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

Physical Sciences and Mathematics Commons

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

Articles 1 - 30 of 38

Full-Text Articles in Physical Sciences and Mathematics

Quest For An Optimal Spin-Polarized Electron Source For The Electron-Ion Collider, J. Biswas, E. Wang, O. Rahman, J. Sharitka, K. Kisslinger, Adam Masters, S. Marsillac, T. Lee Jan 2024

Quest For An Optimal Spin-Polarized Electron Source For The Electron-Ion Collider, J. Biswas, E. Wang, O. Rahman, J. Sharitka, K. Kisslinger, Adam Masters, S. Marsillac, T. Lee

Electrical & Computer Engineering Faculty Publications

Superlattice GaAs photocathodes play a crucial role as the primary source of polarized electrons in various accelerator facilities, including the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson National Laboratory and the Electron-Ion Collider (EIC) at Brookhaven National Laboratory. To increase the quantum efficiency (QE) of GaAs/GaAsP superlattice photocathodes, a Distributed Bragg Reflector (DBR) is grown underneath using metal-organic chemical vapor deposition (MOCVD). There are several challenges associated with DBR photocathodes: the resonance peak may not align with the emission threshold of around 780 nm, non-uniform doping density in the top 5 nm may significantly impact QE and spin polarization, …


Factors Affecting Electrocoagulation Process For Different Water Types: A Review, Shahad Fadhil Abed Al-Rubaye, Naseer A. Alhaboubi, Aiman H. Al-Allaq Jan 2024

Factors Affecting Electrocoagulation Process For Different Water Types: A Review, Shahad Fadhil Abed Al-Rubaye, Naseer A. Alhaboubi, Aiman H. Al-Allaq

Mechanical & Aerospace Engineering Faculty Publications

Raw water must meet specific physical, chemical, and biological requirements to be suitable for drinking. There are various techniques available for treating wastewater, and aside from conventional methods that involve chemicals, electrocoagulation is an efficient and advanced approach. Electrocoagulation has proven effective in treating many pollutants, including bacteria, viruses, iron, fluoride, sulfate, boron, hardness, and turbidity. Total suspended solids, organic and inorganic materials, chemical oxygen demand COD, biochemical oxygen demand BOD, and color. It finds extensive application in treating different types of water and wastewater due to its exceptional ability to remove diverse contaminants. Recently, electrocoagulation has garnered significant attention …


Cebaf Injector Model For KL Beam Conditions, Sunil Pokharel, Geoffrey A. Krafft, A. S. Hofler, R. Kazimi, M. Bruker, J. Grames, S. Zhang Jan 2022

Cebaf Injector Model For KL Beam Conditions, Sunil Pokharel, Geoffrey A. Krafft, A. S. Hofler, R. Kazimi, M. Bruker, J. Grames, S. Zhang

Physics Faculty Publications

The Jefferson Lab KL experiment will run at the Continuous Electron Beam Accelerator Facility with a much lower bunch repetition rate (7.80 or 15.59 MHz) than nominally used (249.5 or 499 MHz). While the proposed average current of 2.5 - 5.0 µA is relatively low compared to the maximum CEBAF current of approximately 180 µA, the corresponding bunch charge is atypically high for CEBAF injector operation. In this work, we investigated the evolution and transmission of low-rep-rate, high-bunch-charge (0.32 to 0.64 pC) beams through the CEBAF injector. Using the commercial software General Particle Tracer, we have simulated and analyzed the …


New Results At Jlab Describing Operating Lifetime Of Gaas Photo-Guns, M. Bruker, J. Grames, C. Hernández-García, M. Poelker, S. Zhang, V. Lizárraga-Rubio, C. Valerio-Lizárraga, Joshua T. Yoskowitz Jan 2022

New Results At Jlab Describing Operating Lifetime Of Gaas Photo-Guns, M. Bruker, J. Grames, C. Hernández-García, M. Poelker, S. Zhang, V. Lizárraga-Rubio, C. Valerio-Lizárraga, Joshua T. Yoskowitz

Physics Faculty Publications

Polarized electrons from GaAs photocathodes have been key to some of the highest-impact results of the Jefferson Lab science program over the past 30 years. During this time, various studies have given insight into improving the operational lifetime of these photocathodes in DC high-voltage photo-guns while using lasers with spatial Gaussian profiles of typically 0.5 mm to 1 mm FWHM, cathode voltages of 100 kV to 130 kV, and a wide range of beam currents up to multiple mA. In this contribution, we show recent experimental data from a 100 kV to 180 kV setup and describe our progress at …


