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Full-Text Articles in Physical Sciences and Mathematics

A Case Study Of Wifi Sniffing Performance Evaluation, Yan Li, Johan Barthelemy, Shuai Sun, Pascal Perez, Bill Moran Jan 2020

A Case Study Of Wifi Sniffing Performance Evaluation, Yan Li, Johan Barthelemy, Shuai Sun, Pascal Perez, Bill Moran

SMART Infrastructure Facility - Papers

Mobile devices regularly broadcast WiFi probe requests in order to discover available proximal WiFi access points for connection. A probe request, sent automatically in the active scanning mode, consisting of the MAC address of the device expresses an advertisement of its presence. A real-time wireless sniffing system is able to sense WiFi packets and analyse wireless traffic. This provides an opportunity to obtain insights into the interaction between the humans carrying the mobile devices and the environment. Susceptibility to loss of the wireless data transmission is an important limitation on this idea, and this is complicated by the lack of …


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 …


Thermoelectric Performance Of Single-Phase Tellurium-Reduced Quaternary (Pbte)0.55(Pbs)0.1(Pbse)0.35, Laaya Shaabani, Graeme Blake, Andrew Manettas, Shokat Keshavarzi, Sima Aminorroaya-Yamini Jan 2019

Thermoelectric Performance Of Single-Phase Tellurium-Reduced Quaternary (Pbte)0.55(Pbs)0.1(Pbse)0.35, Laaya Shaabani, Graeme Blake, Andrew Manettas, Shokat Keshavarzi, Sima Aminorroaya-Yamini

Australian Institute for Innovative Materials - Papers

Lead chalcogenide quaternary systems have been shown to provide high thermoelectric (TE) efficiency superior to those of binary andternary lead chalcogenides, arising from both altered electronic band structures and a reduction in lattice thermal conductivity. Here, we have synthesized single-phase samples of the quaternary compound (PbTe)0.55(PbS)0.1(PbSe)0.35 dopedwith Na and characterized their TE properties. We show that the dopant solubility is limited to 1 at. %. A very low lattice thermal conductivity of∼0.6 Wm−1K−1at 850 K is achieved at all dopant concentrations because of phonon scattering from point defects associated with solute atoms with high contrastatomic mass. As a result, a …


Plasma-Induced Amorphous Shell And Deep Cation-Site S Doping Endow Tio2 With Extraordinary Sodium Storage Performance, Hanna He, Dan Huang, Wei Kong Pang, Dan Sun, Qi Wang, Yougen Tang, Xiaobo Ji, Zaiping Guo, Haiyan Wang Jan 2018

Plasma-Induced Amorphous Shell And Deep Cation-Site S Doping Endow Tio2 With Extraordinary Sodium Storage Performance, Hanna He, Dan Huang, Wei Kong Pang, Dan Sun, Qi Wang, Yougen Tang, Xiaobo Ji, Zaiping Guo, Haiyan Wang

Australian Institute for Innovative Materials - Papers

Structural design and modification are effective approaches to regulate the physicochemical properties of TiO 2 , which play an important role in achieving advanced materials. Herein, a plasma-assisted method is reported to synthesize a surface-defect-rich and deep-cation-site-rich S doped rutile TiO 2 (R-TiO 2- x -S) as an advanced anode for the Na ion battery. An amorphous shell (≈3 nm) is induced by the Ar/H 2 plasma, which brings about the subsequent high S doping concentration (≈4.68 at%) and deep doping depth. Experimental results and density functional theory calculations demonstrate greatly facilitated ion diffusion, improved electronic conductivity, and an increased …


Effect Of Alf3-Coated Li4ti5o12 On The Performance And Function Of The Lini0.5mn1.5o4||Li4ti5o12 Full Battery-An In-Operando Neutron Powder Diffraction Study, Gemeng Liang, Anoop Somanathan Pillai Sushamakumari Amma, Vanessa K. Peterson, Kuan-Yu Ko, Chia-Ming Chang, Cheng-Zhang Lu, Chia-Erh Liu, Shih-Chieh Liao, Jin-Ming Chen, Zaiping Guo, Wei Kong Pang Jan 2018

