Method for testing pore closing temperature of diaphragm

Abstract

The invention discloses a method for testing the pore closing temperature of a diaphragm. The method comprises the following steps: preparing a first standard diaphragm, a second standard diaphragm, athird standard diaphragm, standard green adhesive tapes, a standard copper foil and a standard aluminum-plastic film, wherein the middle of the standard green plastic adhesive is provided with a circular hole with a preset diameter; respectively pasting one to five layers of the first standard diaphragm to one of the standard green adhesive tapes to obtain a first target diaphragm; respectively pasting one to five second standard diaphragms to one of the standard green adhesive tapes to obtain a second target diaphragm; respectively pasting one to five layers of the third standard diaphragm to one of the standard green adhesive tapes to obtain a third target diaphragm; sequentially assembling the first target diaphragm, the second target diaphragm, the third target diaphragm, the standardcopper foil, the standard aluminum-plastic film and a preset battery to obtain a corresponding flexibly packed battery; and measuring impedance of the flexibly packed battery by adopting an electrochemical workstation, linearly fitting the ohmic impedance value and the diaphragm layer number, and calculating the ion conductivity of the diaphragm to obtain the catastrophe point of the ion conductivity of the diaphragm, that is the corresponding pore closing temperature of the diaphragm.

Description

technical field [0001] The invention relates to the technical field of diaphragm closed cell temperature testing, in particular to a diaphragm closed cell temperature test method. Background technique [0002] Lithium-ion batteries have the advantages of high specific energy, high working voltage, no memory effect, long cycle life, and less environmental pollution. With the widespread application of lithium-ion batteries, the safety of batteries has received more and more attention. At present, the safety of lithium-ion batteries is still one of the key issues hindering their large-scale application in electric vehicles, energy storage and other fields. In unexpected situations, lithium-ion batteries may catch fire and explode, causing great personal injury and property loss. [0003] The battery is mainly composed of positive electrode material, negative electrode material, electrolyte and separator. The separator is an important part of the battery. The separator is main...

AI Technical Summary

Problems solved by technology

These test methods are to heat the diaphragm after adding the electrolyte. Because the closed cell temperature of the diaphragm is about 130°C-150°C, the electrolyte will volatilize and decompose during the process of heating to the target temperature. It will cause the resistance to increase, which will have a great impact on the test results

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