Shape-Memory Battery Cell Pressing Plates for Constant Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing apparatuses for pressing battery cells fail to provide constant pressure, which is essential for uniform reaction across the battery, especially in lithium metal cells with significant volume expansion during charging and discharging, leading to potential dendrite formation and reduced cycle life.
Innovation Solution
An apparatus using shape memory materials, such as shape memory polymers, for the pressing plates and coupling fins that adjust their shape in response to the battery cell's volume changes, ensuring constant pressure through a restoring force that maintains the original shape of the plates, thereby uniformly pressing the battery cell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If conventional pressing apparatuses are used for battery cells, then the structure is simple, but constant pressure cannot be provided during battery operation
Solution Approach 1:
The pressing apparatus changes the physical state of the pressing member from rigid to flexible by controlling temperature. At high temperature, the pressing member becomes flexible and conforms to the battery cell shape; at low temperature, it becomes rigid and provides stable pressing force. This temperature-dependent parameter change enables both adaptability and pressure stability.
Solution Approach 2:
The pressing member transitions between different states (flexible/rigid) based on temperature conditions, allowing the system to adapt dynamically to battery volume changes during charging and discharging cycles while maintaining reliable pressing contact.
2Adaptability or versatility
If rigid pressing plates are used, then the structure is simple, but they cannot adapt to battery cell volume expansion and contraction
Solution Approach 1:
The pressing member's flexibility parameter is changed by temperature control. When heated, the material transitions to a flexible state that can adapt to battery volume changes; when cooled, it becomes rigid for stable pressing. This eliminates the need for complex mechanical adjustment mechanisms.
Solution Approach 2:
The patent replaces complex mechanical systems (springs, actuators, adjustable mechanisms) with a thermally-controlled flexible pressing member. The thermal field substitutes for mechanical complexity, providing adaptability through material property changes rather than mechanical design.
3Adaptability or versatility
If flexible pressing members are used to adapt to volume changes, then adaptability is improved, but the pressing force becomes unstable
Solution Approach 1:
The pressing member dynamically transitions between flexible and rigid states based on operational requirements. During battery volume changes, the member remains flexible to maintain contact; during pressing operations, it becomes rigid to provide stable force, eliminating the trade-off between adaptability and stability.
Solution Approach 2:
By changing the temperature parameter of the pressing member, the system achieves both adaptability (when flexible) and pressure stability (when rigid), resolving the contradiction through controlled material property transitions.
4Force
If heavy pressing apparatuses are used to provide sufficient pressing force, then pressing force is adequate, but the overall battery system weight increases
Solution Approach 1:
The patent replaces heavy mechanical pressing systems with a thermally-controlled flexible member that generates pressing force through thermal contraction. This substitutes mechanical weight with thermal energy input, significantly reducing the battery system's overall weight while maintaining adequate pressing force.
Solution Approach 2:
The pressing force is generated not by heavy mass but by changing the temperature parameter of the pressing member, which contracts upon cooling to generate sufficient force. This parameter-based force generation eliminates the need for heavy mechanical components.
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
The apparatus provides a high, consistent pressure necessary for lithium metal cells with a lightweight design, improving cycle life and preventing dendrite formation by utilizing the shape memory effect to adjust to volume changes, thus enhancing the energy density and operational efficiency of the battery.
Implementation Method 1
at least one of the first pressing plate or the second pressing plate is formed of a shape memory material to provide a pressing member. The pressing member is configured to store a shape in accordance with the battery cell at a temperature at which the battery cell is driven and deformation of the pressing member due to a volume expansion of the battery cell acts as a force for returning the shape of the pressing member to an original shape
Data Source
AI summary
An apparatus for pressing a battery cell includes a first pressing plate and a second pressing plate spaced from the first pressing plate to receive a battery cell therebetween and to press the battery cell. At least one of the first pressing plate or the second pressing plate is formed of a shape memory material to provide a pressing member.