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Synthesis Of Hollow Geo2 Nanostructures, Transformation Into Geoc, And Lithium Storage Properties, Li Li, Kuok H. Seng, Chuanqi Feng, Hua-Kun Liu, Zaiping Guo
Synthesis Of Hollow Geo2 Nanostructures, Transformation Into Geoc, And Lithium Storage Properties, Li Li, Kuok H. Seng, Chuanqi Feng, Hua-Kun Liu, Zaiping Guo
Australian Institute for Innovative Materials - Papers
In this work, we synthesize mesoporous and hollow germanium@carbon nanostructures through simultaneous carbon coating and reduction of a hollow ellipsoidal GeO2 precursor. The formation mechanism of GeO 2 ellipsoids and the ratio of Ge4+ to Sn4+ as the starting materials are also investigated. Compared to the solid ellipsoidal Ge@carbon (Ge@C-3), the hollow ellipsoidal Ge@C-1 sample exhibits better cycling stability (100% capacity retention after 200 cycles at the 0.2 C rate) and higher rate capability (805 mA h g-1 at 20 C) compared to Ge@C-3 due to its unique hollow structure; therefore, this hollow ellipsoidal Ge@carbon can be considered as a …
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
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 …
Additive-Free Synthesis Of 3d Porous V2o5 Hierarchical Microspheres With Enhanced Lithium Storage Properties, Chaofeng Zhang, Zhixin Chen, Zaiping Guo, Xiong Wen Lou
Additive-Free Synthesis Of 3d Porous V2o5 Hierarchical Microspheres With Enhanced Lithium Storage Properties, Chaofeng Zhang, Zhixin Chen, Zaiping Guo, Xiong Wen Lou
Faculty of Engineering and Information Sciences - Papers: Part A
A facile synthesis of novel 3D porous V2O5 hierarchical microspheres has been developed, based on an additive-free solvothermal method and subsequent calcination. Due to their unique structure, these V2O5 microspheres display a very stable capacity retention of 130 mA h g (1) over 100 cycles at a current rate of 0.5 C, and show excellent rate capability with a capacity of 105 mA h g (1) even at the 30 C rate. The good electrochemical performance suggests that this unique hierarchical V2O5 material could be a promising candidate as a cathode material for lithium-ion batteries.
Catalytic Role Of Ge In Highly Reversible Geo2/Ge/C Nanocomposite Anode Material For Lithium Batteries, Kuok Hau Seng, Mi-Hee Park, Zai Ping Guo, Hua-Kun Liu, Jaephil Cho
Catalytic Role Of Ge In Highly Reversible Geo2/Ge/C Nanocomposite Anode Material For Lithium Batteries, Kuok Hau Seng, Mi-Hee Park, Zai Ping Guo, Hua-Kun Liu, Jaephil Cho
Faculty of Engineering and Information Sciences - Papers: Part A
GeO2/Ge/C anode material synthesized using a simple method involving simultaneous carbon coating and reduction by acetylene gas is composed of nanosized GeO2/Ge particles coated by a thin layer of carbon, which is also interconnected between neighboring particles to form clusters of up to 30 μm. The GeO2/Ge/C composite shows a high capacity of up to 1860 mAh/g and 1680 mAh/g at 1 C (2.1 A/g) and 10 C rates, respectively. This good electrochemical performance is related to the fact that the elemental germanium nanoparticles present in the composite increases the reversibility of the conversion reaction of GeO2. These factors have …
A Unique Sandwich-Structured C/Ge/Graphene Nanocomposite As An Anode Material For High Power Lithium Ion Batteries, Dan Li, Kuok H. Seng, Dongqi Shi, Zhixin Chen, Hua-Kun Liu, Zaiping Guo
