Battery Cell Cap Plate Melting Path for Thermal Runaway Venting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thermal runaway events in secondary batteries can lead to heat propagation and safety issues due to ignition, posing risks to neighboring cells.
Innovation Solution
A secondary battery design featuring a case with a high-melting-point material and a cap plate with a lower melting point, directing heat and flame away from the battery through the cap plate during thermal events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a uniform high-melting-point material is used for the entire case, then structural strength and containment capability are improved, but heat dissipation efficiency during thermal runaway is reduced
Solution Approach 1:
The case is constructed with different materials for different portions: the first portion (side and bottom) uses a high-melting-point material for structural strength, while the second portion (top/cap) uses a low-melting-point material for heat dissipation. This local differentiation resolves the contradiction by assigning optimal material properties to specific functional zones.
Solution Approach 2:
The case employs a composite structure combining at least two different materials with distinct melting points. The high-melting-point material provides structural integrity while the low-melting-point material facilitates controlled heat release, achieving both strength and heat dissipation efficiency simultaneously.
2Use of energy by moving object
If thermal runaway occurs in a battery cell, then energy release is inevitable, but heat propagation to neighboring cells increases safety risks
Solution Approach 1:
The low-melting-point cap plate material is designed to melt during thermal runaway, converting the harmful heat energy into a beneficial controlled release mechanism. The melting process creates a controlled venting path that directs heat and gas away from neighboring cells, transforming a potentially catastrophic event into a managed safety feature.
Solution Approach 2:
The cap plate acts as an intermediary component between the internal battery environment and the external surroundings. During thermal runaway, it serves as a controlled interface that manages heat and pressure release, preventing direct uncontrolled propagation to adjacent cells while allowing safe energy dissipation.
3Reliability
If the cap plate covers a larger area of the opening, then heat direction control is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies an optimal area coverage range (90-100% of the opening area) that balances heat direction control effectiveness with manufacturing feasibility. This parameter optimization ensures sufficient heat management performance while maintaining reasonable tolerance ranges for mass production.
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
Prevents heat propagation to adjacent cells, reducing the likelihood of thermal runaway and enhancing safety by directing flames and heat through the cap plate with a lower melting point.
Implementation Method 1
a melting point of the second material is lower than a melting point of the first material
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure relates to a battery cell. A battery cell according to an embodiment includes a case including a sidewall portion having a cylindrical shape and including a receiving space, and an opening provided at one end of the sidewall portion, an electrode assembly received in the receiving space, and a cap plate covering the opening, in which the case includes a first material, the cap plate includes a second material, and a melting point of the second material is lower than a melting point of the first material.