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

Engineering Commons

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

Australian Institute for Innovative Materials - Papers

Free

Articles 1 - 30 of 31

Full-Text Articles in Engineering

(Bi0.51 Na0.47)Tio3 Based Lead Free Ceramics With High Energy Density And Efficiency, Yu Huang, Fei Li, Hua Hao, Fangquan Xia, Hanxing Liu, Shujun Zhang Jan 2019

(Bi0.51 Na0.47)Tio3 Based Lead Free Ceramics With High Energy Density And Efficiency, Yu Huang, Fei Li, Hua Hao, Fangquan Xia, Hanxing Liu, Shujun Zhang

Australian Institute for Innovative Materials - Papers

Dielectric ceramics with high energy storage density and energy efficiency play an important role in high power energy storage applications. In this work, lead free relaxor ferroelectric ceramics in (1-x)Bi 0.51 Na 0.47 TiO 3 - xBa(Zr 0.3 Ti 0.7 )O 3 (BNT-BZT100x: x = 0.20, 0.30, 0.40 and 0.50) system are fabricated by conventional solid-state sintering method. The BNT-BZT100x ceramics are sintered dense with minimal pores, exhibiting pseudocubic symmetry and strong relaxor characteristic. A high energy storage density of 3.1 J/cm 3 and high energy efficiency of 91% are simultaneously achieved in BNT-BZT40 ceramic with 0.1 mm in thickness, …


Lead-Free Snte-Based Thermoelectrics: Enhancement Of Thermoelectric Performance By Doping With Gd/Ag, Lijuan Zhang, Jian Li Wang, Zhenxiang Cheng, Qiao Sun, Zhen Li, S X. Dou Jan 2016

Lead-Free Snte-Based Thermoelectrics: Enhancement Of Thermoelectric Performance By Doping With Gd/Ag, Lijuan Zhang, Jian Li Wang, Zhenxiang Cheng, Qiao Sun, Zhen Li, S X. Dou

Australian Institute for Innovative Materials - Papers

SnTe, with the same rock-salt structure as PbTe, is a potentially attractive thermoelectric material. Pristine SnTe has poor thermoelectric performance because of its very high hole concentration resulting from intrinsic Sn vacancies, which leads to a high thermal conductivity and a low Seebeck coefficient. In this work, the thermoelectric properties of SnTe were modified by doping with different contents of gadolinium and silver. It is found that SnTe doped with optimal gadolinium (i.e. Gd0.06Sn0.94Te) exhibited extraordinarily low lattice thermal conductivity that is close to the theoretical minimum. The drastic reduction of lattice thermal conductivity is attributed to the formation of …


Binder-Free And Carbon-Free 3d Porous Air Electrode For Li-O2 Batteries With High Efficiency, High Capacity, And Long Life, Wenbin Luo, Xuanwen Gao, Dongqi Shi, Shulei Chou, Jiazhao Wang, Hua-Kun Liu Jan 2016

Binder-Free And Carbon-Free 3d Porous Air Electrode For Li-O2 Batteries With High Efficiency, High Capacity, And Long Life, Wenbin Luo, Xuanwen Gao, Dongqi Shi, Shulei Chou, Jiazhao Wang, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

Pt-Gd alloy polycrystalline thin film is deposited on 3D nickel foam by pulsed laser deposition method serving as a whole binder/carbon-free air electrode, showing great catalytic activity enhancement as an efficient bifunctional catalyst for the oxygen reduction and evolution reactions in lithium oxygen batteries. The porous structure can facilitate rapid O2 and electrolyte diffusion, as well as forming a continuous conductive network throughout the whole energy conversion process. It shows a favorable cycle performance in the full discharge/charge model, owing to the high catalytic activity of the Pt-Gd alloy composite and 3D porous nickel foam structure. Specially, excellent cycling performance …


Ultrathin Porous Nio Nanoflake Arrays On Nickel Foam As Binder-Free Electrodes For Supercapacitors, Qing Liu, Qinglong Yan, Shuang Wu, Jieqiang Wang, Hua-Kun Liu Jan 2016

Ultrathin Porous Nio Nanoflake Arrays On Nickel Foam As Binder-Free Electrodes For Supercapacitors, Qing Liu, Qinglong Yan, Shuang Wu, Jieqiang Wang, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

