Strain rate effect and micro-buckling behavior of anisotropy macromolecular separator for lithium-ion battery

Abstract

High tensile strength and good toughness play an important role in improving the mechanical performance of separator films, such as resistance to external force, service life and so on. In the present research, the strain rate effect and microbuckling behavior of two types of anisotropic separators for lithium-ion battery (LIB) under different strain rates are investigated. The results conclude that the anisotropy effect and strain rate effect are displayed obviously along the machine direction (MD), diagonal direction (DD) and transverse direction (TD). The constitutive relationship with a strain rate of anisotropic macromolecular separator for LIB is. The separator has high tensile strength along MD and good toughness along DD and TD. The maximum error of strain rate strengthening coefficient and about the material parameter is less than 15%. Finally, the critical stress σ x,crit =-Ekπ 2 (t/B) 2 /12(1-μ 2) characterizing the micro-buckling behavior of macromolecular separators are proposed and discussed. The critical stress error rates are approximately Error = 2-7% compared with experimental results. This research provides guidance to improve the mechanical property of anisotropic separator and addresses the safety of LIB.

Self-Polymerized Dopamine Nanoparticles Modified Separators for Improving Electrochemical Performance and Enhancing Mechanical Strength of Lithium-Ion Batteries

“…The sample was cut along the perimeter of the template on transparent Cartesian graph paper to improve the dimensional accuracy and cut quality. According to the ASTM D638 tension testing standard [26] for polymer material, a mechanical strength experiment was performed using an electronic universal testing machine (SANS CMT 4104, Shenzhen SANS Test Machine Co., Ltd., Shenzhen, China) with a 500 N load cell (accuracy: 0.005 N) [6]. The two ends of the sample were glued with rubber to prevent sliding and tearing and then they were held by the two flat grips of the testing machine.…”

“…Lithium-ion batteries (LIBs) have been widely used in electrochemical energy conversion and storage for a wide range of applications, including electronic devices, electric vehicles and their energy systems, and so forth, due to their high energy density, long cycle life, zero memory effect, low self-discharge, and environmental friendliness [1][2][3][4][5][6][7]. LIBs mainly consist of positive electrodes, negative electrodes, electrolytes, and macromolecular separators.…”

State of charge estimation of lithium-ion battery based on extended Kalman filter algorithm

“…Establishing the carbon-free alliance and developing new sustainable and high-efficiency energy storage device have become an effective method to come up with the ever-increasing energy problems (Chen et al, 2019;Hao et al, 2020a). The durability and safety are the key factors to ensure the smooth operation of energy storage device (Hao et al, 2020b;Hao et al, 2022;Lane et al, 2020). Lithium-ion battery is a kind of efficient green energy due to their excellent power density, high energy density, low self-discharge, wide temperature range and long lifetime.…”

Coupled Effect of Low Temperature and Electrolyte Immersion on the Tensile Properties of Separators in Lithium-Ion Batteries

“…And there are a large number of studies involved in this field. All kinds of separators were tested to obtain the directionality and strain rate sensitivity of the mechanical properties under different loads. – Separators pretreated with the electrolyte showed different degrees of reduction in the mechanical properties. – The studies related to the temperature showed that the mechanical properties of the separators were affected by high temperatures, which mainly reflected in the tensile strength and elastic modulus. The reason was that the thermal exposure caused irreversible changes in material behavior. , Besides, the effects of temperature fluctuations on the mechanical properties of the separators were verified by multicycle depth-sensitive nanoindentation.…”