scholarly journals Analysis of Thermal–Mechanical Properties of Silicon Dioxide/Polyvinylidene Fluoride Reinforced Non-Woven Fabric (Polypropylene) Composites

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 481 ◽  
Author(s):  
Fangyun Kong ◽  
Mengzhou Chang ◽  
Zhenqing Wang
Keyword(s):  
Thermal Stability ◽  
Silicon Dioxide ◽  
Composite Film ◽  
Polyvinylidene Fluoride ◽  
Lithium Ion ◽  
Woven Fabric ◽  
Thermal Shrinkage ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Good Thermal Stability

In this paper, solution casting method is used to prepare the PP (polypropylene) non-woven fabric based composite film filled with silicon dioxide/polyvinylidene fluoride (SiO2/PVDF). The mechanical and thermodynamic properties of PP/SiO2/PVDF composites were studied by a uniaxial tensile test under different temperature and combustion experiment. It is found that the stress of PP/SiO2/PVDF composite film with 4 wt % SiO2 is the maximum value, reaching 18.314 MPa, 244.42% higher than that of pure PP non-woven. Meanwhile, the thermal–mechanical coupling tests indicate that with the increase of temperature, the ultimate stress and strain of the composite decrease. At the same time, the thermal shrinkage property of the composite during the heating process is studied. The modified composite has good thermal stability under 180 °C. Scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric (TG) were used to characterize the pore shape, distribution and crystal phase change of the composite. The modified PP/SiO2/PVDF composite film structure shows high strength and good thermal stability, and can better meet the requirements of strength and thermal performance of lithium-ion battery during the charging and discharging process.

scholarly journals Comprehensive Analysis of Mechanical Properties of CB/SiO2/PVDF Composites

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 146
Author(s):  
Fangyun Kong ◽  
Mengzhou Chang ◽  
Zhenqing Wang
Keyword(s):  
Mechanical Properties ◽  
Silicon Dioxide ◽  
Polyvinylidene Fluoride ◽  
Energy Dispersive Spectrometry ◽  
Comprehensive Analysis ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Notch Angle ◽  
Mixing Method ◽  
Pvdf Matrix

Damage is a key problem that limits the application of polymer membranes. In this paper, conductive carbon black (CB) and silicon dioxide (SiO2)-reinforced polyvinylidene fluoride (PVDF) composites were prepared using a solution mixing method. Through a uniaxial tensile test, the fracture and damage characteristics of the material were analyzed. When the structure had inevitable notch damage, changing the notch angle was very helpful for the material to bear more load. In addition, when there were two kinds of fillers in the PVDF matrix at the same time, there was an interaction between particles. The microstructure of the composite was characterized by scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and thermogravimetric (TG) analysis. The experimental results indicate that, when the ratio of CB:SiO2:PVDF was 1:4:95, the general mechanical properties of the composite were the best.

scholarly journals Efficient Synthesis of PVDF/PI Side-by-Side Bicomponent Nanofiber Membrane with Enhanced Mechanical Strength and Good Thermal Stability

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 39 ◽  
Author(s):  
Ming Cai ◽  
Hongwei He ◽  
Xiao Zhang ◽  
Xu Yan ◽  
Jianxin Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Mechanical Strength ◽  
Polyvinylidene Fluoride ◽  
Chemical Structure ◽  
Electrospun Fiber ◽  
Nanofiber Membrane ◽  
Application Range ◽  
Good Thermal Stability ◽  
Filtration Properties

Bicomponent composite fibers, due to their unique versatility, have attracted great attention in many fields, such as filtration, energy, and bioengineering. Herein, we efficiently fabricated polyvinylidene fluoride/polyimide (PVDF/PI) side-by-side bicomponent nanofibers based on electrospinning, which resulted in the synergism between PVDF and PI, and eventually obtained the effect of 1 + 1 > 2. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the morphology and chemical structure of nanofibers, indicating that a large number of side-by-side nanofibers were successfully prepared. Further, the thermal stability, mechanical strength, and filtration properties of PVDF/PI were carefully investigated. The results revealed that the bicomponent nanofibers possessed both good mechanical strength and remarkable thermal stability. Moreover, the mechanical properties of PVDF/ PI were strengthened by more than twice after the heat treatment (7.28 MPa at 25 °C, 15.49 MPa at 230 °C). Simultaneously, after the heat treatment at 230 °C for 30 min, the filtration efficiency of PVDF/PI membrane was maintained at about 95.45 ± 1.09%, and the pressure drop was relatively low. Therefore, the prepared PVDF/PI side-by-side bicomponent nanofibers have a favorable prospect of application in the field of medium- and high-temperature filtration, which further expands the application range of electrospun fiber membranes.