NiO nanopowders and NiO/nickel foam (NF) hybrid were synthesized by microwave hydrothermal method and the following heating process. NiO nanopowders show the morphology of microspheres (diameter is about 3μm), which are composed of porous nanoflakes. NiO/NF hybrid shows a porous nanoflakes array structure, the thickness of nanoflakes is 10nm. Electrochemical measurements indicate that the maximum specific capacitance of NiO nanopowders is about 85.4 F/g at a scan rate of 5 mV/s, while this value is up to 234.8 F/g for NiO/NF hybrid. Electrochemical impedance spectrum (EIS) data show that the Rs and Rct values of NiO/NF hybrid (1.9Ù and 0.25Ù) …


A Methodical Approach For Fabrication Of Binder-Free Li2s-C Composite Cathode With High Loading Of Active Material For Li-S Battery, Mohammad Kaiser, Xin Liang, Hua-Kun Liu, S X. Dou, Jiazhao Wang Jan 2016

A Methodical Approach For Fabrication Of Binder-Free Li2s-C Composite Cathode With High Loading Of Active Material For Li-S Battery, Mohammad Kaiser, Xin Liang, Hua-Kun Liu, S X. Dou, Jiazhao Wang

Australian Institute for Innovative Materials - Papers

Lithium sulfide (Li2S), which has a theoretical capacity of 1166 mA h/g, is considered as a promising cathode material for the Li-S battery. The electrochemical performance of microsized Li2S is impaired, however, by its low electrical conductivity as well as first cycle high activation potential problem. In this work, microsized Li2S powder had been ball-milled with different carbon sources to synthesize Li2S-C composites as well as to find the suitable carbon sources, which were then capillary-deposited in three-dimensional multi-layered Ni foam from a dioxolane-containing mixture to fabricate a binder-free Li2S-C composite cathode. A large amount of active material (∼5 mg/cm2) …


3d Binder-Free Mose2 Nanosheets/Carbon Cloth Electrodes For Efficient And Stable Hydrogen Evolution Prepared By Simple Electrophoresis Deposition Strategy, Yundan Liu, Long Ren, Zhen Zhang, Xiang Qi, Hongxing Li, Jianxin Zhong Jan 2016

3d Binder-Free Mose2 Nanosheets/Carbon Cloth Electrodes For Efficient And Stable Hydrogen Evolution Prepared By Simple Electrophoresis Deposition Strategy, Yundan Liu, Long Ren, Zhen Zhang, Xiang Qi, Hongxing Li, Jianxin Zhong

Australian Institute for Innovative Materials - Papers

We successfully developed a simple electrophoretic deposition (EPD) method to decorate the MoSe2 nanosheets on the carbon fiber surface of carbon cloth (MoSe2/CC). With this process, MoSe2 nanosheets can be uniformly and tightly deposited on this flexible conductor to form a 3D binder-free electrode for hydrogen evolution reaction (HER). The film thickness can also be controlled by the EPD time. Directly used as binder-free electrodes for hydrogen evolution reaction, the as-prepared 3D MoSe2/CC samples exhibit excellent catalytic activity in an acidic electrolyte (21 mA/cm2 at an over-potential of 250 mV). Variation of MoSe2 nanosheets film thickness in the electrodes could …


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 …


A Versatile Binder-Free Tio2 Paste For Dye-Sensitized Solar Cells, Jeremy H. Yune, Inna Karatchevtseva, P Evans, Klaudia K. Wagner, Matthew J. Griffith, David L. Officer, Gerry Triani Jan 2015

A Versatile Binder-Free Tio2 Paste For Dye-Sensitized Solar Cells, Jeremy H. Yune, Inna Karatchevtseva, P Evans, Klaudia K. Wagner, Matthew J. Griffith, David L. Officer, Gerry Triani

Australian Institute for Innovative Materials - Papers

In this study, binder-free TiO2 colloidal pastes have been prepared using a variety of heterocyclic bases with diverse characteristics to produce robust photoanodes for dye-sensitized solar cells (DSSC) from a single cast film thickness of 5 micron. The influence of the base on the electrode structure and film morphology, including its electron donor characteristics are investigated after low temperature thermal treatment and high temperature sintering. The results show that quinoline in the TiO2 paste is retained within the electrode structure in comparison to piperidine and pyridine after a short thermal treatment of 150 °C for 15 minutes. The …


Free-Standing Composite Hydrogel Films For Superior Volumetric Capacitance, Mahmoud Moussa, Zhiheng Zhao, Maher F. El-Kady, Hua-Kun Liu, Andrew Michelmore, Nobuyuki Kawashima, Peter Majewski, Jun Ma Jan 2015