A Unique Sandwich-Structured C/Ge/Graphene Nanocomposite As An Anode Material For High Power Lithium Ion Batteries, Dan Li, Kuok H. Seng, Dongqi Shi, Zhixin Chen, Hua-Kun Liu, Zaiping Guo
Faculty of Engineering and Information Sciences - Papers: Part A
A unique sandwich-structured C/Ge/graphene composite with germanium nanoparticles trapped between graphene sheets is prepared by a microwave-assisted solvothermal reaction followed by carbon coating and thermal reduction. The graphene sheets are found to be effective in hindering the growth and aggregation of GeO2 nanoparticles. More importantly, the graphene sheets, coupled with the carbon coating, can buffer the volume changes of germanium in electrochemical lithium reactions. The unique sandwich structure features a highly conductive network of carbon, which can improve both the conductivity and the structural stability of the electrode material, and exemplifies a promising strategy for the development of new high …
Rapid Synthesis Of Free-Standing Moo3/Graphene Films By The Microwave Hydrothermal Method As Cathode For Bendable Lithium Batteries, Lukman Noerochim, Jia-Zhao Wang, David Wexler, Zhong Chao, Hua-Kun Liu
Rapid Synthesis Of Free-Standing Moo3/Graphene Films By The Microwave Hydrothermal Method As Cathode For Bendable Lithium Batteries, Lukman Noerochim, Jia-Zhao Wang, David Wexler, Zhong Chao, Hua-Kun Liu
Faculty of Engineering and Information Sciences - Papers: Part A
Highly flexible, binder-free, MoO3 nanobelt/graphene film electrode is prepared by a two-step microwave hydrothermal method. Graphene is first prepared by an ultra-fast microwave hydrothermal method and then mixed with MoO3 solution to synthesize the MoO3 nanobelt/graphene composite, which exhibits the combination of stacked graphene sheets and uniform MoO3 nanobelts with widths of 200-500 nm and lengths of 5-10 μm. The charge-discharge measurements show that the as-synthesized MoO3/graphene hybrid materials demonstrate excellent rate capability, large capacity, and good cycling stability compared to the pure MoO3 film. An initial discharge capacity of 291 mAh g-1 can be obtained at 100 mA g-1, …
Facile Synthesis Of Hierarchical Networks Composed Of Highly Interconnected V2o5 Nanosheets Assembled On Carbon Nanotubes And Their Superior Lithium Storage Properties, Ruixiang Yu, Chaofeng Zhang, Qing Meng, Zhixin Chen, Hua-Kun Liu, Zaiping Guo
Facile Synthesis Of Hierarchical Networks Composed Of Highly Interconnected V2o5 Nanosheets Assembled On Carbon Nanotubes And Their Superior Lithium Storage Properties, Ruixiang Yu, Chaofeng Zhang, Qing Meng, Zhixin Chen, Hua-Kun Liu, Zaiping Guo
Faculty of Engineering and Information Sciences - Papers: Part A
Hierarchical networks with highly interconnected V2O5 nanosheets (NSs) anchored on skeletons of carbon nanotubes (CNTs) are prepared by a facile hydrothermal treatment and a following calcination for the first time. Benefiting from these unique structural features, the as-prepared CNT@V2O5 material shows dramatically excellent electrochemical performance with remarkable long cyclability (137-116 mA h g-1 after 400 cycles) at various high rates (20 C to 30 C) and very good rate capability for highly reversible lithium storage. The excellent electrochemical performance suggests its promising use as a cathode material for future lithium-ion batteries.