Improved Electrostatic Design Of The Jefferson Lab 300 Kv Dc Photogun And The Minimization Of Beam Deflection, M. A. Mamun, D. B. Bullard, J. R. Delayen, J. M. Grames, C. Hernandez-Garcia, Geoffrey A. Krafft, M. Poelker, R. Suleiman, S.A.K. Wijethunga Jan 2022

Improved Electrostatic Design Of The Jefferson Lab 300 Kv Dc Photogun And The Minimization Of Beam Deflection, M. A. Mamun, D. B. Bullard, J. R. Delayen, J. M. Grames, C. Hernandez-Garcia, Geoffrey A. Krafft, M. Poelker, R. Suleiman, S.A.K. Wijethunga

Physics Faculty Publications

An electron beam with high bunch charge and high repetition rate is required for electron cooling of the ion beam to achieve the high luminosity required for the proposed electron-ion colliders. An improved design of the 300 kV DC high voltage photogun at Jefferson Lab was incorporated toward overcoming the beam loss and space charge current limitation experienced in the original design. To reach the bunch charge goal of ~ few nC within 75 ps bunches, the existing DC high voltage photogun electrodes and anode-cathode gap were modified to increase the longitudinal electric field (Ez) at the photocathode. The anode-cathode …


Redesign Of The Jefferson Lab -300 Kv Dc Photo-Gun For High Bunch Charge Operations, S.A.K. Wijethunga, J. Benesch, Jean R. Delayen, C. Hernandez-Garcia, Geoffrey A. Krafft, Gabriel Palacios-Serrano, M.A. Mamun, M. Poelker, R. Suleiman Jan 2021

Redesign Of The Jefferson Lab -300 Kv Dc Photo-Gun For High Bunch Charge Operations, S.A.K. Wijethunga, J. Benesch, Jean R. Delayen, C. Hernandez-Garcia, Geoffrey A. Krafft, Gabriel Palacios-Serrano, M.A. Mamun, M. Poelker, R. Suleiman

Physics Faculty Publications

Production of high bunch charge beams for the ElectronIon Collider (EIC) is a challenging task. High bunch charge (a few nC) electron beam studies at Jefferson Lab using an inverted insulator DC high voltage photo-gun showed evidence of space charge limitations starting at 0.3 nC, limiting the maximum delivered bunch charge to 0.7 nC for beam at -225 kV, 75 ps (FWHM) pulse width, and 1.64 mm (rms) laser spot size. The low extracted charge is due to the modest longitudinal electric field (Ez) at the photocathode leading to beam loss at the anode and downstream beam pipe. To reach …


P2-Type Na2/3ni1/3mn2/3o2as A Cathode Materialwith High-Rate And Long-Life For Sodium Ionstorage, Qiannan Liu, Zhe Hu, Mingzhe Chen, Chao Zou, Huile Jin, Shun Wang, Qinfen Gu, Shulei Chou Jan 2019

P2-Type Na2/3ni1/3mn2/3o2as A Cathode Materialwith High-Rate And Long-Life For Sodium Ionstorage, Qiannan Liu, Zhe Hu, Mingzhe Chen, Chao Zou, Huile Jin, Shun Wang, Qinfen Gu, Shulei Chou

Australian Institute for Innovative Materials - Papers

Layered P2-type Na 2/3 Ni 1/3 Mn 2/3 O 2 was successfully synthesized through a facile sol-gel method and subsequent heat treatment. Resulting from different phase transformation and sodium ion diffusion rates, its electrochemical performance is highly related to the cut-off voltage and the electrolyte used. When the cut-off voltage is set up to 4.5 V or lowered to 1.5 V, capacity fade happens due to the occurrence of P2-O2 transformation and electrolyte decomposition or the redox reaction of the Mn 4+ /Mn 3+ ionic pair and P2-P2′ transformation. The electrode maintained 89.0 mA h g -1 with good cycling …


Structure And Electrochemical Performance Modulation Of A Lini0.8co0.1mn0.1o2 Cathode Material By Anion And Cation Co-Doping For Lithium Ion Batteries, Rong Li, Yong Ming, Wei Xiang, Chunliu Xu, Guilin Feng, Yongchun Li, Yanxiao Chen, Zhenguo Wu, Ben-He Zhong, Xiaodong Guo Jan 2019