Free-Standing Composite Hydrogel Films For Superior Volumetric Capacitance, Mahmoud Moussa, Zhiheng Zhao, Maher F. El-Kady, Hua-Kun Liu, Andrew Michelmore, Nobuyuki Kawashima, Peter Majewski, Jun Ma

Australian Institute for Innovative Materials - Papers

High volumetric capacitance is vital for the development of wearable and portable energy storage devices. We herein introduce a novel simple route for the fabrication of a highly porous, binder-free and free-standing polyaniline/reduced graphene oxide composite hydrogel (PANi/graphene hydrogel) as an electrode with a packing density of 1.02 g cm-3. PANi played critical roles in gelation, which include reduction, crosslinking, creation of pseudocapacitance and as a spacer preventing graphene sheets from stacking. The composite hydrogel film delivered a volumetric capacitance of 225.42 F cm-3 with a two-electrode supercapacitor configuration, which was enhanced to 592.96 F cm-3 …


Robust Scalable Synthesis Of Surfactant-Free Thermoelectric Metal Chalcogenide Nanostructures, Chao Han, Zhen Li, Gao Qing (Max) Lu, S X. Dou Jan 2015

Robust Scalable Synthesis Of Surfactant-Free Thermoelectric Metal Chalcogenide Nanostructures, Chao Han, Zhen Li, Gao Qing (Max) Lu, S X. Dou

Australian Institute for Innovative Materials - Papers

A robust low-cost ambient aqueous method for the scalable synthesis of surfactant-free nanostructured metal chalcogenides (MaXb, M=Cu, Ag, Sn, Pb, and Bi; X=S, Se, and Te; a=1 or 2; and b=1 or 3) is developed in this work. The effects of reaction parameters, such as precursor concentration, ratio of precursors, and amount of reducing agent, on the composition, size, and shape of the resultant nanostructures have been comprehensively investigated. This environmentally friendly approach is capable of producing metal chalcogenide nanostructures in a one-pot reaction on a large scale, which were investigated for their thermoelectric properties towards conversion of waste heat …


One Dimensional Graphitic Carbon Nitrides As Effective Metal-Free Oxygen Reduction Catalysts, Muhammad Nawaz Tahir, Nasir Mahmood, Jinghan Zhu, Asif Mahmood, Faheem K. Butt, Syed Rizwan, Imran Aslam, M Tanveer, Faryal Idrees, Imran Shakir, Chuanbao Cao, Yanglong Hou Jan 2015

One Dimensional Graphitic Carbon Nitrides As Effective Metal-Free Oxygen Reduction Catalysts, Muhammad Nawaz Tahir, Nasir Mahmood, Jinghan Zhu, Asif Mahmood, Faheem K. Butt, Syed Rizwan, Imran Aslam, M Tanveer, Faryal Idrees, Imran Shakir, Chuanbao Cao, Yanglong Hou

Australian Institute for Innovative Materials - Papers

To explore the effect of morphology on catalytic properties of graphitic carbon nitride (GCN), we have studied oxygen reduction reaction (ORR) performance of two different morphologies of GCN in alkaline media. Among both, tubular GCN react with dissolved oxygen in the ORR with an onset potential close to commercial Pt/C. Furthermore, the higher stability and excellent methanol tolerance of tubular GCN compared to Pt/C emphasizes its suitability for fuel cells.


High-Performance Flexible All-Solid-State Supercapacitor From Large Free-Standing Graphene-Pedot/Pss Films, Yuqing Liu, Bo Weng, Joselito M. Razal, Qun Xu, Chen Zhao, Yuyang Hou, Shayan Seyedin, Rouhollah Jalili, Gordon G. Wallace, Jun Chen Jan 2015

High-Performance Flexible All-Solid-State Supercapacitor From Large Free-Standing Graphene-Pedot/Pss Films, Yuqing Liu, Bo Weng, Joselito M. Razal, Qun Xu, Chen Zhao, Yuyang Hou, Shayan Seyedin, Rouhollah Jalili, Gordon G. Wallace, Jun Chen

Australian Institute for Innovative Materials - Papers

Although great attention has been paid to wearable electronic devices in recent years, flexible lightweight batteries or supercapacitors with high performance are still not readily available due to the limitations of the flexible electrode inventory. In this work, highly flexible, bendable and conductive rGO-PEDOT/PSS films were prepared using a simple bar-coating method. The assembled device using rGO-PEDOT/PSS electrode could be bent and rolled up without any decrease in electrochemical performance. A relatively high areal capacitance of 448 mF cm-2 was achieved at a scan rate of 10 mV s-1 using the composite electrode with a high mass loading (8.49 mg …


