Oleg Ostrovski

Faculty of Engineering and Information Sciences - Papers: Part A

Metallurgical cokes were subjected to gasification by CO-CO2-N2 gas with blast furnace-like composition-temperature profile to 1400 °C and annealing under N2 at temperature up to 2000 °C. The degradation of coke strength following reaction and annealing was characterised using tensile testing. Both gasification and annealing decreased the mechanical strength of coke. Degradation of all examined cokes by gasification at 1400 °C was stronger in comparison with annealing at the same temperature.


High Temperature Dislocation Structure And Nbc Precipitation In Three Ni-Fe-Nb-C Model Alloys, Andrii Kostryzhev, Parvez Mannan, Olexandra Marenych Jan 2015

High Temperature Dislocation Structure And Nbc Precipitation In Three Ni-Fe-Nb-C Model Alloys, Andrii Kostryzhev, Parvez Mannan, Olexandra Marenych

Faculty of Engineering and Information Sciences - Papers: Part A

In this original work, the dislocation structure and NbC precipitation were investigated in three Ni-based alloys (70Ni-Fe-0.331Nb-0.040C, 70Ni-Fe-0.851Nb-0.114C and 70Ni-Fe-1.420Nb-0.157C, wt%) thermomechanically processed in the temperature range of 1250-1075 °C. The dislocation structure inhomogeneity (dislocation networks and cell walls), which we observed in the middle and high Nb+C alloys, resulted from the dislocation pile-ups in the vicinity of >200 nm NbC particles. The dislocation density around >200 nm particles exceeded the average values by 5-7 times, and that in the cell walls might exceed the average values by 10 times. Twins and stacking faults were observed in all alloys after …


Split-Half-Tubular Polypyrrole@Sulfur@Polypyrrole Composite With A Novel Three-Layer-3d Structure As Cathode For Lithium/Sulfur Batteries, Xin Liang, Mingang Zhang, Mohammad Kaiser, Xuanwen Gao, Konstantin Konstantinov, Richard Tandiono, Zhaoxiang Wang, Hua-Kun Liu, S X. Dou, Jiazhao Wang Jan 2015

Split-Half-Tubular Polypyrrole@Sulfur@Polypyrrole Composite With A Novel Three-Layer-3d Structure As Cathode For Lithium/Sulfur Batteries, Xin Liang, Mingang Zhang, Mohammad Kaiser, Xuanwen Gao, Konstantin Konstantinov, Richard Tandiono, Zhaoxiang Wang, Hua-Kun Liu, S X. Dou, Jiazhao Wang

Australian Institute for Innovative Materials - Papers

Polypyrrole@Sulfur@Polypyrrole composite with a novel three-layer-3D-structure, which consists of an external polypyrrole coating layer, an intermediate sulfur filling layer, and an internal polypyrrole split-half-tube conducting matrix layer, has been synthesized by the oxidative chemical polymerization method and chemical precipitation method in this article. Due to this unique three-layer-structure, the discharge specific capacity of Polypyrrole@Sulfur@Polypyrrole composite cathode retained at 554mAh g-1 after 50 cycles, which represents 68.8% retention of the initial discharge specific capacity. In comparison, the Sulfur@Polypyrrole composite cathode, with the same components as Polypyrrole@Sulfur@Polypyrrole composite, but without the three-layer-structure, has the discharge specific capacity of 370mAh g-1 after 50 …


Electronic Structure And Photocatalytic Water Oxidation Activity Of Rtino2 (R = Ce, Pr And Nd) Perovskite Nitride Oxides, Spencer H. Porter, Zhenguo Huang, S X. Dou, Samantha Brown-Xu, Md. Golam Mahabub Sarwar, Roberto C. Myers, Patrick M. Woodward Jan 2015

Electronic Structure And Photocatalytic Water Oxidation Activity Of Rtino2 (R = Ce, Pr And Nd) Perovskite Nitride Oxides, Spencer H. Porter, Zhenguo Huang, S X. Dou, Samantha Brown-Xu, Md. Golam Mahabub Sarwar, Roberto C. Myers, Patrick M. Woodward

