Optimizing Performance and Longevity: Discover how detecting leaks early helps maintain the structural integrity of battery cells, enhancing performance and extending their lifespan.
Why is battery leak testing important?
Reliable leak testing of battery cells is crucial because the highly flammable electrolytes they contain can spark fires. Even small amounts of humidity in a battery module can cause the system to short circuit, reduce service life and degrade performance, including a vehicle's driving range.
A method is presented discussing how to reliably and quantitatively detect leakage from battery cells through the detection of escaping liquid electrolyte vapors, typically dimethyl carbonate (DMC). The proposed method does not require the introduction of an additional test gas into battery cells.
Why is leak testing important?
Leak testing plays a critical role in the assembly of battery cells, modules and packs. Batteries need to be leak-free and protected from humidity, water and other liquids for 10 years or more. Reliable leak testing of battery cells is crucial because the highly flammable electrolytes they contain can spark fires.
Why is rapid detection important in the production of battery cells?
Rapid detection of leaks in the production of battery cells is absolutely essential to achieving necessary service life and safety requirements. This applies particularly to small leaks that cannot be detected immediately after the cell has been manufactured, for example by using an electrical discharge method.
How does a battery leak test work?
For instance, the cooling circuit is leak tested with air, while the battery cells are tested with either tracer gas or ionized air methods. “An in-process leak test is to check every battery subassembly, such as cells, cooling plates, cooling circuits, venting valves, trays and covers,” Dewailly points out.
For pouch cells, no reliable method to detect small leak channels is available. This paper examines the spectrum of possible leak scenarios for cylindrical, prismatic and pouch lithium-ion batteries [ Figure 1 ]. Currently no rejection limits have been codified for these batteries.