Aqueous Preparation Of Surfactant-Free Copper Selenide Nanowires, Xinqi Chen, Zhen Li, Jianping Yang, Qiao Sun, S X. Dou Jan 2015

Aqueous Preparation Of Surfactant-Free Copper Selenide Nanowires, Xinqi Chen, Zhen Li, Jianping Yang, Qiao Sun, S X. Dou

Australian Institute for Innovative Materials - Papers

Uniform surfactant-free copper selenide (Cu2- x Se) nanowires were prepared via an aqueous route. The effects of reaction parameters such as Cu/Se precursor ratio, Se/NaOH ratio, and reaction time on the formation of nanowires were comprehensively investigated. The results show that Cu2- x Se nanowires were formed through the assembling of CuSe nanoplates, accompanied by their self-redox reactions. The resultant Cu2- x Se nanowires were explored as a potential thermoelectric candidate in comparison with commercial copper selenide powder. Both synthetic and commercial samples have a similar performance and their figures of merit are 0.29 and 0.38 at …


Liquid Crystalline Graphene Oxide/Pedot: Pss Self-Assembled 3d Architecture For Binder-Free Supercapacitor Electrodes, Md. Monirul Islam, Alfred T. Chidembo, Seyed Hamed Aboutalebi, Dean Cardillo, Hua-Kun Liu, Konstantin K. Konstantinov, S X. Dou Jan 2014

Liquid Crystalline Graphene Oxide/Pedot: Pss Self-Assembled 3d Architecture For Binder-Free Supercapacitor Electrodes, Md. Monirul Islam, Alfred T. Chidembo, Seyed Hamed Aboutalebi, Dean Cardillo, Hua-Kun Liu, Konstantin K. Konstantinov, S X. Dou

Australian Institute for Innovative Materials - Papers

Binder-free self-assembled 3D architecture electrodes have been fabricated by a novel convenient method. Liquid crystalline graphene oxide was used as precursor to interact with poly(3,4-ethylene-dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) in dispersion in order to form a conductive polymer entrapped, self-assembled layer-by-layer structure. This advanced network containing PEDOT:PSS enabled us to ascribe the superior electrochemical properties of particular graphene sheets. This layer-by-layer self-assembled 3D architecture of best performing composite (reduced graphene oxide-PEDOT:PSS 25) showed excellent electrochemical performance of 434 F g−1 through chemical treatment. To highlight these advances, we further explored the practicality of the as-prepared electrode by varying the composite material content. …


Template Free Synthesis Of Cus Nanosheet-Based Hierarchical Microspheres: An Efficient Natural Light Driven Photocatalyst, M Tanveer, Chuanbao Cao, Zulfiqar Ali, Imran Aslam, Faryal Idrees, Waheed S. Khan, Faheem K. Butt, Muhammad Nawaz Tahir, Nasir Mahmood Jan 2014

Template Free Synthesis Of Cus Nanosheet-Based Hierarchical Microspheres: An Efficient Natural Light Driven Photocatalyst, M Tanveer, Chuanbao Cao, Zulfiqar Ali, Imran Aslam, Faryal Idrees, Waheed S. Khan, Faheem K. Butt, Muhammad Nawaz Tahir, Nasir Mahmood

Australian Institute for Innovative Materials - Papers

Well controlled nanosheets-based hierarchical microspheres (NSHMS) of pure covellite phase CuS were synthesized using a facile PVP assisted solvothermal process. The reaction conditions were optimized using various amounts of PVP to develop unique hierarchical structured hollow microspheres. CuS hollow structures have a bandgap of ~1.97 eV. These mesoporous structures exhibit excellent photocatalytic activity in degradation of organic dyes (Methylene Blue) under natural light in comparison to other structures of copper sulphide. These photocatalysts show extraordinary reusability with over 96.5% degradation of organic dye after 6th cycle. A "bottom-up" assembly was successfully developed to synthesize hollow microspheres with unique and well …


Microwave Autoclave Synthesized Multi-Layer Graphene/Single-Walled Carbon Nanotube Composites For Free-Standing Lithium-Ion Battery Anodes, Chao Zhong, Jia-Zhao Wang, David Wexler, Hua-Kun Liu Jan 2014

Microwave Autoclave Synthesized Multi-Layer Graphene/Single-Walled Carbon Nanotube Composites For Free-Standing Lithium-Ion Battery Anodes, Chao Zhong, Jia-Zhao Wang, David Wexler, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

