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1.
Despite the large number of studies on the behavior of LiCoO2 in organic electrolytes and its recent application as a positive electrode in rechargeable water battery prototypes, a little information is available about the lithium intercalation reaction in this layered compound in aqueous electrolytes. This work shows that LiCoO2 electrodes can be reversibly cycled in LiNO3 aqueous electrolytes for tens of cycles at remarkably high rates with impressive values specific capacity higher than 100 mAh/g, and with a coulomb efficiency greater than 99.7%. Stable and reproducible cycling measurements have been made using a simple cell design that can be easily applied to the study of other intercalation materials, assuming that they are stable in water and that their intercalation potential range matches the electrochemical stability window of the aqueous electrolyte. The experimental arrangement uses a three-electrode flooded cell in which another insertion compound acts as a reversible source and sink of lithium ions, i.e., as the counter electrode. A commercial reference electrode is also present. Both the working and the counter electrodes have been prepared as thin layers on a metallic substrate using the procedures typical for the study of electrodes for lithium-ion batteries in organic solvent electrolytes.  相似文献   

2.
Nanoparticles of lithium cobalt oxide (LiCoO2) and nanosheets of lithium vanadium oxide (LiV3O8) were synthesized by a citrate sol–gel combustion route. The physical characterizations of the electrodic materials were carried out by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and also X-ray diffraction (XRD) measurements. Near spherical nanoparticles of ≈100 nm and compact nanosheets with a few nanometers thick were observed by SEM and TEM for LiCoO2 and LiV3O8, respectively. XRD data indicated that the as-prepared active materials presented pure phase of rhombohedral LiCoO2 with R-3m symmetry and monoclinic LiV3O8 with p21/m symmetry. The kinetics of electrochemical intercalation of lithium ion into the nanoparticles of LiCoO2 and nanosheets of LiV3O8 from 1.0 mol l−1 LiNO3 aqueous solution were investigated by cyclic voltammetry and chronoamperometry. An aqueous rechargeable lithium-ion battery consisting of LiCoO2 nanoparticles as positive and LiV3O8 nanosheets as negative electrode was assembled. This battery represented a discharge voltage of about 1 V with good cycling performance.  相似文献   

3.
Crystalline LiV3O8 and LiMn2O4 were prepared by conventional solid-state reaction and characterized by X-ray diffraction analysis. Cyclic voltammetry technique was employed to evaluate the electrochemical behaviors of LiV3O8 and LiMn2O4 in 2 mol/l Li2SO4 aqueous solution, and the results show that both LiV3O8 and LiMn2O4 are very stable in this aqueous electrolyte and can be used as the negative and positive electrode material without evident hydrogen or oxygen evolution. An aqueous rechargeable lithium battery (ARLB) was fabricated by using the above two intercalation compounds as the negative and positive electrodes. This battery exhibits good cycling behavior and the average discharge voltage is about 1.04 V.  相似文献   

4.
Upon electrochemical reduction in a lithium cell, calcite-type FeBO3 gives an amorphous compound which can intercalate 3 Li per formula at 1.1 V, ending with metallic iron for full discharge to 0.9 V. The amorphous phase can be cycled reversibly at 1.5–3 V with capacities as high as 300 Ah/kg. This material was successfully tested as an inexpensive negative electrode for Li-ion batteries with LiCoO2 as the positive electrode. Its behaviour is quite different from that of Fe2O3, both in intercalation potential and cyclability. Electronic Publication  相似文献   

