A method and device for analyzing gas production rate of lithium battery under thermal runaway

Abstract

The invention discloses a method and a device for analyzing the gas production rate of a lithium battery under thermal runaway. The method includes: putting a single battery core with a cut top cover into a heating device for heating, and collecting pressure information and temperature information; Based on the state change of the body cell with the temperature, the self-exothermic start temperature of the single cell and the critical point temperature of thermal runaway are obtained; during the period from the start of the single cell to the self-exothermic start temperature, the heating value is calculated. The relationship between the vapor pressure and temperature of the electrolyte in the device; during the time period from the self-exothermic start temperature of the single cell to the critical point temperature of thermal runaway, the relationship between the pressure and temperature caused by gas production is calculated according to the vapor pressure of the electrolyte ; According to the relationship between the pressure and temperature caused by gas production, the relationship between the gas production rate and temperature of the single cell is calculated; the gas production process is analyzed by adding the electrolyte vapor pressure, and the gas production rate of the single cell is more accurate, which is lithium Battery thermal runaway warning provides more accurate theoretical guidance.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to an analysis method and a device thereof for the gas production rate of a lithium battery under thermal runaway. Background technique [0002] In recent years, with the increasingly serious environmental problems and the gradual depletion of non-renewable energy sources such as petroleum, human demand for new energy vehicles is increasing. Because lithium-ion batteries have the advantages of high energy density, high output power, long service life, low self-discharge rate, wide operating temperature range, green and pollution-free, they are widely used in new energy vehicles. However, in recent years, thermal runaway accidents of electric vehicle battery systems have emerged one after another, endangering people's lives and property, and at the same time hitting people's confidence in electric vehicles. [0003] During the thermal runaway of lithium-ion batteries, a series of ...

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Problems solved by technology

[0005] The invention provides an analysis method and device for the gas production rate of lithium batteries under thermal runaway, in order to solve the problem in the prior art that the calculation accuracy of the battery gas production rate is not high

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