In the high-stakes arena of Electric Vehicle (EV) manufacturing, thermal management is the boundary between peak performance and catastrophic failure. If you are struggling with the Pump-Out Effect – a mechanical phenomenon that degrades thermal transfer and drastically shortens the battery life of EV vehicles, this article is a comprehensive guidance for you to conquer the pump-out effect using advanced TIMs.
Source: Prostech
Transitioning from traditional greases to high-performance Thermal Interface Materials (TIMs) is considered among the most effective ways to conquer this challenge.
1. The Mechanics: What Causes the Pump-Out Effect in EV Manufacturing?
The Pump-Out Effect is a mechanical failure of the thermal bond.
In EV manufacturing, battery modules are dynamic systems; they “breathe” by expanding during rapid charging/discharging and contracting during cooling.
Source: Prostech
This “breathing” cycle is driven by the Coefficient of Thermal Expansion (CTE) mismatch between the battery cells and the aluminum cooling plates. This creates a relentless pumping action on the interface.
Unlike standard greases (Look for technical insights here) that remain in a semi-liquid state, PCMs utilize a Phase Transition Cycle to combat pump-out.
Source: Prostech
When the battery cools, the PCM re-solidifies, significantly increasing its storage modulus. This creates a ‘Mechanical Lock’ within the interface, anchoring the material into surface micro-cavities. This periodic ‘reset’ from liquid to solid effectively halts the cumulative migration (pump-out) caused by CTE mismatch, ensuring the Bond Line Thickness (BLT) remains stable over thermal cycles.
For a general picture, read expert’s guideline about thermal interface materials here.
2. The Impact: How Thermal Failure Shortens the Battery Life of EV Vehicles
Failing to conquer the Pump-Out Effect alters the fundamental electrochemistry of the battery, specifically:
- SEI Layer Growth: Excessive heat accelerates the decomposition of the electrolyte, thickening the Solid Electrolyte Interphase (SEI) layer. This increases internal resistance and reduces power density.
Source: Prostech
- Lithium Plating: Uneven temperature distribution creates a gradient in current density, which risks lithium plating during fast charging, potentially leading to internal short circuits.
- Chemical Aging: The longer the battery is exposed to high temperatures, the shorter its lifespan.
For a more exact and comprehensive assessment of your thermal management, contact our expert here.
3. High-Performance Solutions to Conquer the Pump-Out Effect
To achieve superior thermal management, the industry is shifting toward materials that offer structural stability under thermal cycling.
3.1. Cured-in-Place Gap Fillers (2K Systems)
Liquid gap fillers are recommended for modern EV battery production. These two-component (2K) materials are dispensed as liquids to fill complex geometries and then undergo chemical cross-linking to become soft elastomers.
Source: Henkel
- Why it works: Once cured, the material possesses “Structural Memory.” It stays locked in place, resisting mechanical pumping during thermal cycles.
- Product Recommendation: ELAN-tim® FS 26 OP 0012, 0023; ELAN-tim® FP 21 AP 0092, 0103
For more precise material dispensing, automated 2K dispensing systems are recommended to prevent air entrapment.
Watch the below video to have a look at the 2K Mixing & Dispensing System.
FYI: Here is a detailed comparison between Silicone-based and Non-Silicone Thermal Interface Materials (TIMs) to help you make the best decision for your thermal management needs.
3.2. High-Stability Phase Change Materials (PCMs)
PCMs provide a hybrid solution, offering the performance of grease with the stability of a pad.
Source: Henkel
- Why it works: At Room Temperature, PCM is a solid, stable film or pad. As the battery heats up, the material softens. It achieves optimal surface wetting, flowing into the micro-cavities of the battery cells to eliminate air gaps. When the device cools down, the PCM re-solidifies, “locking” the interface. This self-healing mechanism prevents the material from being pumped out under repeated thermal cycles, ensuring long-term reliability.
Source: Prostech
- Product Recommendation: T-global TGPK27P; T-global TGPK27B; T-global PCM20B
4. Prostech: Your Partner in Superior Thermal Management
At Prostech, we don’t just supply chemicals; we validate your entire production process.
Source: Prostech
We specialize in helping OEMs understand how to conquer the Pump-Out Effect in EV Batteries Production through:
- CTE Mismatch Analysis: We simulate the “breathing” of your battery pack to select a TIM with the most suitable modulus of elasticity.
- Advanced MMD Integration: Our Meter-Mix-Dispense (MMD) systems ensure that 2K gap fillers are applied without air entrapment, which is critical for superior thermal management.
- Long-term Reliability Testing: We conduct accelerated aging tests to prove that our thermal interface materials will protect the battery life of EV vehicles for years.