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1.
锂作为21世纪推动科学技术发展的重要元素之一,被誉为“工业味精”、“能源之星”。目前锂及其相关盐类材料已成为信息产业、核能源、航空航天技术、新型材料及军事科技等行业重点开发领域,具有极高科学价值和广阔商业前景[1 ̄4]。氯化锂是电解制金属锂的主要原料,它的纯度是电 相似文献
2.
Solid-state thin-film lithium-ion battery of LiMn 2O 4/Li 1.3Al 0.3Ti 1.7(PO 4) 3/LiMn 2O 4 is prepared by spray technique using Li 1.3Al 0.3Ti 1.7(PO 4) 3 sintered pellet as both electrolyte and substrate. The thin-film battery is heat-treated by rapid thermal annealing. Phase
identification, morphology and electrochemical properties of the sintered pellets and thin-film battery are investigated by
X-ray diffraction, scanning electron microscopy, electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic
charge-discharge experiments, respectively. The results show that LiMn 2O 4 films with some pores are well deposited on the surface of Li 1.3Al 0.3Ti 1.7(PO 4) 3 sintered pellet. The discharge current density and temperature have considerable effect on discharge capacity of the thin-film
battery. LiMn 2O 4/Li 1.3Al 0.3Ti 1.7(PO 4) 3/LiMn 2O 4 thin-film battery can be easily cycled with a capacity loss of 0.213% per cycle when 50 cycles are carried out. 相似文献
3.
Lithium-ion conductor Li 1.3Al 0.3Ti 1.7(PO 4) 3 with an ultrapure NASICON-type phase is syn-thesized by a 1,2-propylene glycol (1,2-PG)-assisted sol-gel method and characterized by differential thermal analysis-thermo gravimetric analysis, X-ray diffraction, scanning elec-tron microscopy, electrochemical impedance spectroscopy, and chronoamperometry test.Due to the use of 1,2-PG, a homogeneous and light yellow transparent precursor solu-tion is obtained without the precipitation of Ti 4+ and Al 3+ with PO 43-. Well crystallizedLi 1.3Al 0.3Ti 1.7(PO 4) 3 can be prepared at much lower temperatures from 850 oC to 950 oC within a shorter synthesis time compared with that prepared at a temperature above 1000 oC by a conventional solid-state reaction method. The lithium ionic conductivity of the sintered pellets is up to 0.3 mS/cm at 50 oC with an activation energy as low as 36.6 kJ/mol for the specimen pre-sintered at 700 oC and sintered at 850 oC. The high conductivity, good chemi-cal stability and easy fabrication of the Li 1.3Al 0.3Ti 1.7(PO 4) 3 provide a promising candidate as solid electrolyte for all-solid-state Li-ion rechargeable batteries. 相似文献
4.
Dependence of the density of the Li 1.3Al 0.3Ti 1.7(PO 4) 3 (LATP) ceramic on thermal treatment modes was studied. The conditions in which ceramic samples with density exceeding 90% are obtained were determined. It was found that the bulk ionic conductivity of LATP upon sintering at 1000°C for 2–6 h is (1.1–1.3) × 10 –3 S cm –1 at 20°C, which corresponds to the maximum values for lithium-aluminum titanophosphate. 相似文献
5.
The Li 0.33Lia 0.56TiO 3 and Li 1.3Ti 1.7Al 0.3(PO 4) 3 ceramics with the structures of defect-perovskite and NASICON structures with conductivity of 1–6?×?10 ?6 S/cm at the room temperature are obtained. Ceramic electrolytes were developed for a solid-state battery EMF of 4.1 V and high discharge stability in time. Discharge characteristics of solid-state batteries are studied in a laboratory cell. 相似文献
6.
A modified sol-gel process was studied as applied to synthesize a lithium-conducting solid electrolyte of composition Li 1.3Al 0.3Ti 1.7(PO 4) 3 (LATP) using water-soluble salts Al(NO 3) 3 · 9H 2O, LiNO 3 · 3H 2O, and (NH 4) 2HPO 4 and a titanium(IV) citrate complex. As-synthesized samples were characterized using X-ray powder diffraction, DSC/TG, SEM, and impedance spectroscopy. Sintering of as-synthesized amorphous powders at 700°C was found to yield LATP with crystallite sizes of 42–48 nm. Ionic conductivity of the electrolyte measured in the frequency range 25–10 6 Hz in disks having 86–90% density that were sintered at 1000°C was (3–4) × 10 ?4 S/cm. Temperature-dependent ionic conductivity was studied in the range 25–200°C. The activation energy of conduction was determined for LATP. 相似文献
7.
