With the widespread application of lithium batteries in energy storage, electric vehicles, consumer electronics and other fields, their safety assessment has become the core link of product development and quality control. The thermal stability and electrochemical behavior of lithium batteries under extreme temperature conditions are directly related to their safety and reliability. Therefore, simulating high and low temperatures and temperature cycling conditions in a controlled laboratory environment is a key means to evaluate battery performance and safety. In view of the risk of thermal runaway, leakage and even fire and explosion of lithium batteries under abnormal temperature changes, the use of specially designed explosion-proof high and low temperature test chambers for such tests is not only technically necessary, but also an important guarantee for laboratory safety and data reliability.
temperature stress
The electrochemical properties, capacity, internal resistance, and cycle life of lithium batteries are extremely sensitive to temperature changes. High temperature may accelerate electrolyte decomposition, degradation of positive and negative electrode materials, and instability of SEI film, resulting in aggravated capacity attenuation. Low temperature will reduce the conductivity of the electrolyte and reduce the mobility rate of lithium ions, causing the risk of lithium precipitation, which may cause internal short circuits. During the test, the battery sample undergoes rapid temperature change in a confined space, and if the battery has abnormal heat release due to manufacturing defects, overcharging and over-discharging, or internal short circuit, the accumulated energy and possible combustible gas cannot be effectively controlled in the ordinary test chamber, which is very easy to cause safety accidents.
From the analysis of thermal runaway process, the internal reaction exothermic rate Q of the battery can be approximately expressed as:
Q = A · exp(-Ea/RT) · f(SoC, SOH)
where A is the pre-index factor, EaFor the reaction activation energy, R is the gas constant, T is the absolute temperature, SoC is the charged state, and SOH is the healthy state. This equation shows that the increase in temperature will exponentially accelerate the exothermic reaction. In a confined test chamber, sudden pressure and temperature spikes can lead to serious hazards if heat and potentially generated gases cannot be safely evacuated.
Features and Functions:
The explosion-proof high and low temperature test chamber is not a simple reinforcement of ordinary incubators, but is specially optimized for the potential risks of battery testing from structural design, material selection, control system and safety protection. Its core design concept is to provide an accurate and stable temperature environment while controlling the risk of battery runaway inside the cabinet and safely releasing energy to ensure the safety of laboratory personnel, equipment and buildings.
Its key features include:
1. Pressure Relief and Explosion Relief Structure:The box is usually designed with a directional pressure relief device or rupture disc, which can quickly release the high-temperature gas and pressure in a safe direction (such as through the pipeline to the outside) when the internal pressure exceeds the set threshold, avoiding the box bursting.
2. Lumen and material protection:The liner is made of corrosion-resistant, high-temperature, and spark-resistant materials (such as stainless steel), and may be lined with a protective layer to resist the impact and corrosion of battery projectiles.
3. Intrinsically safe or explosion-proof electrical systems:Heaters, fans, sensors and electrical interfaces are all explosion-proof or placed outside the cabinet to eliminate the possibility of electrical components in the box becoming ignition sources.
4. Enhanced Exhaust and Purification System:The air in the box can be quickly replaced after the test or accident, and the exhaust gas treatment device can be optional to filter the toxic and harmful gases that may be generated.
5. Intelligent Security Monitoring:Integrated multi-channel temperature monitoring (especially sample surface temperature), pressure sensor, smoke or combustible gas detector, and linked with the main control system can automatically cut off the test and start the safety protocol in case of abnormality.
Test Standards
A number of domestic and foreign standards put forward explicit or implicit protection requirements for the safety testing environment of lithium batteries. These tests often require batteries to undergo charge-discharge cycles, temperature shocks, or long-term thermal storage under specific temperature conditions, and there are clear risks associated with the process.
| Standard examples | Relevant test items and temperature conditions |
| UN 38.3 (Transport Safety) | High and low temperature cycling, thermal shock test |
| IEC 62660 (Power Battery) | Charging and discharging performance and storage testing at high temperatures |
| GB 38031 (Electric Vehicle Safety) | temperature cycling, heating test, etc |
| UL 1642 (Cell Safety) | Thermal abuse test |
Although many standards do not directly specify the use of explosion-proof boxes, safety precautions are emphasized in their test method descriptions. The use of explosion-proof chambers is the most reliable engineering practice to meet these safety precautions, protect operators, and ensure that testing can be carried out continuously without damaging equipment or interrupting the entire test sequence due to the failure of a single part.
Select Consideration
The introduction of explosion-proof high and low temperature test chambers has value beyond simple risk avoidance. It allows researchers to conduct accelerated life testing, abuse testing, and safety boundary exploration under conditions closer to real-world risk scenarios, resulting in more realistic and reliable data. This is of great significance for battery material research and development, cell design optimization, battery management system (BMS) strategy verification, and final product safety certification.
When choosing such equipment, it is necessary to consider the following factors: test temperature range and rate, box volume and load-bearing, explosion-proof level and pressure relief capacity, compatibility and synchronization of data acquisition systems, after-sales maintenance and safety training support, etc. The equipment should be seamlessly embedded in existing battery test lab workflows and work in tandem with charging and discharging equipment and data logging systems.
Conclusion
In the field of lithium battery R&D and quality verification, explosion-proof high and low temperature test chambers have gradually transformed from a high-standard safety recommendation to an important part of critical testing infrastructure. Through engineered safety design, it effectively controls the inherent thermal runaway risk of batteries in extreme temperature testing, ensuring the safety of personnel and property, while ensuring the continuity of the testing process and data integrity. With the continuous improvement of lithium battery energy density and the continuous expansion of application scenarios, the priority to use explosion-proof safety equipment in relevant environmental reliability tests reflects a rigorous scientific attitude and responsible risk management concept, and is one of the technical cornerstones to promote the safe and steady development of the industry.