Multi-layer graphene sheets have been synthesized by a time-efficient microwave autoclave method and used to form composites in situ with single-walled carbon nanotubes. The application of these composites as flexible free-standing film electrodes was then investigated. According to the transmission electron microscopy and X-ray diffraction characterizations, the average d-spacing of the graphene-single-walled carbon nanotube composites was 0.41 nm, which was obviously larger than that of the as-prepared pure graphene (0.36 nm). The reversible Li-cycling properties of the free-standing films have been evaluated by galvanostatic discharge-charge cycling and electrochemical impedance spectroscopy. Results showed that the free-standing composite film with 70 wt% …


A Germanium/Single-Walled Carbon Nanotube Composite Paper As A Free-Standing Anode For Lithium-Ion Batteries, Jun Wang, Jiazhao Wang, Ziqi Sun, Xuanwen Gao, Chao Zhong, Shulei Chou, Hua-Kun Liu Jan 2014

A Germanium/Single-Walled Carbon Nanotube Composite Paper As A Free-Standing Anode For Lithium-Ion Batteries, Jun Wang, Jiazhao Wang, Ziqi Sun, Xuanwen Gao, Chao Zhong, Shulei Chou, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

Paper-like free-standing germanium (Ge) and single-walled carbon nanotube (SWCNT) composite anodes were synthesized by the vacuum filtration of Ge/SWCNT composites, which were prepared by a facile aqueous-based method. The samples were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Electrochemical measurements demonstrate that the Ge/SWCNT composite paper anode with the weight percentage of 32% Ge delivered a specific discharge capacity of 417 mA h g−1 after 40 cycles at a current density of 25 mA g−1, 117% higher than the pure SWCNT paper anode. The SWCNTs not only function as a flexible mechanical support for …


3d Hierarchical Rutile Tio2 And Metal-Free Organic Sensitizer Producing Dye-Sensitized Solar Cells 8.6% Conversion Efficiency, Jianjian Lin, Yoon-Uk Heo, Andrew Nattestad, Ziqi Sun, Lianzhou Wang, Jung Ho Kim, S X. Dou Jan 2014

3d Hierarchical Rutile Tio2 And Metal-Free Organic Sensitizer Producing Dye-Sensitized Solar Cells 8.6% Conversion Efficiency, Jianjian Lin, Yoon-Uk Heo, Andrew Nattestad, Ziqi Sun, Lianzhou Wang, Jung Ho Kim, S X. Dou

Australian Institute for Innovative Materials - Papers

Three-dimensional (3D) hierarchical nanoscale architectures comprised of building blocks, with specifically engineered morphologies, are expected to play important roles in the fabrication of 'next generation' microelectronic and optoelectronic devices due to their high surface-to-volume ratio as well as opto-electronic properties. Herein, a series of well-defined 3D hierarchical rutile TiO2 architectures (HRT) were successfully prepared using a facile hydrothermal method without any surfactant or template, simply by changing the concentration of hydrochloric acid used in the synthesis. The production of these materials provides, to the best of our knowledge, the first identified example of a ledgewise growth mechanism in a rutile …


Fabrication Of Free-Standing Hierarchical Carbon Nanofiber/Graphene Oxide/Polyaniline Films For Supercapacitors, Dongdong Xu, Qun Xu, Kaixi Wang, Jun Chen, Zhimin Chen Jan 2014

Fabrication Of Free-Standing Hierarchical Carbon Nanofiber/Graphene Oxide/Polyaniline Films For Supercapacitors, Dongdong Xu, Qun Xu, Kaixi Wang, Jun Chen, Zhimin Chen

Australian Institute for Innovative Materials - Papers

A hierarchical high-performance electrode with nanoacanthine-style polyaniline (PANI) deposited onto a carbon nanofiber/graphene oxide (CNF/GO) template was successfully prepared via an in situ polymerization process. The morphology analysis shows that introducing one-dimensional (1D) CNF could significantly decrease/inhibit the staking of laminated GO to form an open-porous CNF/GO architecture. Followed with in situ facial deposition of PANI, the as-synthesized PANI modified CNF/GO exhibits three-dimensional (3D) hierarchical layered nanoarchitecture, which favors the diffusion of the electrolyte ions into the inner region of active materials. The hierarchical free-standing electrodes were directly fabricated into sandwich structured supercapacitors using 1 M H2SO4 as the electrolyte …


