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Full-Text Articles in Engineering
Flexible Free-Standing Graphene-Silicon Composite Film For Lithium-Ion Batteries, Jiazhao Wang, Chao Zhong, Shulei Chou, Hua Liu
Flexible Free-Standing Graphene-Silicon Composite Film For Lithium-Ion Batteries, Jiazhao Wang, Chao Zhong, Shulei Chou, Hua Liu
Shulei Chou
Flexible, free-standing, paper-like, graphene-silicon composite materials have been synthesized by a simple, one-step, in-situ filtration method. The Si nanoparticles are highly encapsulated in a graphene nanosheet matrix. The electrochemical results show that graphene-Si composite film has much higher discharge capacity beyond 100 cycles (708 mAh g− 1) than that of the cell with pure graphene (304 mAh g− 1). The graphene functions as a flexible mechanical support for strain release, offering an efficient electrically conducting channel, while the nanosized silicon provides the high capacity.
Nanocrystalline Nio Hollow Spheres In Conjunction With Cmc For Lithium-Ion Batteries, Chao Zhong, Jiazhao Wang, Shulei Chou, Konstantin Konstantinov, Mokhlesur Rahman, Hua Liu
Nanocrystalline Nio Hollow Spheres In Conjunction With Cmc For Lithium-Ion Batteries, Chao Zhong, Jiazhao Wang, Shulei Chou, Konstantin Konstantinov, Mokhlesur Rahman, Hua Liu
Shulei Chou
Hollow spherical NiO particles were prepared using the spray pyrolysis method with different concentrations of precursor. The electrochemical properties of the NiO electrodes, which contained a new type of binder, carboxymethyl cellulose (CMC), were examined for comparison with NiO electrodes with polyvinylidene fluoride (PVDF) binder. The electrochemical performance of NiO electrodes using CMC binder was significantly improved. For the cell made from 0.3 mol L−1 precursor, the irreversible capacity loss between the first discharge and charge is about 43 and 24% for the electrode with PVDF and CMC binder, respectively. The cell with NiO–CMC electrode has a much higher discharge …
Graphene Wrapped Lifepo4/C Composites As Cathode Materials For Li-Ion Batteries With Enhanced Rate Capability, Yi Shi, Shulei Chou, Jia-Zhao Wang, David Wexler, Hui-Jun Li, Hua-Kun Liu, Yuping Wu
Graphene Wrapped Lifepo4/C Composites As Cathode Materials For Li-Ion Batteries With Enhanced Rate Capability, Yi Shi, Shulei Chou, Jia-Zhao Wang, David Wexler, Hui-Jun Li, Hua-Kun Liu, Yuping Wu
Shulei Chou
To reduce the reaction time, electrical energy consumption, and cost, LiFePO4/C/graphene has been synthesized by a rapid, one-pot, microwave-assisted hydrothermal method within 15 min at a temperature of 200 °C, followed by sintering at 600 °C for 2 h under a H2/Ar (5:95, v/v) atmosphere. The microstructure and morphology of the LiFePO4/C/graphene products were characterized by means of X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy. The carbon coated LiFePO4/C nanoparticles, around 200 nm in size, are thoroughly wrapped by crumpled micrometer-size graphene sheets. In this kind of structure, the bridging graphene nanosheets can form …
Facile Synthesis Of A Interleaved Expanded Graphite-Embedded Sulphur Nanocomposite As Cathode Of Li-S Batteries With Excellent Lithium Storage Performance, Yun-Xiao Wang, Ling Huang, Li-Chao Sun, Su-Yuan Xie, Gui-Liang Xu, Shu-Ru Chen, Yue-Feng Xu, Jun-Tiao Li, Shulei Chou, S. Dou, Shi-Gang Sun
Facile Synthesis Of A Interleaved Expanded Graphite-Embedded Sulphur Nanocomposite As Cathode Of Li-S Batteries With Excellent Lithium Storage Performance, Yun-Xiao Wang, Ling Huang, Li-Chao Sun, Su-Yuan Xie, Gui-Liang Xu, Shu-Ru Chen, Yue-Feng Xu, Jun-Tiao Li, Shulei Chou, S. Dou, Shi-Gang Sun
Shulei Chou
This paper reports the facile synthesis of a unique interleaved expanded graphite-embedded sulphur nanocomposite (S-EG) by melt-diffusion strategy. The SEM images of the S-EG materials indicate the nanocomposites consist of nanosheets with a layer-by-layer structure. Electrochemical tests reveal that the nanocomposite with a sulphur content of 60% (0.6S-EG) can deliver the highest discharge capacity of 1210.4 mAh g−1 at a charge–discharge rate of 280 mA g−1 in the first cycle, the discharge capacity of the 0.6S-EG remains as high as 957.9 mAh g−1 after 50 cycles of charge–discharge. Furthermore, at a much higher charge–discharge rate of 28 A g−1, the …
