Electrochemical Cell Fault Screening by Differential Voltage Measurement
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Solution Overview
Problem
Current methods for detecting internal short circuits in electrochemical cells are time-consuming and insensitive, requiring weeks or months and draining the electro-potential of cells, making them inefficient and risky.
Innovation Solution
Measuring the voltage difference or rate of change in voltage difference between the same polarity terminals of multiple cells to rapidly and sensitively detect internal faults, such as internal shorts, using a high-resolution voltage measurement device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional open circuit voltage monitoring methods are used to detect internal short circuits, then detection sensitivity is achieved, but testing time is excessively long (7-28 days)
Solution Approach 1:
The patent changes the measurement parameter from single-cell open circuit voltage to voltage difference between two cells. This parameter transformation enables detection of internal shorts in less than 1% of the traditional time while maintaining or improving sensitivity, as the differential measurement amplifies the signal from internal faults.
Solution Approach 2:
The patent transitions from one-dimensional measurement (single cell voltage) to two-dimensional measurement (voltage difference between two cells). By introducing a reference cell and measuring the differential voltage, the system gains an additional dimension of information that accelerates detection without sacrificing precision.
2Reliability
If traditional aging protocols are used to screen for internal faults, then internal short detection is achieved, but cell electro-potential is drained
Solution Approach 1:
The patent uses the cells themselves as the measurement source without requiring external energy input or prolonged activation. The voltage difference measurement is passive and does not drain cell electro-potential, allowing rapid screening while preserving cell energy for subsequent use.
Solution Approach 2:
The patent replaces the traditional active aging protocol (which requires prolonged cell activation and energy consumption) with a passive electrical measurement system. The voltage difference measurement requires no cell activation, eliminating energy drain while maintaining detection reliability.
3Reliability
If traditional voltage decay threshold methods are used, then internal shorts are detected, but the screening process dominates total manufacturing cycle time
Solution Approach 1:
The patent performs the critical detection measurement immediately after cell assembly rather than waiting for prolonged aging. The voltage difference measurement can be conducted right away, eliminating the need for weeks of aging and dramatically reducing the portion of manufacturing time dominated by screening.
Solution Approach 2:
The patent skips the traditional prolonged aging step entirely by using voltage difference measurement. This method rushes through the detection process in less than 1% of the traditional time, allowing rapid identification of defective cells without sacrificing detection reliability.
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 method allows for the detection of internal faults in less than 1% of the time required by traditional methods, with greater sensitivity, enabling rapid identification of high-resistance shorts and self-discharge.
Implementation Method 1
measuring a voltage difference or a rate of change in voltage difference between a test terminal of a first electrochemical cell and a test terminal of a second electrochemical cell where the test terminals have the same polarity
Data Source
Figure 1~2B
Figure 3~4
Figure 5~6
AI summary
A process and system for measuring internal faults in an electrochemical cell. The process for detecting an internal fault in an electrochemical cell includes measuring a voltage difference or a rate of change in voltage difference between a common terminal of a first electrochemical cell and a second electrochemical cell. The measuring is a time measurement. The first electrochemical cell or second electrochemical cell is accepted based on the measuring, or first electrochemical cell or second electrochemical cell is rejected based on the measure of the internal fault of the electrochemical cell.