Battery Separator Structure for Cell Expansion and Thermal Insulation
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Solution Overview
Problem
Existing separators in stacked battery cells, which use silica aerogel for thermal insulation, deteriorate when compressed, leading to non-uniform pressure distribution, increased weight and size, and require strong materials, failing to absorb battery expansion effectively.
Innovation Solution
Incorporating rubber-like elastic sheets on the surface of heat insulating sheets with silica aerogel, partitioned into stacked and non-stacked regions, to absorb battery expansion and reduce pressure on end plates and binding bars, maintaining thermal insulation and preventing thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a separator using silica aerogel is used to achieve excellent thermal insulating properties, then thermal insulation is improved, but the thermal insulating properties are deteriorated when the silica aerogel is broken by external pressure
Solution Approach 1:
The patent applies this principle by introducing a flexible support sheet that provides mechanical strength to the separator structure. The support sheet acts as a flexible shell that protects the brittle silica aerogel particles from breaking under external pressure, while allowing the separator to maintain its thermal insulation function. The support sheet is positioned to distribute and disperse the pressing force, preventing concentration of stress on the silica aerogel particles.
2Reliability
If the separator is folded and stacked to form a multilayer structure to prevent destruction of silica aerogel, then thermal insulation stability is improved, but the entire separator becomes thick and the internal structure becomes uneven
Solution Approach 1:
The patent applies this principle by providing the support sheet only in specific regions where pressing forces are concentrated, rather than throughout the entire separator. This localized support prevents silica aerogel destruction in critical areas while avoiding the need for a uniformly thick multilayer structure. The support sheet is strategically positioned to provide reinforcement only where needed, maintaining overall separator thinness.
3Manufacturing precision
If the separator cannot uniformly pressurize and support the pressing surface of the battery cells, then manufacturing precision is improved, but the electrodes of the battery cells are adversely affected
Solution Approach 1:
The patent applies this principle by introducing the support sheet as an intermediary element between the battery cells and the separator. The support sheet acts as a mediator that distributes pressing forces uniformly across the battery cell surfaces, preventing localized stress concentrations that could damage electrodes. This intermediary layer ensures both uniform pressure distribution for manufacturing precision and protection of electrode integrity.
4Device complexity
If the separator does not include elastic material to absorb expansion of battery cells, then device complexity is reduced, but the pressure of battery cells rapidly rises and extremely strong force acts on end plates and binding bars
Solution Approach 1:
The patent applies this principle by changing the physical parameters of the separator through the addition of the support sheet. The support sheet modifies the mechanical properties of the separator, enabling it to withstand and distribute the forces generated by battery cell expansion. This parameter change allows the separator to absorb expansion forces without requiring complex elastic materials, maintaining structural simplicity while reducing peak forces on end plates and binding bars.
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 maintains excellent heat insulation, reduces stress on end plates and binding bars, prevents thermal runaway, and ensures safety by mitigating pressure changes and positional displacement of battery cells.
Implementation Method 1
rubber-like elastic sheets 6 stacked on both surfaces of heat insulating sheet 5 to absorb expansion of battery cells 1
Implementation Method 2
The separator insulates heat conduction between the battery cells and suppresses induction of thermal runaway of the battery cells
Data Source
AI summary
A power supply device has end plates disposed at both ends of a battery block in which a plurality of battery cells and separator are stacked and connected by a binding bar. Separator includes heat insulating sheet including a fiber sheet and silica aerogel, and rubber-like elastic sheets stacked on a surface of heat insulating sheet. Furthermore, separator is provided with stacked region where rubber-like elastic sheets are stacked and non-stacked region where rubber-like elastic sheets are not stacked.