Australian Institute for Innovative Materials - Papers

Three perovskite nitride oxides CeTiNO2, PrTiNO2, and NdTiNO2 have been synthesized and their electronic structures and photocatalytic activities characterized and compared to LaTiNO2. All three compounds have band gaps that fall in the range 2.0 − 2.1 eV, very similar to LaTiNO2, which enables them to absorb a significant fraction of the visible spectrum. Photocatalytic oxygen evolution studies under visible light irradiation in the presence of a sacrificial electron acceptor (Ag+) show that the activity of NdTiNO2 (16 μmol/g/hr) is comparable to that of LaTiNO2 (17 μmol/g/hr), …


The Effect Of Surface Passivation On The Structure Of Sulphur-Rich Pbs Colloidal Quantum Dots For Photovoltaic Application, Victor Malgras, Andrew Nattestad, Yusuke Yamauchi, S X. Dou, Jung Ho Kim Jan 2015

The Effect Of Surface Passivation On The Structure Of Sulphur-Rich Pbs Colloidal Quantum Dots For Photovoltaic Application, Victor Malgras, Andrew Nattestad, Yusuke Yamauchi, S X. Dou, Jung Ho Kim

Australian Institute for Innovative Materials - Papers

The use of PbS colloidal quantum dots in photovoltaic devices is very promising because of their simple and low cost production processes and their unique properties, such as bandgap tunability and potential multiple exciton generation. Here we report the synthesis of PbS nanocrystals used for application in solar cells. The sulphur-rich nature of their surface appears to be caused by the exposure to ambient conditions. The use of methanol as medium during the ligand exchange process has a crucial role in the removal of native oleate ligands. Without proper ligand exchange, the unpassivated surface is subject to ambient hydroxylation leading …


Improvement In Structure And Superconductivity Of Bulk Fese0.5te0.5 Superconductors By Optimizing Sintering Temperature, Ning Chen, Yongchang Liu, Zongqing Ma, Liming Yu, Huijun Li Jan 2015

Improvement In Structure And Superconductivity Of Bulk Fese0.5te0.5 Superconductors By Optimizing Sintering Temperature, Ning Chen, Yongchang Liu, Zongqing Ma, Liming Yu, Huijun Li

Australian Institute for Innovative Materials - Papers

Sintering temperature plays a vital role in the evolution of phase structure and microstructure in polycrystalline FeSe0.5Te0.5 bulks fabricated by the two-step sintering method, and thus significantly influences their superconducting properties. Elevated sintering temperature (600-700°C) at second step facilitates the substitution of Te into the superconducting phase, which leads to the increased lattice distortion and thus contributes to the enhancement of superconductivity (the value of Tc reaches 15.6K). At the same time, the accelerated growth of the superconducting grains and the improved homogeneity motivated by elevated sintering temperature serve as the main reason for the sharp superconducting transition.


Role Of Anions On Structure And Pseudocapacitive Performance Of Metal Double Hydroxides Decorated With Nitrogen-Doped Graphene, Nasir Mahmood, Muhammad Nawaz Tahir, Asif Mahmood, Wenlong Yang, Xingxing Gu, Chuanbao Cao, Yawen Zhang, Yanglong Hou Jan 2015

Role Of Anions On Structure And Pseudocapacitive Performance Of Metal Double Hydroxides Decorated With Nitrogen-Doped Graphene, Nasir Mahmood, Muhammad Nawaz Tahir, Asif Mahmood, Wenlong Yang, Xingxing Gu, Chuanbao Cao, Yawen Zhang, Yanglong Hou

Australian Institute for Innovative Materials - Papers

Electrochemical capacitors (EC) bear faster charge-discharge; however, their real applications are still on a long away due to lower capacitance and energy densities which mainly arise from simple surface charge accumulation or/and reaction. Here, a novel synthesis strategy was designed to obtain the purposeful hybrids of nickel cobalt double hydroxide (NiCoDH) with genetic morphology to improve their electrochemical performance as electrode of EC. Nanostructures of metal hydroxides were grown on t he nitrogen-doped graphene (NG) sheets by utilizing defects as nucleation sites and their composition was optimized both by tuning the ratio of Ni:Co as well as the counter halogen …