5.
Polyaniline (PANI)/LiCoO2 nanocomposite materials are successfully ready through a solid-stabilized emulsion (Pickering emulsion) route. The properties of nanocomposite materials have been put to the test because of their possible relevance to electrodes of lithium batteries. Such nanocomposite materials appear thanks to the polymerization of aniline in Pickering emulsion stabilized with LiCoO2 particles. PANI has been produced through oxidative polymerization of aniline and ammonium persulfate in HCl solution. The nanocomposite materials of PANI/LiCoO2 could be formed with low amounts of PANI. The morphology of PANI/LiCoO2 nanocomposite materials shows nanofibers and round-shape-like morphology. It was found that the morphology of the resulting nanocomposites depended on the amount of LiCoO2 used in the reaction system. Ammonium persulfate caused the loss of lithium from LiCoO2 when it was used at high concentration in the polymerization recipe. Highly resolved splitting of 006/102 and 108/110 peaks in the XRD pattern provide evidence to well-ordered layered structure of the PANI/LiCoO2 nanocomposite materials with high LiCoO2 content. The ratios of the intensities of 003 and 104 peaks were found to be higher than 1.2 indicating no pronounced mixing of the lithium and cobalt cations. The electrochemical reactivity of PANI/LiCoO2 nanocomposites as positive electrode in a lithium battery was examined during lithium ion deinsertion and insertion by galvanostatic charge–discharge testing; PANI/LiCoO2 nanocomposite materials exhibited better electrochemical performance by increasing the reaction reversibility and capacity compared to that of the pristine LiCoO2 cathode. The best advancement has been observed for the PANI/LiCoO2 nanocomposite 5 wt.% of aniline.  相似文献   

6.
The accidental overcharging is emulated in fully charged LiCoO2/mesocarbon microbeads (MCMB) batteries through initial one-off overcharging and successive long-term normal cycling. The aging mechanism and effect of accidental overcharging on the performance of LiCoO2/MCMB battery is studied by the electrochemical tests and physical characterizations. The result clearly shows that not all accidentally overcharged batteries should be discarded and the extent of the degradation is highly dependent on the overcharging cutoff voltages. Compared with the blank batteries, low overcharging cutoff voltages have almost no influence on the performance degradation during successive long-term normal cycling. Under this condition, the aging is primarily due to the consumption of active lithium. However, high overcharging cutoff voltages, even just one time, decay the battery. Furthermore, further cycling accelerates the aging and changes the aging mechanism of battery under normal operation condition. Under this condition, the surface structure destruction of the LiCoO2 is revealed as the primary contributor to battery degradation, which is related to the dissolution and reduction of cobalt ions after overcharging at high cutoff voltages and successive long-term normal cycling.  相似文献   

7.
Rechargeable lithium batteries that use non-aqueous electrolytes may not be suitable for electric vehicle applications, which require safe, inexpensive, and high energy density. In this paper, we showed that reversible lithium intercalation can occur in MnO2 cathode coupled with Zn anode while using LiOH aqueous electrolyte. This new Zn|LiOH|MnO2 aqueous rechargeable cell could operate around 1.5 V for multiple cycles and possibly be used in battery packs, are of low cost, and environmentally benign. However, higher energy density, power density, and cycling life of the Zn|LiOH|MnO2 system are required for exploiting this technology to better compete with the lithium battery counterparts. Serendipitously, high energy density (270 Wh/Kg) that was achieved with physically mixed additives (Bi2O3 and TiB2) on MnO2 is reported. Physically modified cathode containing multiple additives is shown to be superior in energy density and capacity retention compared to that of the additive-free MnO2 or carbon-coated MnO2 using polyvinylpyrrolidone as the source. The role of the additives (Bi2O3 and Bi2O3?+?TiB2) in the MnO2 electrode is found to avoid the formation of unwanted (non-rechargeable) products and to decrease the polarization of the electrode.  相似文献   