Structure And Electrochemical Performance Modulation Of A Lini0.8co0.1mn0.1o2 Cathode Material By Anion And Cation Co-Doping For Lithium Ion Batteries, Rong Li, Yong Ming, Wei Xiang, Chunliu Xu, Guilin Feng, Yongchun Li, Yanxiao Chen, Zhenguo Wu, Ben-He Zhong, Xiaodong Guo

Australian Institute for Innovative Materials - Papers

Ni-rich layered transition metal oxides show great energy density but suffer poor thermal stability and inferior cycling performance, which limit their practical application. In this work, a minor content of Co and B were co-doped into the crystal of a Ni-rich cathode (LiNi0.8Co0.1Mn0.1O2) using cobalt acetate and boric acid as dopants. The results analyzed by XRD, TEM, XPS and SEM reveal that the modified sample shows a reduced energy barrier for Li+ insertion/extraction and alleviated Li+/Ni2+ cation mixing. With the doping of B and Co, corresponding enhanced cycle stability was achieved with a high capacity retention of 86.1% at 1.0C …


High Current High Charge Magnetized And Bunched Electron Beam From A Dc Photogun For Jleic Cooler, S. Zhang, P. A. Adderley, J. F. Benesch, D. B. Bullard, Jean R. Delayen, J. M. Grames, J. Guo, F. E. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, Geoffrey A. Krafft, M. A. Mamun, M. Poelker, R. Suleiman, M.G. Tiefenback, Y.W. Wang, S.A.K. Wijethunga Jan 2019

High Current High Charge Magnetized And Bunched Electron Beam From A Dc Photogun For Jleic Cooler, S. Zhang, P. A. Adderley, J. F. Benesch, D. B. Bullard, Jean R. Delayen, J. M. Grames, J. Guo, F. E. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, Geoffrey A. Krafft, M. A. Mamun, M. Poelker, R. Suleiman, M.G. Tiefenback, Y.W. Wang, S.A.K. Wijethunga

Physics Faculty Publications

A high current, high charge magnetized electron beamline that has been under development for fast and efficient cooling of ion beams for the proposed Jefferson Lab Electron Ion Collider (JLEIC). In this paper, we present the latest progress over the past year that include the generation of picosecond magnetized beam bunches at average currents up to 28 mA with exceptionally long photocathode lifetime, and the demonstrations of magnetized beam with high bunch charge up to 700 pC at 10s of kHz repetition rates. Detailed studies on a stable drive laser system, long lifetime photocathode, beam magnetization effect, beam diagnostics, and …


Simulation Study Of The Emittance Measurements In Magnetized Electron Beam, S.A.K. Wijethunga, J. Benesch, Jean R. Delayen, F. E. Hannon, Geoffrey A. Krafft, M. A. Mamun, G. Palacios-Serrano, M. Poelker, R. Suleiman, S. Zhang Jan 2019

Simulation Study Of The Emittance Measurements In Magnetized Electron Beam, S.A.K. Wijethunga, J. Benesch, Jean R. Delayen, F. E. Hannon, Geoffrey A. Krafft, M. A. Mamun, G. Palacios-Serrano, M. Poelker, R. Suleiman, S. Zhang

Physics Faculty Publications

Electron cooling of the ion beam is key to obtaining the required high luminosity of proposed electron-ion colliders. For the Jefferson Lab Electron Ion Collider, the expected luminosity of 10³⁴ 〖 cm〗⁻² s⁻¹ will be achieved through so-called ’magnetized electron cooling’, where the cooling process occurs inside a solenoid field, which will be part of the collider ring and facilitated using a circulator ring and Energy Recovery Linac (ERL). As an initial step, we generated magnetized electron beam using a new compact DC high voltage photogun biased at -300 kV employing an alkali-antimonide photocathode. This contribution presents the characterization of …


Magnetized Electron Source For Jleic Cooler, R. Suleiman, P.A. Adderley, J.F. Benesch, D.B. Bullard, J.R. Delayen, J.M. Grames, J. Guo, F.E. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, G.A. Krafft, M.A. Mamun, M. Poelker, M.G. Tiefenback, Y.W. Wang, S.A.K. Wijethunga, J. T. Yoskowitz, S. Zhang Jan 2019

Magnetized Electron Source For Jleic Cooler, R. Suleiman, P.A. Adderley, J.F. Benesch, D.B. Bullard, J.R. Delayen, J.M. Grames, J. Guo, F.E. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, G.A. Krafft, M.A. Mamun, M. Poelker, M.G. Tiefenback, Y.W. Wang, S.A.K. Wijethunga, J. T. Yoskowitz, S. Zhang

