Synthesis of Nanosized Lithium Manganate For Lithium-ion Secondary Batteries

2001 ◽  
Vol 703 ◽  
Author(s):  
Hsien-Cheng Wang ◽  
Yueh Lin ◽  
Ming-Chang Wen ◽  
Chung-Hsin Lu
Keyword(s):  
Particle Size ◽  
Aqueous Phase ◽  
Ultrafine Particles ◽  
Specific Capacity ◽  
Volume Ratio ◽  
Lithium Ion ◽  
Submicron Particles ◽  
Lithium Ions ◽  
Lithium Manganate ◽  
Precursor Powders

ABSTRACTNanosized lithium manganate powders are successfully synthesized via a newly developed reverse-microemulsion (RμE) process. Monophasic LiMn2O4 powders are obtained after calcining the precursor powders at 700°C. The particle size of the spinel compound significantly depends on the concentration of the aqueous phase. Increasing the water-to-oil volume ratio results in an increase in the particle size. While the aqueous phase is equal to 0.5 M, the size of the obtained LiMn2O4 powder is around 60-70 nm. It is found that the specific capacity of nanosized LiMn2O4 particles is greater than that of submicron particles. The large surface area of ultrafine particles is considered to facilitate the intercalation and deintercalation of lithium ions during the cycling test.

Influence of the emulsification conditions on the microstructures and electrochemical characteristics of spinel lithium manganese oxide powders

2003 ◽  
Vol 18 (3) ◽  
pp. 552-559 ◽  
Author(s):  
Chung-Hsin Lu ◽  
Yueh Lin
Keyword(s):  
Particle Size ◽  
Manganese Oxide ◽  
Aqueous Phase ◽  
Specific Capacity ◽  
Volume Ratio ◽  
Lithium Manganese Oxide ◽  
Electrochemical Characteristics ◽  
Oil Emulsion ◽  
Oxide Powders ◽  
Lithium Manganese

Lithium manganese oxide powders (LiMn2O4) with a spinel structure were synthesized via an optimized water-in-oil emulsion process. The influence of the emulsification conditions on the microstructures and physicochemical properties of LiMn2O4 powders was investigated. The phase purity of the synthesized powders significantly depends on the water-to-oil volume ratio in the emulsion. Increasing the water-to-oil ratio tends to decrease the stability of the emulsion that in turn leads to a segregation of water and oil phases. The unstable emulsion system results in the formation of an impure phase—Li2MnO3—that markedly decreases the charge and discharge capacities of the cathode materials. When water/oil volume ratio equals 1/5 or 1/10, monophasic spinel powders are formed at temperatures as low as 400 °C. In addition, decreasing the concentration of the aqueous phase substantially reduces the particle size of LiMn2O4 powders. Nanometered-LiMn2O4 powders with a particle size of 50 nm are obtained when the concentration of the aqueous phase is 1.0 M and the water-to-oil volume ratio is 1/5. Decreasing the particle size of LiMn2O4 powders was demonstrated to effectively increase the specific capacity and improve the cyclability of LiMn2O4 powders.

scholarly journals The influence of different Si : C ratios on the electrochemical performance of silicon/carbon layered film anodes for lithium-ion batteries

RSC Advances ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 6660-6666 ◽  
Author(s):  
Jun Wang ◽  
Shengli Li ◽  
Yi Zhao ◽  
Juan Shi ◽  
Lili Lv ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Anode Materials ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Lithium Ions ◽  
High Specific Capacity ◽  
Silicon Carbon ◽  
Silicon Based

With a high specific capacity (4200 mA h g−1), silicon based materials have become the most promising anode materials in lithium-ions batteries.

