Lithium-ion Battery Fire Protection And Thermal Runaway Prevention System

By Author: Dan Thompson
Total Articles: 9
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Introduction
The main function of thermal runaway prevention is to prevent the thermal runaway of lithium-ion batteries during normal operation, charging and discharging.
In order to effectively prevent the occurrence of thermal runaway, it is necessary to fully understand the mechanisms of thermal runaway in lithium-ion batteries.
When lithium-ion batteries are overcharged or undercharged, they may enter a state of negative temperature coefficient and generate internal heat at a higher temperature than normal. When lithium-ion batteries are overcharged or undercharged, they may be overheated to a certain temperature. Lithium-ion batteries generally have three ways to generate internal heat during normal operation: 1) battery voltage drop due to current leakage through the electrolyte; 2) battery voltage drop due to charge transfer resistance between electrodes and electrolytes; 3) battery self discharge caused by irreversible chemical reaction or corrosion phenomenon caused by electrode material degradation process (especially combustion products).
Takeaway: When there are abnormal conditions (e.g., ...
... overcharge, over discharge) in lithium-ion battery charging / discharging process, the separator will dry out firstly, then react with electrode materials (especially combustion products), forming slag that forms on the surface; The amount of slag produced by the separator reaction will increase with increasing temperature; If the battery is not removed from this situation until it becomes unable to work normally (for example, overcooling), it will continue to produce more slag that causes severe damage to electrodes and separators and leads to more rapid deterioration of performance characteristics ; This phenomenon is referred to as "thermal runaway".
The main function of thermal runaway prevention is to prevent the thermal runaway of lithium-ion batteries during normal operation, charging and discharging.
The main function of thermal runaway prevention is to prevent the thermal runaway of lithium-ion batteries during normal operation, charging and discharging. Thermal runaway prevention can be divided into two categories: active and passive. In an active thermal runaway prevention system, a control circuit detects over-temperature conditions in the battery pack or cells and disconnects them from the power source to avoid further damage. When a passive thermal runaway prevention device senses high temperatures inside a cell or battery pack it vents heated gases through a relief valve so that no flame will occur in case there is any kind of fire inside your lithium ion cell or battery pack
In order to effectively prevent the occurrence of thermal runaway, it is necessary to fully understand the mechanisms of thermal runaway in lithium-ion batteries.
In order to effectively prevent the occurrence of thermal runaway, it is necessary to fully understand the mechanisms of thermal runaway in lithium-ion batteries. The following article provides an overview of this topic:
What is thermal runaway?
Causes and effects of thermal runaway.
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When lithium-ion batteries are overcharged or undercharged, they may enter a state of negative temperature coefficient and generate internal heat at a higher temperature than normal.
When lithium-ion batteries are overcharged or undercharged, they may enter a state of negative temperature coefficient and generate internal heat at a higher temperature than normal. This can lead to thermal runaway and cause fire.
The main purpose of our system is to detect abnormal temperatures in the battery pack and prevent it from overheating. The system consists of two parts: one is an intelligent controller that monitors the battery temperature through its embedded thermocouple sensor; the other part includes cooling fans controlled by PWM (pulse width modulation).
When lithium-ion batteries are overcharged or undercharged, they may be overheated to a certain temperature.
When lithium-ion batteries are overcharged or undercharged, they may be overheated to a certain temperature. When the battery is charged in an excessive voltage range, it will cause thermal runaway of the battery and lead to fire.
Undercharging can also cause thermal runaway and fire due to over discharge. If you leave your phone on charge all night, or don't check your laptop power supply regularly and use it until it runs out of juice, then this could result in severe damage - not just for your device but also yourself!
Lithium-ion batteries generally have three ways to generate internal heat during normal operation.
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The internal resistance of lithium-ion batteries increases with temperature, and the internal resistance of lithium-ion batteries increases with the number of cycles.
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When charging or discharging, there is a certain amount of heat generated by the chemical reaction between positive and negative electrodes (positive electrode oxidation reaction). This process is irreversible, so it cannot be completely avoided; however, if it happens too fast or too much, thermal runaway may occur due to overcharging or over discharging (overheating).
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When there are abnormal conditions (e.g., overcharge, over discharge) in lithium-ion battery charging / discharging process, the separator will dry out firstly, then react with electrode materials (especially combustion products), forming slag that forms on the surface; The amount of slag produced by the separator reaction will increase with increasing temperature; If the battery is not removed from this situation until it becomes unable to work normally (for example, over-cooling), it will continue to produce more slag that causes severe damage to electrodes and separators and leads to more rapid deterioration of performance characteristics ; This phenomenon is referred to as "thermal runaway".
If you want to avoid the risk of thermal runaway, you should pay attention to the following points:
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Do not charge or discharge lithium-ion batteries at temperatures above 40 degrees Celsius (104 Fahrenheit).
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The battery should be charged in an environment with good ventilation, such as a well-ventilated room. If possible, place it on a heat sink so that heat generated within the battery will dissipate more easily;
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When charging/discharging lithium-ion batteries, do not let them overcharge/undercharge;
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Do not use mechanical shock or vibration when handling these batteries because this may cause them to explode or ignite;
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Conclusion
Lithium-ion batteries are one of the most promising energy storage devices for use in electric vehicles and other applications. However, they have some safety issues that need to be addressed before they can be widely used in these applications. One way to address these issues is through nitrogen gas thermal runaway prevention systems that monitor battery temperatures and prevent overcharging or undercharging.

I am a part-time writter. My current job is working as project manager in Shenzhen Guchen Electronic. The company is specialized in manufacturing and exporting of EV HV Components, such as EV high voltage connector, high voltage wire harness, high voltage cable, MSD connector, PDU, MCU, and other related products on BESS interconnection such as battery pole connector and copper bus bar connector. Guchen Electronic has advanced production equipment and testing equipment. We adhere to the concept of "quality first" service tenet; our products have passed CE certification. The products are exported to Europe, America and Southeast Asia countries etc.. The company has introduced advanced equipment from Germany and Japan to ensure product quality, which makes us one of the leading manufacturers in China's electric vehicle industry. Our main customers are major automotive manufacturers in China such as BYD Automobile Co., Ltd., Chery Automobile Co., Ltd., Changan Automobile Co., Ltd., Dongfeng Motor Corporation Limited (DFM) etc..