Physics Faculty Publications

Magnetized bunched-beam electron cooling is a critical part of the Jefferson Lab Electron Ion Collider (JLEIC). Strong cooling of ion beams will be accomplished inside a cooling solenoid where the ions co-propagate with an electron beam generated from a source immersed in magnetic field. This contribution describes the production and characterization of magnetized electron beam using a compact 300 kV DC high voltage photogun and bialkali-antimonide photocathodes. Beam magnetization was studied using a diagnostic beamline that includes viewer screens for measuring the shearing angle of the electron beamlet passing through a narrow upstream slit. Correlated beam emittance with magnetic field …


Space Charge Study Of The Jefferson Lab Magnetized Electron Beam, Sajini A.K. Wijethunga, J. F. Benesch, Jean R. Delayen, F. E. Hannon, C. Hernandez-Garcia, Geoffrey A. Krafft, M. A. Mamun, M. Poelker, R. Suleiman, S. Zhang Jan 2019

Space Charge Study Of The Jefferson Lab Magnetized Electron Beam, Sajini A.K. Wijethunga, J. F. Benesch, Jean R. Delayen, F. E. Hannon, C. Hernandez-Garcia, Geoffrey A. Krafft, M. A. Mamun, M. Poelker, R. Suleiman, S. Zhang

Physics Faculty Publications

Magnetized electron cooling could result in high luminosity at the proposed Jefferson Lab Electron-Ion Collider (JLEIC). In order to increase the cooling efficiency, a bunched electron beam with high bunch charge and high repetition rate is required. We generated magnetized electron beams with high bunch charge using a new compact DC high voltage photo-gun biased at -300 kV with alkali-antimonide photocathode and a commercial ultrafast laser. This contribution explores how magnetization affects space charge dominated beams as a function of magnetic field strength, gun high voltage, laser pulse width, and laser spot size.


Production Of Magnetized Electron Beam From A Dc High Voltage Photogun, M.A. Mamun, P.A. Adderly, J. Benesch, B. Bullard, J. Delayen, J. Grames, J. Guo, F. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, Geoffrey Krafft, M. Poelker, R. Suleiman, M. Tiefenback, Y. Wang, Sajini Wijethunga, S. Zhang Jan 2018

Production Of Magnetized Electron Beam From A Dc High Voltage Photogun, M.A. Mamun, P.A. Adderly, J. Benesch, B. Bullard, J. Delayen, J. Grames, J. Guo, F. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, Geoffrey Krafft, M. Poelker, R. Suleiman, M. Tiefenback, Y. Wang, Sajini Wijethunga, S. Zhang

Physics Faculty Publications

Bunched-beam electron cooling is a key feature of all proposed designs of the future electron-ion collider, and a requirement for achieving the highest promised collision luminosity. At the Jefferson Lab Electron Ion Collider (JLEIC), fast cooling of ion beams will be accomplished via so-called 'magnetized cooling' implemented using a recirculator ring that employs an energy recovery linac. In this contribution, we describe the production of magnetized electron beam using a compact 300 kV DC high voltage photogun with an inverted insulator geometry, and using alkali-antimonide photocathodes. Beam magnetization was assessed using a modest diagnostic beamline that includes YAG view screens …


300 Kv Dc High Voltage Photogun With Inverted Insulator Geometry And Csk₂Sb Photocathode, Y.W. Wang, P.A. Adderley, J. F. Benesch, D.B. Bullard, J.M. Grames, F. E. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, Geoffrey A. Krafft, M. A. Mamun, G. G. Palacios Serrano, M. Poelker, R. Suleiman, M. G. Tiefenback, S.A.K. Wijethunga Jan 2018

300 Kv Dc High Voltage Photogun With Inverted Insulator Geometry And Csk₂Sb Photocathode, Y.W. Wang, P.A. Adderley, J. F. Benesch, D.B. Bullard, J.M. Grames, F. E. Hannon, J. Hansknecht, C. Hernandez-Garcia, R. Kazimi, Geoffrey A. Krafft, M. A. Mamun, G. G. Palacios Serrano, M. Poelker, R. Suleiman, M. G. Tiefenback, S.A.K. Wijethunga

Physics Faculty Publications

A compact DC high voltage photogun with inverted-insulator geometry was designed, built and operated reliably at 300 kV bias voltage using alkali-antimonide photocathodes. This presentation describes key electrostatic design features of the photogun with accompanying emittance measurements obtained across the entire photocathode surface that speak to field non-uniformity within the cathode/anode gap. A summary of initial photocathode lifetime measurements at beam currents up to 4.5 mA is also presented.