Ambient Scalable Synthesis Of Surfactant-Free Thermoelectric Cuagse Nanoparticles With Reversible Metallic-N-P Conductivity Transition, Chao Han, Qiao Sun, Zhenxiang Cheng, Jianli Wang, Zhen Li, Gao Qing (Max) Lu, S X. Dou Jan 2014

Ambient Scalable Synthesis Of Surfactant-Free Thermoelectric Cuagse Nanoparticles With Reversible Metallic-N-P Conductivity Transition, Chao Han, Qiao Sun, Zhenxiang Cheng, Jianli Wang, Zhen Li, Gao Qing (Max) Lu, S X. Dou

Australian Institute for Innovative Materials - Papers

Surfactant-free CuAgSe nanoparticles were successfully synthesized on a large scale within a short reaction time via a simple environmentally friendly aqueous approach under room temperature. The nanopowders obtained were consolidated into pellets for investigation of their thermoelectric properties between 3 and 623 K. The pellets show strong metallic characteristics below 60 K and turn into an n-type semiconductor with increasing temperature, accompanied by changes in the crystal structure (i.e., from the pure tetragonal phase into a mixture of tetragonal and orthorhombic phases), the electrical conductivity, the Seebeck coefficient, and the thermal conductivity, which leads to a figure of merit (ZT) …


A Study Of Tio2 Binder-Free Paste Prepared For Low Temperature Dye-Sensitized Solar Cells, Jeremy H. Yune, Inna Karatchevtseva, Gerri Triani, Klaudia Wagner, David Officer Jan 2013

A Study Of Tio2 Binder-Free Paste Prepared For Low Temperature Dye-Sensitized Solar Cells, Jeremy H. Yune, Inna Karatchevtseva, Gerri Triani, Klaudia Wagner, David Officer

Australian Institute for Innovative Materials - Papers

A binder-free titania paste was prepared by chemical modification of an acidic TiO2 sol with ammonia. By varying the ammonia concentration, the viscosity of the acidic TiO2 suspension increased, thereby allowing uniform films to be cast. The photoelectrochemical performance of TiO2 electrodes, cast as single layers, was dependent on the thermal treatment cycle. Fourier transform infrared spectroscopy was used to characterize the extent of residual organics and found that acetates from the TiO2 precursor preparation were retained within the electrode structure after thermal treatment at 150 °C. Electrodes of nominal thickness 4 lm produced an energy conversion efficiency as high …


Hollow Structured Li3vo4 Wrapped With Graphene Nanosheets In Situ Prepared By One-Pot Template-Free Method As An Anode For Lithium-Ion Batteries, Yi Shi, Jia-Zhao Wang, Shulei Chou, David Wexler, Hui-Jun Li, Kiyoshi Ozawa, Hua-Kun Liu, Yu-Ping Wu Jan 2013

Hollow Structured Li3vo4 Wrapped With Graphene Nanosheets In Situ Prepared By One-Pot Template-Free Method As An Anode For Lithium-Ion Batteries, Yi Shi, Jia-Zhao Wang, Shulei Chou, David Wexler, Hui-Jun Li, Kiyoshi Ozawa, Hua-Kun Liu, Yu-Ping Wu

Australian Institute for Innovative Materials - Papers

To explore good anode materials of high safety, high reversible capacity, good cycling, and excellent rate capability, a Li3VO4 microbox with wall thickness of 40 nm was prepared by a one-pot and template-free in situ hydrothermal method. In addition, its composite with graphene nanosheets of about six layers of graphene was achieved. Both of them, especially the Li3VO4/graphene nanosheets composite, show superior electrochemical performance to the formerly reported vanadium-based anode materials. The composite shows a reversible capacity of 223 mAh g−1 even at 20C (1C = 400 mAh g−1). After 500 cycles at 10C there is no evident capacity fading.


Flux Pinning Mechanism In Bafe1.9ni0.1as2 Single Crystals: Evidence For Fluctuation In Mean Free Path Induced Pinning, M Shahbazi-Manshadi, X L Wang, K Y Choi, S X. Dou Jan 2013

Flux Pinning Mechanism In Bafe1.9ni0.1as2 Single Crystals: Evidence For Fluctuation In Mean Free Path Induced Pinning, M Shahbazi-Manshadi, X L Wang, K Y Choi, S X. Dou