The new scandium/aluminium co-doped NASICON phases Li 1?+?x Al y Sc x???y Ti 2???x (PO 4) 3 ( x?=?0.3, y?=?0,0.1,0.2,0.3) were prepared by mechanical milling followed by annealing of the mixtures at 950 °C. X-ray diffraction of all samples showed the formation of NASICON structure with space group R-3c along with a minor impurity. Rietveld refinement of the X-ray data was performed to identify the structural variation. Doping with Sc 3+ caused elongation of a- and c- axes for all the compounds when compared with undoped LiTi 2(PO 4) 3. The compound Li 1.3Sc 0.3Ti 1.7(PO 4) 3 showed a maximum of a?=?8.5504(7), c?=?20.986(3) Å at room temperature and exhibited highest coefficient of thermal expansion. The highest ionic conductivity ( σ), 7.28×10 ?4 S cm ?1 was observed for Li 1.3Sc 0.3Ti 1.7(PO 4) 3, two orders of magnitude higher than for the undoped phase. 相似文献
8.
Compatibility of the lithium-titanium spinel Li 4Ti 5O 12 in contact with precursors of lithium-conducting solid electrolytes of composition Li 1.3Al 0.3Ti 1.7(PO 4) 3 (LATP), Li 1.5Al 0.5Ge 1.5(PO 4) 3 (LAGP), Li 0.5La 0.5TiO 3 (LLT) was studied. It was found that, in sintering of Li 4Ti 5O 12 brought in contact with LATP and LAGP, a solid-phase reaction occurs to give nonconducting phases (TiO 2 and Li 3PO 4). The conductivity of the stable composite Li 4Ti 5O 12/LLT (10%) is higher than that of the starting Li 4Ti 5O 12, which makes it possible to regard the composite as a promising anode material for lithium-ion batteries. 相似文献
9.
Single-phase LiVPO 4F and LiVPO 4F/Li 3V 2(PO 4) 3 nanostructured composite cathode materials were prepared by heating of the VPO 4?+?LiF mechanochemically activated mixture to 700 °C and subsequent quick or slow cooling to room temperature, respectively. The formation of the composites was proved by a combination of different physico-chemical methods, including XRD, FTIR, 6Li and 31P NMR, SEM, TEM, and HRTEM. It has been shown that in the composites LiVPO 4F and Li 3V 2(PO 4) 3 nanocrystals well inset into each other resulting in the nanodomain composite formation. Charge–discharge curves of the composites have a sloping profile both in the high-voltage (3.0–4.5 V) and in the low-voltage (1.3–2.5 V) ranges, noticeably different from plateaus for a phase-pure LiVPO 4F, thus indicating a probable change of a two-phase regime of lithium intercalation for a single-phase one. Enhanced rate capability of the LiVPO 4F/Li 3V 2(PO 4) 3 composites is associated with their microstructure and high ionic conductivity of Li 3V 2(PO 4) 3. 相似文献
10.
Synthesis from aqueous peroxide solutions provides lithium-aluminum titanophosphate Li 1.3Al 0.3Ti 1.7(PO 4) 3 (LATP) with particles of submicron size and conductivity of (4–5) × 10 ?4 S/cm at the room temperature. LATP were characterized using the methods of XRD, DTA/TG, measurement of specific surface area, ionic and electronic conductivity. According to XRD, a single-phase crystalline product with the specific surface area of 8.2 m 2/g is formed as a result of precursor sintering at 700°C (the average particle size of electrolyte was 250 nm). Sizes of coherent-scattering region were calculated on the basis of the values of intrinsic broadening of diffraction maximums. Analysis of broadening of diffraction maximums indicates that the size of primary LATP crystallites after sintering at 700°C was 90 nm according to peak (113) (2θ = 24.5°) and 110 nm according to peak (104) (2θ = 20.9°). The synthesized submicron LATP powders are suitable for formation of solid electrolyte films using the method of aerosol deposition. 相似文献
11.
The process for producing the electrode material LiCoPO 4 modified by the lithium-conducting solid electrolyte Li 1.3Al 0.3Ti 1.7(PO 4) 3 (LATP) was studied. To create a composite consisting of an electrochemically active substance and an electrically conductive additive distributed uniformly between LiCoPO 4 particles, a peroxide solution of a LATP precursor was used. After annealing at 700°C, the two-phase composite LiCoPO 4/LATP was obtained, the conductivity of which was two orders of magnitude higher than that of binary lithium cobalt phosphate at room temperature. 相似文献
12.
