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1.
Long Wang Lin-Chao Zhang Ingo Lieberwirth Hong-Wei Xu Chun-Hua Chen 《Electrochemistry communications》2010,12(1):52-55
A monoclinic lithium vanadium phosphate (Li3V2(PO4)3) and carbon composite thin film (LVP/C) is prepared via electrostatic spray deposition. The film is studied with X-ray diffraction, scanning and transmission electron microscopy and galvanostatic cell cycling. The LVP/C film is composed of carbon-coated Li3V2(PO4)3 nanoparticles (50 nm) that are well distributed in a carbon matrix. In the voltage range of 3.0–4.3 V, it exhibits a reversible capacity of 118 mA h g?1 and good capacity retention at the current rate of 1 C, while delivers 80 mA h g?1 at 24 C. These results suggest a practical strategy to develop new cathode materials for high power lithium-ion batteries. 相似文献
2.
Eiji Kobayashi Larisa S. Plashnitsa Takayuki Doi Shigeto Okada Jun-ichi Yamaki 《Electrochemistry communications》2010,12(7):894-896
All-solid-state phosphate symmetric cells using Li3V2(PO4)3 for both the positive and negative electrodes with the phosphate Li1.5Al0.5Ge1.5(PO4)3 as the solid electrolyte were proposed. Amorphous Li1.5Al0.5Ge1.5(PO4)3 was added into the electrode to increase the interface area between the active materials and the electrolyte. Any other phases were not formed at the electrode/electrolyte interface even after hot pressing at 600 °C. The discharge capacity was 92 mAh g? 1 at 22 µA cm? 2 at 80 °C, and 38 mAh g? 1 at 25 °C, respectively. Symmetric cell configuration leads to simplify the fabrication process for all-solid-state batteries and will reduce manufacturing costs. 相似文献
3.
This work aims to maximize the number of active sites for energy storage per geometric area, by approaching the investigation to 3D design for microelectrode arrays. Self-organized Li4Ti5O12/TiO2/Li3PO4 composite nanoforest layer (LTL) is obtained from a layer of self organized TiO2/Li3PO4 nanotubes. The electrochemical response of this thin film electrode prepared at 700 °C exhibited lithium insertion and de-insertion at 1.55 and 1.57 V respectively, which is the typical potential found for lithium titanates. The effects of lithium phosphate on lithium titanate are explored for the first time. By cycling between 2.7 and 0.75 V the LTL/LiFePO4 full cell delivered 145 mA h g− 1 at an average potential of 1.85 V leading to an energy density of 260 W h kg− 1 at C/2. Raman spectroscopy revealed that the γ-Li3PO4/lithium titanate structure is preserved after prolonged cycling. This means that Li3PO4 plays an important role for enhancing the electronic conductivity and lithium ion diffusion. 相似文献
4.
Xin Zhang Suqin Liu Kelong Huang Shuxin Zhuang Jun Guo Tao Wu Ping Cheng 《Journal of Solid State Electrochemistry》2012,16(3):937-944
The macroporous Li3V2(PO4)3/C composite was synthesized by oxalic acid-assisted carbon thermal reaction, and the common Li3V2(PO4)3/C composite was also prepared for comparison. These samples were characterized by X-ray diffraction (XRD), scanning electron
microscope (SEM), and electrochemical performance tests. Based on XRD and SEM results, the sample has monoclinic structure
and macroporous morphology when oxalic acid is introduced. Electrochemical tests show that the macroporous Li3V2(PO4)3/C sample has a high initial discharge capacity (130 mAh g−1 at 0.1 C) and a reversible discharge capacity of 124.9 mAh g−1 over 20 cycles. Moreover, the discharge capacity of the sample is still 91.5 mAh g−1, even at a high rate of 2 C, which is better than that of the sample with common morphology. The improvement in electrochemical
performance should be attributed to its improved lithium ion diffusion coefficient for the macroporous morphology, which was
verfied by cyclic voltammetry and electrochemical impedance spectroscopy. 相似文献
5.
This work introduces an effective, inexpensive, and large-scale production approach to the synthesis of Fe2O3 nanoparticles with a favorable configuration that 5 nm iron oxide domains in diameter assembled into a mesoporous network. The phase structure, morphology, and pore nature were characterized systematically. When used as anode materials for lithium-ion batteries, the mesoporous Fe2O3 nanoparticles exhibit excellent cycling performance (1009 mA h g− 1 at 100 mA g− 1 up to 230 cycles) and rate capability (reversible charging capacity of 420 mA h g− 1 at 1000 mA g− 1 during 230 cycles). This research suggests that the mesoporous Fe2O3 nanoparticles could be suitable as a high rate performance anode material for lithium-ion batteries. 相似文献
6.
