Prismatic Battery Discharge Pipe for Electrolyte-First Venting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary batteries are prone to thermal runaway due to electrolyte decomposition and pressure buildup, which can lead to rupture and fire, despite existing vents that discharge gas, as residual electrolyte remains and continues to decompose.
Innovation Solution
Incorporating a discharge pipe within the battery case that discharges electrolyte before gas, using an insulating material non-reactive with the electrolyte, to prevent further decomposition and thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a vent is provided to discharge gas when pressure exceeds a certain level, then the internal pressure of the battery is maintained at a safe level, but thermal runaway may still occur due to residual electrolyte decomposition
Solution Approach 1:
The discharge pipe is positioned at the lower end of the case to preliminarily discharge electrolyte before gas discharge occurs. This preliminary action removes the decomposable electrolyte in advance, preventing thermal runaway that would otherwise occur after pressure relief
Solution Approach 2:
The discharge function is segmented into two separate pathways: a gas discharge vent at the upper end and an electrolyte discharge pipe at the lower end. This segmentation allows independent control of gas and electrolyte discharge, enabling selective removal of electrolyte to prevent thermal runaway
2Object-generated harmful factors
If the vent opens to discharge gas, then pressure is relieved, but the residual electrolyte continues to decompose and may cause rupture and fire
Solution Approach 1:
The electrolyte is extracted and removed from the system through the discharge pipe positioned at the lower end, separate from the gas vent. This extraction eliminates the harmful residual electrolyte that would otherwise continue to decompose after pressure relief
Solution Approach 2:
The discharge pipe structure converts the harmful effect of electrolyte decomposition into a beneficial outcome by providing a dedicated pathway for electrolyte removal. The lower-positioned pipe utilizes pressure differential to automatically discharge electrolyte, transforming the decomposition risk into a controlled discharge mechanism
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 thermal runaway by discharging residual electrolyte first, thereby minimizing further decomposition and reducing the risk of rupture and fire.
Implementation Method 1
When the pressure inside the case exceeds a reference pressure, the vent may open to discharge the electrolyte and then to discharge the gas from inside the case
Implementation Method 2
The discharge pipe may be made of an insulating material that is non-reactive with the electrolyte
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A secondary battery includes: a prismatic case; an electrode assembly accommodated inside the case with an electrolyte; a cap assembly coupled to one end of the case and having a vent; and a discharge pipe inside the case and having one end adjacent to a lower surface of the case and another end in communication with the vent.