Battery Cell Vent Fuse for Pressure Relief and Current Blocking
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Solution Overview
Problem
Battery cells face safety and reliability issues due to excessive heat and pressure buildup, leading to potential fires and thermal runaway, which can cause chain ignition of adjacent cells.
Innovation Solution
A battery cell design that includes a vent fuse system, which blocks current flow and delays thermal runaway by discharging gas or deforming a vent cover when internal pressure exceeds a threshold, preventing the propagation of flames to adjacent cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a vent cover is disposed in a venting hole to open when pressure reaches a threshold, then gas discharge and pressure relief are improved, but current flow blocking and thermal runaway prevention are not adequately addressed
Solution Approach 1:
A vent fuse is introduced as an intermediary component between the electrode terminal and the outside environment. This vent fuse includes a fuse body with a melting portion that responds to abnormal conditions (excessive current, temperature, or pressure) by melting and blocking the venting hole, thereby preventing harmful gas discharge and current flow while allowing normal venting operation under safe conditions
Solution Approach 2:
The vent fuse operates autonomously by utilizing the abnormal conditions themselves (excessive current, temperature, or pressure) to trigger its protective function. When these abnormal conditions occur, they directly cause the melting portion to melt and block the venting hole, eliminating the need for external control systems or additional sensors
2Stress or pressure
If the venting hole is opened to discharge gas, then pressure relief is improved, but current flow continues to pose a safety risk
Solution Approach 1:
The vent fuse acts as an intermediary that simultaneously addresses both gas discharge and current flow control. The fuse body with its melting portion blocks both the venting hole and the electrical circuit when abnormal conditions occur, preventing harmful gas discharge and current flow through a single integrated component
Solution Approach 2:
The vent fuse combines multiple protective functions into a single component: it serves as both a pressure relief mechanism (by controlling gas discharge through the venting hole) and an electrical circuit protection device (by blocking current flow through the electrode terminal). This merging of functions eliminates the need for separate safety mechanisms
3Reliability
If thermal runaway occurs in one battery cell, then that cell experiences flame propagation, but adjacent battery cells are not protected
Solution Approach 1:
The vent fuse provides segmentation by creating an isolated blocking mechanism within each individual battery cell. When abnormal conditions occur in one cell, the vent fuse in that specific cell blocks the venting hole and current flow, preventing flame propagation to adjacent cells while allowing other cells to continue operating normally
Solution Approach 2:
The vent fuse implements preliminary anti-action by proactively blocking the venting hole and current flow before thermal runaway can spread to adjacent cells. When abnormal conditions (excessive current, temperature, or pressure) are detected, the melting portion melts and creates a barrier that prevents flame propagation in advance
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 effectively stabilizes the battery cell by blocking current flow and reducing the risk of thermal runaway, thereby enhancing the safety and reliability of battery devices by preventing the spread of fires between adjacent cells.
Implementation Method 1
a vent fuse electrically connected to the electrode terminal and configured to operate to block current flow between the electrode terminal and the outside thereof by discharging gas through the vent cover or by deforming the vent cover
Data Source
AI summary
Provided is a battery cell including: a case configured to accommodate an electrode assembly; a cap plate configured to cover the case; an electrode terminal disposed on the cap plate and electrically connected to the electrode assembly; a vent cover disposed in a venting hole to open the venting hole when pressure inside the case is equal to or greater than a predetermined pressure; and a vent fuse electrically connected to the electrode terminal and configured to operate to block current flow between the electrode terminal and the outside thereof by discharging gas through the vent cover or by deforming the vent cover.