《Electrochemistry communications》2007,9(1):103-108
The whole range of solid solutions Li(Li(1−x)/3CoxMn(2−2x)/3)O2 (0 ⩽ x ⩽ 1) was firstly synthesized by an aqueous solution method using poly-vinyl alcohol as a synthetic agent to investigate their structure and electrochemical properties. X-ray diffraction results indicated that the synthesized solid solutions showed a single phase without any detectable impurity phase and have a hexagonal structure with some additional peaks caused by monoclinic distortion, especially in the solid solutions with a low Co amount. In the electrochemical examination, the solid solutions in the range between 0.2 ⩽ x ⩽ 0.9 showed higher discharge capacity and better cyclability than LiCoO2 (x = 1) on cycling between 2.0 and 4.6 V with 100 mA g−1 at 25 °C. For example, Li(Li0.2Co0.4Mn0.4)O2 (x = 0.4) exhibited a high discharge capacity of 180 mA h g−1 at the 50th cycle. By synthesizing the solid solution between Li2MnO3 and LiCoO2, the electrochemical properties of the end members were improved. 相似文献
7.
Worm-like mesoporous carbon synthesized from metal–organic coordination polymers for supercapacitors
Dingsheng Yuan Jingxing Chen Sanxiang Tan Nannan Xia Yingliang Liu 《Electrochemistry communications》2009,11(6):1191-1194
A green and efficient route has been employed to synthesize a worm-like mesoporous carbon with high specific surface area (2587 m2 g?1) and large pore volume (3.14 cm3 g?1). Three electrochemical methods have been used to measure its electrochemical performance. Worm-like mesoporous carbon performs the high specific capacitance (344 F g?1) at constant-current densities of 50 mA g?1. 相似文献
8.
Na4Co2.4Mn0.3Ni0.3(PO4)2P2O7 has been evaluated as a positive electrode for sodium-ion batteries. The novel material has two redox couples around 4.2 V and 4.6 V and can deliver the high capacity of ca. 103 mAh g− 1 at the high current density of 850 mA g− 1 (5 C). X-ray absorption spectroscopy (XAS) results show that the redox reactions of Co, Mn and Ni ions proceed simultaneously in the charge process and it is indicated the novel material provide high mixed potential by the redox reactions of Co, Mn and Ni ions. These findings suggest that the derivatives of Na4Co3(PO4)2P2O7 should be employed as high potential and high capacity electrode materials. 相似文献
9.
《Solid State Sciences》2012,14(7):864-869
A series of Li3V2(PO4)3/C cathode materials with different morphologies were successfully prepared by controlling temperatures using maleic acid as carbon source via a simple sol–gel reaction method. The Li3V2(PO4)3/C nanorods synthesized at 700 °C with diameters of about 30–50 nm and lengths of about 800 nm show the highest initial discharge capacity of 179.8 and 154.6 mA h g−1 between 3.0 and 4.8 V at 0.1 and 0.5 C, respectively. Even at a discharge rate of 0.5 C over 50 cycles, the products still can deliver a discharge capacity of 140.2 mA h g−1 in the potential region of 3.0–4.8 V. The excellent electrochemical performance can be attributed to one-dimensional nanorod structure and uniform particle size distribution. All these results indicate that the resulting Li3V2(PO4)3/C is a very strong candidate to be a cathode in a next-generation Li-ion battery for electric-vehicle applications. 相似文献
10.
《Electrochemistry communications》2007,9(3):485-491
Lithium insertion into various iron vanadates has been investigated. Fe2V4O13 and Fe4(V2O7)3 · 3H2O have discharge capacities approaching 200 mAh g−1 above 2.0 V vs. Li+/Li. Although the potential profiles change significantly between the first and subsequent discharges, capacity retention is unexpectedly good. Other phases, structurally related to FeVO4, containing copper and/or sodium ions were also studied. One of these, β-Cu3Fe4(VO4)6, reversibly consumes almost 10 moles of electrons per formula unit (ca. 240 mAh g−1) between 3.6 and 2.0 V vs. Li+/Li, in a non-classical insertion process. It is proposed that both copper and vanadium are electrochemically active, whereas iron(III) reacts to form LiFeIIIO2. The capacity of the Cu3Fe4(VO4)6/Li system is nearly independent of cycling rate, stabilizing after a few cycles at 120–140 mAh g−1. Iron vanadates exhibit better capacities than their phosphate analogues, whereas the latter display more constant discharge potentials. 相似文献
11.