On the Latest Development of some Typical Cathode Materials for Lithium Ion Battery

2018 ◽  
Vol 783 ◽  
pp. 137-143
Author(s):  
Yong Tao Zhang ◽  
Xiao Li Hu
Keyword(s):  
Thermal Stability ◽  
Power Systems ◽  
Cathode Material ◽  
Lithium Ion Battery ◽  
Cathode Materials ◽  
Rate Capability ◽  
Lithium Ion ◽  
Modern Society ◽  
High Rate ◽  
Good Thermal Stability

The lithium-ion battery is widely and increasingly used in many portable electronic devices and high-power systems in the modern society. Currently, it is significant to develop excellent cathode materials to meet stringent standards for batteries. In this paper, recent developments were reviewed for several typical cathode materials with high voltages and good capacities. These cathode materials referred to LiCoO2, LiNiO2, LiMn2O4, LiMPO4 (M=Fe, Mn, Co and Ni, et al), and their composites. The technical bottlenecks about the cathode material is required to be conquered. For instance, LiCoO2 and LiNiO2 have high coulombic capacity and good cycling characteristics, but are costly and exhibit poor thermal stability. Simultaneously, LiMn2O4 exhibit good thermal stability, high voltage and high rate capability, but have low capacity. Thus it is advantageous to produce a composite which shares the benefits of both materials. The composite cathode material is superior over any single electrode material because the former has more balanced performance, and therefore, is promising to manufacture the next generation of batteries.

A facile method for the preparation of a high-performance, hybrid separator for use in lithium-ion batteries

2021 ◽  
pp. 004051752110066
Author(s):  
Pok Yin Wong ◽  
Chunhong Zhu ◽  
Qianyu Wang ◽  
Jian Shi ◽  
Kenji Hyodo ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Lithium Ion Batteries ◽  
High Performance ◽  
Lithium Ion ◽  
Nonwoven Fabric ◽  
Liquid Electrolyte ◽  
Thermal Shrinkage ◽  
Homogeneous Distribution ◽  
Dimensional Shape ◽  
The Difference

Polyethylene (PE) membrane has poor wettability and poor thermal stability, which results in insufficient wetting by liquid electrolytes, thermal shrinkage, and no guarantee of safety. In addition, polyethylene terephthalate (PET) nonwoven fabric has inhomogeneous pores and no shutdown function. Therefore, it may cause some problems for independent use, either in the assembly or in usage. In this study, a hybrid separator used in lithium-ion batteries was investigated. The separator was fabricated by laminating a PE membrane and PET nonwoven fabric with or without a ceramic coating on the PET nonwoven. The morphology, wettability, thermal stability, and battery performance were evaluated, and the results showed that the homogeneous distribution of pores can be obtained from the hybrid separators. The wettability properties were also improved in terms of contact angle, liquid electrolyte absorption height, and the decrease in the spreading area. Moreover, with laminated PET nonwoven fabric, the hybrid separators kept the dimensional shape at 180°C for 1 hour of heating, but the PE membrane shrank and became a small wad. The difference between the shutdown and meltdown temperatures ensured that the battery was safe to use. In addition, the evaluation of the battery’s performance indicated that the hybrid separators can be used instead of a PE membrane. This study showed a facile method for the preparation of a hybrid composite separator with improved wettability, thermal stability, and safety for lithium-ion batteries, and it has the potential to be used extensively in the future.

scholarly journals On the Solubility and Stability of Polyvinylidene Fluoride

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1354
Author(s):  
Jean E. Marshall ◽  
Anna Zhenova ◽  
Samuel Roberts ◽  
Tabitha Petchey ◽  
Pengcheng Zhu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Dielectric Constant ◽  
Circular Economy ◽  
Polyvinylidene Fluoride ◽  
High Dielectric Constant ◽  
Widespread Application ◽  
Good Thermal Stability ◽  
Carbon Backbone ◽  
Crystal Phases ◽  
High Dielectric

This literature review covers the solubility and processability of fluoropolymer polyvinylidine fluoride (PVDF). Fluoropolymers consist of a carbon backbone chain with multiple connected C–F bonds; they are typically nonreactive and nontoxic and have good thermal stability. Their processing, recycling and reuse are rapidly becoming more important to the circular economy as fluoropolymers find widespread application in diverse sectors including construction, automotive engineering and electronics. The partially fluorinated polymer PVDF is in strong demand in all of these areas; in addition to its desirable inertness, which is typical of most fluoropolymers, it also has a high dielectric constant and can be ferroelectric in some of its crystal phases. However, processing and reusing PVDF is a challenging task, and this is partly due to its limited solubility. This review begins with a discussion on the useful properties and applications of PVDF, followed by a discussion on the known solvents and diluents of PVDF and how it can be formed into membranes. Finally, we explore the limitations of PVDF’s chemical and thermal stability, with a discussion on conditions under which it can degrade. Our aim is to provide a condensed overview that will be of use to both chemists and engineers who need to work with PVDF.

scholarly journals A Novel Electrospinning Polyacrylonitrile Separator with Dip-Coating of Zeolite and Phenoxy Resin for Li-ion Batteries

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 267
Author(s):  
Danxia Chen ◽  
Xiang Wang ◽  
Jianyu Liang ◽  
Ze Zhang ◽  
Weiping Chen
Keyword(s):  
Thermal Stability ◽  
Ionic Conductivity ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Dip Coating ◽  
High Rate ◽  
Great Promise ◽  
Good Thermal Stability ◽  
Electrolyte Uptake