8.
In this review, we describe briefly the historical development of aqueous rechargeable lithium batteries, the advantages and challenges associated with the use of aqueous electrolytes in lithium rechargeable battery with an emphasis on the electrochemical performance of various electrode materials. The following materials have been studied as cathode materials: LiMn2O4, MnO2, LiNiO2, LiCoO2, LiMnPO4, LiFePO4, and anatase TiO2. Addition of certain additives like TiS2, TiB2, CeO2, etc. is found to increase the performance of MnO2 cathode. The following materials have been studied as anode materials: VO2 (B), LiV3O8, LiV2O5, LiTi2(PO4)3, TiP2O3, and very recently conducting polymer, polypyrrole (PPy). The cell PPy/LiCoO2, constructed using polypyrrole as anode delivers an average voltage of 0.86?V with a discharge capacity of 47.7?mA?h?g?1. It retains the capacity for first 120 cycles. The cell, LiTi2(PO4)3/1?M Li2SO4/LiMn2O4, delivers a capacity of 40?mA?h?g?1 and specific energy of 60?mW?h?g?1 with an output voltage of 1.5?V over 200 charge?Cdischarge cycles. An aqueous lithium cell constructed using MWCNTs/LiMn2O4 as cathode material is found to exhibit more than 1,000 cycles with good rate capability.  相似文献   

9.
LiCrTiO4, which crystallizes in the orthorhombic ramsdellite structure, has been obtained by heating spinel LiCrTiO4 at 1250 °C in air. The refined cell parameters are a = 4.9835(6) Å, b = 9.5095(8) Å and c = 2.9282(2) Å, space group Pbnm, as determined from Rietveld refinement of X‐ray powder diffraction data. The intercalation chemistry of LiCrTiO4 has been investigated. Lithium can be extracted from LiCrTiO4 due to oxidation of CrIII at rather high potential 4 V. On the other hand, lithium intercalation proceeds readily at 1.5 V due to the reduction of tetravalent titanium. Regarding practical applications, as an electrode for lithium rechargeable batteries, specific capacities of 100 and 120 mAh·g?1 are developed at 0.1 mA·cm?2, respectively. These findings point out that the ramsdellite form of LiCrTiO4 may be an ambivalent electrode, which can be used either as the positive electrode or the negative electrode of a lithium ion rechargeable battery.  相似文献   

10.
The properties of electrolyte systems based on standard nonaqueous solvent composed of a mixture of dialkyl and alkylene carbonates and new commercially available lithium salts potentially capable of being an alternative to thermally unstable and chemically active lithium hexafluorophosphate LiPF6 in the mass production of lithium-ion rechargeable batteries are surveyed. The advantages and drawbacks of electrolytes containing lithium salts alternative to LiPF6 are discussed. The real prospects of substitution for LiPF6 in electrolyte solutions aimed at improving the functional characteristics of lithium-ion batteries are assessed. Special attention is drawn to the efficient use of new lithium salts in the cells with electrodes based on materials predominantly used in the current mass production of lithium-ion batteries: grafitic carbon (negative electrode), LiCoO2, LiMn2O4, LiFePO4, and also solid solutions isostructural to lithium cobaltate with the general composition LiMO2 (M = Co, Mn, Ni, Al) (positive electrode).  相似文献   

11.
A lithium cobalt phosphate (LiCoPO4) cathode was synthesised by citric acid assisted sol?Cgel method and its electrochemical behaviour in alkaline secondary battery (using novel lithium hydroxide as the electrolyte) is reported. The sol?Cgel method using metal acetate precursors with citric acid as a chelating agent influenced the particle size and the homogeneity while yielding a single phase LiCoPO4 at a considerably lower temperature and shortened heating time, compared to that of the conventional solid state reaction. The cyclic voltammogram of LiCoPO4 showed a reversible redox process implying that de-intercalation and intercalation of lithium can occur in aqueous electrolyte. This was supported by X-ray diffraction (XRD) and Infra-red (IR) studies. The charge?Cdischarge performance of the Zn/LiCoPO4 battery showed good capacity retention (after 25 cycles it delivered 90?% of its initial capacity). This enhanced capacity retention was attributed to the synergistic effect of particle homogeneity, reduced Li+ diffusion path and stability of the non-reactive aqueous electrolyte between the electrode and the electrolyte interface.  相似文献   