Controlling the Voltage Window for Improved Cycling Performance of SnO2 as Anode Material for Lithium-Ion Batteries

2020 ◽  
Vol 20 (11) ◽  
pp. 7051-7056
Author(s):  
Jungwon Heo ◽  
Anupriya K. Haridas ◽  
Xueying Li ◽  
Rakesh Saroha ◽  
Younki Lee ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Material ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Oxide Materials ◽  
Capacity Fading ◽  
Lithium Ions ◽  
Volume Variation ◽  
Capacity Decay

Transition metal oxide materials with high theoretical capacities have been studied as substitutes for commercial graphite in lithiumion batteries. Among these, SnO2 is a promising alloying reaction-based anode material. However, the problem of rapid capacity fading in SnO2 due to volume variation during the alloying/dealloying processes must be solved. The lithiation of SnO2 results in the formation of a Li2O matrix. Herein, the volume variation of SnO2 was suppressed by controlling the voltage window to 1 V to prevent the delithiation reaction between Li2O and Sn. Using this strategy the unreacted Li2O matrix was enriched with metallic Sn particles, thereby providing a pathway for lithium ions. The specific capacity decay in the voltage window of 0.05–3 V was 1.8% per cycle. However, the specific capacity decay was improved to 0.04% per cycle after the voltage window was restricted (in the range of 0.05–1 V). This strategy resulted in a specific capacity of 374.7 mAh g−1 at 0.1 C after 40 cycles for the SnO2 anode.

scholarly journals ZnFe2O4, a Green and High-Capacity Anode Material for Lithium-Ion Batteries: A Review

2021 ◽  
Vol 11 (24) ◽  
pp. 11713
Author(s):  
Marcella Bini ◽  
Marco Ambrosetti ◽  
Daniele Spada
Keyword(s):  
Lithium Ion Batteries ◽  
Broad Class ◽  
High Surface ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Rate Capability ◽  
Volume Ratio ◽  
Lithium Ion ◽  
Structural Features ◽  
Synthesis Methods

Ferrites, a broad class of ceramic oxides, possess intriguing physico-chemical properties, mainly due to their unique structural features, that, during these last 50–60 years, made them the materials of choice for many different applications. They are, indeed, applied as inductors, high-frequency materials, for electric field suppression, as catalysts and sensors, in nanomedicine for magneto-fluid hyperthermia and magnetic resonance imaging, and, more recently, in electrochemistry. In particular, ZnFe2O4 and its solid solutions are drawing scientists’ attention for the application as anode materials for lithium-ion batteries (LIBs). The main reasons are found in the low cost, abundance, and environmental friendliness of both Zn and Fe precursors, high surface-to-volume ratio, relatively short path for Li-ion diffusion, low working voltage of about 1.5 V for lithium extraction, and the high theoretical specific capacity (1072 mA h g−1). However, some drawbacks are represented by fast capacity fading and poor rate capability, resulting from a low electronic conductivity, severe agglomeration, and large volume change during lithiation/delithiation processes. In this review, the main synthesis methods of spinels will be briefly discussed before presenting the most recent and promising electrochemical results on ZnFe2O4 obtained with peculiar morphologies/architectures or as composites, which represent the focus of this review.

scholarly journals Solvents Adjusted Pure Phase CoCO3 as Anodes for High Cycle Stability

2020 ◽  
Author(s):  
Liming Liu ◽  
X.X. Huang ◽  
Zengyan Wei ◽  
Xiaoming Duan ◽  
Bo Zhong ◽  
...  
Keyword(s):  
Particle Size ◽  
High Current Density ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Cycle Performance ◽  
Electrochemical Characteristics ◽  
Cycle Stability ◽  
Pure Phase ◽  
Small Primary ◽  
High Theoretical Capacity

Abstract CoCO3 with high theoretical capacity has been considered as a candidate anode for the next generation of lithium-ion batteries. However, the electrochemical characteristics of CoCO3 itself, especially the cycle stability under high current density, hindering its application. Herein, pure phase CoCO3 particles with different particle and pore sizes were prepared by adjusting the solvents. CoCO3 synthesized with diethylene glycol (DG-CC) as the reaction solvent shows the best electrochemical performance for the particle size of about 0.85 µm, which because the small primary particle size within and the mesopores maintain the structural stability. A high specific capacity of after 1000 cycles was achieved, and an excellent capacity retention was presented. The capacity provided by different electrochemical reactions and the impedance of DG-CC under different cycles were further compared. Those results provide an important reference for the structural design and stable cycle performance of pure CoCO3.

