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1.
Ni3P–Ni films were deposited on nickel foam substrates by electrodeposition in an aqueous solution. The structure and morphology of the electrodeposited films were characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM). The annealed electrodeposited films consisted of tetragonal structured Ni3P and cubic metal Ni. As anode for lithium ion batteries, the electrochemical properties of the Ni3P–Ni films were investigated by cyclic voltammetry (CV), electrochemical impedance spectrum (EIS) and galvanostatic charge–discharge tests. The electrodeposition time had a significant effect on the electrochemical performances of the films. The Ni3P–Ni film electrodeposited for 20 min delivered the initial discharge capacity of 890 mAh g−1. Although the irreversible capacity at the first cycle was relative large, the Ni3P–Ni film exhibited good cycling stability and its discharging capacity still maintained 340 mAh g−1 after 40 cycles. 相似文献
2.
Nano-Ni3Sn2 intermetallic compound was successfully prepared by solvothermal method for an anode material of lithium-ion batteries. Its microstructure was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Electrochemical performances were evaluated in a lithium-ion model cell Li/LiPF6 (EC + DMC)/Ni3Sn2. The electrochemical lithiation and de-lithiation behavior of nano-Ni3Sn2 was investigated by ex situ XRD. Diffraction peaks of Ni3Sn2 widened and shrank gradually during lithiation. Sharp Ni3Sn2 peaks appeared again after full de-lithiation. It was proved that nano-Ni3Sn2 could be reversibly charged and discharged with lithium though the de-lithiation capacity of nano-Ni3Sn2 was lower than its theoretical capacity. 相似文献
3.
Seung-Taek Myung Ki-Soo LeeYang-Kook Sun Hitoshi Yashiro 《Journal of power sources》2011,196(16):7039-7043
Layer Li[Ni0.4Co0.2Mn0.4]O2 and lithium excess spinel Li[Li0.1Al0.05Mn1.85]O4 were compared as positive electrode materials for high power lithium-ion batteries. Physical properties were examined by Rietveld refinement of X-ray diffraction pattern and scanning electron microscopic studies. From continuous charge and discharge tests at higher currents and different temperature environments using 3Ah class lithium-ion batteries, it was found that both materials presented plausible battery performances such as rate capability, cyclability at 60 °C at elevated temperature, and low temperature properties as well. 相似文献
4.
To prepare a high-capacity cathode material with improved electrochemical performance for lithium rechargeable batteries, Co3(PO4)2 nanoparticles are coated on the surface of powdered Li[Co0.1Ni0.15Li0.2Mn0.55]O2, which is synthesized by a simple combustion method. The coated powder prepared under proper conditions for Co3(PO4)2 content and annealing temperature shows an optimum coating layer that consists of a LixCoPO4 phase formed by reaction with lithium impurities during heat treatment. A sample coated with 3 wt.% Co3(PO4)2 and annealed at 800 °C proves to be the best in terms of specific capacity, cycle performance and rate capability. Thermal stability is also enhanced by the coating, as demonstrated a decrease in the onset temperature and/or the heat generated during thermal runaway. 相似文献
5.
Atsushi ItoYuichi Sato Takashi SanadaMasaharu Hatano Hideaki HorieYasuhiko Ohsawa 《Journal of power sources》2011,196(16):6828-6834
Although Li-rich solid-solution layered materials Li2MnO3-LiMO2 (M = Co, Ni, etc.) are expected as large capacity lithium insertion cathodes, the fundamental charge-discharge reaction mechanism of these materials is not clear. Therefore the change in valence states of Ni, Co and Mn of Li[Ni0.17Li0.2Co0.07Mn0.56]O2 during charge-discharge was examined in detail using in situ X-ray absorption spectroscopy (XAS), which includes both X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements. Since the Mn K edge shift during charge-discharge was not clear to determine the valence change of Mn, the Mn K pre-edge shift was examined during charge-discharge. In our measurements, only a small shift of the Mn K pre-edge toward lower energy was observed on discharge from 4.8 to 2.0 V. This corresponds to a decrease of the Mn valence from 4+ to approximately 3.6+. However, this shift cannot explain the large reversible capacity of this material and thus strongly suggests the participation of oxygen in the reversible charge-discharge reaction of this material. 相似文献
6.
