Pouch Battery CID with Pressure Ball Safety
Solution Overview
Problem
Conventional pouch type lithium ion secondary batteries for vehicles have low physical strength and lack cell-level safety devices, leading to safety concerns such as thermal runaway and abnormal voltage induction during overcharging, which compromises driving safety.
Innovation Solution
A high voltage battery design incorporating a pouch type current interruptive device (CID) with a bypass function, featuring a 3-way CID operated by a pressure ball and functional safety plates to interrupt electric current and prevent overcharging, while increasing physical strength and assembly efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a conventional pouch type lithium ion secondary battery is used to increase energy storage capacity, then the energy storage capacity increases, but the physical strength of the sheath remains low and cell-level safety devices are absent
Solution Approach 1:
The patent employs composite material structures in the battery design, combining multiple materials with different properties to achieve both high energy storage capacity and enhanced physical strength. The sheath and internal components utilize composite constructions that maintain flexibility while improving mechanical robustness.
2Quantity of substance
If a conventional pouch type lithium ion secondary battery is used to increase energy storage capacity, then the energy storage capacity increases, but cell-level safety devices are not provided
Solution Approach 1:
The battery system is segmented into multiple independent safety zones, with individual cell-level safety devices installed in each pouch cell. This segmentation allows each cell to be monitored and protected independently, preventing catastrophic failure across the entire battery pack while maintaining high energy storage capacity.
Solution Approach 2:
Current interruptive devices (CID) and positive temperature coefficient (PTC) elements are introduced as intermediary safety components between the electrodes and external circuitry. These intermediaries detect abnormal conditions and automatically interrupt current flow, providing cell-level safety without compromising the energy storage capacity of the battery.
3Use of energy by moving object
If the battery is overcharged, then gas is generated and temperature increases, but thermal runaway may be induced resulting in fire
Solution Approach 1:
The battery system incorporates preliminary protective measures including CID devices and PTC elements that act before thermal runaway can occur. These devices continuously monitor charging conditions and preemptively interrupt current flow when abnormal temperature rise or gas generation is detected, preventing the harmful thermal runaway sequence from initiating.
Solution Approach 2:
The patent converts potentially harmful overcharging effects into beneficial safety signals. Gas generation and temperature increase, which are harmful indicators of overcharging, are detected by safety devices that transform these harmful effects into triggering mechanisms for current interruption, thereby preventing catastrophic failure.
4Quantity of substance
If an abnormal cell reaction occurs in one unit cell, then abnormal voltage is induced in the battery pack, but driving safety is reduced
Solution Approach 1:
The battery pack is divided into independently monitored and protected pouch cells, each equipped with cell-level safety devices. This segmentation isolates abnormal reactions to individual cells, preventing abnormal voltage from propagating across the entire battery pack and maintaining overall driving safety while preserving total energy storage capacity.
Solution Approach 2:
Cell-level safety devices including CID and PTC elements serve as intermediary protective barriers between individual cells and the battery pack system. When an abnormal cell reaction occurs, these intermediaries detect the anomaly and interrupt current flow in the affected cell, preventing abnormal voltage induction from spreading to other cells and compromising driving safety.
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 realizes cell-level safety and pack voltage safety by physically shorting the circuit upon abnormal pressure changes, preventing overcharge-induced igniting and enhancing the durability and marketability of vehicle batteries.
Implementation Method 1
the second part extension may move apart from the first part extension and may come into contact with the cathode extension while compressing the cushion
Implementation Method 2
a pouch type current interruptive device (CID, used as an overcharge safety device) having a bypass function, featuring a 3-way CID operated by a pressure ball
Data Source
AI summary
A high voltage battery for vehicles includes an anode tab that is divided into a first part placed near a battery cell and a second part placed near a terminal. A first part extension extends from the first part and is fixed to a lower pouch. A second part extension extends from the second part, comes into contact with the first part extension, and is fixed at an upper end thereof to an upper pouch. An cathode extension extends from a cathode tab and is spaced apart from the upper end of the second part extension. A cushion is interposed between the second part extension and the cathode extension, with a reference level of pressure formed in the cushion.