IMPROVING ELECTROCHEMICAL PERFORMANCE OF LiCoO2 BY TiO2 COATING AS CATHODE FOR AQUEOUS RECHARGEABLE LITHIUM BATTERIES

2013 ◽  
Vol 06 (02) ◽  
pp. 1350016 ◽  
Author(s):  
S. TIAN ◽  
L. L. LIU ◽  
Y. S. ZHU ◽  
Y. Y. HOU ◽  
C. L. HU ◽  
...  
Keyword(s):  
Current Density ◽  
Sol Gel ◽  
Rate Capability ◽  
Cycling Performance ◽  
X Ray Diffraction ◽  
Rechargeable Lithium Batteries ◽  
Capacity Fading ◽  
X Ray ◽  
Discharge Behavior ◽  
Initial Capacity

Modified LiCoO2 was prepared via a sol–gel method followed by a TiO2 coating and characterized by X-ray diffraction analysis, transmission electronic microscopy and various measurements of charge/discharge behavior. Its cycling performance and rate capability were greatly improved compared to the original LiCoO2 . The initial capacity of the TiO2 -coated LiCoO2 is 134 mAh g-1 at the current density of 5000 mA g-1. When the current density increases to 10,000 mA g-1, the cathode displays an initial capacity of 128 mAh g-1, much higher than that (<101 mAh g-1) for the virginal LiCoO2 , and shows no evident capacity fading after 100 cycles.

IMPROVING THE BATTERY PERFORMANCE OF LiVPO4F BY CHROMIUM DOPING

2013 ◽  
Vol 06 (06) ◽  
pp. 1350053 ◽  
Author(s):  
YANGHAO LIU ◽  
YOULONG XU ◽  
XIAOFEI SUN
Keyword(s):  
Rate Capability ◽  
Cycling Performance ◽  
High Energy ◽  
X Ray Diffraction ◽  
Rechargeable Lithium Batteries ◽  
X Ray ◽  
Chromium Doping ◽  
Specific Discharge ◽  
Cr Doping ◽  
Discharge Capacities

Polyanion LiVPO 4 F has been recently recognized as a promising high energy cathode material for next generation rechargeable lithium batteries. With the aim of performance advancement in this paper, 3 at.% chromium are used to dope LiVPO 4 F during carbothermal reduction synthesis. Rietveld refinement of X-ray diffraction pattern indicates that most of the chromium favors occupying the lithium site. Energy dispersive X-ray spectrum on selected area of the particle further demonstrates successful Cr doping into LiVPO 4 F . Both the rate capability and cycling performance of LiVPO 4 F are found noticeably improved possibly due to the stabilized crystalline structure and increased electric conductivity by Cr doping. The specific discharge capacities at C/24, C/5, 1 C and 8 C rates are 144.3, 135.1, 108.5 and 89.6 mA h g-1, respectively. Moreover, it delivers a capacity of 128.7 mA h g-1 at C/2 with the retention of 88.2% after 100 cycles.

GaP-TiO2-C Nanocomposite as High-Performance Sodium-Ion Batteries Anode

2021 ◽  
Vol 21 (7) ◽  
pp. 3897-3902
Author(s):  
Vo Pham Hoang Huy ◽  
Jaehyun Hur
Keyword(s):  
Current Density ◽  
High Performance ◽  
Structural Characteristics ◽  
Rate Capability ◽  
Cycling Performance ◽  
High Energy ◽  
X Ray Diffraction ◽  
Volume Changes ◽  
X Ray ◽  
Transmission Electron

GaP-TiO2-C composites with three different C concentrations are synthesized via a high-energy mechanical milling. The analysis of the structural characteristics of GaP-TiO2-C using X-ray diffraction and high-resolution transmission electron microscopy reveals that the nanosized GaP and TiO2 crystallites are uniformly distributed in the amorphous C matrix. The GaP-TiO2-C(20%) composite exhibits a high Na storage capacity of 266 mAh g−1 at the current density of 0.1 A g−1 after 100 cycles, and the remarkable rate capability of 224 mAh g−1 even at the higher current density of 10 A g−1. In addition, the GaP-TiO2-C(20%) composite presents great cycling performance and the capacity of 213 mAh g−1 at the current density of 0.5 A g−1 after 300 cycles. The outstanding cycling performance and rate capability of GaP-TiO2-C(20%) anode can be attributed to the favorable morphology of GaP-TiO2-C composite that accommodates large volume changes during cycling.

Effect of Synthesis Conditions on the Structure and Electrochemical Properties of LiNi1/2Mn1/2O2 by Sol Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 1447-1450
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu
Keyword(s):  
Electrochemical Properties ◽  
Sol Gel ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
Capacity Fading ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Synthesis Conditions ◽  
A Current

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.