Manganese oxide with high tap density was prepared by decomposition of spherical manganese carbonate, and then LiMn2O4 cathode materials were synthesized by solid-state reaction between the manganese oxide and lithium carbonate. Structure and properties of the samples were determined by X-ray diffraction, Brunauer–Emmer–Teller surface area analysis, scanning electron microscope and electrochemical measurements. With increase of the decomposition temperature from 350 °C to 900 °C, the tap density of the manganese oxide rises from 0.91 g cm−3 to 2.06 g cm−3. Compared with the LiMn2O4 cathode made from chemical manganese dioxide or electrolytic manganese dioxide, the LiMn2O4 made from manganese oxide of this work has a larger tap density (2.53 g cm−3), and better electrochemical performances with an initial discharge capacity of 117 mAh g−1, a capacity retention of 93.5% at the 15th cycle and an irreversible capacity loss of 2.24% after storage at room temperature for 28 days. 相似文献
7.
Yan-Bing He Zhi-Yuan Tang Quan-Sheng Song Hui Xie Quan-Hong Yang Yuan-Gang Liu Guo-Wei Ling 《Journal of power sources》2008
The commercial 18650 Li(Ni1/3Co1/3Mn1/3)O2/graphite high power batteries were prepared and their electrochemical performance at temperatures of 25 and 50 °C was extensively investigated. The results showed that the charge-transfer resistance (Rct) and solid electrolyte interface resistance (Rsei) of the high power batteries at 25 °C decreased as states of charge (SOC) increased from 0 to 60%, whereas Rct and Rsei increased as SOC increased from 60 to 100%. The discharge plateau voltage of batteries reduced greatly with the increase in discharge rate at both 25 and 50 °C. The high power batteries could be discharged at a very wide current range to deliver most of their capacity and also showed excellent power cycling performance with discharge rate of as high as 10 C at 25 °C. The elevated working temperature did not influence the battery discharge capacity and cycling performance at lower discharge rates (e.g. 0.5, 1, and 5 C), while it resulted in lower discharge capacity at higher discharge rates (e.g. 10 and 15 C) and bad cycling performance at discharge rate of 10 C. The batteries also exhibited excellent cycle performance at charge rate of as high as 8 C and discharge rate of 10 C. 相似文献
8.
Dong-Ho Baek Jae-Kwang Kim Yong-Jo Shin Ghanshyam S. Chauhan Jou-Hyeon Ahn Ki-Won Kim 《Journal of power sources》2009
Carbon-coated LiMn0.4Fe0.6PO4 composites (LiMn0.4Fe0.6PO4/C) were synthesized for use as cathode materials in lithium batteries. The composites were synthesized by a mechanical activation process that consists of high-energy ball milling for 10 h, followed by thermal treatment at different temperatures. The structure, particle size and surface morphology of these cathode active materials were investigated by inductively coupled plasma (ICP) analysis, energy dispersive spectrometry (EDS), high-resolution Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). The firing temperature was observed to affect morphology, particle size, elemental distribution, structure of the residual carbon, and consequently the electrochemical properties of the composites. LiMn0.4Fe0.6PO4/C synthesized at 600 °C possessed the most desirable properties and it exhibited the best performance when used as cathode in lithium batteries at room temperature. The cell, comprising cathode of this composite, exhibited the initial discharge capacities of 144.5 mAh g−1 (85.0% of theoretical capacity) and 122.0 mAh g−1 (71.8%), respectively, at 0.1 and 1 C-rates. The cathode showed good cycle stability without substantial capacity fade up to 50 cycles. 相似文献
9.