A Hybrid Electrolyte Energy Storage Device With High Energy And Long Life Using Lithium Anode And Mno2 Nanoflake Cathode, Shulei Chou, Yun-Xiao Wang, Jiantie Xu, Jia-Zhao Wang, Hua-Kun Liu, S X. Dou
A Hybrid Electrolyte Energy Storage Device With High Energy And Long Life Using Lithium Anode And Mno2 Nanoflake Cathode, Shulei Chou, Yun-Xiao Wang, Jiantie Xu, Jia-Zhao Wang, Hua-Kun Liu, S X. Dou
Australian Institute for Innovative Materials - Papers
A hybrid electrolyte energy storage system combining the features of supercapacitors and lithium batteries has been constructed. It consists of MnO2 nanoflakes in 1 M Li2SO4 aqueous electrolyte as the cathode and lithium foil in ionic liquid (1 M lithium bis(trifluoromethanesulfonyl)imide (LiNTf2) in N-methyl-N-propyl pyrrolidinium bis(trifluoromethanesulfonyl)imide ([C(3)mpyr][NTf2])) electrolyte as the anode, separated by a lithium super ionic conductor glass ceramic film (LiSICON). This system shows the advantages of both a supercapacitor (long cycle life) and a lithium battery (high energy), as well as low cost and improved safety due to the combination of ionic liquid and ceramic solid state electrolyte …
Polypyrrole Doped With Redox-Active Poly(2-Methoxyaniline-5-Sulfonic Acid) For Lithium Secondary Batteries, Yang Yang, Caiyun Wang, Syed A. Ashraf, Gordon G. Wallace
Polypyrrole Doped With Redox-Active Poly(2-Methoxyaniline-5-Sulfonic Acid) For Lithium Secondary Batteries, Yang Yang, Caiyun Wang, Syed A. Ashraf, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
Polypyrrole is a promising electrode material for flexible/bendable energy storage devices due to its inherent fast redox switching, mechanical flexibility, easy processability and being environmentally benign. However, its low attainable capacity limits its practical applications. Here, we synthesise a polypyrrole/poly(2-methoxyaniline-5-sulfonic acid) (PPy/PMAS) composite by incorporating redox-active PMAS into a PPy matrix via an electropolymerization method. For comparison, polypyrrole containing the electrochemically inert dopant p-toluenesulfonate (PPy-pTS) was prepared under the same conditions. The resultant PPy/PMAS film shows greatly improved electrochemical properties by harnessing the contribution from PMAS, i.e. higher specific capacity, better rate capability and improved cycling stability when used as …
A Facile Route To Synthesize Transition Metal Oxide/Reduced Graphene Oxide Composites And Their Lithium Storage Performance, Chongjun Zhao, Shulei Chou, Yunxiao Wang, Cuifeng Zhou, Hua-Kun Liu, S X. Dou
A Facile Route To Synthesize Transition Metal Oxide/Reduced Graphene Oxide Composites And Their Lithium Storage Performance, Chongjun Zhao, Shulei Chou, Yunxiao Wang, Cuifeng Zhou, Hua-Kun Liu, S X. Dou
Australian Institute for Innovative Materials - Papers
Transition metal oxide (Mn3O4, Fe2O3, Co3O4, and ZnO) and reduced graphene oxide (RGO) composites were successfully synthesized via a hydrothermal method using the direct reaction between the corresponding metal powder and graphene oxide (GO). In this process, the GO can be reduced by transition metal powder in water, and the nanosized metal oxide can be obtained, and homogeneously mixed with and wrapped by RGO to form a metal oxide/RGO composite at the same time. X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy were used to characterize the as-prepared materials. The different experimental parameters, including reactants, …
The Effects Of Fec (Fluoroethylene Carbonate) Electrolyte Additive On The Lithium Storage Properties Of Nio (Nickel Oxide) Nanocuboids, Kuok H. Seng, Li Li, Dapeng Chen, Zhixin Chen, Xiaolin Wang, Hua-Kun Liu, Zaiping Guo
The Effects Of Fec (Fluoroethylene Carbonate) Electrolyte Additive On The Lithium Storage Properties Of Nio (Nickel Oxide) Nanocuboids, Kuok H. Seng, Li Li, Dapeng Chen, Zhixin Chen, Xiaolin Wang, Hua-Kun Liu, Zaiping Guo
Australian Institute for Innovative Materials - Papers
Nanocuboid shaped NiO (nickel oxide) has been synthesized using an optical floating zone furnace. It was found that the nanocuboids exhibit single crystalline nature, and have clean and sharp edges. Furthermore, the NiO nanocuboids were tested for their electrochemical performances as anode material for LIBs (lithium-ion batteries) in a coin-type half cell. The effects of FEC (fluoroethylene carbonate) additive on the lithium storage performance were also investigated, which is the first of such studies for transition metal oxides. It was found that FEC has a positive effect on the cycling stability and also improves the rate performances of the nanocuboids. …
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
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.
