Immersion cooling involves directly immersing the battery cells (or modules) in a single-phase dielectric (non-conductive) fluid that does not boil. Heat is removed by conduction and convection to a heat exchanger via controlled fluid circulation.
Cross-cutting benefits:
High thermal uniformity (reduced intra-pack variations) → stable performance and more consistent aging.
Increased power density (charge/discharge), better peaks and consistency.
Better controlled fast charging (consistent temperature → less risk of lithium deposition).
Safety: better management of local runaway and eliminated propagation through rapid heat evacuation and surface insulation.
Simplified thermal architecture: fewer cold plates, internal channels, and interface materials.
Energy efficiency of the TMS (especially when stationary).
Specific applications and advantages
Specific applications and advantages
Light electric vehicles (PV), commercial vehicles, buses, and heavy goods vehicles
Requirements: fast charging, sustained power, longevity, safety, space.
Advantages of single-phase immersion:
Uniform temperature under high-intensity charging.
Repeatable performance (climbs, overtaking, urban cycles).
Enhanced safety (propagation mitigation).
Potential reduction in thermal structure weight (fewer plates/IFTM), partially offsetting the mass of the fluid
2/3 wheels (scooters, light motorcycles, motorcycle taxis) with battery swapping option
Requirements: safety, compacity, quick swapping, durability
Advantages:
Mitigation of fire and propagation risks .
Uniformity of the cell temperature.
Range improved.
Fast charge.
Stationary energy storage (BESS: utility, C&I, microgrids)
Requirements: safety, 24H availability, overall efficiency.
Advantages:
Easier safety and compliance (spread management at rack level).
Energy-efficient cooling (vs. intensive HVAC), especially in hot climates.
Improved energy density in containers.
Uniform aging → better availability
Aeronautics / eVTOL / heavy drones (subject to certification constraints)
Requirements: maximum safety, very high C-rates, altitude performance.
Advantages:
Uniform cooling at high C-rates.
Reduced risk of propagation and improved thermal containment.
Potential simplification of TMS, with particular attention to weight.
Marine (ships, ferries, offshore)
Requirements: safety, compactness, strict standards.
Advantages:
Mitigation of fire and propagation risks in enclosed spaces.
Dense integration in small technical compartments.
Reliable thermal management during power peaks.
Off-highway vehicles (mining, construction, agricultural), light rail
Requirements: robustness, continuous loads, harsh environments.
Advantages:
Thermal stability under prolonged load, less derating.
Increased reliability (fewer rigid internal thermal interfaces).
Predictive maintenance facilitated via sensors in the fluid.
Data centers / UPS & power continuity
Requirements: reliability, security, technical room integration.
Advantages:
Increased intrinsic safety in critical environments.
Optimizable footprint; maintenance via closed-loop instrumentation.
Less dependence on local HVAC dedicated to batteries.
Conclusion.
Single-phase immersion is essential when seeking safety, thermal uniformity, and high performance (fast charging, sustained power) with effective thermal management and dense integration, particularly for BESS, high-power EVs, 2W/3W with or without swapping, and off-highway/marine applications. However, it requires rigorous fluid-materials engineering and careful environmental choices