12.
This paper describes a novel redox flow battery–single flow acid Cd–chloranil battery. The electrolyte of this battery for both negative electrode and positive electrode is the aqueous intermixture of H2SO4–(NH4)2SO4–CdSO4, the negative electrode is inert metal such as copper foil, and the positive electrode is an insoluble organic material, tetrachloro-p-benzoquinone (chloranil). Typically, the electrolyte is continuously circulated to pass though the cells by means of a single pump as the battery is on duty. There is no requirement for a membrane. Tetrachloro-p-benzo-hydroquinone is oxidized to chloranil at positive electrode and the cadmium ions is reduced to cadmium and electroplated onto the negative electrode during charge. The reverse occurs during discharge. Results obtained with a small laboratory cell show that high efficiencies can be achieved with an average coulombic efficiency of 99% and energy efficiency of 82% over 100 cycles at the current density of 10 mA cm?2.  相似文献   

13.
Two synthetic routes including Mg doping and MgO-surface modification were applied to the preparation of LiCoO2 showing enhanced reversible cycling behaviour as cathode material in lithium ion batteries. Mg-doped LiCoO2 was obtained by the citrate precursor method in the temperature range 750–900°C. The surface of LiCoO2 was modified by coating with Mg(CH3COO)2 and subsequent heating at 600°C. XRD, chemical oxidative analysis and electron paramagnetic resonance (EPR) of Ni3+ spin probes were used to characterize the Mg distribution in LiCoO2. Substitution of Co by Mg in the CoO2-layers was found to have a positive effect on the cycling stability, while Mg dopants in LiO2-layers did not influence the capacity fade. The accumulation of MgO on the surface of LiCoO2 improves the cycling stability without loss of initial capacity.  相似文献   

14.
A novel redox flow battery–single flow Zn/NiOOH battery is proposed. The electrolyte of this battery for both negative electrode and positive electrode is high concentration solutions of ZnO in aqueous KOH, the negative electrode is inert metal such as nickel foil, and the positive electrode is nickel oxide for secondary alkaline batteries. Typically, there is no requirement for a membrane in the battery. Ni(OH)2 is oxidized to NiOOH at positive electrode and the zincate ions is reduced to zinc and electroplated onto the negative electrode during charge. The reverse occurs during discharge. Results obtained with a small laboratory cell show that high efficiencies can be achieved with an average coulombic efficiency of 96% and energy efficiency of 86% over 1000 cycles. High performance obtained indicates that the single flow zinc/nickel battery is a promising battery.  相似文献   

15.
Lithium-ion batteries are commonly used for electrical energy storage in portable devices and are promising systems for large-scale energy storage. However, their application is still limited due to electrode degradation and stability issues. To enhance the fundamental understanding of electrode degradation, we report on the Raman spectroscopic characterization of LiCoO2 cathode materials of working Li-ion batteries. To facilitate the spectroscopic analysis of the solid electrolyte interface (SEI), we apply in situ surface-enhanced Raman spectroscopy under battery working conditions by using Au nanoparticles coated with a thin SiO2 layer (Au@SiO2). We observe a surface-enhanced Raman signal of Li2CO3 at 1090 cm−1 during electrochemical cycling as an intermediate. Its formation/decomposition highlights the role of Li2CO3 as a component of the SEI on LiCoO2 composite cathodes. Our results demonstrate the potential of Raman spectroscopy to monitor electrode/electrolyte interfaces of lithium-ion batteries under working conditions thus allowing relations between electrochemical performance and structural changes to be established.  相似文献   

16.
The electrochemical intercalation of lithium into single graphite particles was studied in situ using Raman microscopy combined with confocal microscopy. The degree of intercalation during cycling was obtained from changes in the Raman bands of carbon. Confocal microscopy was used to image the graphite electrode in order to monitor the intercalation into single graphite particles. An industrial button cell was modified such that Raman spectra and microscopic images of the back side of the negative electrode could be taken through a window in the cup of the cell. The liquid electrolyte consisted of a 1:1 mixture of ethylenecarbonate/dimethylcarbonate (EC/DMC) with 1 M LiPF6. The spectroscopy and microscopy showed that lithium does not intercalate into the graphite in a homogeneous manner. Inhomogeneous lithium intercalation was even observed in single graphite particles.  相似文献   