An Overview - Functional Nanomaterials For Lithium Rechargeable Batteries, Supercapacitors, Hydrogen Storage, And Fuel Cells, Hua-Kun Liu
Australian Institute for Innovative Materials - Papers
There is tremendous worldwide interest in functional nanostructured materials, which are the advanced nanotechnology materials with internal or external dimensions on the order of nanometers. Their extremely small dimensions make these materials unique and promising for clean energy applications such as lithium ion batteries, supercapacitors, hydrogen storage, fuel cells, and other applications. This paper will highlight the development of new approaches to study the relationships between the structure and the physical, chemical, and electrochemical properties of functional nanostructured materials. The Energy Materials Research Programme at the Institute for Superconducting and Electronic Materials, the University of Wollongong, has been focused on …
Simple Synthesis Of Yolk-Shelled Znco2o4 Microspheres Towards Enhancing The Electrochemical Performance Of Lithium-Ion Batteries In Conjunction With A Sodium Carboxymethyl Cellulose Binder, Jingfa Li, Jiazhao Wang, David Wexler, Dongqi Shi, Jianwen Liang, Hua-Kun Liu, Shenglin Xiong, Yitai Qian
Simple Synthesis Of Yolk-Shelled Znco2o4 Microspheres Towards Enhancing The Electrochemical Performance Of Lithium-Ion Batteries In Conjunction With A Sodium Carboxymethyl Cellulose Binder, Jingfa Li, Jiazhao Wang, David Wexler, Dongqi Shi, Jianwen Liang, Hua-Kun Liu, Shenglin Xiong, Yitai Qian
Australian Institute for Innovative Materials - Papers
Mixed metal oxides have been attracting more and more attention recently because of their advantages and superiorities, which can improve the electrochemical performance of single metal oxides. These advantages include structural stability, good electronic conductivity, and reversible capacity. In this work, uniform yolk-shelled ZnCo2O4 microspheres were synthesized by pyrolysis of ZnCo-glycolate microsphere precursors which were prepared via a simple refluxing route without any precipitant or surfactant. The formation process of the yolk-shelled microsphere structure during the thermal decomposition of ZnCo-glycolate is discussed, which is mainly based on the heterogeneous contraction caused by non-equilibrium heat treatment. The performances of the as-prepared …
Spinel Linixmn2-Xo4 As Cathode Material For Aqueous Rechargeable Lithium Batteries, F X. Wang, S Y. Xiao, Y Shi, L L. Liu, Y S. Zhu, Y P. Wu, J. Z. Wang, R Holze
Spinel Linixmn2-Xo4 As Cathode Material For Aqueous Rechargeable Lithium Batteries, F X. Wang, S Y. Xiao, Y Shi, L L. Liu, Y S. Zhu, Y P. Wu, J. Z. Wang, R Holze
Australian Institute for Innovative Materials - Papers
Ni-doped spinel LiNixMn2-xO4 (x = 0, 0.05, 0.10) samples were prepared by a sol-gel method. Structure and morphology of the samples were characterized by X-ray diffraction, scanning electron microscopy, Brunnauer-Emmet-Teller method and inductively coupled plasma atomic absorption spectrometry. The electrochemical behavior as a cathode material (positive mass) for aqueous rechargeable lithium batteries (ARLBs) was investigated by cyclic voltammetry, electrochemical impedance spectroscopy, capacity measurements and cycling tests. The results show that the LiNi 0.1Mn1.9O4 electrode presents the best rate and cycling performance but low reversible capacity. In contrast, the LiNi 0.05Mn1.95O4 electrode shows a higher reversible capacity and relatively good cycling …
Nanocomposites Of Silicon And Carbon Derived From Coal Tar Pitch: Cheap Anode Materials For Lithium-Ion Batteries With Long Cycle Life And Enhanced Capacity, Yun-Xiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Nanocomposites Of Silicon And Carbon Derived From Coal Tar Pitch: Cheap Anode Materials For Lithium-Ion Batteries With Long Cycle Life And Enhanced Capacity, Yun-Xiao Wang, Shulei Chou, Hua-Kun Liu, S X. Dou