Simulation Study Of The Magnetized Electron Beam, S.A.K. Wijethunga, J.F. Benesch, Jean R. Delayen, F. E. Hannon, Geoffrey A. Krafft, M. A. Poelker, R. Suleiman Jan 2018

Simulation Study Of The Magnetized Electron Beam, S.A.K. Wijethunga, J.F. Benesch, Jean R. Delayen, F. E. Hannon, Geoffrey A. Krafft, M. A. Poelker, R. Suleiman

Physics Faculty Publications

Electron cooling of the ion beam plays an important role in electron ion colliders to obtain the required high luminosity. This cooling efficiency can be enhanced by using a magnetized electron beam, where the cooling process occurs inside a solenoid field. This paper compares the predictions of ASTRA and GPT simulations to measurements made using a DC high voltage photogun producing magnetized electron beam, related to beam size and rotation angles as a function of the photogun magnetizing solenoid and other parameters.


Direct Regeneration Of Cathode Materials From Spent Lithium Iron Phosphate Batteries Using A Solid Phase Sintering Method, X Song, T Hu, C Liang, H L. Long, L Zhou, W Song, L You, Z S. Wu, J W. Liu Jan 2017

Direct Regeneration Of Cathode Materials From Spent Lithium Iron Phosphate Batteries Using A Solid Phase Sintering Method, X Song, T Hu, C Liang, H L. Long, L Zhou, W Song, L You, Z S. Wu, J W. Liu

Australian Institute for Innovative Materials - Papers

A direct regeneration of cathode materials from spent LiFePO4 batteries using a solid phase sintering method has been proposed in this article. The spent battery is firstly dismantled to separate the cathode and anode plate, and then the cathode plate is soaked in DMAC organic solvent to separate the cathode materials and Al foil at optimal conditions of 30 min at 30 °C and solid liquid ratio of 1[thin space (1/6-em)]:[thin space (1/6-em)]20 g ml−1. XRD and SEM results of the spent LiFePO4 after separation show that there are some impurity phase components and irregular morphologies with many agglomerations. The …


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) …


A High-Performance Rechargeable Mg2+/Li+ Hybrid Battery Using One-Dimensional Mesoporous Tio2(B) Nanoflakes As The Cathode, Shuojian Su, Yanna Nuli, Zhenguo Huang, Qi Miao, Jun Yang, Jiulin Wang Jan 2016

A High-Performance Rechargeable Mg2+/Li+ Hybrid Battery Using One-Dimensional Mesoporous Tio2(B) Nanoflakes As The Cathode, Shuojian Su, Yanna Nuli, Zhenguo Huang, Qi Miao, Jun Yang, Jiulin Wang

Australian Institute for Innovative Materials - Papers

Mg2+/Li+ hybrid batteries have recently been constructed combining a Mg anode, a Li+-intercalation electrode, and an electrolyte containing both Mg2+ and Li+. These batteries have been reported to outperform all the previously reported magnesium batteries in terms of specific capacity, cycling stability, and rate capability. Herein, we report the outstanding electrochemical performance of Mg2+/Li+ hybrid batteries consisting of a one-dimensional mesoporous TiO2(B) cathode, a Mg anode, and an electrolyte consisting of 0.5 mol L-1 Mg(BH4)2 + 1.5 mol L-1 LiBH4 in tetraglyme. A highly synergetic interaction between Li+ and Mg2+ ions toward the pseudo-capacitive reaction is proposed. The hybrid batteries …


Effective Enhancement Of The Electrochemical Performance Of Layered Cathode Li1.5mn0.75ni0.25o2.5 Via A Novel Facile Molten Salt Method, Zhuo Zheng, Wei-Bo Hua, S Liao, Yan Jun Zhong, En-Hui Wang, Bin-Bin Xu, Hua-Kun Liu, Ben-He Zhong Jan 2015

Effective Enhancement Of The Electrochemical Performance Of Layered Cathode Li1.5mn0.75ni0.25o2.5 Via A Novel Facile Molten Salt Method, Zhuo Zheng, Wei-Bo Hua, S Liao, Yan Jun Zhong, En-Hui Wang, Bin-Bin Xu, Hua-Kun Liu, Ben-He Zhong