Synthesis, Characterization And Electrochemical Properties Of Aluminum-Substituted Alpha-Ni(Oh)(2) Hollow Spheres, Yueming Li, Weiyang Li, Shulei Chou, Jun Chen
Synthesis, Characterization And Electrochemical Properties Of Aluminum-Substituted Alpha-Ni(Oh)(2) Hollow Spheres, Yueming Li, Weiyang Li, Shulei Chou, Jun Chen
Shulei Chou
In this work, we reported on the preparation and electrochemical properties of aluminum (Al)-substituted α-Ni(OH)2 hollow spheres. Polystyrene microspheres were used as the templates in large scale to prepare Al-substituted α-Ni(OH)2 hollow spheres. The charge/discharge performance of Al-substituted α-Ni(OH)2 hollow spheres was further investigated as the positive electrode material of alkaline rechargeable batteries. The results showed that the 20.4% Al-containing α-Ni(OH)2 hollow spheres exhibited high discharge capacity (391.1 mAh/g) and excellent cycling reversibility due to the high stability of Al-substituted α-Ni(OH)2 hollow sphere structures in alkaline media, indicating their potential application in the development of high-power alkaline rechargeable batteries.
Hydrothermal Synthesis Of Nanostructured Mno2 Under Magnetic Field For Rechargeable Lithium Batteries, Chao Zhong, Jiazhao Wang, Zhen-Zhen Zhu, Shulei Chou, Z. Chen, Ying Li, Hua Liu
Hydrothermal Synthesis Of Nanostructured Mno2 Under Magnetic Field For Rechargeable Lithium Batteries, Chao Zhong, Jiazhao Wang, Zhen-Zhen Zhu, Shulei Chou, Z. Chen, Ying Li, Hua Liu
Shulei Chou
Nanocrystalline MnO2 was synthesized by the hydrothermal method with or without pulsed magnetic fields. It was found that the morphology of the MnO2 prepared without magnetic field has an urchin-like structure, while the MnO2 prepared with magnetic fields has a rambutan-like structure. A pronounced increase in the Brunauer–Emmett–Teller specific surface area was obtained when the intensities of the pulsed magnetic fields increased. The battery performances were improved for the samples prepared with magnetic fields. The MnO2 prepared under a magnetic field of 4 T shows a capacity of 121.8 mAh g−1, while the MnO2 prepared without magnetic field only shows …
Free-Standing Single-Walled Carbon Nanotube/Sno2 Anode Paper For Flexible Lithium-Ion Batteries, Lukman Noerochim, Jia-Zhao Wang, Shulei Chou, David Wexler
Free-Standing Single-Walled Carbon Nanotube/Sno2 Anode Paper For Flexible Lithium-Ion Batteries, Lukman Noerochim, Jia-Zhao Wang, Shulei Chou, David Wexler
Shulei Chou
Free-standingsingle-walledcarbonnanotube/SnO2 (SWCNT/SnO2) anodepaper was prepared by vacuum filtration of SWCNT/SnO2 hybrid material which was synthesized by the polyol method. From field emission scanning electron microscopy and transmission electron microscopy, the CNTs form a three-dimensional nanoporous network, in which ultra-fine SnO2 nanoparticles, which had crystallite sizes of less than 5 nm, were distributed, predominately as groups of nanoparticles on the surfaces of singlewalled CNT bundles. Electrochemical measurements demonstrated that the anodepaper with 34 wt.% SnO2 had excellent cyclic retention, with the high specific capacity of 454 mAh g−1 beyond 100 cycles at a current …
Electrodeposition Synthesis And Electrochemical Properties Of Nanostructured Γ-Mno2 Films, Shulei Chou, Fangyi Cheng, Jun Chen
Electrodeposition Synthesis And Electrochemical Properties Of Nanostructured Γ-Mno2 Films, Shulei Chou, Fangyi Cheng, Jun Chen
Shulei Chou
The thin films of carambola-like γ-MnO2 nanoflakes with about 20nm in thickness and at least 200nm in width were prepared on nickel sheets by combination of potentiostatic and cyclic voltammetric electrodeposition techniques. The as-prepared MnO2 nanomaterials, which were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), were used as the active material of the positive electrode for primary alkaline Zn/MnO2 batteries and electrochemical supercapacitors. Electrochemical measurements showed that the MnO2 nanoflake films displayed high potential plateau (around 1.0V versus Zn) in primary Zn/MnO2 batteries at the discharge current density of …