Australian Institute for Innovative Materials - Papers
From energy and environmental consideration, an industrial waste product, coal tar pitch (CTP), is used as the carbon source for Si/AC composite. We exploited a facile sintering method to largely scale up Si/amorphous carbon nanocomposite. The composites with 20 wt.% silicon with PVdF binder exhibited stable lithium storage ability for prolonged cycling. The composite anode delivered a capacity of 400.3 mAh g−1 with a high capacity retention of 71.3% after 1000 cycles. Various methods are used to investigate the reason for the outstanding cyclability. The results indicate that the silicon nanoparticles are wrapped by amorphous SiOx and AC in Si/AC …
Highly Uniform Tio2/Sno2/Carbon Hybrid Nanofibers With Greatly Enhanced Lithium Storage Performance, Zunxian Yang, Qing Meng, Zaiping Guo, Xuebin Yu, Tailiang Guo, Rong Zeng
Highly Uniform Tio2/Sno2/Carbon Hybrid Nanofibers With Greatly Enhanced Lithium Storage Performance, Zunxian Yang, Qing Meng, Zaiping Guo, Xuebin Yu, Tailiang Guo, Rong Zeng
Australian Institute for Innovative Materials - Papers
Highly uniform, relatively large area TiO2/SnO 2/carbon hybrid nanofibers were synthesized by a simple method based on thermal pyrolysis and oxidation of an as-spun titanium-tin/polyacrylonitrile nanoweb composite in an argon atmosphere. This novel composite features the uniform dispersion and encapsulation of highly uniform nanoscale TiO 2/SnO2 crystals in a porous carbon matrix. The high porosity of the nanofiber composite material, together with the conductive carbon matrix, enhanced the electrochemical performance of the TiO 2/SnO2/carbon nanofiber electrode. The TiO 2/SnO2/carbon nanofiber electrode displays a reversible capacity of 442.8 mA h g-1 for up to 100 cycles, and exhibits excellent rate capability. …
In Situ One-Step Synthesis Of A 3d Nanostructured Germanium-Graphene Composite And Its Application In Lithium-Ion Batteries, Chao Zhong, Jia-Zhao Wang, Xuan-Wen Gao, David Wexler, Hua-Kun Liu
In Situ One-Step Synthesis Of A 3d Nanostructured Germanium-Graphene Composite And Its Application In Lithium-Ion Batteries, Chao Zhong, Jia-Zhao Wang, Xuan-Wen Gao, David Wexler, Hua-Kun Liu
Faculty of Engineering and Information Sciences - Papers: Part A
A germanium-graphene nanocomposite material with three-dimensional nanostructures has been synthesized by an efficient one-step, in situ, and aqueous-based method. The electrochemical properties of the germanium-graphene nanocomposite have been evaluated by galvanostatic discharge-charge cycling, cyclic voltammetry, and electrochemical impedance spectroscopy. Results show that the germanium-graphene nanocomposite has a much more stable cycling performance than that of the pure germanium, with a capacity of about 832 mA h g-1 after 50 cycles. The rate capability is also improved significantly. The superior performance is attributed to the graphene content, which increases the material's conductivity, enlarges the specific surface area, delivers enough sites to …
Smart Multifunctional Fluids For Lithium Ion Batteries: Enhanced Rate Performance And Intrinsic Mechanical Protection, Jie Ding, Tongfei Tian, Qing Meng, Zaiping Guo, Weihua Li, Peng Zhang, Fabio T. Ciacchi, Jewel Huang, Wenrong Yang
Smart Multifunctional Fluids For Lithium Ion Batteries: Enhanced Rate Performance And Intrinsic Mechanical Protection, Jie Ding, Tongfei Tian, Qing Meng, Zaiping Guo, Weihua Li, Peng Zhang, Fabio T. Ciacchi, Jewel Huang, Wenrong Yang
Faculty of Engineering and Information Sciences - Papers: Part A
