Lithium battery thermal runaway early warning and automatic control method

Abstract

The invention provides a lithium battery thermal runaway early warning and automatic control method, which is characterized by, to begin with, establishing a mathematic model for judging lithium battery thermal runaway development process by utilizing environmental data; then, collecting environmental data of a lithium battery in real time by utilizing a plurality of sensors, and carrying out on-line analysis on change of the collected multiple environmental data with reference to the established mathematic model to judge lithium battery thermal runaway occurrence risk or thermal runaway; and once thermal runaway causes fire, a fire control device is automatically and immediately started to control expansion of the thermal runaway, thereby reducing thermal runaway risk to the lowest degree, and preventing serious safety accidents of an electric automobile to the maximum degree.

Description

technical field [0001] The invention relates to the technical fields of lithium batteries, lithium battery energy storage, and electric vehicles, in particular to an early warning and automatic control method for thermal runaway of lithium batteries. Background technique [0002] The lithium battery described in the present invention refers to the general designation of lithium metal battery and lithium ion battery, especially the lithium alloy metal oxide widely used at present is a high-performance lithium ion battery with positive electrode material, including ternary materials, lithium iron phosphate and other lithium ion batteries. Battery. Lithium battery cells have limited energy. In actual use, they are often connected in series and parallel to form a battery pack, which is packaged in a battery box and used as a power battery as a whole. [0003] With the rapid development of lithium battery energy storage, especially the practical application of lithium batteries ...

AI Technical Summary

Problems solved by technology

[0004] Invention Patent Application No. 201310302644.1 provides an automatic fire extinguishing method for electric vehicles using a flame detector to detect and ignite a gas fire extinguishing device. This method relies on the flame detector to detect the fire in the battery box, and cannot warn of the occurrence of thermal runaway of the battery. The fire extinguishing can only be started when the thermal runaway of the battery causes serious consequences of open flame burning; the fire extinguishing gas is nitrogen, and the efficiency of extinguishing the fire caused by the thermal runaway of the battery is not high; the fire extinguishing gas generator is installed outside the battery box and passes through the outlet of the gas generator Connected with the battery box, the structure is complex, destroying the overall structure and sealing of the battery box

Invention patent application number 201510285595.4 provides a thermal runaway alarm method for power battery packs based on the battery management system, mainly through setting the temperature threshold to warn of thermal runaway events. Depending on the location and environment where the temperature sensor is installed, it is difficult to quickly and accurately provide a reliable early warning of thermal runaway. Only using a fixed threshold to judge is often affected by environmental factors, resulting in misjudgment or missed judgment.

Invention patent application number 201610060396.8 discloses a method of monitoring temperature changes in different temperature stages to judge the thermal runaway of a single battery. This method requires real-time detection of the temperature of each single battery. The economy and practicability of the power battery box composed of batteries are very low; secondly, this method uses a fixed temperature change rate threshold and temperature range as the basis for judgment, and can only warn of heat for specific types of batteries and specific laboratory environments. For the occurrence of runaway, accurate judgment cannot be guaranteed for different types of batteries, and in practical applications, it will be affected by environmental factors and cause misjudgment or missed judgment

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