Feng Yu Jingjie Zhang Yanfeng Yang Guangzhi Song 《Journal of Solid State Electrochemistry》2010,14(5):883-888
Composite Li3V2(PO4)3/C cathode material can be synthesized by spray-drying and carbothermal method. The monoclinic-phase Li3V2(PO4)3/C was prepared with the process of double spray drying at 260 °C and subsequent heat treatment at 750 °C for 12 h. The results
indicate that the Li3V2(PO4)3/C presents large reversible discharge capacity of 121.9 mA h g−1 and charge capacity of 131.8 mA h g−1 at the current density of C/5, good rate capability with 61.1 mA h g−1 at 20C, and excellent capacity retention rate close to 100% at various current densities in the region of 3.0–4.3 V. 相似文献
12.
Yao-Kang Lv Yun-Long Feng Li-Hua Gan Ming-Xian Liu Liang Xu Cao Liu Hao-Wen Zheng Jie Li 《Journal of solid state chemistry》2012
A novel trinuclear cobalt-oxo cluster 2[Co3O(Ac)6(H2O)3]·H2O (Co-OXO) has been obtained and characterized by X-ray single-crystal diffraction and elemental analysis. The structure of Co-OXO displays 3D supramolecular networks through hydrogen bonds and generates boron nitride (bnn) topology. Co-OXO was further used as a precursor to synthesize Co-containing mesoporous carbon foams (Co-MCFs), which exhibit highly ordered mesostructure with specific surface area of 614 m2 g?1 and uniform pore size of 2.7 nm. Charge–discharge tests show that the specific discharge capacitance of Co-MCFs is 7% higher than that of the MCFs at the current density of 100 mA g?1, and 26% higher than that of MCFs at the current density of 3 A g?1. The electrochemical behaviors of Co-MCFs are obviously improved due to the improved wettability, increased graphitization degree and the pseudo-capacitance through additional faradic reactions arising from cobalt. 相似文献
13.
《Electrochemistry communications》2007,9(1):71-75
A SnO2–mesoporous organo-silica nanoarray (MOSN) composite was prepared by surfactant mediated synthesis combined with a sol–gel vacuum suction method in which SnO2 has been successfully incorporated inside the periodic nanoholes in the MOSN or coated on its surface. The MOSN with a high aspect ratio of length to width could not only maintain its structure but also effectively accommodate the volume expansion of the SnO2 during electrochemical reactions with Li+. The SnO2–MOSN composite showed a higher reversible capacity of 420 mA h g−1 with greatly improved capacity retention and lower initial irreversible capacity compared to SnO2 powder. This interesting anodic performance of SnO2–MOSN composite supports the potential use of MOSN for lithium ion batteries. 相似文献
14.
PbO2 thin films were prepared by pulse current technique on Ti substrate from Pb(NO3)2 plating solution. The hybrid supercapacitor was designed with PbO2 thin film as positive electrode and activated carbon (AC) as negative electrode in the 5.3 M H2SO4 solution. Its electrochemical properties were determined by cyclic voltammetry (CV), charge–discharge test and electrochemical impedance spectroscopy (EIS). The results revealed that the PbO2/AC hybrid supercapacitor exhibited large specific capacitance, high-power and stable cycle performance. In the potential range of 0.8–1.8 V, the hybrid supercapacitor can deliver a specific capacitance of 71.5 F g?1 at a discharge current density of 200 mA g?1(4 mA cm?2) when the mass ratio of AC to PbO2 was three, and after 4500 deep cycles, the specific capacitance remains at 64.4 F g?1, or 32.2 Wh Kg?1 in specific energy, and the capacity only fades 10% from its initial value. 相似文献
15.
Yan Lu Yong Wang Yuqin Zou Zheng Jiao Bing Zhao Yaqin He Minghong Wu 《Electrochemistry communications》2010,12(1):101-105
This paper reports the microwave-assisted synthesis of Co3O4 nanomaterials with different morphologies including nanoparticles, rod-like nanoclusters and macroporous platelets. The new macroporous platelet-like Co3O4 morphology was found to be the best suitable for reversible lithium storage properties. It displayed superior cycling performances than nanoparticles and rod-like nanoclusters. More interestingly, excellent high rate capabilities (811 mAh g?1 at 1780 mA g?1 and 746 mAh g?1 at 4450 mA g?1) were observed for macroporous Co3O4 platelet. The good electrochemical performance could be attributed to the unique macroporous platelet structure of Co3O4 materials. 相似文献
16.