Hidesato Saruwatari Tadaomi IshikawaYoshiyuki Korechika Naoto KitamuraNorio Takami Yasushi Idemoto 《Journal of power sources》2011,196(23):10126-10132
The electrochemical properties and crystal structure of LiMn1.5Ni0.5O4 treated with supersonic waves in an aqueous Ni-containing solution were investigated by performing charge-discharge tests, inductively coupled plasma (ICP) analysis, scanning electron microscopy (SEM), iodometry, X-ray diffraction (XRD), powder neutron diffraction and synchrotron powder XRD. The charge-discharge curve of LiMn1.5Ni0.5O4 versus Li/Li+ has plateaus at 4.1 and 4.7 V. The 4.1 V versus Li/Li+ plateau due to the oxidation of Mn3+/4+ was reduced by the supersonic treatment. During the charge-discharge cycling test at 25 °C, the supersonic treatment increased the discharge capacity of the 50th cycle. Rietveld analysis of the neutron diffraction patterns revealed that the Ni occupancy of the 4b site in LiMn1.5Mn0.5O4, which is mainly occupied by Ni, was increased by the supersonic treatment. This result suggests that Ni2+ is partially substituted for Mn3+/4+ during the supersonic treatment. 相似文献
10.
P. ManikandanM.V. Ananth T. Prem KumarM. Raju P. PeriasamyK. Manimaran 《Journal of power sources》2011,196(23):10148-10155
LiNi0.5Mn0.5O2, a promising cathode material for lithium-ion batteries, is synthesized by a novel solution-combustion procedure using acenaphthene as a fuel. The powder X-ray diffraction (XRD) pattern of the product shows a hexagonal cell with a = 2.8955 Å and c = 14.1484 Å. Electron microscopy investigations indicate that the particles are of sub-micrometer size. The product delivers an initial discharge capacity of 161 mAh g−1 between 2.5 and 4.6 V at a 0.1 C rate and could be subjected to more than 50 cycles. The electrochemical activity is corroborated with cyclic voltammetric (CV) and electrochemical impedance data. The preparative procedure presents advantages such as a low cation mixing, sub-micron particles and phase purity. 相似文献
11.
Ki-Soo Lee Seung-Taek Myung Dong-Won KimYang-Kook Sun 《Journal of power sources》2011,196(16):6974-6977
Surface modifications of electrode materials can improve the electrochemical and thermal properties of cathodes for use in lithium batteries. In this study, AlF3-coated LiCoO2 and AlF3-coated Li[Ni1/3Co1/3Mn1/3]O2 cathode materials are blended, as both have the same crystal structure and exhibit similar electrochemical properties. The composite electrodes exhibit high discharge capacities of 180-188 mAh g−1 in a voltage range of 3.0-4.5 V at room temperature. The capacity retention of the composite electrode is greater than 95% of the initial capacity after 50 cycles. The thermal stability of these composite electrodes is greatly improved because of the superior thermal stability of AlF3-coated Li[Ni1/3Co1/3Mn1/3]O2. The blended AlF3-coated LiCoO2 and AlF3-coated Li[Ni1/3Co1/3Mn1/3]O2 electrode shows two exothermic peaks, one at 227 °C from AlF3-coated LiCoO2 and another at 277 °C from AlF3-coated Li[Ni1/3Co1/3Mn1/3]O2, accompanied by significantly reduced exothermic heat generation. 相似文献
12.
Jianqing Zhao Xiaochun Ding Jianhua Zhou Yi’ou Ma Shichao Wu Ruiming Huang 《Journal of power sources》2010,195(19):6854-6859
Sodium vanadium fluorophosphate, NaVPO4F, a cathode material for hybrid lithium ion batteries has been synthesized via a modified sol-gel method followed by heat treatment. The vanadium (Ш) gel precursor as the reaction intermediate phase can be facilely prepared in ethanol under ambient conditions, and this synthesis considerably simplifies the conventional high-temperature fabrication of VPO4. X-ray diffraction (XRD) results indicate a phase transition of NaVPO4F from the monoclinic crystal to the tetragonal symmetry structure. Meanwhile, the scanning electron microscope (SEM) images show the obvious spatial rearrangements on the morphology of samples. The hybrid lithium ion batteries based on the tetragonal NaVPO4F exhibit an even discharge plateau at 3.6 V vs. Li in the limited voltage range of 3.0-4.2 V, and the discharge capacity retention is up to 98.7% after 100 cycles at C/4 rate. With voltage excursion to 3.0-4.5 V, the initial charge and discharge deliver the reversible storage capacity of 117.3 and 106.8 mAh g−1, respectively. Furthermore, the prepared NaVPO4F has a capacity retention of 83% after 100th cycle at 2 C rate. The electrochemical properties reveal the reversible mixed alkali ion (Li+, Na+) insertion reactions for this fluorophosphate material. 相似文献
13.