Electrochemical Performance Cr Doped Spinel LiMn2O4 Cathode for Lithium Ion Batteries

2014 ◽  
Vol 636 ◽  
pp. 49-53
Author(s):  
Si Qi Wen ◽  
Liang Chao Gao ◽  
Jia Li Wang ◽  
Lei Zhang ◽  
Zhi Cheng Yang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Cycle Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Discharge Test

To improve the cycle performance of spinel LiMn2O4as the cathode of 4 V class lithium ion batteries, spinel were successfully prepared using the sol-gel method. The dependence of the physicochemical properties of the spinel LiCrxMn2-xO4(x=0,0.05,0.1,0.2,0.3,0.4) powders powder has been extensively investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), charge-discharge test and electrochemical impedance spectroscopy (EIS). The results show that as Mn is replaced by Cr, the initial capacity decreases, but the cycling performance improves due to stabilization of spinel structure. Of all, the LiCr0.2Mn1.8O4has best electrochemical performance, 107.6 mAhg-1discharge capacity, 96.1% of the retention after 50 cycles.

Preparation and Electrochemical Properties of Nano Si-C Composite

2016 ◽  
Vol 852 ◽  
pp. 278-282
Author(s):  
Xiao Chen ◽  
Yun Yang ◽  
Shui Jin Yang ◽  
Chuan Qi Feng ◽  
Zai Ping Guo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Current Density ◽  
Reversible Capacity ◽  
Testing System ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initial Capacity ◽  
Scanning Electron

nanoSi-C composite was prepared using eletronspinning technique. The microstructure and morphology of the Si-C composite were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical performances of the Si-C composite were tested by battery testing system. The results showed that the Si-C composite not only behaved high initial capacity but also good cycle performances. The reversible discharge capacity could remain at 860 mAhg-1 when current density was 50 mAg-1. The rate reversible capacity is much higher than that of pure nanoSi anode at same condition.

Synthesis and Electrochemical Properties of LiNi0.5Mn0.5O2 Cathode Materials by a Carbonate Co-Precipitation Method

2011 ◽  
Vol 347-353 ◽  
pp. 3497-3500 ◽  
Author(s):  
Zhi Yong Yu ◽  
Yun Jiang Cui ◽  
Han Xing Liu
Keyword(s):  
Discharge Rate ◽  
Lithium Ion ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Capacity Fading ◽  
Voltage Range ◽  
X Ray ◽  
Initial Charge ◽  
Discharge Behavior ◽  
Co Precipitation

The layered LiNi0.5Mn0.5O2 used as a cathode material for lithium-ion batteries was synthesized from precursor Ni0.5Mn0.5CO3 prepared via a carbonate co-precipitation method. The precursor Ni0.5Mn0.5CO3 was synthesized by the addition of KHCO3 to an aqueous solution of Ni, Mn sulphates. The powder LiNi0.5Mn0.5O2 was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Spherical LiNi0.5Mn0.5O2 with well development layered structure was obtained by the carbonate co-precipitation method. The LiNi0.5Mn0.5O2 samples adopted the α-NaFeO2 structure with a space group R-3m. Galvanostatic charge-discharge behavior of the LiNi0.5Mn0.5O2 cathodes delivered a initial charge and discharge capacity of 144.4 mAh/g and 140.2 mAh/g, respectively in the voltage range 2.5-4.5V at a discharge rate of 0.02A/g. The capacity showed no dramatic capacity fading during 50 cycles.

AlPO4-coated V2 O5 nanoplatelet and its electrochemical properties in aqueous electrolyte

2014 ◽  
Vol 86 (5) ◽  
pp. 651-659 ◽  
Author(s):  
Honglai Zhang ◽  
Jie Yang ◽  
Qichang Xiao ◽  
Zhaohui Li ◽  
Gangtie Lei ◽  
...  
Keyword(s):  
Lithium Batteries ◽  
Aqueous Electrolyte ◽  
Sol Gel ◽  
Rate Capability ◽  
Cycling Performance ◽  
Coated Sample ◽  
Rechargeable Lithium Batteries ◽  
Promising Application ◽  
Discharge Capacities ◽  
Good Rate Capability

Abstract Vanadium pentoxide (V2 O5) nanoplatelet was prepared through an exfoliation method by using β-cyclodextrin (β-CD) as intercalating template. To improve its electrochemical performance in the aqueous electrolyte, the nanoplatelet was coated with amorphous AlPO4 by sol-gel method. The effect of this coating layer on the rate and cycling properties is investigated by cyclic voltammetry and galvanostatic charge-discharge. The 1.6 % AlPO4-coated sample could deliver an initial capacity of 128 mAh g–1 at 0.1 C rate, and remain 99 % of the initial one after 50 cycles. The discharge capacities in the first cycle are 119, 113, and 104 mAh g–1 at the rates of 0.3, 1.5, and 3 C, respectively. The corresponding maintaining ratios are 98, 92, and 87 % after 50 cycles. The results suggest the AlPO4-coated V2 O5 nanoplatelet has good rate capability and cycling performance, indicating its promising application as an anode material in aqueous rechargeable lithium batteries.

