Battery Housing Humidity Control via Selective Membrane Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In battery housings, especially those with lithium-ion batteries, humidity from external air penetrates due to the permeability of Teflon membranes to water vapor, leading to condensation and potential short circuits or corrosion, despite existing pressure equalization systems.
Innovation Solution
A method and device using selectively permeable membranes with a cooling device to condense water vapor in an intermediate space, allowing only dry gas with reduced humidity to enter the housing, while preventing liquid condensation from entering, and incorporating a control valve for pressure equalization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If Teflon membranes are used for pressure equalization in battery housings, then pressure differences can be compensated, but water vapor penetrates through the membranes causing humidity increase and condensation
Solution Approach 1:
The system is divided into multiple functional membranes: a first Teflon membrane for pressure equalization and a second selectively permeable membrane for humidity blocking. This segmentation allows each membrane to perform its specific function without compromising the other, resolving the contradiction between pressure compensation and humidity protection.
Solution Approach 2:
A desiccant is introduced as an intermediary substance in the intermediate space between the two membranes. The desiccant actively absorbs water vapor that penetrates through the first membrane, preventing humidity accumulation and condensation while maintaining the pressure equalization function of the Teflon membrane.
2Reliability
If the housing is sealed to protect batteries, then protection against environment is improved, but pressure equalization becomes necessary preventing simple sealing
Solution Approach 1:
The first Teflon membrane serves multiple functions: it acts as a pressure equalization element allowing pressure compensation while simultaneously serving as a sealing component that prevents liquid water penetration. This multi-functionality reduces the need for additional separate components, simplifying the overall system while maintaining reliable protection.
3Reliability
If cooling systems are added to maintain battery temperature, then operational reliability is improved, but condensation of water vapor occurs leading to short circuits and corrosion
Solution Approach 1:
The desiccant is placed in advance in the intermediate space between the membranes to preemptively absorb water vapor before it can enter the housing and cause condensation on the cooling system. This preliminary action prevents the formation of harmful condensation water that would otherwise lead to short circuits and corrosion.
Solution Approach 2:
The system converts the potentially harmful effect of water vapor penetration through the first membrane into a beneficial process by using the desiccant to actively manage humidity levels. The water vapor that would otherwise cause condensation is captured and absorbed, transforming a harmful moisture source into a controlled humidity management system that protects the cooling apparatus.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Significantly reduces humidity within the battery housing, preventing condensation and corrosion, while effectively managing pressure differences through controlled introduction of dry gas, ensuring reliable operation of lithium-ion batteries.
Implementation Method 1
a first selectively permeable membrane as an inlet... Selectively permeable membranes of this type which are used can also be called semipermeable membranes which are permeable for gas and are impermeable for liquids
Implementation Method 2
the gas is subsequently cooled in the intermediate space by means of a cooling device in such a way that a water vapor fraction of the gas is condensed to form water
Implementation Method 3
the gas with a reduced water vapor content is guided through the second selectively permeable membrane into the housing interior... the second selectively permeable membrane being impermeable for liquids
Data Source
AI summary
A method and a device for reducing the humidity of a gas in a housing interior, in particular in a battery housing interior, includes leading a gas through a first selectively permeable membrane and into an intermediate space. The intermediate space has the first selectively permeable membrane as an inlet and a second selectively permeable membrane as an outlet. The gas is then cooled in the intermediate space by a cooling unit such that a water vapor portion of the gas is condensed into water and the gas having a reduced water vapor content is directed through the second selectively permeable membrane into the housing interior.