Effect of additives on wettability, thermal stability and electrochemical properties of γ-Al2O3-coating separator for lithium-ion batteries

2021 ◽  
pp. 1-15
Author(s):  
Ji Yan ◽  
Zhen Li ◽  
Min-Yun Wang ◽  
Kezheng Gao ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electrochemical Properties ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Thermal Shrinkage ◽  
Al2o3 Coating ◽  
Effect Of Additives ◽  
Electrolyte Uptake ◽  
Superior Cycling Stability ◽  
Battery Application

Abstract Physical properties of separator, as important parameters in affecting electrochemical performance and safety of lithium ion batteries, should be paid more attention. In this study, three kinds of surfactants and dispersants were adopted to investigate their effects on thermal stability, wettability and electrochemical properties of γ-Al2O3 coating polyethylene-based separator. The experimental results showed that with the synergistic helpfulness of PEG-2000 as surfactant and D-067 as dispersant, γ-Al2O3 coating polyethylene separator demonstrates superior thermal stability (no significant thermal shrinkage after heating at 120°C), electrolyte uptake ability and improved wettability (contact angle of 27.9°). Based on further testing results in Li//MCMB coin cells, the cell with γ-Al2O3 coating polyethylene separator exhibits higher capacity and superior cycling stability than other two bare counterparts separators at room temperature after 200 cycles. These results demonstrate that the as-prepared separator is highly promising for lithium ion battery application with the help of suitable surfactant and dispersant.

scholarly journals The Effect of Different Ratios of Malonic Acid to Plyvinylalcohol on Electrochemical and Mechanical Properties of Polyacrylonitrile Electrospun Separators in Lithium-Ion Batteries

2021 ◽  
Author(s):  
Fartash Khodaverdi ◽  
Mehran Javanbakht ◽  
Ali Vaziri ◽  
Mehdi Jahanfar
Keyword(s):  
Lithium Ion Batteries ◽  
Malonic Acid ◽  
Lithium Ion ◽  
Thermal Shrinkage ◽  
Performance Tests ◽  
Optimum Ratio ◽  
A Value ◽  
Electrolyte Uptake ◽  
Hydrophilic Materials ◽  
Modified Separator

The present study aimed to investigate the mechanical, thermal, and electrochemical properties of Polyacrylonitrile (PAN) electrospun separators in the presence of Polyvinylalcohol (PVA) hydrophilic materials and Malonic Acid (MA) crosslinker inside the lithium-ion batteries. The results showed that the M3 modified separator with the MA to PVA+MA (wt./wt.) optimum ratio of 37.5 % had the best performance in all tests. This separator had a value of 3.16 mS/cm in the ion conductivity test. Additionally, it had an electrolyte uptake of 1172 % (2.39 times more than the neat PAN separator) and thermal shrinkage of 7.4 % at 180 °C, where this value was 14.5 % for neat PAN separator at the same experimental condition. Furthermore, the acceptable performance in the battery performance tests was compared with other separators.

scholarly journals Design of A High Performance Zeolite/Polyimide Composite Separator for Lithium-Ion Batteries

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 764 ◽  
Author(s):  
Yanling Li ◽  
Xiang Wang ◽  
Jianyu Liang ◽  
Kuan Wu ◽  
Long Xu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Lithium Ion Batteries ◽  
Phase Inversion ◽  
High Performance ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cycle Performance ◽  
Electrolyte Uptake ◽  
Composite Separator ◽  
Free Transport

A zeolite/polyimide composite separator with a spongy-like structure was prepared by phase inversion methods based on heat-resistant polyimide (PI) polymer matrix and ZSM-5 zeolite filler, with the aim to improve the thermal stability and electrochemical properties of corresponding batteries. The separator exhibits enhanced thermal stability and no shrinkage up to 180 °C. The introduction of a certain number of ZSM-5 zeolites endows the composite separator with enhanced wettability and electrolyte uptake, better facilitating the free transport of lithium-ion. Furthermore, the composite separator shows a high ionic conductivity of 1.04 mS cm−1 at 25 °C, and a high decomposition potential of 4.7 V. Compared with the PP separator and pristine PI separator, the ZSM-5/PI composite separator based LiFePO4/Li cells have better rate capability (133 mAh g−1 at 2 C) and cycle performance (145 mAh g-1 at 0.5 C after 50 cycles). These results demonstrate that the ZSM-5/PI composite separator is promising for high-performance and high-safety lithium-ion batteries.

