All-Solid-State Battery Short-Circuit Layer Evaluation
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Solution Overview
Problem
Existing methods for evaluating power storage devices when internal short-circuiting occurs due to conductive foreign matter are inefficient, particularly for high-capacity devices, as they struggle to control the number of short-circuited layers.
Innovation Solution
A method involving a conductive rod-shaped member inserted into the power storage device's stack portion, with potential differences measured between the reference electrode and the rod-shaped member to control the insertion and stop the rod when specific potential differences are detected, allowing for controlled short-circuiting between single layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the evaluation jig is inserted into the power storage device to a depth where internal short-circuiting occurs, then local internal short-circuiting can be caused, but it is difficult to control the number of short-circuited layers in high-capacity power storage devices
Solution Approach 1:
The patent implements feedback control by continuously monitoring the voltage of the power storage device during insertion of the evaluation jig. When the voltage change reaches a predetermined threshold, the insertion is automatically stopped. This feedback mechanism enables precise control of the number of short-circuited layers while maintaining evaluation efficiency, resolving the contradiction between measurement precision and productivity.
2Measurement precision
If the power storage device is disassembled to insert a conductive foreign matter for evaluation, then local internal short-circuiting can be precisely controlled, but the operation becomes complex and requires high skills
Solution Approach 1:
The patent applies preliminary action by pre-setting the voltage change threshold that determines when to stop insertion. This predetermined criterion eliminates the need for complex manual operations and high skills during the evaluation process, while still achieving precise control over short-circuited layers. The operation is simplified to merely inserting the evaluation jig until the automatic stop condition is met.
Solution Approach 2:
The patent replaces the mechanical/disassembly-based method with an electrical measurement-based method. Instead of physically disassembling the device and manually positioning conductive foreign matter, the system uses voltage monitoring to control the insertion depth of the evaluation jig, substituting mechanical precision requirements with electrical measurement and control.
3Ease of operation
If the evaluation jig insertion is stopped when voltage lowering exceeds a threshold value, then the operation is simple, but it is difficult to control the number of short-circuited layers in high-capacity power storage devices
Solution Approach 1:
The patent changes the monitoring parameter from absolute voltage lowering to voltage lowering rate or voltage change per unit insertion distance. This parameter transformation maintains operational simplicity while enabling precise control of short-circuited layers, as the modified parameter scales appropriately with device capacity and provides better correlation with the number of affected layers.
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 enables precise control over the number of short-circuited layers, facilitating efficient evaluation of power storage devices, including high-capacity ones, without the need for disassembly.
Implementation Method 1
a potential difference between a reference electrode and the rod-shaped member is measured
Data Source
AI summary
A method of evaluating an all-solid-state battery includes preparing the all-solid-state battery. A charge level of the all-solid-state battery is adjusted to produce a first potential difference between a positive electrode and a negative electrode. The positive electrode or the negative electrode is selected as a reference electrode. After the charge level is adjusted, an operation to insert a conductive rod-shaped member into a stack portion along a direction of stack of the positive electrode and the negative electrode is performed while a second potential difference between the reference electrode and the rod-shaped member is measured. The rod-shaped member is stopped. The all-solid-state battery is evaluated based on a state of the all-solid-state battery after the rod-shaped member is stopped.