Battery Module Membrane Venting for Thermal Isolation
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Solution Overview
Problem
Existing battery modules lack effective safety measures to prevent overheated cells from causing thermal runaway and damaging neighboring cells, as they do not efficiently divert and dissipate hot gases generated during venting.
Innovation Solution
A battery module design featuring cylindrical cells with safety valves and a membrane system that directs hot gases away from neighboring cells, utilizing a membrane with predetermined bursting points and an electrical circuit to track venting events, along with a gas channel and valve system to expedite gas discharge, ensuring safe and targeted venting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hot gas from vented battery cells is allowed to escape directly into the battery module, then the venting function is achieved, but thermal contact with neighboring cells occurs causing thermal runaway risk
Solution Approach 1:
The battery module is divided into separate cavities for each battery cell, with each cavity independently sealed. This segmentation prevents hot gas from one cell from contacting neighboring cells, as each cell operates in its own isolated thermal zone defined by partitions and sealed with individual membranes.
Solution Approach 2:
A membrane is introduced as an intermediary component between the battery cells. The membrane seals each cell's cavity and can be opened by overpressure to vent hot gas away from neighboring cells. This intermediary structure enables controlled venting while maintaining thermal isolation between cells.
2Reliability
If a membrane system with predetermined bursting points is implemented to direct hot gases, then thermal isolation is improved, but device complexity increases
Solution Approach 1:
A membrane made of flexible material is used to seal each battery cell cavity. The membrane incorporates predetermined bursting points that fail at specific pressure thresholds, providing automatic venting functionality. This thin-film approach achieves thermal isolation and pressure relief with relatively simple structure compared to rigid mechanical valves.
Solution Approach 2:
The membrane system with predetermined bursting points provides self-service pressure relief without external control. When overpressure occurs in a battery cell cavity, the membrane automatically bursts at the predetermined point to vent hot gas, eliminating the need for complex electronic sensors or actuated valves.
3Reliability
If safety valves are arranged on each end face of cylindrical battery cells, then venting coverage is improved, but manufacturing complexity increases
Solution Approach 1:
Safety valves are segmented and distributed on each end face of cylindrical battery cells rather than concentrated in one location. This segmentation ensures that each cell has adequate venting capability from multiple directions, improving overall venting coverage while maintaining manageable manufacturing complexity through modular assembly.
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
This design enhances safety by preventing thermal contact between overheated cells and neighbors, facilitates easy identification and replacement of defective cells, and reduces the risk of module-wide temperature increases through controlled gas discharge, thereby improving overall module reliability and maintenance.
Implementation Method 1
A part of the membrane is designed to be opened by an overpressure in the cavity
Implementation Method 2
The metal layer can be provided, for example, to stiffen the elastomer layer and/or to dissipate heat or cool
Implementation Method 3
The membrane has an electrical circuit. The electrical circuit is set up to be changed by an opened predetermined rupture point. The position of the opened predetermined bursting point can then be determined as a function of the change in the electrical circuit, for example the position is determined as a function of a change in resistance in the electrical circuit
Data Source
Figure 1
Figure 2
AI summary
Battery module (100) comprising at least two battery cells (110) each with a safety valve (111) for venting the battery cell (110), wherein the safety valve (111) of the battery cell (110) is arranged on one side (112) of the battery cell (110) facing a cavity (130), wherein each battery cell (110) has a separate cavity (130) at the safety valve (111) of the battery cell (110), the cavity (130) being bounded by the battery cell (110), a sealing element (120, 160) and a membrane (140), and a part of the membrane (140) being arranged to be opened by an overpressure in the cavity (130).