A New Method for Improving the Capacity of Li1+xV3O8 in Rechargeable Lithium Batteries

2012 ◽  
Vol 512-515 ◽  
pp. 933-937
Author(s):  
Dao Rong Lu ◽  
Zhi Xian Li ◽  
Ying Chun Xie
Keyword(s):  
Lithium Batteries ◽  
Sol Gel ◽  
New Method ◽  
Cycle Performance ◽  
X Ray Diffraction ◽  
Rechargeable Lithium Batteries ◽  
X Ray ◽  
Good Thermal Stability ◽  
Transmission Electron ◽  
Time Of Reaction

A new method was used to synthesize the cathode material Li1+xV3O8, and it simplified the process of preparing and shortened the time of reaction in comparison with previous Sol-gel method with the citric acid. The characteristics of Li1+xV3O8 were investigated by X-ray diffraction, thermogravimetry and differential thermal analysis, and transmission electron microscopy, which showed the material Li1+xV3O8 with a good thermal stability had been obtained via the new method. The electrochemical performance of Li1+xV3O8 was measured, which indicated that the material obtained had a remarkable discharge capacity of 380mAh/g and a good cycle performance.

PENGGUNAAN TiO2 PARTIKEL NANO HASIL SINTESIS BERBASIS AIR MENGGUNAKAN METODA SOL-GEL PADA BAHAN KAPAS SEBAGAI APLIKASI UNTUK TEKSTIL ANTI UV

Arena Tekstil ◽  
2013 ◽  
Vol 28 (1) ◽  
Author(s):  
Maya Komalasari ◽  
Bambang Sunendar
Keyword(s):  
Fourier Transform ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sol Gel ◽  
Crosslinking Agent ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
X Ray ◽  
Infra Red ◽  
Scanning Electron

Partikel nano TiO2 berbasis air dengan pH basa telah berhasil disintesis dengan menggunakan metode sol-gel dan diimobilisasi pada kain kapas dengan menggunakan kitosan sebagai zat pengikat silang. Sintesis dilakukan  dengan prekursor TiCl4 pada konsentrasi 0,3 M, 0,5 M dan 1 M, dan menggunakan templat kanji dengan proses kalsinasi pada suhu 500˚C selama 2 jam. Partikel nano TiO2 diaplikasikan ke kain kapas dengan metoda pad-dry-cure dan menggunakan kitosan sebagai crosslinking agent. Berdasarkan hasil Scanning Electron Microscope (SEM),diketahui bahwa morfologi partikel TiO2 berbentuk spherical dengan ukuran nano (kurang dari 100 nm). Karakterisasi X-Ray Diffraction (XRD) menunjukkan adanya tiga tipe struktur kristal utama, yaitu (100), (101) dan (102) dengan fasa kristal yang terbentuk adalah anatase dan rutile. Pada karakterisasi menggunakan SEM terhadap serbuk dari TiO2 yang telah diaplikasikan ke permukaan kain kapas, terlihat adanya imobilisasi partikel nano TiO2 melalui ikatan hidrogen silang dengan kitosan pada kain kapas. Hasil analisa tersebut kemudian dikonfirmasi dengan FTIR (Fourier Transform Infra Red) yang hasilnya memperlihatkan puncak serapan pada bilangan gelombang 3495 cm-1, 2546 cm-1, dan 511 cm-1,  yang masing-masing diasumsikan sebagai adanya vibrasi gugus fungsi O-H, N-H dan Ti-O-Ti. Hasil SEM menunjukkan pula bahwa kristal nano yang terbentuk diantaranya adalah fasa rutile , yang berdasarkan literatur terbukti dapatberfungsi sebagai anti UV.

scholarly journals Y3+ substituted Sr-hexaferrites: sol-gel synthesis, structural, magnetic and electrical characterization

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 274-281 ◽  
Author(s):  
S. S. Satpute ◽  
S. R. Wadgane ◽  
S. R. Kadam ◽  
D. R. Mane ◽  
R. H. Kadam
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Combustion Method ◽  
Hexagonal Structure ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Studies ◽  
Auto Combustion

Abstract Y3+ substituted strontium hexaferrites having chemical composition SrYxFe12-xO19 (x= 0.0, 0.5, 1.0, 1.5) were successfully synthesized by sol-gel auto-combustion method. The structural and morphological studies of prepared samples were investigated by using X-ray diffraction technique, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy. The X-ray diffraction pattern confirmed the single-phase hexagonal structure of yttrium substituted strontium ferrite and the lattice parameters a and c increased with the substitution of Y3+ ions. The crystallite size also varied with x content from 60 to 80 nm. The morphology was studied by FE-SEM, and the grain size of nanoparticles ranged from 44 to 130 nm. The magnetic properties were investigated by using vibrating sample magnetometer. The value of saturation magnetization decreased from 49.60 to 35.40 emu/g. The dielectric constant decreased non-linearly whereas the electrical dc resistivity increased with the yttrium concentration in strontium hexaferrite.

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