Electrochemical and Safety Performances of Polyimide Nano fiber-based Nonwoven Separators for Li-ion Batteries

Kim, Yeon-Joo; Lee, Sang‐Min; Kim, Seok Hong; Kim, Hyunsoo

doi:10.5229/jecst.2015.6.1.26

Cited by 9 publications

(2 citation statements)

References 22 publications

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“…To improve the safety of the cell, many materials with better thermal stability have been developed, and some operating methods for the battery system have been suggested. Among various components of a cell, the cathode material [5][6][7], anode material [8][9][10], separator [11][12][13], and electrolyte [14][15][16] have been mostly studied. For example, Fergus [5] investigated the safety of different cathode materials and the results show that the safeties of different cathode materials rank as: LiFePO 4 (LFP) > LiMn 2 O 4 (LMO) > LiCoO 2 (LCO) > LiNiO 2 .…”

Section: Introductionmentioning

confidence: 99%

The Evolution of Lithium-Ion Cell Thermal Safety with Aging Examined in a Battery Testing Calorimeter

Zhang

et al. 2016

Batteries

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Abstract:The effect of calendar aging on the thermal safety of 4.6 Ah pouch cells with a LiMn 2 O 4 (LMO) cathode was investigated by a battery test calorimeter (BTC) that can be used to determine the heat evolved during an uncontrolled exothermic runaway reaction. Cells were stored at 55˝C and 100% state of charge (SOC) for accelerated aging, and they were taken out after 10, 20, 40, 68, and 90 days of storage to obtain different aging states. Those cells were then put into the BTC for thermal safety tests. The results show the cell thermal safety improves after aging: (1) the self-heating temperature increases; (2) the thermal runaway temperature increases; and (3) the exothermal rate during the process of thermal runaway decreases. The cell voltage drops to zero about 40˝C earlier than the thermal runaway, indicating the voltage can be used as a signal for cell safety monitoring.

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Section: Introductionmentioning

confidence: 99%

The Evolution of Lithium-Ion Cell Thermal Safety with Aging Examined in a Battery Testing Calorimeter

Zhang

et al. 2016

Batteries

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“…Polyolefin separators have become the most commercialized membranes applied in LIBs owing to their outstanding mechanical properties, low cost, and good electrochemical stability. , However, the polyolefin separators exhibit unsatisfactory dimensional thermostability, electrolyte wettability, and lithium-ion transport efficiency due to the low melting points, inherent nonpolarity, and low porosities, which may lead to safety issues and severely limit the electrochemical performances of LIBs. , To overcome the poor heat resistance of polyolefin separators, separators have been prepared using heat-resistant polymer materials, including polyimide (PI), poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP), and poly(ether ether ketone)(PEEK) . However, the use of a single high-temperature-resistant polymer as a battery separator compared with the composite modified polymer separator often leads to unsatisfied lithium-ion transmission efficiency and electrochemical performance of the battery in long-term use. , The use of high-molecular polymers with excellent performances and other suitable materials as battery separators is considered promising.…”

Section: Introductionmentioning

confidence: 99%

Construction of Diversified Ion Channels in Lithium-Ion Battery Separator Using Polybenzimidazole and Ion-Modified Metal–Organic Framework

Min

Liu

Guo

et al. 2022

ACS Appl. Energy Mater.

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The preparation of separators using heat-resistant polymers is an effective approach to improve the safety of lithium-ion batteries (LIBs). However, separators using a single heat-resistant polymer compared with the composite modified polymer have low conductivities, which leads to low battery performances. In this study, for the first time, a heat-resistant separator was successfully prepared using an ion-modified metal–organic framework (MOF) and poly(aryl ether benzimidazole)(OPBI). Diversified ion channels were constructed by ion modification combined with phase inversion and physical mixing. The lithium-ion transmission efficiency and safety of the LIBs were effectively improved. The hybrid separator exhibited a satisfactory thermal stability (absence of shrinkage at 200 °C for 1 h), higher ionic conductivity (1.46 mS cm–1), and better electrolyte uptake rate. Moreover, the hybrid separator is conducive to inhibiting the growth of Li dendrites. A cell assembled with the hybrid separator delivered a reversible capacity of 157 mA h g–1 at 0.5 C. The capacity retention of the cell was up to 94% after 200 cycles. Thus, the hybrid membrane is a valuable candidate to enhance the safety and electrochemical properties of LIBs.

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Polyimide fibers prepared by a dry‐spinning process: Enhanced mechanical properties of fibers containing biphenyl units

Wang

Dong

et al. 2016

J of Applied Polymer Sci

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Polyimide (PI) fibers with enhanced mechanical properties and high thermal and dimensional stability were prepared via a two-step dry-spinning process through the introduction of 3,3 0 ,4,4 0 -biphenyl tetracarboxylic dianhydride (BPDA) containing biphenyl units into rigid homopolyimide of pyromellitic dianhydride (PMDA) and 4,4 0 -oxydianiline. The attenuated total reflectanceFourier transform infrared spectra results imply that the incorporated BPDA moieties accelerate the imidization process and increase the imidization degree (ID) of the precursor fibers; this was attributed to the increased molecular mobility of the polymer chains. Two-dimensional wide-angle X-ray diffraction spectra indicated that the prepared PI fibers possessed a well-defined crystal structure and polymer chains in the crystalline region were highly oriented along the fiber axis. The PI fiber, with the molar ratio of PMDA/ BPDA being 7/3, showed optimum tensile strength and modulus values of 8.55 and 73.21 cN/dtex, respectively; these were attributed to the high IDs and molecular weights. Meanwhile, the PI fibers showed better dimensional stability than the commercial P84 fiber, and this is beneficial for its security applications.

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Electrochemical and Safety Performances of Polyimide Nano fiber-based Nonwoven Separators for Li-ion Batteries

Cited by 9 publications

References 22 publications

The Evolution of Lithium-Ion Cell Thermal Safety with Aging Examined in a Battery Testing Calorimeter

The Evolution of Lithium-Ion Cell Thermal Safety with Aging Examined in a Battery Testing Calorimeter

Construction of Diversified Ion Channels in Lithium-Ion Battery Separator Using Polybenzimidazole and Ion-Modified Metal–Organic Framework

Polyimide fibers prepared by a dry‐spinning process: Enhanced mechanical properties of fibers containing biphenyl units

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