Commercial separators (polyolefin separators) for lithium-ion batteries still have defects such as low thermostability and inferior interface compatibility, which result in serious potential safety distress and poor electrochemical performance. Zeolite/Polyacrylonitrile (Z/PAN) composite separators have been fabricated by electrospinning a polyacrylonitrile (PAN) membrane and then dip-coating it with zeolite (ZSM-5). Different from commercial separators, the Z/PAN composite separators exhibit high electrolyte uptake, excellent ionic conductivity, and prominent thermal stability. Specifically, the Z/PAN-1.5 separator exhibits the best performance, with a high electrolyte uptake of 308.1% and an excellent ionic conductivity of 2.158 mS·cm−1. The Z/PAN-1.5 separator may mechanically shrink less than 10% when held at 180 °C for 30 min, proving good thermal stability. Compared with the pristine PAN separator, the Li/separator/LiFePO4 cells with the Z/PAN-1.5 composite separator have excellent high-rate discharge capacity (102.2 mAh·g−1 at 7 C) and favorable cycling performance (144.9 mAh·g−1 at 0.5 C after 100 cycles). Obviously, the Z/PAN-1.5 separator holds great promise in furthering the safety and performance of lithium-ion batteries.

scholarly journals Physical chemical and electrochemical study of the electrolyte based on bis(trifluoromethanesulfonyl)imidur 1-(2,2,2-trifluoroethyl)-3-methylimidazolium

2016 ◽  
Vol 19 (4) ◽  
pp. 167-176
Author(s):  
Phung My Loan Le ◽  
Khanh Hoang Phuong Ngo ◽  
Thanh Duy Vo ◽  
Man Van Tran
Keyword(s):  
Thermal Stability ◽  
Ionic Liquid ◽  
Organic Solvent ◽  
Lithium Ion ◽  
Ultrasound Irradiation ◽  
High Viscosity ◽  
Good Thermal Stability ◽  
Degradation Temperature ◽  
Physico Chemical ◽  
Electrochemical Window

In seeking the electrolyte replacing the conventional electrolyte based on organic solvent, bis(trifluoromethanesulfonyl)imidur-1-(2,2,2-trifluoroethyl)-3-methylimidazolium ionic liquid was studied for using as electrolyte in lithium batteries. Bis(trifluoromethanesulfonyl)-imidur-1-(2,2,2-trifluoroethyl)-3-methylimidazo-lium was synthesized via tosylate 2,2,2-trifluoroethyl by using microwave or ultrasound irradiation. The physico-chemical and electrochemical properties including melting temperature (Tm), degradation temperature (Td), density, viscosity, ionic conductivity and electrochemical window of synthesized ILs were characterized and compared to those of commercial electrolyte and electrolytes based on imidazolium and ammonium cations. Bis(trifluoromethanesulfonyl)imidur-1-(2,2,2-trifluoroethyl)-3-methylimidazolium exhibited good thermal stability, excellent electrochemical stability in comparing to the commercial electrolyte and ammonium cation based ILs. However, the high viscosity of ILs is still an obstacle for lithium-ion batteries application. Thus, the addition with small amount of organic solvent is able to improve the viscosity, the cycling behavior without destroying the non-volatility and thermal stability of the ionic liquid.

To enhance the capacity of Li-rich layered oxides by surface modification with metal–organic frameworks (MOFs) as cathodes for advanced lithium-ion batteries

2016 ◽  
Vol 4 (12) ◽  
pp. 4440-4447 ◽  
Author(s):  
Qi-Qi Qiao ◽  
Guo-Ran Li ◽  
Yong-Long Wang ◽  
Xue-Ping Gao
Keyword(s):  
Thermal Stability ◽  
Surface Modification ◽  
Lithium Ion Batteries ◽  
Discharge Capacity ◽  
Metal Organic Frameworks ◽  
Lithium Ion ◽  
Layered Oxides ◽  
Good Thermal Stability ◽  
Metal Organic ◽  
Large Discharge

A Li-rich layered oxide, modified with Mn-based metal–organic frameworks (MOFs), shows a large discharge capacity, and good thermal stability as a cathode for lithium ion batteries.

Ethyl cyanoacrylate reinforced polyvinylidene fluoride separators for robust lithium ion batteries

2021 ◽  
Author(s):  
Mengqiu Yang ◽  
Yuanpeng Liu ◽  
Botao Yuan ◽  
Zhaoxu Guang ◽  
Jipeng Liu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Polyvinylidene Fluoride ◽  
Lithium Ion ◽  
High Thermal Stability ◽  
Li Ion Batteries ◽  
High Mechanical Strength ◽  
Key Characteristics ◽  
Li Ion ◽  
Composite Separator ◽  
Ethyl Cyanoacrylate

Ideal separators of Li-ion batteries should own key characteristics simultaneously, including high mechanical strength, high thermal stability and high electrolyte wettability. Herein a composite separator is proposed to realize these...

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