PEI-SiO2 composite membranes with high thermal stability: Synthesis by self-assembled in situ growth and application in lithium-ion batteries

2020 ◽  
pp. 095400832096455
Author(s):  
Wei Song ◽  
Weiwei Cui ◽  
Xu Wang ◽  
Zeyu Lin ◽  
Wei Deng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Lithium Ion Batteries ◽  
Composite Membrane ◽  
Retention Rate ◽  
Lithium Ion ◽  
Composite Membranes ◽  
High Porosity ◽  
Electrolyte Uptake ◽  
Electrochemical Window

To improve the safety of lithium-ion batteries (LIBs), a polyether amide–silica (PEI-SiO2) composite membrane was developed by the in situ hydrolysis of tetraethylorthosilicate (TEOS) and its subsequent self-assembly on the surface of PEI fibers. Because of the presence of the SiO2 shell, the PEI-SiO2 composite membrane exhibited good thermal stability at high temperatures. The composite membrane did not change its color and size after heating at 200°C for 1 h as well as exhibited excellent flame retardancy. Moreover, the membrane maintained its high porosity even after the introduction of shell layers. The electrolyte is completely absorbed in the membrane within 0.5 s. The electrolyte uptake was up to 625%, and the ionic conductivity was up to 1.9 mS/cm at room temperature. Compared to the polyolefin membrane and the pure PEI membrane, the PEI-SiO2 composite membrane showed higher electrochemical stability, with an electrochemical window of up to 5.5 V. The battery assembled with the composite membrane showed excellent cycle stability, and the capacity retention rate was as high as 98.6% after 50 cycles. The LIBs based on the PEI-SiO2 composite membrane exhibited safe operation and high electrochemical performance, thus highlighting the applicability of the composite membrane in high-power batteries.

Thermal Stability and Electrochemical Properties of Fluorine Compounds as Nonflammable Solvents for Lithium-Ion Batteries

2010 ◽  
Vol 157 (6) ◽  
pp. A707 ◽  
Author(s):  
Takashi Achiha ◽  
Tsuyoshi Nakajima ◽  
Yoshimi Ohzawa ◽  
Meiten Koh ◽  
Akiyoshi Yamauchi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electrochemical Properties ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Fluorine Compounds

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 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.

Composite Nanofiber Membrane for Lithium-Ion Batteries Prepared by Electrostatic Spun/Spray Deposition

2016 ◽  
Vol 13 (1) ◽  
Author(s):  
Bin Yu ◽  
Xiao-Ming Zhao ◽  
Xiao-Ning Jiao ◽  
Dong-Yue Qi
Keyword(s):  
Lithium Ion Batteries ◽  
Vinylidene Fluoride ◽  
Spray Deposition ◽  
Lithium Ion ◽  
Cycle Performance ◽  
Thermal Shrinkage ◽  
Electrostatic Spray Deposition ◽  
Electrolyte Uptake ◽  
Poly Vinylidene Fluoride ◽  
Electrostatic Spray

A new kind of sandwiched composite membrane (SCM) for lithium-ion batteries is prepared by depositing zirconia microparticle between two layers of electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) nanofibers by electrostatic spray deposition. The thermal shrinkage, electrochemical properties of the separator, and cycle performance for batteries with the SCM were investigated. The results show that the SCM has a high electrolyte uptake and easily absorbs electrolyte to form gelled polymer electrolytes (GPEs). The SCM GPEs have a high ionic conductivity of up to 2.06 × 10−3 S cm−1 at room temperature and show a high electrochemical stability potential of 5.4 V. With LiCoCO2 as cathode, the cell with SCM GPEs exhibits a high initial discharge capacity of 149.7 mAh g−1.

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