scholarly journals Hydrothermal Synthesis of Cellulose-Derived Carbon Nanospheres from Corn Straw as Anode Materials for Lithium ion Batteries

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 93 ◽  
Author(s):  
Kaifeng Yu ◽  
Jingjing Wang ◽  
Kexian Song ◽  
Xiaofeng Wang ◽  
Ce Liang ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Materials ◽  
Structural Damage ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Hydrothermal Carbonization ◽  
Corn Straw ◽  
Carbon Nanospheres ◽  
Transport Pathway ◽  
Lithium Ions

As a most attractive renewable resource, biomass has the advantages of low pollution, wide distribution and abundant resources, promoting its applications in lithium ion batteries (LIBs). Herein, cellulose-derived carbon nanospheres (CCS) were successfully synthesized by hydrothermal carbonization (HTC) from corn straw for use as an anode in LIBs. The uniform distribution and cross-linked structure of carbon nanospheres were obtained by carefully controlling reaction time, which could not only decrease the transport pathway of lithium ions, but also reduce the structural damage caused by the intercalation of lithium ions. Especially, obtained after hydrothermal carbonization for 36 h, those typical characteristics make it deliver excellent cycling stability as well as the notable specific capacity of 577 mA h g−1 after 100 cycles at 0.2C. Hence, this efficient and environment-friendly method for the fabrication of CCS from corn straw could realize the secondary utilization of biomass waste, as well as serve as a new choice for LIBs anode materials.

Carbonaceous Materials Containing Silicon as Anodes for Lithium-Ion Cells

1995 ◽  
Vol 393 ◽  
Author(s):  
A.M. Wilsons ◽  
J.R. Dahn ◽  
J.S. Xue ◽  
Y. Gao ◽  
X.H. Feng
Keyword(s):  
Anode Materials ◽  
Vapour Deposition ◽  
Specific Capacity ◽  
Chemical Vapour ◽  
Lithium Ion ◽  
Electrochemical Cells ◽  
Rechargeable Lithium Batteries ◽  
Lithium Ions ◽  
Lithium Ion Cells ◽  
Li Ion

ABSTRACTGraphite and pregraphitic carbons capable of reversibly reacting with lithium ions are hosts commonly used in Li-ion cells. As a continuation of previous work, we have used chemical vapour deposition of benzene and silicon-containing precursors to prepare carbons containing nanodispersed silicon. The silicon resides within the unorganized regions in the pregraphitic carbons. These materials reversibly react with lithium in electrochemical cells and the reversible specific capacity has been known to increase from -300 mAhg−1, in the absence of silicon, to near 500 mAhg−1 as silicon is added. We also report on Si-O-C materials which have been shown to reversibly react with Li in electrochemical cells with reversible specific capacities as high as 770mAhg−1. These materials have been made by thermal pyrolysis of siloxane polymers and epoxy-silane composites prepared from hardened mixtures of epoxy novolac resin and epoxy-functional silane. These materials all show promise for use as anode materials in advanced rechargeable lithium batteries.

Controlled Crystallization Synthesis of Porous FePO4·3H2O Micro-Spheres for Fabricating High Performance LiFePO4/C Cathode Materials

2011 ◽  
Vol 399-401 ◽  
pp. 1510-1514
Author(s):  
Wen Kui Zhang ◽  
Hui Juan Zeng ◽  
Yang Xia ◽  
Ling Chao Qian ◽  
Bin Zhao ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Cathode Materials ◽  
High Performance ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Crystallization Method ◽  
Initial Discharge ◽  
Controlled Crystallization

Amorphous porous FePO4·3H2O micro-spheres were synthesized via a controlled crystallization method. These micro-spheres have a particle size distribution from 10 to 28 μm. There are larger numbers of pores on the surface of FePO4·3H2O microspheres, which are important to synthesize high performance LiFePO4 cathode materials for the application of lithium ion battery. The electrochemical properties of the LiFePO4/C electrode, preparing by using the above porous spherical FePO4·3H2O particles, were measured. The electrochemical results show that the obtained LiFePO4/C has a high initial discharge specific capacity of 141.4 mAhg-1 and good cycling performance at 0.5 C. The microstructural and electrochemical analyses indicate that this porous spherical FePO4·3H2O is a fascinating precursor for preparing LiFePO4/C cathode materials.

