Electrode Assembly Pulse Testing for Micro-Short Detection
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Solution Overview
Problem
Medium-to-large sized rechargeable batteries face issues with microscopic short circuits in separators due to pinholes, leading to electrochemical reactions that can cause salt precipitation and ignition, which existing testing methods struggle to detect effectively.
Innovation Solution
An electrode assembly short-circuit test apparatus and method that applies continuous pulses and improves surface pressure using silicon pads with varying thicknesses and hardnesses to enhance detection of micro-short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional testing methods are used to detect micro-short circuits in separators, then the testing process is simple, but the detection rate of micro-short circuits and foreign substances is low
Solution Approach 1:
The patent applies periodic pulse voltage instead of continuous voltage to the electrode assembly. The pulse voltage is applied in cycles with specific width and interval parameters, creating periodic action that generates cumulative thermal effects at micro-short circuit sites while avoiding continuous heating that would mask the detection signal
Solution Approach 2:
The patent changes the voltage application parameters by using pulsed voltage with specific width (e.g., 1ms) and interval (e.g., 9ms) ratios, rather than continuous voltage. This parameter change enables the detection system to distinguish between normal thermal effects and those caused by micro-short circuits
2Measurement precision
If surface pressure is increased to improve detection of micro-short circuits, then detection sensitivity improves, but the electrode assembly may be damaged
Solution Approach 1:
The periodic pulsing of voltage creates intermittent thermal stress rather than continuous stress, allowing the electrode assembly to recover between pulses and preventing cumulative damage while still enabling detection of micro-short circuits through thermal response
Solution Approach 2:
The patent applies voltage pulses with width and interval parameters that are optimized to provide just enough stress to detect micro-short circuits without exceeding the tolerance of the electrode assembly structure
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 method significantly increases the detection rate of foreign substances and micro-short circuits in electrode assemblies, ensuring reliable and safe battery performance by identifying potential issues before they escalate.
Implementation Method 1
when a current/voltage is applied to the electrode assembly, the lattice at a micro-short circuit site in the separator impacts with electrons and is ionized, and the additionally generated electrons impact with other lattices and become ionized, raising a temperature in a short period of time
Implementation Method 2
a first plate configured to press a first side of an electrode assembly... a second plate configured to press a second side of the electrode assembly against the first plate
Data Source
AI summary
An electrode assembly short-circuit test apparatus for a rechargeable battery, includes: a first plate to press a first side of an electrode assembly, the electrode assembly including a negative electrode, a positive electrode, and a separator between the negative electrode and the positive electrode; a second plate to press a second side of the electrode assembly against the first plate; and a continuous pulser connected to a negative electrode tab and a positive electrode tab of the electrode assembly to apply continuous pulses to the negative electrode tab and the positive electrode tab.