Improved Electrochemical Performance of LiCoPO4 Nanoparticles for Lithium Ion Batteries

2007 ◽  
Vol 7 (11) ◽  
pp. 4037-4040 ◽  
Author(s):  
Hal-Bon Gu ◽  
Bo Jin ◽  
Dae-Kyoo Jun ◽  
Zhenji Han
Keyword(s):  
Single Phase ◽  
Coulombic Efficiency ◽  
Lithium Ion ◽  
Structural Performance ◽  
X Ray Diffraction ◽  
Voltage Range ◽  
X Ray ◽  
Li Battery ◽  
Li Batteries ◽  
Charge Discharge

Single phase LiCoPO4 nanoparticles were synthesized by solid-state reaction. LiCoPO4/Li batteries were fabricated in an argon-filled glove box, and their electrochemical properties were analyzed by cyclic voltammetry (CV) and charge–discharge tests. The structural performance of LiCoPO4 nanoparticles was investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD result demonstrated that LiCoPO4 nanoparticles had an orthorhombic olivine-type structure with a space group of Pmnb. The charge–discharge tests indicated that the initial discharge capacity and coulombic efficiency of LiCoPO4/Li batteries were 110 mA h/g and 48% in cut-off voltage range of 3.0–5.3 V,90 mA h/g and 54% in cut-off voltage range of 3.0–5.1 V, 70 mA h/g and 60% in cut-off voltage range of 3.0–5.0 V, respectively. After 30 cycles, the coulombic efficiency was 78% for 3.0–5.3 V, 88% for 3.0–5.1 V, 91% for 3.0–5.0 V, respectively. These results indicated that the coulombic efficiency of LiCoPO4 /Li battery increased upon cycling and upon decreasing in charge upper limit voltage, respectively.

scholarly journals High Tap Density SphericalLi[Ni0.5Mn0.3Co0.2]O2Cathode Material Synthesized via Continuous Hydroxide Coprecipitation Method for Advanced Lithium-Ion Batteries

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Shunyi Yang ◽  
Xianyou Wang ◽  
Xiukang Yang ◽  
Ziling Liu ◽  
Qiliang Wei ◽  
...  
Keyword(s):  
Size Distribution ◽  
Photoelectron Spectroscopy ◽  
Rate Capability ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Voltage Range ◽  
X Ray ◽  
Tap Density ◽  
Plate Shape ◽  
Hydroxide Coprecipitation

Spherical[Ni0.5Mn0.3Co0.2](OH)2precursor with narrow size distribution and high tap density has been successfully synthesized by a continuous hydroxide coprecipitation, andLi[Ni0.5Mn0.3Co0.2]O2is then prepared by mixing the precursor with 6% excessLi2CO3followed by calcinations. The tap density of the obtainedLi[Ni0.5Mn0.3Co0.2]O2powder is as high as 2.61 g cm−3. The powders are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), particle size distribution (PSD), and charge/discharge cycling. The XRD studies show that the preparedLi[Ni0.5Mn0.3Co0.2]O2has a well-ordered layered structure without any impurity phases. Good packing properties of spherical secondary particles (about 12 μm) consisted of a large number of tiny-thin plate-shape primary particles (less than 1 μm), which can be identified from the SEM observations. In the voltage range of 3.0–4.3 V and 2.5–4.6 V,Li[Ni0.5Mn0.3Co0.2]O2delivers the initial discharge capacity of approximately 175 and 214 mAh g−1at a current density of 32 mA g−1, and the capacity retention after 50 cycles reaches 98.8% and 90.2%, respectively. Besides, it displays good high-temperature characteristics and excellent rate capability.

Lithium-Ion Battery Anode Electrochemical Properties of Si/C Composites Using Graphite and Glucose as Carbon Source

2011 ◽  
Vol 347-353 ◽  
pp. 3506-3509
Author(s):  
Xu Ma ◽  
Yu Ling Liu ◽  
Ling Long Kong ◽  
Yan Hong Ding ◽  
Jie Zhao ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Carbon Source ◽  
Coulombic Efficiency ◽  
Lithium Ion ◽  
Charge Capacity ◽  
X Ray ◽  
Battery Anode ◽  
Charge Discharge ◽  
Scanning Electron ◽  
Discharge Test

Si/C composites were synthesized by using graphite and glucose as carbon source. The samples were characterized by X-ray diffractometer (XRD) and field emission scanning electron microscope(SEM). The electrochemical charge/discharge test was used to evaluate capacity and cycling stability of the composites. The first discharge and charge capacity of SGC composite using graphite and glucose as carbon source were 1661mAh/g and 1259.1 mAh/g, and the first coulombic efficiency was 75.8%. After 20 cycles, the capacity of SGC composite was 380 mAh/g and the coulombic efficiency remained over 98%.

