Flexible Sealing Plate Deformation for Battery Short Circuit Interruption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In battery systems where multiple cells are connected in parallel, internal short circuits can lead to excessive current flow, causing thermal runaway and safety hazards, as existing current interruption methods like fuses are inefficient and consume power, making it difficult to reliably prevent thermal runaway without unnecessary power loss.
Innovation Solution
A battery system design featuring flexible sealing plates that deform under increased internal pressure, triggering a current interrupt mechanism to disconnect parallel connections, thereby interrupting short circuit currents without the need for additional current interruption elements like fuses, ensuring safety by preventing thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fuse or traditional current interruption element is used to interrupt short circuit current, then the short circuit current can be interrupted, but unnecessary power is consumed and additional components are required
Solution Approach 1:
The sealing plate itself serves as the detection and actuation mechanism. When internal pressure rises due to thermal runaway, the sealing plate deforms autonomously to open the exhaust valve, interrupting the short circuit current without requiring external power or additional components like fuses
Solution Approach 2:
The sealing plate performs multiple functions: it seals the battery cell, detects internal pressure changes through deformation, and acts as the actuation mechanism to open the exhaust valve for current interruption, eliminating the need for separate detection and actuation components
2Reliability
If a CID (current interrupt device) is incorporated inside the battery cell to interrupt current when internal pressure rises, then current interruption is achieved, but the device cannot operate when internal temperature becomes abnormally high and insulating material melts
Solution Approach 1:
The sealing plate is designed as a flexible thin film structure that deforms under internal pressure. This flexible membrane maintains its structural integrity and responsiveness even at high temperatures, unlike rigid insulating materials that melt, enabling reliable current interruption under extreme thermal conditions
3Power
If multiple battery cells are connected in parallel to increase output current, then output power is increased, but thermal runaway can spread to adjacent cells through heat transfer
Solution Approach 1:
The harmful short circuit current is extracted and interrupted by opening the exhaust valve when the sealing plate deforms. This removes the electrical connection during thermal runaway, preventing heat transfer to parallel-connected cells while maintaining the parallel configuration for normal high-power operation
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 solution effectively and reliably prevents thermal runaway in adjacent battery cells by detecting deformation of the flexible sealing plates and interrupting short circuit currents, ensuring high safety without consuming unnecessary power or requiring additional current interruption elements.
Implementation Method 1
when a large current flows due to an internal short circuit and the internal pressure rises abnormally
Implementation Method 2
the sealing plate of the prismatic battery cell is a plate material having flexibility that deforms when an internal pressure rises
Data Source
AI summary
A short circuit current interruption method of a battery system including: stacking a plurality of prismatic battery cells and connecting the plurality of prismatic battery cells with a parallel connection bus bar in parallel to form a battery block, wherein a sealing plate of the prismatic battery cell is a plate material having flexibility that deforms when an internal pressure rises due to an internal short circuit, and when a rise in the internal pressure due to the internal short circuit of the prismatic battery cell causes deformation, the deformation of the sealing plate is detected, and when an amount of deformation exceeds a setting value, the short circuit current of the battery connected in parallel with the internally short circuited battery is interrupted.