The Effect Of Different Binders On Electrochemical Properties Of Lini1/3mn1/3c1/3o2 Cathode Material In Lithium Ion Batteries, Jiantie Xu, Shulei Chou, Qinfen Gu, Hua Liu, S Dou
The Effect Of Different Binders On Electrochemical Properties Of Lini1/3mn1/3c1/3o2 Cathode Material In Lithium Ion Batteries, Jiantie Xu, Shulei Chou, Qinfen Gu, Hua Liu, S Dou
Shulei Chou
LiNi1/3Mn1/3Co1/3O2 (NMC) as a cathode material for lithium ion batteries has been synthesized by the sol-gel method. The X-ray diffraction Rietveld refinement results indicated that single-phase NMC with hexagonal layered structure was obtained. Scanning electron microscope images revealed well crystallized NMC with uniform particle size in the range of 100-200 nm. The performance of the NMC electrodes with sodium carboxylmethyl cellulose (CMC), poly(vinylidene fluoride) (PVDF), and alginate from brown algae as binders was compared. Constant current charge-discharge test results demonstrated that the NMC electrode using CMC as binder had the highest rate capability, followed by those using alginate and PVDF …
Electrochemical Deposition Of Ni(Oh)(2) And Fe-Doped Ni(Oh)(2) Tubes, Shulei Chou, Fangyi Cheng, Jun Chen
Electrochemical Deposition Of Ni(Oh)(2) And Fe-Doped Ni(Oh)(2) Tubes, Shulei Chou, Fangyi Cheng, Jun Chen
Shulei Chou
Arrays of Ni(OH)2 and Fe-doped Ni(OH)2 tubes were successfully prepared by electrochemical deposition in porous alumina membranes under ambient conditions. Extensive analysis of the tubes was carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) equipped with energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The results show that the electrodeposition method yielded uniform Ni(OH)2 and Fe-doped Ni(OH)2 tubes with inner diameters of 150–180 nm, wall thicknesses of 20–30 nm, and lengths of about 60 μm. This template-based electrochemical deposition method can be extended to the synthesis of …
Irradiation Si On Carbon Nanotube Paper As A Flexible Anode Material For Lithium-Ion Batteries, Shulei Chou, Mihail Ionescu, Jia-Zhao Wang, Brad Winton, Hua Liu
Irradiation Si On Carbon Nanotube Paper As A Flexible Anode Material For Lithium-Ion Batteries, Shulei Chou, Mihail Ionescu, Jia-Zhao Wang, Brad Winton, Hua Liu
Shulei Chou
Silicon single walled carbon nanotube composite paper was modified by low energy ion implantation using 5i to obtain a flexible composite paper. Raman and FE-SEM results show that structure of SWCNT could be destroyed by the implantation. Electrochemical measurements display that the implanted SI can improve the specific capacity and the reversible capacity of CNT paper. After 50 cycles, the specific capacity of 5Hmplanted CNT paper is 30 per cent higher than the pristine CNT.
Self-Oriented Ca3co4o9 Thin Film As An Anode Material For Enhanced Cycling Stability Of Lithium-Ion Batteries, Xuebin Zhu, Shulei Chou, Lin Wang, Qi Li, Dongqi Shi, Jiazhao Wang, Z. Chen, Yuping Sun, Hua-Kun Liu, S. X. Dou
Self-Oriented Ca3co4o9 Thin Film As An Anode Material For Enhanced Cycling Stability Of Lithium-Ion Batteries, Xuebin Zhu, Shulei Chou, Lin Wang, Qi Li, Dongqi Shi, Jiazhao Wang, Z. Chen, Yuping Sun, Hua-Kun Liu, S. X. Dou
Shulei Chou
Self-oriented Ca3Co4O9 nanoflake thin film has been prepared by a simple sol–gel method as the anode for thin-film lithium-ion batteries. The X-ray diffraction and transmission electron microscopy results show that the prepared Ca3Co4O9/Pt film is -axis self-oriented and composed of nanoflakes approximately 2ym in diameter and 200–300 nm thick. The reversible lithium storage capacity of the Ca3Co4O9 thin-film electrode at 1 C is around 800mAhg-1 , and it retains more than 70% capacity after 50 cycles, suggesting that the Ca3Co4O9 thin film can be used as the anode for lithium-ion batteries.