A new type of three-dimensional (3D) oxy-phosphate materials are explored for the application of Li and Na batteries. The molybdenum tungsten oxy phosphate, MoWO3(PO4)2, was synthesized by solid-state method and evaluated for Li/Na insertion/de-insertion electrode material for the first time. The cell at charged state (vs. Li+/Li) showed a discharge capacity of 786 mAh g−1 within the voltage window of 0.3 V with amorphization of crystalline MoWO3(PO4)2 as observed from ex-situ powder XRD analysis. The structural integrity was revealed in this material, even with nearly more than 5 Li+ ions into the lattice, leading to the discharge capacity of 250 mAh g−1. The reversible charge/discharge behavior with insertion/de-insertion of 2.4 Li+ ions in the voltage range of 1.65 − 3.5 V resulted in 110 and 95 mAh g−1 at C/10 and C/5 rates, respectively. On the other hand, poor cycling performance was noticed for Na ion insertion and desertion, with a discharge capacity of 250 mAh/g within the voltage range of 0.3 − 3.5 V (vs. Na+/Na). 相似文献
13.
Triclinic LiVPO 4F and monoclinic Li 3V 2(PO 4) 3 are synthesized through a soft chemical process with mechanical activation assist, followed by annealing. In this process, ascorbic acid is used as reducing agent as well as carbon source. The as-prepared samples are coated with amorphous carbon. XPS analysis results show the expected valency states of ions in LiVPO 4F and Li 3V 2(PO 4) 3. The electrochemical properties of the prepared LiVPO 4F/C and Li 3V 2(PO 4) 3/C cathodes are evaluated. The as-prepared LiVPO 4F/C cathode shows an initial discharge specific capacity of 140?±?3 mAh?g ?1 at 30 mA?g ?1 in the voltage range of 3.0~4.4 V, compared with that of 138?±?3 mAh?g ?1 possessed by Li 3V 2(PO 4) 3/C. Both samples exhibit good cycle performance at different current densities. The capacity delivered by LiVPO 4F remains 95.5 and 91.7 % of its initial discharge capacity after 50 cycles at 150 and 750 mA?g ?1, respectively, while 97.4 and 90.6 % for Li 3V 2(PO 4) 3/C. But the rate capability of LiVPO 4F/C is not so good compared with as-prepared Li 3V 2(PO 4) 3/C. 相似文献
14.
A convenient method named wet coordination is used to prepare the sample or carbon-coated Li 3V 2(PO 4) 3 in the furnace with a flowing argon atmosphere at 600 °C for 1 h. The sample is characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy dispersive analysis of X-rays (EDAX). Galvanostatic charge–discharge between 3.3 and 4.3 V (vs. Li/Li +) shows that the sample exhibits a high discharge capacity of 128 mAh g ?1 with a good reversible performance under a current density of 95 mA g ?1. It suggests that carbon-coated Li 3V 2(PO 4) 3 with good electrochemical performance can be obtained via this method, which is suitable for large-scale production. 相似文献
15.
A new NASICON-related structure of lithium titanium phosphate Li 2.72Ti 2(PO 4) 3 has been determined. This compound crystallizes in an orthorhombic system, Pbcn, with a = 12.064 (3) Å, b = 8.663 (3) Å, c = 8.711 (4) Å, V = 910.4 (8) Å 3, and Z = 4. The single crystal structure of this novel mixed valent titanium(III/IV) phosphate reveals one titanium atom per asymmetric unit. Two lithium sites are characterized by a pair of distorted polyhedra, Li(1)O 4 and Li(2)O 5, which share a common edge resulting in a short Li(1) … Li(2) distance, i.e., 2.29 (5) Å. Magnetic susceptibility and microprobe analysis confirmed the structural composition. The room temperature ionic conductivity is comparable with that of the known Li 1+xTi IV2−xIn IIIx(PO 4) 3, which suggests possible fast ionic conductivity. 相似文献
16.