Effect Of Alf3-Coated Li4ti5o12 On The Performance And Function Of The Lini0.5mn1.5o4||Li4ti5o12 Full Battery-An In-Operando Neutron Powder Diffraction Study, Gemeng Liang, Anoop Somanathan Pillai Sushamakumari Amma, Vanessa K. Peterson, Kuan-Yu Ko, Chia-Ming Chang, Cheng-Zhang Lu, Chia-Erh Liu, Shih-Chieh Liao, Jin-Ming Chen, Zaiping Guo, Wei Kong Pang

Australian Institute for Innovative Materials - Papers

The LiNi0.5Mn1.5O4||Li4Ti5O12(LMNO||LTO) battery possesses a relatively-high energy density and cycle performance, with further enhancement possible by application of an AlF3coating on the LTO electrode particles. We measure the performance enhancement to the LMNO||LTO battery achieved by a AlF3coating on the LTO particles through electrochemical testing and use in-operando neutron powder diffraction to study the changes to the evolution of the bulk crystal structure during battery cycling. We find that the AlF3coating along with parasitic Al doping slightly increases capacity and greatly increases rate capability of the LTO electrode, as well as significantly reducing capacity loss on cycling, facilitating a gradual …


Porous Nati2(Po4)(3) Nanocubes Anchored On Porous Carbon Nanosheets For High Performance Sodium-Ion Batteries, Ziqi Wang, Jiaojiao Liang, Kai Fan, Xiaodi Liu, Caiyun Wang, Jianmin Ma Jan 2018

Porous Nati2(Po4)(3) Nanocubes Anchored On Porous Carbon Nanosheets For High Performance Sodium-Ion Batteries, Ziqi Wang, Jiaojiao Liang, Kai Fan, Xiaodi Liu, Caiyun Wang, Jianmin Ma

Australian Institute for Innovative Materials - Papers

NaTi2(PO4)3 has attracted great interest as anode material for sodium ion batteries owing to its open three-dimensional framework structure and limited volume changes during the charge and discharge process. However, the poor intrinsic electronic conductivity of NaTi2(PO4)3 needs to be improved for high rate capability. In this work, porous NaTi2(PO4)3 nanocubes anchored on porous carbon nanosheets (NaTi2(PO4)3/C) are designed and developed. This material exhibits a large discharge capacity and good rate capacity including a first discharge capacity of 485 mAh g−1 at a current density of 0.1 A g−1, and 98 mAh g−1 retained at a high rate of 4 …


Investigation On The Catalytic Performance Of Reduced‐Graphene‐Oxide‐Interpolated Fes2 And Fes For Oxygen Reduction Reaction, Hengyi Fang, Taizhong Huang, Jianfeng Mao, Shuo Yao, M Dinesh, Yue Sun, Dong Liang, Lei Qi, Jiemei Yu, Zhankun Jiang Jan 2018

Investigation On The Catalytic Performance Of Reduced‐Graphene‐Oxide‐Interpolated Fes2 And Fes For Oxygen Reduction Reaction, Hengyi Fang, Taizhong Huang, Jianfeng Mao, Shuo Yao, M Dinesh, Yue Sun, Dong Liang, Lei Qi, Jiemei Yu, Zhankun Jiang

Australian Institute for Innovative Materials - Papers

The oxygen reduction reaction (ORR) plays a key role in many kinds of energy conversion and energy storage devices, especially in fuel cells. Developing low-cost, easily prepared, and high-efficiency catalysts is a crucial factor for the large-scale applications of fuel cells. Herein, we report the reduced graphene oxide (rGO) interpolated FeS2and FeS as low cost and high performance electrocatalyst for ORR in the alkaline electrolyte. Cyclic voltammetry tests indicate that the onset potential of the ORR for FeS2@rGO is −0.142 V, which is close to the state-of-the-art commercial Pt/C (-0.114 V) catalyst. A low Tafel slope of ∼ 98 mV/decade …


Capillary-Induced Ge Uniformly Distributed In N-Doped Carbon Nanotubes With Enhanced Li-Storage Performance, Haipeng Guo, Boyang Ruan, Lili Liu, Lei Zhang, Zhanliang Tao, Shulei Chou, Jiazhao Wang, Hua-Kun Liu Jan 2017