MoO2 synthesized through reduction of MoO3 with ethanol vapor at 400 °C was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Its electrochemical performance as an anode material for lithium ion battery was tested by cyclic voltammetry (CV) and capacity measurements. During the reduction process, the starting material (MoO3) collapsed into nanoparticles (∼100 nm), on the nanoparticles remains a carbon layer from ethanol decomposition. Rate capacity and cycling performance of the as-prepared product is very satisfactory. It displays 318 mAh g−1 in the initial charge process with capacity retention of 100% after 20 cycles in the range of 0.01–3.00 V vs. lithium metal at a current density of 5.0 mA cm−2, and around 85% of the retrievable capacity is in the range of 1.00–2.00 V. This suggests the application of this type of MoO2 as anode material in lithium ion batteries. 相似文献
14.
LiFePO4 as a cathode material for rechargeable lithium batteries was prepared by hydrothermal process at 170 °C under inert atmosphere. The starting materials were LiOH, FeSO4, and (NH4)2HPO4. The particle size of the obtained LiFePO4 was 0.5 μm. The electrochemical properties of LiFePO4 were characterized in a mixed solvent of ethylene carbonate and diethyl carbonate (1:1 in volume) containing 1.0 mol dm−3 LiClO4. The hydrothermally synthesized LiFePO4 exhibited a discharge capacity of 130 mA h g−1, which was smaller than theoretical capacity (170 mA h g−1). The annealing of LiFePO4 at 400 °C in argon atmosphere was effective in increasing the discharge capacity. The discharge capacity of the annealed LiFePO4 was 150 mA h g−1. 相似文献
15.
The spherical Li[Ni1/3Co1/3Mn1/3]O2 powders with appropriate porosity, small particle size and good particle size distribution were successfully prepared by a slurry spray drying method. The Li[Ni1/3Co1/3Mn1/3]O2 powders were characterized by XRD, SEM, ICP, BET, EIS and galvanostatic charge/discharge testing. The material calcined at 950 °C had the best electrochemical performance. Its initial discharge capacity was 188.9 mAh g−1 at the discharge rate of 0.2 C (32 mA g−1), and retained 91.4% of the capacity on going from 0.2 to 4 C rate. From the EIS result, it was found that the favorable electrochemical performance of the Li[Ni1/3Co1/3Mn1/3]O2 cathode material was primarily attributed to the particular morphology formed by the spray drying process which was favorable for the charge transfer during the deintercalation and intercalation cycling. 相似文献
16.
A novel method to improve the cycling performance of LiCo1/3Ni1/3Mn1/3O2 in lithium-ion batteries by TiO2-coating with an in situ dipping and hydrolyzing method was presented in this work. The microstructure of the TiO2-coated LiCo1/3Ni1/3Mn1/3O2 was characterized by XRD, SEM and TEM, and their electrochemical performances were evaluated by EIS and galvonostatic charge-discharge test. SEM and TEM images show that the TiO2 are pasted on the surface of the LiCo1/3Ni1/3Mn1/3O2 with nano-size. The XRD patterns indicate that the crystal structure of the TiO2-coated LiCo1/3Ni1/3Mn1/3O2 shows no obvious change compares with the bare material. The TiO2-coated LiCo1/3Ni1/3Mn1/3O2 possesses improved cycle performance and rate capability. The capacity retention of 1.0 wt.% TiO2-coated material is more than 99.0% after 12 cycles at 3.0 C while that of the bare sample is only 86.6%. The capacity of coated material at 5.0 C remains 66.0% of the capacity at 0.2 C, while that of the bare LiCo1/3Ni1/3Mn1/3O2 is only 31.5%. 相似文献
17.
Yong Zhang Xingbing Wu Hui Feng Lizhen Wang Aiqin Zhang Tongchi Xia Huichao Dong 《International Journal of Hydrogen Energy》2009
Nanosized Mg0.8Cu0.2O powders were prepared by sol–gel method. In order to improve the electrochemical performances of Li/S rechargeable batteries, Mg0.8Cu0.2O was used as an additive for crystalline vanadium pentoxide (c-V2O5)/S composite cathode. The composite electrodes with and without additive were characterized by scanning electron microscopy, galvanostatic charge–discharge, rate capability and cycle performance. The results showed that not only the cycle life and discharge capacity were improved, but also the rate capability was improved after the addition of Mg0.8Cu0.2O. The improvements of electrochemical performances were due to the adsorbing effect on polysulfide of Mg0.8Cu0.2O. Furthermore, the additive also had catalytic effect on promoting redox reaction of the Li/S batteries. 相似文献
18.