Australian Institute for Innovative Materials - Papers

A series of nanocrystalline lithium-rich cathode materials Li1.5Mn0.75Ni0.25O2.5 have been prepared by a novel synthetic process, which combines the co-precipitation method and a modified molten salt method. By using a moderate excess of 0.5LiNO3-0.5LiOH eutectic salts as molten media and reactants, the usage of deionized water or alcohol in the subsequent wash process is successfully reduced, compared with the traditional molten salt method. The materials with different excess Li salt content, Li/M (M = Ni + Mn) = 1.55, 1.65, 1.75, 1.85, 1.95, 2.05, molar ratio, show distinct differences in their …


Gold Nanocrystals With Variable Index Facets As Highly Effective Cathode Catalysts For Lithium-Oxygen Batteries, Dawei Su, S X. Dou, Guoxiu Wang Jan 2015

Gold Nanocrystals With Variable Index Facets As Highly Effective Cathode Catalysts For Lithium-Oxygen Batteries, Dawei Su, S X. Dou, Guoxiu Wang

Australian Institute for Innovative Materials - Papers

Cathode catalysts are the key factor in improving the electrochemical performance of lithium-oxygen (Li-O2) batteries via their promotion of the oxygen reduction and oxygen evolution reactions (ORR and OER). Generally, the catalytic performance of nanocrystals (NCs) toward ORR and OER depends on both composition and shape. Herein, we report the synthesis of polyhedral Au NCs enclosed by a variety of index facets: cubic gold (Au) NCs enclosed by {100} facets; truncated octahedral Au NCs enclosed by {100} and {110} facets; and trisoctahedral (TOH) Au NCs enclosed by 24 high-index {441} facets, as effective cathode catalysts for Li-O2 batteries. All Au …


Large-Scale Synthesis Of Ordered Mesoporous Carbon Fiber And Its Application As Cathode Material For Lithium-Sulfur Batteries, Hongqiang Wang, Chaofeng Zhang, Zhixin Chen, Hua-Kun Liu, Zaiping Guo Jan 2015

Large-Scale Synthesis Of Ordered Mesoporous Carbon Fiber And Its Application As Cathode Material For Lithium-Sulfur Batteries, Hongqiang Wang, Chaofeng Zhang, Zhixin Chen, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

A novel type of one-dimensional ordered mesoporous carbon fiber has been prepared via the electrospinning technique by using resol as the carbon source and triblock copolymer Pluronic F127 as the template. Sulfur is then encapsulated in this ordered mesoporous carbon fibers by a simple thermal treatment. The interwoven fibrous nanostructure has favorably mechanical stability and can provide an effective conductive network for sulfur and polysulfides during cycling. The ordered mesopores can also restrain the diffusion of long-chain polysulfides. The resulting ordered mesoporous carbon fiber sulfur (OMCF-S) composite with 63% S exhibits high reversible capacity, good capacity retention and enhanced rate …


One-Dimensional Manganese-Cobalt Oxide Nanofibres As Bi-Functional Cathode Catalysts For Rechargeable Metal-Air Batteries, Kyu-Nam Jung, Soomin Hwang, Min-Sik Park, Ki Jae Kim, Jae-Geun Kim, S X. Dou, Jung Ho Kim, Jongwon Lee Jan 2015

One-Dimensional Manganese-Cobalt Oxide Nanofibres As Bi-Functional Cathode Catalysts For Rechargeable Metal-Air Batteries, Kyu-Nam Jung, Soomin Hwang, Min-Sik Park, Ki Jae Kim, Jae-Geun Kim, S X. Dou, Jung Ho Kim, Jongwon Lee

Australian Institute for Innovative Materials - Papers

Rechargeable metal-air batteries are considered a promising energy storage solution owing to their high theoretical energy density. The major obstacles to realising this technology include the slow kinetics of oxygen reduction and evolution on the cathode (air electrode) upon battery discharging and charging, respectively. Here, we report non-precious metal oxide catalysts based on spinel-type manganese-cobalt oxide nanofibres fabricated by an electrospinning technique. The spinel oxide nanofibres exhibit high catalytic activity towards both oxygen reduction and evolution in an alkaline electrolyte. When incorporated as cathode catalysts in Zn-air batteries, the fibrous spinel oxides considerably reduce the discharge-charge voltage gaps (improve the …