Lithium ion batteries are attractive power sources for the consumer electronics market and are being aggressively developed for road transportation. Nevertheless, issues with safety and reliability need to be solved prior to the large-scale uptake of these batteries. There have recently been significant development and assessment of materials with resistance to mechanical abuse, with the aims of reinforcing the battery and preventing puncturing during a crash. Most of the work on battery mechanical safety has concentrated on the external packaging of batteries, with little attention being paid to the enclosed electrolyte. We report on smart multifunctional fluids that act as …
Polypyrrole-Coated Α-Lifeo2 Nanocomposite With Enhanced Electrochemical Properties For Lithium-Ion Batteries, Zhi-Jia Zhang, Jia-Zhao Wang, Shulei Chou, Hua-Kun Liu, Kiyoshi Ozawa, Hui-Jun Li
Polypyrrole-Coated Α-Lifeo2 Nanocomposite With Enhanced Electrochemical Properties For Lithium-Ion Batteries, Zhi-Jia Zhang, Jia-Zhao Wang, Shulei Chou, Hua-Kun Liu, Kiyoshi Ozawa, Hui-Jun Li
Faculty of Engineering and Information Sciences - Papers: Part A
A conducting alpha-LiFeO2-polypyrrole (alpha-LiFeO2-PPy) nanocomposite material was prepared by the chemical polymerization method as a cathode material for lithium-ion batteries. The porous alpha-LiFeO2 was prepared via the microwave hydrothermal method and a post-annealing. The X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy measurements showed that the alpha-LiFeO2 nanoparticles were coated with PPy. The polypyrrole coating improves the reversible capacity and cycling stability (104 mAh g(-1) at 0.1C after 100 cycles) for lithium-ion batteries. Even at the high rate of 10C, the electrode showed more than 40% of the capacity at low rate (0.1C).
Self-Assembly Of Hierarchical Star-Like Co3o4 Micro/Nanostructures And Their Application In Lithium Ion Batteries, Li Li, Kuok Hau Seng, Zhixin Chen, Zaiping Guo, Hua-Kun Liu
Self-Assembly Of Hierarchical Star-Like Co3o4 Micro/Nanostructures And Their Application In Lithium Ion Batteries, Li Li, Kuok Hau Seng, Zhixin Chen, Zaiping Guo, Hua-Kun Liu
Faculty of Engineering and Information Sciences - Papers: Part A
A novel hierarchical star-like Co3O4 was successfully synthesized from self-assembled hierarchical Co(OH)F precursors via a facile hydrothermal method and subsequent annealing in air. The morphological evolution process of the Co(OH)F precursors was investigated by examining the different reaction times during synthesis. First, hexagonal plates are formed, and then nanodiscs grow on the surface of the plates. Subsequently, dissolution and regrowth of Co(OH)F occur to form the star-like hierarchical structures. Co3O4 obtained from thermal decomposition of the Co(OH)F precursor in air at 350 °C exhibited high reversible capacity as an anode material in lithium ion batteries. The specific charge capacity of …
Enhanced Rate Performance Of Cobalt Oxide/Nitrogen Doped Graphene Composite For Lithium Ion Batteries, Dan Li, Dongqi Shi, Zhixin Chen, Hua-Kun Liu, Dianzeng Jia, Zaiping Guo
Enhanced Rate Performance Of Cobalt Oxide/Nitrogen Doped Graphene Composite For Lithium Ion Batteries, Dan Li, Dongqi Shi, Zhixin Chen, Hua-Kun Liu, Dianzeng Jia, Zaiping Guo
Faculty of Engineering and Information Sciences - Papers: Part A
Ultrafine Co3O4 nanocrystals homogeneously attached to nitrogen doped reduced graphene oxide (rGO) by the hydrothermal reaction method are demonstrated as anode materials for lithium ion batteries. Transmission electron microscope images revealed that the crystal size of Co3O4 in Co3O4/N-rGO and Co3O4/rGO is 5-10 nm, much smaller than that of bare Co3O4, indicating that the reduced graphene oxide sheets with Co3O4 nanocrystals attached could hinder the growth and aggregation of Co3O4 crystals during synthesis. The graphene sheets can also effectively buffer the volume change of Co3O4 upon lithium insertion/extraction, thus improving the cycling performance of the composite electrodes. The doped nitrogen …