Surface Modification of Spinel LiMn2O4 with Y2O3 for Lithium-Ion Battery

2011 ◽  
Vol 391-392 ◽  
pp. 1069-1074 ◽  
Author(s):  
Ying Bai ◽  
Feng Wu ◽  
Hua Tong Yang ◽  
Yu Zhong ◽  
Chuan Wu
Keyword(s):  
Surface Modification ◽  
Chemical Process ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Discharge Characteristics ◽  
X Ray ◽  
Passivating Films ◽  
Discharge Capacities ◽  
Charge Discharge

Spinel LiMn2O4was modified with Y2O3coating by a chemical process. The crystal structures of the as-prepared samples were investigated by X-ray diffraction (XRD). The charge/discharge characteristics of the modified samples were evaluated at different rates between 3.0 and 4.4V. The discharge capacities of 2.0 wt.% Y2O3-coated LiMn2O4are 116 mAh•g−1, 99.7mAh•g−1, 93.3mAh•g−1and 82.9mAh•g−1at 0.1C, 0.5C, 1C and 2C rates (at 20◦C). The cycle abilities improvement of the spinel LiMn2O4coated with Y2O3are demonstrated at elevated temperature (55◦C) and high rates (2C). From the analysis of electrochemical impedance spectroscopy (EIS), the improvement of cycle ability may be attributed to the suppression on the formation of the passivating films and the reduction of Mn dissolution, which result from the surface modification with Y2O3.

A Novel Composite Li3V2(PO4)3∥Li2NaV2(PO4)3/C as Cathode Material for Li-Ion Batteries

2018 ◽  
Vol 71 (7) ◽  
pp. 497
Author(s):  
Lingfang Li ◽  
Changling Fan ◽  
Jiaxing Yang
Keyword(s):  
Electrochemical Performance ◽  
Metal Ion ◽  
Coulombic Efficiency ◽  
Sol Gel ◽  
Lithium Ion ◽  
Composite Cathode ◽  
X Ray Diffraction ◽  
Li Ion ◽  
Ion Intercalation ◽  
Charge Discharge

A novel composite cathode for lithium ion batteries, Li3V2(PO4)3‖Li2NaV2(PO4)3/C, was synthesized by a sol-gel method. Cetyltrimethylammonium bromide (CTAB) was used as a surfactant while polyvinylidene difluoride (PVDF) was the carbon source. X-ray diffraction (XRD) and Raman results showed that the components of this composite are monoclinic Li3V2(PO4)3, rhombohedral Li2NaV2(PO4)3 and an amorphous carbon-coating. Four potential plateaus occur at the charge/discharge curves and the longest plateau is observed at a potential of 3.8/3.7 V. Therefore, the alkali metal ion intercalation and deintercalation mostly occur at this potential, which is different to that observed for Li3V2(PO4)3. In addition to the stable working potential, this composite also possesses an outstanding electrochemical performance. The sample containing 8.32 % carbon content delivers a capacity of 119 mAh g−1 at 0.2 C rate and 87 mAh g−1 at 12 C. After 50 charge/discharge cycles at 1 C, a coulombic efficiency of 98.4 % is maintained. This enhancement of the electrochemical performance could be attributed to the synergistic effect between monoclinic Li3V2(PO4)3 and rhombohedral Li2NaV2(PO4)3.

Synthesis and Electrochemical Performance of K-Doped Li4Ti5O12 as Anode Material for Lithium-Ion Batteries

2014 ◽  
Vol 633-634 ◽  
pp. 495-498
Author(s):  
Xiao Bing Huang ◽  
Hong Hui Chen ◽  
Shi Biao Zhou ◽  
Yuan Dao Chen ◽  
Bei Ping Liu ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Rate Performance ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
X Ray ◽  
State Method ◽  
Traditional Solid State Method ◽  
Initial Capacity ◽  
Charge Discharge ◽  
Discharge Test

Spinel Li4-xKxTi5O12(x=0, 0.03) were successfully synthesized by a traditional solid-state method and systematically investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and the charge-discharge test, respectively. The results demonstrated that Li3.97K0.03Ti5O12exhibited much better rate performance in comparsion with Li4Ti5O12. At 0.2 C and 10 C, it delivered a discharge capacity of 173 mAh g-1and 124 mAh g-1respectively, and after 100 cycles at 10 C, 96.1% of its initial capacity was retained.