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 …


Facile Method To Synthesize Na-Enriched Na1+Xfefe(Cn)6 Frameworks As Cathode With Superior Electrochemical Performance For Sodium-Ion Batteries, Weijie Li, Shulei Chou, Jiazhao Wang, Yong-Mook Kang, Jianli Wang, Yong Liu, Qinfen Gu, Hua-Kun Liu, S X. Dou Jan 2015

Facile Method To Synthesize Na-Enriched Na1+Xfefe(Cn)6 Frameworks As Cathode With Superior Electrochemical Performance For Sodium-Ion Batteries, Weijie Li, Shulei Chou, Jiazhao Wang, Yong-Mook Kang, Jianli Wang, Yong Liu, Qinfen Gu, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

Different Na-enriched Na1+xFeFe(CN)6 samples can be synthesized by a facile one-step method, utilizing Na4Fe(CN)6 as the precursor in a different concentration of NaCl solution. As-prepared samples were characterized by a combination of synchrotron X-ray powder diffraction (S-XRD), Mössbauer spectroscopy, Raman spectroscopy, magnetic measurements, thermogravimetric analysis, X-ray photoelectron spectroscopy, and inductively coupled plasma analysis. The electrochemical results show that the Na1.56Fe[Fe(CN)6]·3.1H2O (PB-5) sample shows a high specific capacity of more than 100 mAh g-1 and excellent capacity retention of 97% over 400 cycles. The details structural evolution during …


Three-Dimensional-Network Li3v2(Po4) 3/C Composite As High Rate Lithium Ion Battery Cathode Material And Its Compatibility With Ionic Liquid Electrolytes, Jiantie Xu, Shulei Chou, Cuifeng Zhou, Qinfen Gu, Hua-Kun Liu, S X. Dou Jan 2014

Three-Dimensional-Network Li3v2(Po4) 3/C Composite As High Rate Lithium Ion Battery Cathode Material And Its Compatibility With Ionic Liquid Electrolytes, Jiantie Xu, Shulei Chou, Cuifeng Zhou, Qinfen Gu, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

A high performance Li3V2(PO4)3 cathode material for lithium ion batteries was synthesized by the microwave-assisted hydrothermal method followed by a post annealing process. The synchrotron X-ray diffraction analysis results confirmed that single-phase Li3V2(PO4)3 with monoclinic structure was obtained. Scanning electron microscope and transmission electron microscope images revealed that the as-prepared Li3V 2(PO4)3 was composed of nanowires and microsized particles. Electrochemical results demonstrated that the Li 3V2(PO4)3 electrode measured at 10 C after 500 cycles can deliver discharge capacities of 85.4 mAh g-1 and 103.4 mAh g-1, with a capacity retention of 99.3% and 95.9%, in the voltage ranges of 3.0-4.3 …


One-Step Synthesis Of Graphene/Polypyrrole Nanofiber Composites As Cathode Material For A Biocompatible Zinc/Polymer Battery, Sha Li, Kewei Shu, Chen Zhao, Caiyun Wang, Zaiping Guo, Gordon G. Wallace, Hua-Kun Liu Jan 2014

One-Step Synthesis Of Graphene/Polypyrrole Nanofiber Composites As Cathode Material For A Biocompatible Zinc/Polymer Battery, Sha Li, Kewei Shu, Chen Zhao, Caiyun Wang, Zaiping Guo, Gordon G. Wallace, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

The significance of developing implantable, biocompatible, miniature power sources operated in a low current range has become manifest in recent years to meet the demands of the fast-growing market for biomedical microdevices. In this work, we focus on developing high-performance cathode material for biocompatible zinc/polymer batteries utilizing biofluids as electrolyte. Conductive polymers and graphene are generally considered to be biocompatible and suitable for bioengineering applications. To harness the high electrical conductivity of graphene and the redox capability of polypyrrole (PPy), a polypyrrole fiber/graphene composite has been synthesized via a simple one-step route. This composite is highly conductive (141 S cm …


A Novel Codoping Approach For Enhancing The Performance Of Polypyrrole Cathode In A Bioelectric Battery, Yang Yang, Caiyun Wang, Chunming Zhang, Dan Wang, Dannong He, Gordon G. Wallace Jan 2014

A Novel Codoping Approach For Enhancing The Performance Of Polypyrrole Cathode In A Bioelectric Battery, Yang Yang, Caiyun Wang, Chunming Zhang, Dan Wang, Dannong He, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