Capillary-Induced Ge Uniformly Distributed In N-Doped Carbon Nanotubes With Enhanced Li-Storage Performance, Haipeng Guo, Boyang Ruan, Lili Liu, Lei Zhang, Zhanliang Tao, Shulei Chou, Jiazhao Wang, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

Germanium (Ge) is a prospective anode material for lithium-ion batteries, as it possesses large theoretical capacity, outstanding lithium-ion diffusivity, and excellent electrical conductivity. Ge suffers from drastic capacity decay and poor rate performance, however, owing to its low electrical conductivity and huge volume expansion during cycling processes. Herein, a novel strategy has been developed to synthesize a Ge at N-doped carbon nanotubes (Ge at N-CNTs) composite with Ge nanoparticles uniformly distributed in the N-CNTs by using capillary action. This unique structure could effectively buffer large volume expansion. When evaluated as an anode material, the Ge at N-CNTs demonstrate enhanced cycling …


Structure-Property Relationships Of Organic Electrolytes And Their Effects On Li/S Battery Performance, Mohammad Kaiser, Shulei Chou, Hua-Kun Liu, Shi Xue Dou, Chunsheng Wang, Jiazhao Wang Jan 2017

Structure-Property Relationships Of Organic Electrolytes And Their Effects On Li/S Battery Performance, Mohammad Kaiser, Shulei Chou, Hua-Kun Liu, Shi Xue Dou, Chunsheng Wang, Jiazhao Wang

Australian Institute for Innovative Materials - Papers

Electrolytes, which are a key component in electrochemical devices, transport ions between the sulfur/carbon composite cathode and the lithium anode in lithium-sulfur batteries (LSBs). The performance of a LSB mostly depends on the electrolyte due to the dissolution of polysulfides into the electrolyte, along with the formation of a solid-electrolyte interphase. The selection of the electrolyte and its functionality during charging and discharging is intricate and involves multiple reactions and processes. The selection of the proper electrolyte, including solvents and salts, for LSBs strongly depends on its physical and chemical properties, which is heavily controlled by its molecular structure. In …


Ag-Mg Antisite Defect Induced High Thermoelectric Performance Of Α-Mgagsb, Zhenzhen Feng, Jihua Zhang, Yuli Yan, Guangbiao Zhang, Chao Wang, Chengxiao Peng, Fengzhu Ren, Yuan Xu Wang, Zhenxiang Cheng Jan 2017

Ag-Mg Antisite Defect Induced High Thermoelectric Performance Of Α-Mgagsb, Zhenzhen Feng, Jihua Zhang, Yuli Yan, Guangbiao Zhang, Chao Wang, Chengxiao Peng, Fengzhu Ren, Yuan Xu Wang, Zhenxiang Cheng

Australian Institute for Innovative Materials - Papers

Engineering atomic-scale native point defects has become an attractive strategy to improve the performance of thermoelectric materials. Here, we theoretically predict that Ag-Mg antisite defects as shallow acceptors can be more stable than other intrinsic defects under Mg-poor-Ag/Sb-rich conditions. Under more Mg-rich conditions, Ag vacancy dominates the intrinsic defects. The p-type conduction behavior of experimentally synthesized ¿-MgAgSb mainly comes from Ag vacancies and Ag antisites (Ag on Mg sites), which act as shallow acceptors. Ag-Mg antisite defects significantly increase the thermoelectric performance of ¿-MgAgSb by increasing the number of band valleys near the Fermi level. For Li-doped ¿-MgAgSb, under more …


Ultra-Light And Flexible Pencil-Trace Anode For High Performance Potassium-Ion And Lithium-Ion Batteries, Zhixin Tai, Yajie Liu, Qing Zhang, Tengfei Zhou, Zaiping Guo, Hua-Kun Liu, Shi Xue Dou Jan 2017

Ultra-Light And Flexible Pencil-Trace Anode For High Performance Potassium-Ion And Lithium-Ion Batteries, Zhixin Tai, Yajie Liu, Qing Zhang, Tengfei Zhou, Zaiping Guo, Hua-Kun Liu, Shi Xue Dou

