Battery Cell Restriction Structure for Expansion and Vibration
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Solution Overview
Problem
Conventional power storage devices face issues of case damage due to expansion of batteries and resonance during vibration, which can lead to structural integrity problems.
Innovation Solution
A power storage device with a restriction unit that allows relative displacement of power storage cells at a low modulus of elasticity during expansion and restricts displacement at a higher modulus during vibration, using materials with dilatancy characteristics or corrugated plates to absorb expansion and reduce resonance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the case is made rigid to prevent damage during battery expansion, then the case can withstand expansion forces, but the battery cells will resonate during vibration due to inability to displace
Solution Approach 1:
The restriction unit is designed with dynamic characteristics that change based on operating conditions. It provides different modulus of elasticity values at different velocities: a first modulus when batteries expand at low velocity, and a second (higher) modulus when batteries vibrate at high velocity. This dynamic adaptation resolves the contradiction by being flexible during expansion but rigid during vibration.
Solution Approach 2:
The restriction unit's key parameter (modulus of elasticity) is designed to change based on velocity. At first velocity (expansion rate), it shows first modulus of elasticity (lower). At second velocity (vibration rate), it shows second modulus of elasticity (higher). This parameter change allows the same component to serve dual functions: accommodating expansion and suppressing resonance.
2Stability of the object's composition
If the restriction unit is made stiff to reduce resonance during vibration, then battery cell displacement is restricted, but the case may be damaged during battery expansion
Solution Approach 1:
The restriction unit dynamically adjusts its stiffness based on the velocity of battery displacement. During expansion at first velocity, it exhibits lower first modulus of elasticity to protect the case. During vibration at second velocity, it exhibits higher second modulus of elasticity to reduce resonance. This dynamic behavior resolves the contradiction between protecting the case and stabilizing batteries.
Solution Approach 2:
The modulus of elasticity parameter of the restriction unit is designed to vary with velocity. It transitions from first modulus (at first velocity during expansion) to second modulus (at second velocity during vibration), where second modulus > first modulus. This parameter change enables the restriction unit to provide appropriate resistance for each operational condition.
3Strength
If the case is made flexible to accommodate battery expansion, then the case can withstand expansion without damage, but the battery cells will resonate during vibration
Solution Approach 1:
The restriction unit provides velocity-dependent mechanical response. During expansion at first velocity, it allows movement with lower first modulus of elasticity. During vibration at second velocity, it restricts movement with higher second modulus of elasticity. This dynamic characteristic resolves the contradiction between flexibility for expansion and rigidity for vibration suppression.
Solution Approach 2:
The restriction unit's modulus of elasticity changes from first modulus at first velocity to second modulus at second velocity. This parameter change enables the system to be flexible during expansion (accommodating battery growth) while being rigid during vibration (suppressing resonance), thus resolving the contradiction.
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 solution effectively reduces case damage and resonance by absorbing cell expansion at low velocity and restricting displacement at high velocity, enhancing structural stability and cooling efficiency.
Implementation Method 1
The restriction unit shows a first modulus of elasticity when each of the plurality of power storage cells is displaced relative to the case at a first velocity
Implementation Method 2
The restriction unit shows a second modulus of elasticity when each of the plurality of power storage cells is displaced relative to the case at a second velocity in the one direction. The second velocity is higher than the first velocity, and the second modulus of elasticity is higher than the first modulus of elasticity
Data Source
AI summary
A power storage device includes power storage cells stacked in one direction, a case for accommodating the power storage cells, and a restriction unit placed in the case and restricting a relative displacement of each power storage cell to the case in the one direction. The restriction unit shows a first modulus of elasticity when each power storage cell is displaced relative to the case at a first velocity and shows a second modulus of elasticity when each power storage cell is displaced relative to the case at a second velocity in the one direction. The first velocity is a relative velocity of each power storage cell to the case when each power storage cell expands, the second velocity is higher than the first velocity, and the second modulus of elasticity is higher than the first modulus of elasticity.