Zhensheng Hong Mingdeng Wei Xiaokun Ding Lilong Jiang Kemei Wei 《Electrochemistry communications》2010,12(6):720-723
Spinel Li2ZnTi3O8 nanorods were first synthesized using titanate nanowires as a precursor. The synthesized nanorods are highly crystalline and used as an anode material in a rechargeable Li-ion battery. A large capacity of 220 mA h g? 1 was kept after 30 cycles at a current density of 0.1 A g? 1, which is close to the theoretic capacity. The electrochemical measurements indicate that the anode material made of spinel Li2ZnTi3O8 nanorods displayed a highly reversible capacity and excellent cycling stability. 相似文献
17.
Comparative investigations of LiVPO4F/C and Li3V2(PO4)3/C synthesized in similar soft chemical route
Jiexi Wang Zhixing Wang Xinhai Li Huajun Guo Wei Xiao Silin Huang Zhenjiang He 《Journal of Solid State Electrochemistry》2013,17(1):1-8
Triclinic LiVPO4F and monoclinic Li3V2(PO4)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 LiVPO4F and Li3V2(PO4)3. The electrochemical properties of the prepared LiVPO4F/C and Li3V2(PO4)3/C cathodes are evaluated. The as-prepared LiVPO4F/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 Li3V2(PO4)3/C. Both samples exhibit good cycle performance at different current densities. The capacity delivered by LiVPO4F 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 Li3V2(PO4)3/C. But the rate capability of LiVPO4F/C is not so good compared with as-prepared Li3V2(PO4)3/C. 相似文献
18.
Dong-Wook Han Yong-Mook Kang Ri-Zhu Yin Min-Sang Song Hyuk-Sang Kwon 《Electrochemistry communications》2009,11(1):137-140
LiCo1?xFexPO4/C composites with various amounts of Fe (x = 0, 0.05 and 0.1) were synthesized by vibrant type ball-milling coupled with microwave heating to investigate the role of doped Fe2+ in LiCo1?xFexPO4/C composites. The initial charge–discharge curves and cyclic voltammetry profiles of LiCo1?xFexPO4/C composites apparently featured an improved kinetic property compared to LiCoPO4. It was observed that the initial discharge capacity (120 mA hg?1) of LiCo0.95Fe0.05PO4 is higher than that (108 mA hg?1) of LiCoPO4 and the difference between the oxidation–reduction peaks is getting smaller with the increase of Fe doping. The electrochemical improvement in LiCo1?xFexPO4/C composites could be attributed to the enhanced Li+ diffusivity induced by the enlargement of 1D channel in polyanion structure of LiCoPO4. 相似文献
19.
《Electrochemistry communications》2007,9(4):663-666
A novel network composite cathode was prepared by mixing LiFePO4 particles with multiwalled carbon nanotubes for high rate capability. LiFePO4 particles were connected by multiwalled carbon nanotubes to form a three-dimensional network wiring. The web structure can improve electron transport and electrochemical activity effectively. The initial discharge capacity was improved to be 155 mA h/g at C/10 rate (0.05 mA/cm2) and 146 mA h/g at 1C rate. The comparative investigation on MWCNTs and acetylene black as a conducting additive in LiFePO4 proved that MWCNTs addition was an effective way to increase rate capability and cycle efficiency. 相似文献
20.
《Solid State Sciences》2007,9(6):521-526
Members of the spinel solid solution between Li4/3Ti5/3O4 and LiCrTiO4, i.e., Li(4−x)/3Ti(5−2x)/3CrxO4 (0 ≤ x ≤ 0.9), have been investigated as possible negative electrodes for future lithium-ion batteries. Electrochemical behaviour have been studied over the potential range 1–3.5 V vs Li+/Li. Results are promising with anodic capacities between 129 and 163 mA h/g with a flat operating voltage at about 1.5 V, which is attributed to the pair Ti4+/Ti3+. The inclusion of Cr3+ in the spinel structure enhances the specific capacity. In-situ X-ray diffraction experiments confirm that the reaction proceeds in a topotactic manner. 相似文献