Lithium-Ion Battery Cell Temperature Homogenization via Recirculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion battery packs for motor vehicles face temperature homogeneity issues due to inefficient heat dissipation in existing cooling methods, leading to uneven aging and reduced service life, particularly in air-cooled systems where cabin air's limited heat absorption capacity results in significant temperature gradients.
Innovation Solution
A method that utilizes a blower to circulate cooling air through lithium-ion batteries, with a directional control valve switching between cabin air and recirculated air to maintain temperature homogeneity, allowing for increased air flow rates without compromising interior comfort, thereby extending the service life and ensuring uniform aging of the battery cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If direct air cooling with cabin air is used, then the cooling system is simple and easy to implement, but the heat absorption capacity is limited due to restricted volume flow
Solution Approach 1:
The patent recycles the air that has already passed through the battery cells by routing it back through the battery via recirculation channels. This allows the same air to absorb heat from multiple cells sequentially, effectively multiplying the heat absorption capacity without requiring additional air volume or a more complex cooling system architecture.
2Ease of manufacture
If cooling air is supplied from the interior of the motor vehicle, then the system is simple to implement, but significant temperature gradients occur between cells due to limited heat absorption capacity
Solution Approach 1:
The patent divides the air cooling path into multiple segments by introducing recirculation channels that allow air to pass through different groups of cells in sequence. This segmentation of the cooling flow path ensures that heat is distributed more evenly across all cells, preventing significant temperature gradients while maintaining system simplicity.
3Temperature
If air flow rate is increased to improve heat dissipation, then temperature homogeneity improves, but interior comfort is compromised
Solution Approach 1:
The patent implements continuous recirculation of air through the battery cells, allowing the same air to repeatedly absorb heat and be re-cooled. This continuous cyclic process maintains effective heat dissipation and temperature homogeneity without requiring high air flow rates that would compromise interior comfort.
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
This approach effectively reduces temperature gradients between cells, enhancing the service life and aging behavior of lithium-ion batteries by increasing air flow rates in recirculation mode, ensuring more uniform temperature distribution and efficient heat dissipation without compromising vehicle comfort.
Implementation Method 1
cooling air is sucked in from an interior of a motor vehicle into an air supply line by a blower, conveyed by the air supply line through the lithium-ion battery, the cooling air being guided past the cells arranged one after the other
Implementation Method 2
heat is generated, such as Joule heat, which can be described by the electrical current and the internal resistance of the cell
Implementation Method 3
cooling air is guided past the cells arranged one after the other... convectively absorbs the heat flow generated in the cells
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a method for homogenizing the temperature distribution in the cells (11, 12) of a lithium-ion battery (10) for a motor vehicle and to a lithium-ion battery (10) for a motor vehicle.