17.
石琴  门春艳  李娟 《物理化学学报》2013,29(8):1691-1697
以FeCl3-甲基橙(MO)为模板, 通过化学原位聚合法成功制备出氧化石墨烯/聚吡咯(GO/PPy)插层复合材料. 采用X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱、扫描电镜(SEM)和透射电镜(TEM)等测试技术对复合材料进行物性表征. 此外, 利用循环伏安、恒电流充放电和交流阻抗测试方法对复合材料在两种不同水系电解液(1 mol·L-1 Na2SO4和1 mol·L-1 H2SO4)中的电化学性能进行了研究. 结果显示: 氧化石墨烯和聚吡咯表现出各自优势并发挥协同作用, 使得GO/PPy插层复合材料在中性和酸性电解液中都显示出可观的比电容. 电流密度为0.5 A·g-1时, GO/PPy 插层复合材料在Na2SO4和H2SO4电解液中的比电容分别为449.1 和619.0 F·g-1, 明显高于纯PPy的比电容. 经过800 次循环稳定性测试后, 两种不同电解液中, 复合材料初始容量的保持率分别为92%和62%. 其中酸性电解液体系中初始容量更大, 而中性溶液中具有更稳定的循环性能.  相似文献   

18.
The synthesis process of LiCoO2 prepared by l-apple acid (l-HOOCCH(OH)CH2COOH) assisted sol–gel method is studied by using Fourier transforms infrared spectroscopy, mass spectroscopy, simultaneous thermogravimetric and differential thermal analysis, X-ray diffraction analysis, and elemental analysis. The results show that lithium and cobalt ions are trapped homogeneously on an atomic scale throughout the precursor. Lithium carbonate and Co3O4 are intermediate products during heat treatment of the precursor. Moreover, the kinetics for formation of LiCoO2 by l-apple acid assisted sol–gel method is faster than the case of the conventional solid-state reaction between lithium carbonate and Co3O4. In comparison with the solid-state reaction, the sol–gel method significantly shortens the required reaction time for synthesizing LiCoO2, and also reduces the particle size. In the electrochemical test, it is found that the specific discharge/charge capacities as well as the coulomb efficiency substantially increase with increasing the calcination temperature. It is considered that LiCoO2 with a good-layered structure facilitates the insertion and de-insertion of lithium ions in aqueous electrolyte. As a result, the combination of the sol–gel method with proper calcination processes is highly successful in producing LiCoO2 powders with large specific capacity and good cycle performance in aqueous lithium-ion battery.  相似文献   

19.
Rechargeable LI2O2 electrode for lithium batteries   总被引:2,自引:0,他引:2  
Rechargeable lithium batteries represent one of the most important developments in energy storage for 100 years, with the potential to address the key problem of global warming. However, their ability to store energy is limited by the quantity of lithium that may be removed from and reinserted into the positive intercalation electrode, Li(x)CoO(2), 0.5 < x < 1 (corresponding to 140 mA.h g(-1) of charge storage). Abandoning the intercalation electrode and allowing Li to react directly with O(2) from the air at a porous electrode increases the theoretical charge storage by a remarkable 5-10 times! Here we demonstrate two essential prerequisites for the successful operation of a rechargeable Li/O(2) battery; that the Li(2)O(2) formed on discharging such an O(2) electrode is decomposed to Li and O(2) on charging (shown here by in situ mass spectrometry), with or without a catalyst, and that charge/discharge cycling is sustainable for many cycles.  相似文献   

20.
The University of Texas at Austin Neutron Depth Profiling (UT-NDP) facility was utilized to analyze varying cathode compositions in lithium battery materials. Battery materials included LiCoO2, LiMn1/3Ni1/3Co1/3O2, and LiFePO4. The cells were made at The University of Texas at Austin as coin cells with lithium anodes. The NDP analysis method for Li in battery materials was benchmarked between two facilities and with computational models.  相似文献   

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