Australian Institute for Innovative Materials - Papers

Engineering design of battery configurations and new battery system development are alternative approaches to achieve high performance batteries. A novel flexible and ultra-light graphite anode is fabricated by simple friction drawing on filter paper with a commercial 8B pencil. Compared with the traditional anode using copper foil as current collector, this innovative current-collector-free design presents capacity improvement of over 200% by reducing the inert weight of the electrode. The as-prepared pencil-trace electrode exhibits excellent rate performance in potassium-ion batteries (KIBs), significantly better than in lithium-ion batteries (LIBs), with capacity retention of 66% for the KIB vs. 28% for the LIB …


Significant Enhancement Of The Cycling Performance And Rate Capability Of The P/C Composite Via Chemical Bonding (P-C), Weijie Li, Shulei Chou, Jiazhao Wang, Hua-Kun Liu, S X. Dou Jan 2016

Significant Enhancement Of The Cycling Performance And Rate Capability Of The P/C Composite Via Chemical Bonding (P-C), Weijie Li, Shulei Chou, Jiazhao Wang, Hua-Kun Liu, S X. Dou

Australian Institute for Innovative Materials - Papers

Among anode materials for sodium ion batteries, red phosphorus is a very promising one due to its abundant reserves, low-cost and high theoretical capacity of 2600 mA h g-1. However, its huge volume expansion on sodiation (∼490%) and poor conductivity leads to dramatic capacity decay, restraining its practical application. To improve the electrochemical performance, here, we prepared a red phosphorus and graphene nanoplate composite using cheap red P and natural graphite as the starting materials via a simple and scalable ball-milling method. The phosphorus-carbon bond formed during the milling process improves the electrical connectivity between P particles and graphene nanoplates, …


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 …


Expeditious And Eco-Friendly Hydrothermal Polymerization Of Pedot Nanoparticles For Binderfree High Performance Supercapacitor Electrodes, Murugesan Rajesh, C Justin Raj, Byung Chul Kim, Ramu Manikandan, Sung Jin Kim, Sang-Yeup Prof Sang-Yeup Park, Kwangsoo Lee, Kook Hyun Yu Jan 2016

Expeditious And Eco-Friendly Hydrothermal Polymerization Of Pedot Nanoparticles For Binderfree High Performance Supercapacitor Electrodes, Murugesan Rajesh, C Justin Raj, Byung Chul Kim, Ramu Manikandan, Sung Jin Kim, Sang-Yeup Prof Sang-Yeup Park, Kwangsoo Lee, Kook Hyun Yu

Australian Institute for Innovative Materials - Papers

Poly(3,4-ethylenedioxythiophene) (PEDOT) is a promising conjugated polymer that has attracted attention because of its outstanding electronic properties, useful for a wide range of applications in energy storage devices. However, synthesis of high-quality PEDOT occurs via vapour phase polymerization and chemical vapour deposition techniques using extrinsic hard templates or complicated experimental setups. This study introduces a simple hydrothermal polymerization technique using ferric chloride (FeCl3) as an oxidizing agent to overcome the above drawback, which results in good conductive, crystalline PEDOT nanodendrites and nanospheres. The effects of varying the molar ratio of FeCl3 oxidant were investigated in terms of the structural, morphological …


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 …


Superior Sodium-Ion Storage Performance Of Co3o4@Nitrogen-Doped Carbon: Derived From A Metal–Organic Framework, Ying Wang, Caiyun Wang, Yijing Wang, Hua-Kun Liu, Zhenguo Huang Jan 2016

Superior Sodium-Ion Storage Performance Of Co3o4@Nitrogen-Doped Carbon: Derived From A Metal–Organic Framework, Ying Wang, Caiyun Wang, Yijing Wang, Hua-Kun Liu, Zhenguo Huang

Australian Institute for Innovative Materials - Papers

Nitrogen-doped carbon coated Co 3 O 4 nanoparticles (Co 3 O 4 @NC) with high Na-ion storage capacity and unprecedented long-life cycling stability are reported in this paper. The Co 3 O 4 @NC was derived from a metal – organic framework ZIF-67, where the Co ions and organic linkers were, respectively, converted to Co 3 O 4 nanoparticle cores and nitrogen-doped carbon shells through a controlled two-step annealing process. The Co 3 O 4 @NC shows a porous nature with a surface area of 101 m 2 g 1 . When applied as an anode for sodium ion batteries …