Australian Institute for Innovative Materials - Papers

The flux pinning mechanism of BaFe1.9Ni0.1As2 superconducting crystals have been investigated systematically by magnetic measurements up to 13 T at various temperatures. The field dependence of the critical current density, Jc, was analysed within the collective pinning model. A remarkably good agreement between the experimental results and theoretical dl pinning curve is obtained, which indicates that pinning in BaFe1.9Ni0.1As2 crystal originates from spatial variation of the mean free path. Moreover, the normalized pinning force density, Fp, curves versus h1/4B/Birr (Birr is the irreversibility field) were scaled using the Dew-Hughes model. Analysis suggests that point pinning alone cannot explain the observed …


Microstructural Origin For The Piezoelectricity Evolution In (K0.5na0.5)Nbo3-Based Lead-Free Ceramics, Hanzheng Guo, Shujun Zhang, Scott P. Beckman, Xiaoli Tan Jan 2013

Microstructural Origin For The Piezoelectricity Evolution In (K0.5na0.5)Nbo3-Based Lead-Free Ceramics, Hanzheng Guo, Shujun Zhang, Scott P. Beckman, Xiaoli Tan

Australian Institute for Innovative Materials - Papers

Chemically modified (K0.5Na0.5)NbO3 compositions with finely tuned polymorphic phase boundaries (PPBs) have shown excellent piezoelectric properties. The evolution of the domain morphology and crystal structure under applied electric fields of a model material, 0.948(K0.5Na0.5)NbO3-0.052LiSbO3, was directly visualized using in situ transmission electron microscopy. The in situ observations correlate extremely well with measurements of the electromechanical response on bulk samples. It is found that the origin of the excellent piezoelectric performance in this lead-free composition is due to a tilted monoclinic phase that emerges from the PPB when poling fields greater than 14 kV/cm are applied. 2013 AIP Publishing LLC.


Free-Standing Single-Walled Carbon Nanotube/Sno2 Anode Paper For Flexible Lithium-Ion Batteries, Lukman Noerochim, Jia-Zhao Wang, Shulei Chou, David Wexler Jan 2012

Free-Standing Single-Walled Carbon Nanotube/Sno2 Anode Paper For Flexible Lithium-Ion Batteries, Lukman Noerochim, Jia-Zhao Wang, Shulei Chou, David Wexler

Australian Institute for Innovative Materials - Papers

Free-standingsingle-walledcarbonnanotube/SnO2 (SWCNT/SnO2) anodepaper was prepared by vacuum filtration of SWCNT/SnO2 hybrid material which was synthesized by the polyol method. From field emission scanning electron microscopy and transmission electron microscopy, the CNTs form a three-dimensional nanoporous network, in which ultra-fine SnO2 nanoparticles, which had crystallite sizes of less than 5 nm, were distributed, predominately as groups of nanoparticles on the surfaces of singlewalled CNT bundles. Electrochemical measurements demonstrated that the anodepaper with 34 wt.% SnO2 had excellent cyclic retention, with the high specific capacity of 454 mAh g−1 beyond 100 cycles at a current …


All-Polymer Battery System Based On Polypyrrole (Ppy)/Para (Toluene Sulfonic Acid) (Pts) And Polypyrrole (Ppy)/Indigo Carmine (Ic) Free Standing Films, Irin Sultana, Md. Mokhlesur Rahman, Jiazhao Wang, Caiyun Wang, Gordon G. Wallace, Hua-Kun Liu Jan 2012

All-Polymer Battery System Based On Polypyrrole (Ppy)/Para (Toluene Sulfonic Acid) (Pts) And Polypyrrole (Ppy)/Indigo Carmine (Ic) Free Standing Films, Irin Sultana, Md. Mokhlesur Rahman, Jiazhao Wang, Caiyun Wang, Gordon G. Wallace, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

In this study, we introduce a novel all-polymer battery system based on conducting polymer (polypyrrole, PPy) doped with dopants of para (toluene sulfonic acid) (pTS) and indigo carmine (IC), respectively. The performance of the systems consisting of polypyrrole-para (toluene sulfonic acid) (PPy-pTS) as cathode and polypyrrole-indigo carmine (PPy-IC) as anode in conjunction with either a polymer based electrolyte or a commercial organic electrolyte of 1M LiPF6 in a 50:50 (v/v) mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) was evaluated. In the system, all the free-standing PPy-pTS and PPy-IC films were directly …


In-Field Jc Improvement By Oxygen-Free Pyrene Gas Diffusion Into Highly Dense Mgb2 Superconductor, Minoru Maeda, Jung Ho Kim, Y Zhao, Yoon-Uk Heo, K Takase, Y Kubota, C Moriyoshi, F Yoshida, Y Kuroiwa, S X. Dou Jan 2011