Hydrothermal Synthesis of Li2MnSiO4 Powders as a Cathode Material for Lithium Ion Cells

2012 ◽  
Vol 512-515 ◽  
pp. 1588-1591 ◽  
Author(s):  
Shao Hua Luo ◽  
Ming Wang ◽  
Xu Zhu ◽  
Gui Hong Geng
Keyword(s):  
Discharge Capacity ◽  
Hydrothermal Reaction ◽  
Raw Materials ◽  
Coulombic Efficiency ◽  
Lithium Ion ◽  
Cycle Performance ◽  
X Ray Diffraction ◽  
Cycle Number ◽  
Voltage Range ◽  
Unit Formula

Li2MnSiO4 cathode materials were prepared by hydrothermal reaction at 150°C using LiOH, Si(OC2H5)4 and Mn(Ac)2.4H2O as raw materials followed by a low temperature heat annealing at 650°C. The samples were characterized by X-ray diffraction, scanning electron microscopy, FTIR. The powders electrochemical performance was investigated in terms of cycling behavior. Nanometer-sized flake crystalline particles of Li2MnSiO4 are obtained with some degree of agglomeration and little impure phases are detected after annealing. The charge capacity of the Li2MnSiO4 samples is 306 mAh/g (about 1.84 Li+ per unit formula extracted), and the discharge capacity is 114 mAh/g (about 0.68 Li+ per unit formula inserted) in the first cycle in the voltage range of 1.5–4.8 V under a rate of C⁄20. With increasing cycle number, the cell exhibits a well cycle performance with more than 95% coulombic efficiency and the maintenance of 61% of its discharge capacity after 50 cycles.

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.

Surface Modification of LiCo1/3Ni1/3Mn1/3O2 with LaF3 for Lithium-Ion Batteries

2011 ◽  
Vol 399-401 ◽  
pp. 1515-1518
Author(s):  
Zhan Xu Yang ◽  
Qing Dong Qiao
Keyword(s):  
Coating Layer ◽  
Specific Capacity ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
X Ray ◽  
Discharge Specific Capacity ◽  
Initial Discharge ◽  
Surface Modified ◽  
Charge Discharge

LiCo1/3Ni1/3Mn1/3O2 has been modified with LaF3. The surface modified materials were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and galvanostatic charge-discharge cycling. The LaF3-coated LiCo1/3Ni1/3Mn1/3O2 had an initial discharge specific capacity of 178.0 mAh•g–1 within the potential ranges 2.75–4.5 V (vs. Li+/Li), and its discharge specific capacity is 168.7 mAh•g–1 after 50 cycles, much higher than that of the pristine LiCo1/3Ni1/3Mn1/3O2 (148.4 mAh•g–1). The improvement could be attributed to the LaF3 coating layer that hinders interaction between LiCo1/3Ni1/3Mn1/3O2 and electrolyte and stabilizes the structure of LiCo1/3Ni1/3Mn1/3O2 .

Synthesis and Electrochemical Performance of Li3V2(PO4)3 Cathode Material by Microwave Method

2012 ◽  
Vol 490-495 ◽  
pp. 3624-3627
Author(s):  
Sheng Kui Zhong ◽  
Hui Ping Hu ◽  
Jie Qun Liu
Keyword(s):  
Perfect Crystal ◽  
Microwave Method ◽  
Initial Discharge Capacity ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Voltage Range ◽  
X Ray ◽  
Initial Discharge ◽  
Charge Discharge ◽  
Discharge Test

Monoclinic Li3V2(PO4)3 was synthesized by a microwave method. The influence of sintering temperatures and time on the synthesis of Li3V2(PO4)3 was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and charge-discharge test. The results of these tests shows that the Li3V2(PO4)3 sample synthesized at 850 °C for 15 min has pure and perfect crystal. The charge-discharge test shows the Li3V2(PO4)3 sample with optimal synthesis condition has the best initial discharge capacity of 120 mAh/g, with capacity retention of 101 mAh/g after 50 cycles, in the voltage range of 3.0 V–4.2 V.

A Study of LiMn(2-X)FexO4 Cathodic Nano Material for Lithium-Ion Batteries

2014 ◽  
Vol 1043 ◽  
pp. 7-11
Author(s):  
A.F.M. Fadzil ◽  
F.H. Muhammad
Keyword(s):  
Particle Size ◽  
Bulk Material ◽  
Sol Gel ◽  
Specific Capacity ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Discharge Performance ◽  
X Ray ◽  
Nano Material ◽  
Charge Discharge

LiMn1.5Fe0.5O4is synthesized using sol-gel method and annealed at 850°C for 24 hours. It is then characterized using X-ray diffraction (XRD) and charge discharge analysis. The bulk material are then proceed to further grinding to become nanosize. The nanosample is then characterized using XRD and charge discharge performance, and the specific capacities of the two materials are compared. nanosample of LiMn1.5Fe0.5O4shows higher specific capacity which is 160.16 mAhg-1compares to the bulk which gives only 128.663mAhg-1. This shows that with smaller particle size, the battery performance has improved in terms of its capacity.

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