IPMC-Based Internal Short Circuit Evaluation Method
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for evaluating internal short circuits in secondary batteries are limited by requiring high temperatures, high pressures, or causing unintended chemical reactions, making it difficult to accurately assess stability and safety.
Innovation Solution
A method using an ionic polymer-metal composite (IPMC) is inserted into the battery to induce internal short circuits by bending deformation, allowing evaluation at room temperature and atmospheric pressure, with adjustable voltage to control the location, area, and duration of the short circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nail penetration test or crush test is used to induce internal short circuit, then internal short circuit can be caused, but chemical reaction occurs at the broken separator part causing unintended reactions
Solution Approach 1:
The patent introduces a shape memory alloy as an intermediary device to induce internal short circuit. The shape memory alloy acts as a mediator that, when heated, changes its shape to physically contact the electrodes and cause short circuit without directly breaking the separator, thereby avoiding the chemical reaction problem associated with direct penetration or crushing methods.
Solution Approach 2:
The patent replaces the direct mechanical penetration or crushing method with a thermally-actuated shape memory alloy mechanism. Instead of using nails or crush bars that directly break the separator, the system uses thermal energy to activate the shape memory alloy, which then mechanically induces the short circuit in a controlled manner.
2Reliability
If shape memory alloy is used to induce internal short circuit, then internal short circuit can be caused, but high temperature atmosphere or heating above specific temperature is required
Solution Approach 1:
The shape memory alloy is pre-installed within the battery structure in a specific configuration. The preliminary positioning of the shape memory alloy allows it to be activated by relatively mild heating, as its pre-positioned state enables efficient thermal actuation and direct contact with electrodes when activated.
Solution Approach 2:
The patent utilizes the temperature-dependent phase transformation property of shape memory alloy. By changing the temperature parameter (heating above the transformation temperature), the alloy undergoes a reversible phase change that alters its shape and triggers the internal short circuit, providing a controlled method to induce failure conditions.
3Reliability
If traditional internal short circuit evaluation methods are used, then stability assessment can be performed, but evaluation is limited to specific conditions (high temperature, high pressure) and cannot be performed at room temperature
Solution Approach 1:
The shape memory alloy-based evaluation method provides a universal approach that can be applied across different battery types and testing conditions. The same shape memory alloy mechanism can induce internal short circuits both at room temperature and under extreme conditions, making the evaluation method versatile and adaptable to various testing scenarios without requiring different test setups.
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
Enables precise evaluation of internal short circuits at desired positions and times, improving safety assessments and stability testing of secondary batteries without the limitations of traditional methods.
Implementation Method 1
by inserting an ionic polymer-metal composite (IPMC) inside the battery cell and applying a voltage to an external conductor electrically connected to the ionic polymer-metal composite, an internal short circuit is induced by bending deformation of the ionic polymer-metal composite
Data Source
AI summary
A method for evaluating an internal short, of the present invention, inserts ionic polymer-metal composites (IPMC) in a battery cell, and applies a voltage to an external conducting wire electrically connected to the IPMC, so as to induce an internal short by means of flexural deformation of the IPMC, thereby evaluating whether the internal short occurs. The method for evaluating an internal short, according to the present invention, inserts and positions, in a battery, the IPMC capable of operating even at room temperature and low voltages and adjusts the voltage, thereby having an advantage of enabling a short to occur at a desired position and area and for a desired period of time.