With the widespread application of lithium batteries in new energy vehicles, consumer electronics, energy storage systems, and other fields, the safety of lithium batteries has become particularly important. Lithium batteries may experience dangerous situations such as overheating, short circuits, overcharging, etc. during charging, discharging, or improper external stimuli, which can lead to battery expansion, fire, or explosion. Therefore, specialized lithium battery explosion-proof chamber have become necessary equipment for safety testing of lithium batteries. Although high and low temperature test chambers have been widely used in many fields, they cannot replace lithium battery explosion-proof chambers. This is because there are essential differences in the design principles, application purposes, and testing functions between the two.

This article will analyze from multiple perspectives why high and low temperature test chambers cannot replace lithium battery explosion-proof chambers, helping you better understand the differences between them.

1 Different design purposes

The main purpose of the high and low temperature test chamber is to simulate the performance of products in extreme temperature environments and evaluate their stability and reliability under different temperature conditions. It tests the product’s resistance to high and low temperatures, thermal shock, aging, and other performance by setting environmental parameters such as high temperature, low temperature, and temperature cycling. High and low temperature test chambers are commonly used to evaluate the adaptability of materials, electronic components, mechanical parts, and other products under conventional temperature changes.

The lithium battery explosion-proof chamber is a safety protection device specifically designed for lithium batteries, aimed at preventing dangerous events such as overcharging, overdischarging, short circuit, high temperature, etc. that may cause explosions or fires during the testing process. There are specialized structures and protective measures inside the explosion-proof chamber to ensure that the battery does not cause greater danger in the event of a malfunction, preventing the spread of fire or the production of harmful gases by the battery. Therefore, the design of explosion-proof chambers places more emphasis on the safety protection of batteries, far beyond the scope of temperature environment testing.

2 Different security protection functions

The core function of the high and low temperature test chamber is to test the performance of products in extreme temperature environments. Although it can accurately control temperature, humidity, and wet heat alternation, it does not have the ability to handle battery hazardous reactions that may occur in high temperature and high pressure environments. High and low temperature test chambers usually do not have safety protection designs such as fire prevention, explosion prevention, and gas leakage.

Unlike this, the lithium battery explosion-proof chamber is equipped with multiple safety protection measures. Common explosion-proof chamber designs include:

• Gas leakage detection and emission system: Lithium batteries may release harmful gases in the event of a malfunction. Explosion proof chamber usually equipped with specialized gas detection systems. Once an abnormality occurs, the ventilation and exhaust system will be automatically activated to prevent the accumulation of harmful gases and reduce danger.

• Thermal insulation and fire protection design: The explosion-proof box is equipped with a firewall and insulation layer to prevent the spread of flames in the event of a battery fire. The temperature difference between the inside and outside is controlled by a temperature control system to ensure that battery failure does not cause more serious safety accidents.

• Pressure release device: In the event of a lithium battery failure, it may rapidly expand or even explode. The explosion-proof box is equipped with a pressure release device to ensure that the battery explosion will not affect the outside world.

3 Different testing methods and functions

The testing of high and low temperature test chambers mainly focuses on the impact of temperature environment on products, including high temperature, low temperature, temperature and humidity, thermal cycling, etc., to evaluate the reliability of products in long-term use. Although the high and low temperature test chamber can simulate the working environment of batteries under extreme temperature conditions, it does not have the ability to simulate the impact of battery failure modes (such as overcharging, overdischarging, short circuiting, etc.) on safety.

The explosion-proof chamber for lithium batteries has a dedicated testing mode, such as:

• Short circuit test: Simulate the performance of a battery in the event of a short circuit fault to prevent thermal runaway caused by a short circuit.

• Overcharge and overdischarge testing: Simulate the reaction of a battery under overcharge or overdischarge conditions, and test whether the battery will expand, catch fire, or explode.

• Drop test and impact test: Test the performance of the battery after being impacted or dropped by external forces to ensure that accidents do not occur after collision.

• Thermal runaway test: Simulate the safety performance of batteries under overheating conditions to prevent the risks caused by thermal runaway.

When simulating these failure modes, the explosion-proof chamber has safety protection measures that can prevent accidents to the greatest extent possible, while the high and low temperature test box cannot provide similar safety guarantees.

4 Temperature and pressure changes

Although the high and low temperature test chamber can accurately control the temperature environment, its temperature change rate and pressure control ability are relatively limited. For some extreme testing conditions, especially the internal pressure changes during high temperature, low temperature, and charge discharge cycles of lithium batteries, normal high and low temperature test chamber performance is not as good as higher specification explosion-proof chamber .

The changes in internal temperature, pressure, and electrochemical reactions during the operation of lithium batteries are very complex. During the charging and discharging, short circuit, or thermal runaway of batteries, rapid temperature rise and rapid pressure changes may cause violent reactions in the battery, and even lead to fires and explosions. The explosion-proof chamber design takes into account this special situation and can effectively prevent the expansion of danger even if abnormalities occur during testing through specialized technical means and safety mechanisms.