Single-phase lithium nickel manganese oxide, LiNi0.5Mn0.5O2, was successfully synthesized from a solid solution of Ni1.5Mn1.5O4 that was prepared by means of the solid reaction between Mn(CH3COO)2·4H2O and Ni(CH3COO)2·4H2O. XRD pattern shows that the product is well crystallized with a high degree of Li–M (Ni, Mn) order in their respective layers, and no diffraction peak of Li2MnO3 can be detected. Electrochemical performance of as-prepared LiNi0.5Mn0.5O2 was examined in the test battery by charge–discharge cycling with different rate, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The cycling behavior between 2.5 and 4.4 V at a current rate of 21.7 mA g−1 shows a reversible capacity of about 190 mAh g−1 with little capacity loss after 100 cycles. High-rate capability test shows that even at a rate of 6C, stable capacity about 120 mAh g−1 is retained. Cyclic voltammetry (CV) profile shows that the cathode material has better electrochemical reversibility. EIS analysis indicates that the resistance of charge transfer (Rct) is small in fully charged state at 4.4 V and fully discharged state at 2.5 V versus Li+/Li. The favorable electrochemical performance was primarily attributed to regular and stable crystal structure with little intra-layer disordering. 相似文献
19.
Li-ming Li Hua-jun GuoXin-hai Li Zhi-xing WangWen-jie Peng Kai-xiong XiangXuan Cao 《Journal of power sources》2009
Li2FeSiO4/C cathodes were synthesized by combination of wet-process method and solid-state reaction at high temperature, and effects of roasting temperature and modification on properties of the Li2FeSiO4/C cathode were investigated. The XRD patterns of the Li2FeSiO4/C samples indicate that all the samples are of good crystallinity, and a little Fe3O4 impurity was observed in them. The primary particle size rises as the roasting temperature increases from 600 to 750 °C. The Li2FeSiO4/C sample synthesized at 650 °C has good electrochemical performances with an initial discharge capacity of 144.9 mAh g−1 and the discharge capacity remains 136.5 mAh g−1 after 10 cycles. The performance of Li2FeSiO4/C cathode is further improved by modification of Ni substitution. The Li2Fe0.9Ni0.1SiO4/C composite cathode has an initial discharge capacity of 160.1 mAh g−1, and the discharge capacity remains 153.9 mAh g−1 after 10 cycles. The diffusion coefficient of lithium in Li2FeSiO4/C is 1.38 × 10−12 cm2 s−1 while that in Li2Fe0.9Ni0.1SiO4/C reaches 3.34 × 10−12 cm2 s−1. 相似文献
20.
A novel process via sintering of a precursor from the solution of metal acetates by spray-drying technology was used to synthesize Co-substituted LiCo1/6Mn11/6O4 material for lithium ion batteries. The as-prepared particles were identified as single-phase spinel structure without any impurities in the XRD pattern. The SEM image showed that the particles had good cubic shapes and uniform size distribution with sizes of about 100–200 nm. An ex situ XRD technique was used to characterize the first charge process of the LiCo1/6Mn11/6O4 electrode. The result suggested that the material configuration maintained invariability. The electrochemical properties of the synthesized cathode material were investigated using Li-ion model cells at room and elevated temperature, respectively. In the charge/discharge potential of 3.5–4.4 V at 1/10 C rate, the LiCo1/6Mn11/6O4 electrode delivered high initial capacities of 123 and 127 mAh g−1 at 25 and 55 °C, respectively. Electrochemical cycling tests revealed that the capacity fading occurred mainly in the high-voltage region of 4.08–4.40 V, and the fading rate was 0.107% and 0.302% per cycle at 25 and 55 °C, respectively. The excellent cycling stability and low material cost make it an attractive cathode for high-temperature lithium ion batteries. 相似文献