The Preparation Of PLGA-PLL-Peg Nanoparticles Simultaneously Loaded With Daunorubicin and Tetrandrine By Modified Double-Emulsion Method

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4918-4918
Author(s):  
Ran Liu ◽  
Yonglu Wang ◽  
Liyao Wang ◽  
Jian Cheng ◽  
Guohua Xia ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Aqueous Phase ◽  
Conflicts Of Interest ◽  
Double Emulsion ◽  
Volume Ratio ◽  
Processing Parameters ◽  
Diffusion Method ◽  
Transmission Electron ◽  
Efficient Delivery

Abstract A functional polymer composed of PLGA, PLL and PEG was synthesized, which was used as carrier material for fabricating drug delivery system of nanoparticles. PLGA-PLL-PEG nanoparticles simultaneously loaded with daunorubicin (DNR) and tetrandrine (Tet) were prepared in order to inhibit MDR activity and enhance the antitumor activity of DNR. A modified double-emulsion solvent evaporation/diffusion method was used to increase the incorporation of DNR (hydrophilic) and Tet (hydrophobic) into PLGA-PLL-PEG nanoparticles (NPs). The influence of various processing parameters on particle size and drug loadings were investigated systematically, such as the molecular weight, such as the molecular weight and concentration of PLGA-PLL-PEG, volume ratio of acetone to dichloromethane, PVA concentration in the external aqueous phase, the volume ratio of internal aqueous phase to external aqueous phase and the surfactants of internal aqueous phase. The particle size of the nanoparticles produced by optimized formulation and preparation was 213.0±12 nm (n = 3) with low polydispersity index (0.075 ± 0.023, n = 3). Transmission electron microscopy (TEM) examination showed that the morphology of the prepared nanoparticles was spherical in shape with a smooth surface. The drug loadings were 3.63±0.15% for DNR and 4.27±0.13% for Tet (n = 3). The entrapment efficiencies were 70.23±1.91% for DNR and 86.5±0.7% for Tet (n = 3). The release of DNR and Tet were sustained over one week. The PLGA-PLL-PEG-NPs formulation was potentially useful for hydrophilic and hydrophobic drugs that require efficient delivery to cancer cells. Disclosures: No relevant conflicts of interest to declare.

Preparation of Chitosan Nanospheres by Miniemulsion Crosslinking Method

2015 ◽  
Vol 1094 ◽  
pp. 68-71
Author(s):  
Qing Shan Liu ◽  
Qing Fang Yan ◽  
Xiao Ying Yin
Keyword(s):  
Particle Size ◽  
Acetic Acid ◽  
Acid Solution ◽  
Size Distribution ◽  
Aqueous Phase ◽  
Acetic Acid Solution ◽  
Volume Ratio ◽  
Preparation Condition ◽  
Paraffin Liquid

Objective To obtain immobilized nanomaterials with good performance, the preparation condition of chitosan nanospheres by miniemulsion crosslinking method was optimized. Methods The chitosan nanospheres were synthesized by miniemulsion crosslinking method with Span80 and Tween80 as the emulsifier, glutaraldehyde as the crosslinker, n-hexane and paraffin liquid as oil phase,chitosan acetic acid solution as aqueous phase. The particle size was measured by Zetasizer nanoanalyzer. Results The results of the univariate tests show that the optimal preparation condition of chitosan nanospheres can be obtained when water/oil volume ratio is 3:2. The size distribution of chitosan nanospheres is 18.17nm to 190.1nm. Conclusion The chitosan nanospheres by miniemulsion crosslinking method are suitable materials as enzymes and proteins immobilized carrier.

Sign in / Sign up

Export Citation Format

Share Document