A conducting polymer (CP) based bioelectric battery provides a promising alternative to commercial lithium batteries to drive biomedical devices. However, the low power density limits practical application. Here, we synthesize a polypyrrole (PPy)/anthraquinone sulfonate (AQS)/reduced graphene oxide (r-GO) composite via a facile electrochemical route, and use this as a novel cathode material for bioelectric batteries. The presence of r-GO significantly enhanced the electrochemical properties of PPy and led to greatly improved cell performance compared to that of PPy/AQS. The resultant PPy/AQS/r-GO composite delivered a maximum power density of 6240.5 mW m(-2), 14.2 times higher than that of PPy/p-toluenesulfonate (pTS) as …


Study On Vanadium Substitution To Iron In Li2fep 2o7 As Cathode Material For Lithium-Ion Batteries, Jiantie Xu, Shulei Chou, Qinfen Gu, M F. Md Din, Hua-Kun Liu, S X. Dou Jan 2014

Study On Vanadium Substitution To Iron In Li2fep 2o7 As Cathode Material For Lithium-Ion Batteries, Jiantie Xu, Shulei Chou, Qinfen Gu, M F. Md Din, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

A series of Li2Fe1-3x/2VxP 2O7 (x = 0, 0.025, 0.05, 0.075, and 0.1) cathode materials for LIBs were prepared by the sol-gel method. Structural characterization of Li2Fe1-3x/2VxP2O7 (x = 0, 0.025, 0.05, 0.075, and 0.1) samples was conducted by synchrotron X-ray diffraction. The morphology and oxidation states of Fe2+ and V 3+ in the Li2Fe1-3x/2VxP 2O7 samples were confirmed by scanning electron microscopy and magnetic susceptibility measurements, respectively. The electrochemical measurements indicated that Li2Fe1-3x/2VxP 2O7 (x = 0.025) delivered the higher reversible capacity of 79.9 mAh g-1 at 1 C in the voltage range of 2.0 - 4.5 V with …


Zno-Doped Lifepo4 Cathode Material For Lithium-Ion Battery Fabricated By Hydrothermal Method, Yemin Hu, Jun Yao, Zhe Zhao, Mingyuan Zhu, Ying Li, Hongming Jin, Huijun Zhao, Jiazhao Wang Jan 2013

Zno-Doped Lifepo4 Cathode Material For Lithium-Ion Battery Fabricated By Hydrothermal Method, Yemin Hu, Jun Yao, Zhe Zhao, Mingyuan Zhu, Ying Li, Hongming Jin, Huijun Zhao, Jiazhao Wang

Australian Institute for Innovative Materials - Papers

LiFePO4 particles doped with zinc oxide was synthesized via a hydrothermal route and used as cathode material for lithium-ion battery. Sample of preferable shape and structure was obtained by a concise and efficient process. ZnO doping into the LiFePO4 matrix was positively confirmed by the results of X-ray diffraction (XRD); high-resolution transmission electron microscopy (HRTEM); energy dispersive spectrometer (EDS), and X-ray photoelectron spectroscopy (XPS). LiFePO4 doped with ZnO tends to form nanometer-size and homogeneous particles, which can improve markedly the performance and stability of charge-discharge cycle. A specific discharge capacity of ZnO-doped LiFePO4 at 132.3 mAh g-1 was achieved, with …


Polypyrrole As Cathode Materials For Zn-Polymer Battery With Various Biocompatible Aqueous Electrolytes, Sha Li, Irin Sultana, Zaiping Guo, Caiyun Wang, G G. Wallace, Hua-Kun Liu Jan 2013

Polypyrrole As Cathode Materials For Zn-Polymer Battery With Various Biocompatible Aqueous Electrolytes, Sha Li, Irin Sultana, Zaiping Guo, Caiyun Wang, G G. Wallace, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

Polypyrrole films doped with p-toluenesulfonic anions on stainless steel mesh substrates were prepared by the electropolymerization method. A Zn/aqueous solution/polymer battery system was thus established with the polymer film as the cathode and three different biocompatible aqueous electrolytes. The mechanism of the anode reaction can be explained as the dissolution of Zn. It was found, however, that the discharge performance, including the discharge plateaus and capacities, were significantly affected by the polymer reactions. To elucidate the reaction mechanisms of the conductive polymer, its electrochemical properties were systematically studied by several techniques, including cyclic voltammetry, electrochemical impedance spectroscopy, and monitoring mass …