From Thermal Runaway to Total Control: PUW Explosion-Proof Valves Designed for Lithium Battery Safety

One of the gravest dangers in the design of lithium batteries is thermal runaway. The overheating of one trigger a chain of  events that cause disastrous breakdown. Although a great deal of attention is paid to battery management systems, as well as cell chemistry, there is an explosion-proof valve, which is an equally important mechanical element. Today, PUW is a market leader in the explosion-proof valve in China, which assists battery manufacturers to shed fear of thermal runaway and to have complete control of pressure management.

Understanding the Pressure Cascade Before Failure

Before thermal runaway  reaches a critical level, pressure in the battery pack increases. This pressure is due to normal generation of heat during the charge and discharge process, but when a cell starts failing, this pressure will increase significantly. The gases which escape through overheating cells have no outlet in a confined container and the pressure builds up until the container bursts or the pack explodes. This hazardous cascade is broken by PUW explosion-proof valves. These offer quick pressure release when the internal pressure is above a safe level and this will discharge the hot gases before it reaches the level of structural failure. Such early intervention may result in a controlled venting incident versus a disastrous explosion.

IP68 Protection as the First Line of Defense

Basic environmental protection should not be compromised with the achievement of effective pressure management. Battery packs should be kept airtight against moisture, dust and road contaminants during the entire life of the battery. PUW explosion-proof valves aid battery packs to reach IP68 protection, that is, complete dust tightness and persistence to the continued immersion in water. The secret is in the waterproof breathable membrane which is a highly engineered substance that does not allow water or particles to pass through, and at the same time, does not exclude air and pressure. This implies that a battery pack is resistant to rain, road spray, pressure wash and even temporary flooding and at the same time, it can discharge harmful pressure instantly when necessary.

Precision Engineering Backed by a CNAS Lab and 200 Patents

PUW is not a producer of generic valves. The company has CNAS certified laboratory and a research and development team dedicated to it, which has developed over 200 patents. This level of technical expertise enables PUW to provide tailored and precision designed solutions to custom battery pack designs. Each of the valves is designed to crack at a certain pressure and expel gas at a certain rate and also close up again after releasing the gas. The group will be testing every design under temperature extremes, changes in humidity, and vibration over time, to maintain the same performance. To manufacturers of batteries who require the ultimate control of the safety margins, this type of accuracy is not negotiable.

Quality Systems That Ensure Every Valve Performs as Designed

The safety elements should work flawlessly each and every time. It is not subject to any variation. PUW products are in line with the international quality management standards such as ISO 9001 and IATF 16949 which is the strictest quality management system in the automotive industry. The company is also guided by ISO 14001 which deals with environmental management systems. The standards control the sourcing of raw materials, calibration of the production line to the final testing. At the time a PUW explosion-proof valve comes out of the factory, it has already been checked to the same specifications as all of the other valves of that batch of production. It is this uniformity that is needed by the manufacturers of batteries worldwide when developing safety-critical systems.

Global Infrastructure for Reliable Supply and Support

PUW has two large production bases in Jiangxi and Guangdong provinces covering about 40,000 square meters and four service centers in China and Germany. Having 22 production lines, the company can cater to the large scale battery manufacturers and at the same time be flexible to customized orders. Flexible supply chain and smart inventory systems have ensured delivery on time and a professional customer service team has been working closely with the clients to sort out any technical or logistical challenges in time. As a battery manufacturer, it is critical to have the confidence that valves will be delivered on time and deliver the expected performance to ensure that production plans and safety approvals are kept.

Total Control Through Proven Technology

PUW explosion-proof valves have become more important in the safety of lithium batteries. With the ever increasing battery energy densities and continuously decreasing charge times, there is a possibility of pressure related failures. PUW is a solution that has been tried, tested and trusted by the world renowned enterprises with regard to profound collaboration and a consistent performance. Through thermal runaway to complete control, PUW explosion-proof valves provide battery manufacturers with the assurance to stretch the limits of performance without jeopardizing safety.