In-Field Jc Improvement By Oxygen-Free Pyrene Gas Diffusion Into Highly Dense Mgb2 Superconductor, Minoru Maeda, Jung Ho Kim, Y Zhao, Yoon-Uk Heo, K Takase, Y Kubota, C Moriyoshi, F Yoshida, Y Kuroiwa, S X. Dou

Australian Institute for Innovative Materials - Papers

Oxygen-free pyrene gas as a carbon (C) dopant was delinked and incorporated into highly dense MgB2 structure via a gas phase diffusion method. The technique offers the advantages that molecular C is homogeneously distributed into MgB2 and substituted at the boron sites without any severe deterioration of grain connectivity. The C substitution causes a significant shrinkage of the a-lattice parameter and an increase in the lattice strain, resulting in high disorder. The introduction of structural disorder as a result of C doping leads to a considerable enhancement of the in-field critical current density (Jc) and upper critical …


Compact-Designed Supercapacitors Using Free-Standing Single-Walled Carbon Nanotube Films, Zhiqiang Niu, Weiya Zhou, Jun Chen, Guoxing Feng, Hong Li, Wenjun Ma, Jinzhu Li, Haibo Dong, Yan Ren, Duan Zhao, Sishen Xie Jan 2011

Compact-Designed Supercapacitors Using Free-Standing Single-Walled Carbon Nanotube Films, Zhiqiang Niu, Weiya Zhou, Jun Chen, Guoxing Feng, Hong Li, Wenjun Ma, Jinzhu Li, Haibo Dong, Yan Ren, Duan Zhao, Sishen Xie

Australian Institute for Innovative Materials - Papers

We reported the realization of assembling compact-designed supercapacitors using large-scaled freestanding and flexible single-walled carbon nanotube (SWCNT) films as both anode and cathode. A prototype of the processing procedures was developed to obtain the uniform spreading of the SWCNT films onto the separators serving as both electrodes and charge collectors without metallic current collectors, leading to a simplified and lightweight architecture. The area of SWCNT film on a separator can be scaled up and its thickness can be extended. High energy and power densities (43.7 Wh kg-1 and 197.3 kW kg-1, respectively) were achieved from the prepared …


Lead-Free Potassium Bismuth Titanate Thin Film With Complex Aurivillius Layer Structure, Zhenxiang Cheng, Xiaolin Wang, Hongyang Zhao, Hideo Kimura Jan 2010

Lead-Free Potassium Bismuth Titanate Thin Film With Complex Aurivillius Layer Structure, Zhenxiang Cheng, Xiaolin Wang, Hongyang Zhao, Hideo Kimura

Australian Institute for Innovative Materials - Papers

A ferroelectric thin film of Aurivillius phase K0.5Bi4.5Ti4O15 (KBT) with a complex bismuth layer-structure was fabricated using the pulsed laser deposition method. The thin film grown on Pt/Ti/SiO2/ Si substrate shows a strong c-axis orientation, as revealed by x-ray diffraction results, and platelike growth of grains. A Pt/KBT/Pt capacitor shows a maximum polarization of about 20 µC/cm2. In addition, the capacitor also shows good fatigue resistance, with a decrease of 14.5% in the remanent polarization after 107 switching cycles. This Aurivillius phase with four layers of TiO6 …


Flux-Pinning Mechanism In Silicone-Oil Doped Mgb2: Evidence For Charge-Carrier Mean Free Path Fluctuation Pinning, Shaban R. Ghorbani, Xiaolin Wang, S X. Dou, Sung-Ik Lee, Md S. Hossain Jan 2008

Flux-Pinning Mechanism In Silicone-Oil Doped Mgb2: Evidence For Charge-Carrier Mean Free Path Fluctuation Pinning, Shaban R. Ghorbani, Xiaolin Wang, S X. Dou, Sung-Ik Lee, Md S. Hossain

Australian Institute for Innovative Materials - Papers

Flux-pinning mechanism of MgB2 doped with 10 wt % silicone-oil sintered at low and high temperatures has been investigated by magnetic measurements. The field dependence of the critical current density, jc(B), was analysed within the collective pinning model. A crossover field, Bsb, from the single vortex to the small vortex bundle-pinning regime was observed. For both types of sintered samples, the temperature dependence of Bsb(T) at low temperature is in good agreement with the δl pinning mechanism, i.e., pinning associated with charge-carrier mean free path fluctuation. At temperatures close to the critical …