Light Activated Electrochemistry: Light Intensity And Ph Dependence On Electrochemical Performance Of Anthraquinone Derivatized Silicon, Ying Yang, Simone Ciampi, Moinul H. Choudhury, J Justin Gooding Jan 2016

Light Activated Electrochemistry: Light Intensity And Ph Dependence On Electrochemical Performance Of Anthraquinone Derivatized Silicon, Ying Yang, Simone Ciampi, Moinul H. Choudhury, J Justin Gooding

Australian Institute for Innovative Materials - Papers

We seek to understand how the thermodynamics and kinetics of anthraquinone-containing self-assembled monolayer on silicon electrodes are affected by two key experimental variables: the intensity of the light assisting the anthraquinone/anthrahydroquinone redox process and the local solution environment. The substrates are chemically passivated poorly doped p-type silicon electrodes. The study presents a strategy for the selective modulation of either the anodic or the cathodic process occurring at the interface. Cyclic voltammetry studies showed that unlike for a proton-coupled electron transfer process performed at metallic electrodes, for the redox reaction of the anthraquinone unit on a silicon electrode it becomes possible …


Characteristics And Cadmium Extraction Performance Of Pvc/Aliquat 336 Electrospun Fibres In Comparison With Polymer Inclusion Membranes, Nurul Syazana Binti Abdul Halim, Philip G. Whitten, Long D. Nghiem Jan 2016

Characteristics And Cadmium Extraction Performance Of Pvc/Aliquat 336 Electrospun Fibres In Comparison With Polymer Inclusion Membranes, Nurul Syazana Binti Abdul Halim, Philip G. Whitten, Long D. Nghiem

Australian Institute for Innovative Materials - Papers

Electrospun fibres and polymer inclusion membranes (PIMs) were prepared from polyvinyl chloride (PVC) and Aliquat 336. Morphological and thermomechanical properties of the electrospun mats differed notably from those of PIMs. The plasticizing effect of Aliquat 336 on electrospun PVC/Aliquat 336 fibres was confirmed by the shifting of the glass transition temperature (Tg). By contrast, Aliquat 336 did not act as a plasticizer in PIMs as Tg was independent of Aliquat 336 concentration. Cadmium extraction to electrospun fibres could occur at a lower Aliquat 336 content (i.e. 6 wt.%) compared with PIMs. At 40 wt.% Aliquat 336 content, both PIMs and …


Effect Of Tensile Load On The Actuation Performance Of Ph-Sensitive Hydrogels, Sina Naficy, Geoffrey M. Spinks Jan 2015

Effect Of Tensile Load On The Actuation Performance Of Ph-Sensitive Hydrogels, Sina Naficy, Geoffrey M. Spinks

Australian Institute for Innovative Materials - Papers

pH-responsive hydrogels are capable of converting chemical energy to mechanical work. To optimize their use as actuators, their response when operating against an external load must be fully characterized. Here, the actuation strain of a model pH-sensitive hydrogel as a function of different constant loads is studied. The experimental actuation strain, produced by switching the pH from 2 to 12, decreases significantly and monotonically with increasing initial tensile load. Two models are developed to predict the actuation strain as a function of applied stress. Simple mechanical models based on the change in hydrogel modulus and cross sectional area due to …


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 …


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 …


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 …


Increased Upconversion Performance For Thin Film Solar Cells: A Trimolecular Composition, Yuen Yap Cheng, Andrew Nattestad, Tim F. Schulze, Rowan W. Macqueen, Burkhard Fückel, Klaus Lips, Gordon G. Wallace, Tony Khoury, Maxwell J. Crossley, Timothy W. Schmidt Jan 2015

Increased Upconversion Performance For Thin Film Solar Cells: A Trimolecular Composition, Yuen Yap Cheng, Andrew Nattestad, Tim F. Schulze, Rowan W. Macqueen, Burkhard Fückel, Klaus Lips, Gordon G. Wallace, Tony Khoury, Maxwell J. Crossley, Timothy W. Schmidt

