Lithium-ion batteries are powerful – but thermally sensitive. Precise pressure measurement is key to preventing overheating and optimizing cooling systems.
Whether it's exploding laptops or burning electric vehicles – thermal runaway of lithium-ion batteries can have dramatic consequences. This instability often results from overloading or high ambient temperatures and occurs in several dangerous stages:
- from 80 °C: Dissolution of the SEI layer, initial exothermic reactions
- from 110 °C: Decomposition of organic solvents, gas formation, pressure increase
- from 135 °C: Melting of separator foil → short circuit
- from 200 °C: Decomposition of cathode, oxygen release, ignition
Thermal management through liquid cooling
To control these risks, modern EV batteries use liquid-cooled systems. Coolers and BMS (Battery Management System) regulate temperature and heat dissipation.
Designing these systems requires sound data: temperature and pressure measurements during charge and discharge cycles form the basis. Only then can cooling channels be dimensioned and simulations set up – for example with software like PTC CreoParametric 3D.
Why pressure measurement is crucial
Optimal heat transfer depends on the interplay of coolant flow, temperature, and pressure. A pressure difference of just 0.008 bar between inlet and outlet can be decisive – demanding highest precision in pressure measurement.
Sensors like the ATM.1ST from STS meet these requirements. They offer:
- Very high measurement accuracy at low differential pressures
- Long-term stability over broad temperature ranges
- Compact, media-resistant design for contact with liquids
Engineers use this data to compare pressure losses along various channel designs – visually represented in curves for minimal and maximum flow rates. The Bernoulli equation shows: Higher flow rate = quadratically increasing pressure loss.
Design optimization through measurement data
For this reason, developers adopt wider cooling channels with multiple passages to improve heat dissipation via forced convection. The result: more stable cell temperatures, reduced risk of thermal runaway, and higher cycle life.
Conclusion
Accurate pressure measurement makes an essential contribution to the safety and efficiency of lithium-ion batteries – especially during development. Sensors like the ATM.1ST from STS enable optimization of cooling concepts, reduction of risks, and long-term system performance security.