Comparison of the electrochemical insertion of lithium into ATi 2(PS 4) 3 with A = Li, Na, Ag and ATi 2(PO 4) 3 with Li, Ag is striking. Whereas only four lithium per formula unit (Li/f.u.) can be inserted reversibly into the phosphates, up to 7 and 10 Li/f.u. can be inserted reversibly in the thiophosphates with A = Li and Ag. Moreover, the Ag + to Ag 0 reduction in AgTi 2(PO 4) 3 is not reversible, but in AgTi 2(PS 4) 3 it is reversible. Strong hybridization of the Ag-5s and host antibonding bands stabilizes the formal valences Ag 0, Ti +, and (PS 4) 4− in the discharged state of AgTi 2(PS 4) 3; but only the formal valence Ti 2+ is accessible in LiTi 2(PS 4) 3. Unfortunately the large volume change associated with the lithium insertion renders the structure progressively more amorphous on cycling, which causes the capacity to fade quite dramatically on further cycling. The thiophosphates transform to the phosphates on heating in air. 相似文献
17.
Various structures and morphologies of Li 3V 2(PO 4) 3 precursors are synthesized by a novel ionothermal method using three kinds of imidazolium-based ionic liquids as both reaction mediums and structure-directing agents at ambient pressure. Nanostructured Li 3V 2(PO 4) 3/C cathode materials can be successfully prepared by a subsequent short calcination process. The structures, morphologies, and electrochemical properties are characterized by X-ray diffractometry, thermogravimetry, scanning and transmission electron microscopy, charge–discharge test, cyclic voltammetry, and electrochemical impedance spectroscopy. It shows that three kinds of materials synthesized present different morphologies and particle sizes. The result can be due to imidazolium-based ionic liquids, which combined with different anions play important role in forming the size and morphology of Li 3V 2(PO 4) 3 material. These materials present excellent performance with high rate capacity and cycle stability. Especially, the Li 3V 2(PO 4) 3/C material prepared in 1-ethyl-3-methylimadozolium trifluoromethanesulfonate ([emim][OTf]) can deliver discharge capacities of 127.4, 118.9, 105.5, and 92.8 mAh?g ?1 in the voltage range of 3.0–4.3 V at charge–discharge rate of 0.1, 1, 10, and 20 C after 50 cycles, respectively. The excellent rate performance can be attributed to the uniform nanostructure, which can make the lithium-ion diffusion and electron transfer more easily across the Li 3V 2(PO 4) 3/electrolyte interfaces. 相似文献
18.
The liquid-solid phase diagram of the binary systems AlPO 4?M 3PO 4( M=Li, Na, K) have been established. The additional compounds Na 3Al(PO 4) 2, Na 3Al 2(PO 4) 3 and K 3Al 2(PO 4) 3 have been found again. A new compound K 3Al(PO 4) 2 is observed. The melting point of Na 3PO 4 is 1545°C and K 3PO 4 does not melt up to 1700°C. 相似文献
19.
The effect of Al 2O 3 -coating on Li 3V 2(PO 4) 3/C cathode material for lithium-ion batteries has been investigated. The crystalline structure and morphology of the synthesized powders have been characterized by XRD, SEM, and HRTEM, and their electrochemical performances are evaluated by CV, EIS, and galvanostatic charge/discharge tests. It is found that Al 2O 3 -coating modification stabilizes the structure of the cathode material, decreases the polarization of electrode and suppresses the rise of the surface film resistance. Electrochemical tests indicate that cycling performance and rate capability of Al 2O 3-coated Li 3V 2(PO 4) 3/C are enhanced, especially at high rates. The Al 2O 3-coated material delivers discharge capacity of 123.03 mAh g ?1 at 4 C rate, and the capacity retention of 94.15 % is obtained after 5 cycles. The results indicate that Al 2O 3 -coating should be an effective way to improve the comprehensive properties of the cathode materials for lithium-ion batteries. 相似文献
20.
Single crystals of NASICON-type material Li 1+xTi 2−xAl x(PO 4) 3 (LATP) with 0 ≤ x ≤ 0.5 were successfully grown using long-term sintering techniques. Sample material was studied by chemical analysis, single crystal X-ray and neutron diffraction. The Ti 4+ replacement scales very well with the Al 3+ and Li + incorporation. The additional Li + thereby enters the M3 cavity of the NASICON framework at x, y, z ∼ (0.07, 0.34, 0.09) and is regarded to be responsible for the enhanced Li + conduction of LATP as compared to Al-free LTP. Variations in structural parameters, associated with the Ti 4+ substitution with Al 3+ + Li + will be discussed in detail in this paper. 相似文献
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