Australian Institute for Innovative Materials - Papers

Photochemical upconversion based on triplet-triplet annihilation (TTA-UC) is employed to enhance the short-circuit currents generated by two varieties of thin-film solar cells, a hydrogenated amorphous silicon (a-Si:H) solar cell and a dye-sensitized solar cell (DSC). TTA-UC is exploited to harvest transmitted sub-bandgap photons, combine their energies and re-radiate upconverted photons back towards the solar cells. In the present study we employ a dual-emitter TTA-UC system which allows for significantly improved UC quantum yields as compared to the previously used single-emitter TTA systems. In doing so we achieve record photo-current enhancement values for both the a-Si:H device and the DSC, surpassing …


Synthesis Of Nitrogen-Doped Graphene Via Thermal Treatment Of Graphene Oxide Within Methylimidazole And Its Capacitance Performance As Electric Double Layer Capacitor, Md. Monirul Islam, Shaikh Nayeem Faisal, Anup Kumar Roy, Sonia Ansari, Dean Cardillo, Konstantin K. Konstantinov, Enamul Haque Jan 2015

Synthesis Of Nitrogen-Doped Graphene Via Thermal Treatment Of Graphene Oxide Within Methylimidazole And Its Capacitance Performance As Electric Double Layer Capacitor, Md. Monirul Islam, Shaikh Nayeem Faisal, Anup Kumar Roy, Sonia Ansari, Dean Cardillo, Konstantin K. Konstantinov, Enamul Haque

Australian Institute for Innovative Materials - Papers

Nitrogen-doped graphene was successfully synthesised from graphene oxide (GO) and 2-methylimidazole composite via thermal treatment under argon flow at 700oC within 1h. This synthesised N-doped graphene exhibits homogeneous nitrogen doping with concentration of ~5% in three different nitrogen configuration namelypyridinic N, pyrrolic N and graphitic N. The electric double layer capacitor (EDLC) made up with this N-doped graphene showed excellent specific capacitance 274 F/g at current density of 1A/g, which was ~7 times higher than GO. This EDLC capacitor showed excellent cyclic stability up to 5000 cycles with capacity retention of ~91%.


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 …


A New Strategy For Achieving A High Performance Anode For Lithium Ion Batteries-Encapsulating Germanium Nanoparticles In Carbon Nanoboxes, Dan Li, Hongqiang Wang, Hua-Kun Liu, Zaiping Guo Jan 2015

A New Strategy For Achieving A High Performance Anode For Lithium Ion Batteries-Encapsulating Germanium Nanoparticles In Carbon Nanoboxes, Dan Li, Hongqiang Wang, Hua-Kun Liu, Zaiping Guo

Australian Institute for Innovative Materials - Papers

A novel strategy to improve the electrochemical performance of a germanium anode is proposed via encapsulating germanium nanoparticles in carbon nanoboxes by carbon coating the precursor, germanium dioxide cubes, and then subjecting them to a reduction treatment. The complete and robust carbon boxes are shown to not only provide extra void space for the expansion of germanium nanoparticles after lithium insertion but also offer a large reactive area and reduced distance for the lithium diffusion. Furthermore, the thus-obtained composite, composed of densely stacked carbon nanoboxes encapsulating germanium nanoparticles (germanium at carbon cubes (Ge at CC)), exhibits a high tap density …


Superior Intrinsic Thermoelectric Performance With Zt Of 1.8 In Single-Crystal And Melt-Quenched Highly Dense Cu2-Xse Bulks, Lanling Zhao, Xiaolin Wang, Ji-Yang Wang, Zhenxiang Cheng, S X. Dou, Jun Wang, L Liu Jan 2015

Superior Intrinsic Thermoelectric Performance With Zt Of 1.8 In Single-Crystal And Melt-Quenched Highly Dense Cu2-Xse Bulks, Lanling Zhao, Xiaolin Wang, Ji-Yang Wang, Zhenxiang Cheng, S X. Dou, Jun Wang, L Liu

Australian Institute for Innovative Materials - Papers

Practical applications of the high temperature thermoelectric materials developed so far are partially obstructed by the costly and complicated fabrication process. In this work, we put forward two additional important properties for thermoelectric materials, high crystal symmetry and congruent melting. We propose that the recently discovered thermoelectric material Cu2-xSe, with figure of merit, zT, over 1.5 at T of ~ 1000 K, should meet these requirements, based on our analysis of its crystal structure and the Cu-Se binary phase diagram. We found that its excellent thermoelectric performance is intrinsic, and less dependent on grain size, while highly dense samples can …


Performance Modulation Of Α-Mno2 Nanowires By Crystal Facet Engineering, W Li, Xiangyuan Cui, R Zeng, Guodong Du, Ziqi Sun, Rongkun Zheng, Simon Peter Ringer, S X. Dou Jan 2015

Performance Modulation Of Α-Mno2 Nanowires By Crystal Facet Engineering, W Li, Xiangyuan Cui, R Zeng, Guodong Du, Ziqi Sun, Rongkun Zheng, Simon Peter Ringer, S X. Dou

Australian Institute for Innovative Materials - Papers

Modulation of material physical and chemical properties through selective surface engineering is currently one of the most active research fields, aimed at optimizing functional performance for applications. The activity of exposed crystal planes determines the catalytic, sensory, photocatalytic, and electrochemical behavior of a material. In the research on nanomagnets, it opens up new perspectives in the fields of nanoelectronics, spintronics, and quantum computation. Herein, we demonstrate controllable magnetic modulation of α-MnO2 nanowires, which displayed surface ferromagnetism or antiferromagnetism, depending on the exposed plane. First-principles density functional theory calculations confirm that both Mn- and O-terminated α-MnO2 (1 …


3d Hierarchical Porous Graphene Aerogel With Tunable Meso-Pores On Graphene Nanosheets For High-Performance Energy Storage, Long Ren, K N. Hui, K S. Hui, Yundan Liu, Xiang Qi, Jianxin Zhong, Yi Du, Jianping Yang Jan 2015

3d Hierarchical Porous Graphene Aerogel With Tunable Meso-Pores On Graphene Nanosheets For High-Performance Energy Storage, Long Ren, K N. Hui, K S. Hui, Yundan Liu, Xiang Qi, Jianxin Zhong, Yi Du, Jianping Yang

Australian Institute for Innovative Materials - Papers

New and novel 3D hierarchical porous graphene aerogels (HPGA) with uniform and tunable mesopores (e.g., 21 and 53 nm) on graphene nanosheets (GNS) were prepared by a hydrothermal self-assembly process and an in-situ carbothermal reaction. The size and distribution of the meso-pores on the individual GNS were uniform and could be tuned by controlling the sizes of the Co3O4 NPs used in the hydrothermal reaction. This unique architecture of HPGA prevents the stacking of GNS and promises more electrochemically active sites that enhance the electrochemical storage level significantly. HPGA, as a lithium-ion battery anode, exhibited superior electrochemical performance, including a …


Effects Of Cu Substitution For Sn On The Electrochemical Performance Of La0.7mg0.3al0.3mn0.4sn0.5−Xcuxni3.8 (X = 0-0.5) Alloys For Ni-Mh Batteries, Julio Cesar Serafim Casini, Zaiping Guo, Hua-Kun Liu, Rubens Nunes Faria, Hidetoshi Takiishi Jan 2015

Effects Of Cu Substitution For Sn On The Electrochemical Performance Of La0.7mg0.3al0.3mn0.4sn0.5−Xcuxni3.8 (X = 0-0.5) Alloys For Ni-Mh Batteries, Julio Cesar Serafim Casini, Zaiping Guo, Hua-Kun Liu, Rubens Nunes Faria, Hidetoshi Takiishi

Australian Institute for Innovative Materials - Papers

The effects of substitution of Cu for Sn on the electrochemical discharge capacity performance of La0.7Mg0.3Al0.3Mn0.4Sn0.5−xCuxNi3.8 (x = 0.0, 0.1, 0.2, 0.3, and 0.5) negative electrode alloys were investigated. Results indicate that increasing Cu content enhanced electrochemical behavior by increasing the maximum discharge capacity from 239.8 mA·h/g (x = 0) to 305.2 mA·h/g (x = 0.5), the discharge capacity retention at the 100th cycle from 78.0% (x = 0) to 81.8% (x = 0.5), and the high rate dischargeability (HRD) from 25.7% (x = 0) to 80.6% (x = 0.5).