Battery Cell Impedance Jig Layout for Low-Inductance Measurement
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Solution Overview
Problem
Existing impedance measurement methods for rechargeable batteries are distorted by inductance due to the structure or arrangement of measurement equipment components, which affects the accuracy of the impedance readings.
Innovation Solution
A characteristic measuring apparatus with a support and impedance measuring part that includes non-overlapping terminals for current and voltage, minimizing inductance interference by arranging the terminals in a non-collinear manner to reduce magnetic field effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional measurement equipment components (current lines, voltage lines) are arranged in overlapping or collinear manner, then device complexity is reduced, but inductance increases causing impedance measurement distortion
Solution Approach 1:
The patent applies asymmetry by arranging current terminals and voltage terminals in non-overlapping, non-collinear positions on the battery cell terminals. Specifically, the current terminals are positioned at opposite ends of the battery cell while voltage terminals are positioned at adjacent locations, creating an asymmetric configuration that minimizes inductance. This asymmetric arrangement breaks the symmetry of conventional overlapping terminal configurations, reducing magnetic field coupling and inductance effects that distort impedance measurements.
Solution Approach 2:
The patent transitions from a one-dimensional collinear or overlapping terminal arrangement to a two-dimensional spatial distribution. The terminals are positioned at different locations on the battery cell surface rather than along a single line, creating a planar configuration. This dimensional change increases the spatial separation between current and voltage terminals, reducing mutual inductance and improving measurement accuracy without significantly increasing device complexity.
2Measurement precision
If terminals for current and voltage are arranged in overlapping manner, then device complexity is minimized, but inductance increases causing measurement distortion
Solution Approach 1:
The patent extracts the harmful inductance effect by separating current terminals from voltage terminals in space. By removing the overlapping arrangement and positioning terminals at distinct locations on the battery cell, the magnetic field generated by current flow does not couple with the voltage sensing leads. This spatial extraction of current paths from voltage measurement paths eliminates the primary source of inductance interference, allowing accurate impedance measurement.
Solution Approach 2:
The patent converts the potential harm of close terminal proximity into benefit by deliberately positioning terminals at optimal distances. The non-overlapping arrangement ensures that terminals are close enough to maintain good electrical contact and minimize contact resistance, yet far enough to reduce mutual inductance. This optimized positioning transforms the geometric relationship from harmful (overlapping causing high inductance) to beneficial (spatially optimized for low inductance and low contact resistance).
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 apparatus effectively reduces inductance, improving the accuracy of impedance measurements by minimizing resistance and distortion, allowing for precise characterization of battery cells.
Implementation Method 1
an impedance measuring part that is detachable from the positive electrode terminal and the negative electrode terminal of the battery cell
Data Source
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AI summary
A characteristic measuring jig of a battery cell for a rechargeable battery according to an embodiment of the present disclosure includes a support on which a battery cell including a positive electrode terminal and a negative electrode terminal is provided, an impedance measuring part that is detachable to the positive electrode terminal and the negative electrode terminal of the battery cell, and an elevating part connected to the impedance measuring part to be fixed to the support, and configured to elevate the impedance measuring part. The impedance measuring part includes first and second positive electrode contact parts in contact with the positive electrode terminal, first and second negative electrode contact parts in contact with the negative electrode terminal and disposed opposite to the first and second positive electrode contact parts, a first terminal for current connected to the first positive electrode contact part and for applying current to the battery cell, a first terminal for voltage connected to the second positive electrode contact part and for measuring the voltage of the battery cell, a second terminal for current connected to the first negative electrode contact part and for applying current to the battery cell, and a second terminal for voltage connected to the second negative electrode contact part and for measuring voltage of the battery cell. The elevating part is connected to the first and second positive electrode contact parts or the first and second negative electrode contact parts, and is configured to elevate the first and second positive electrode contact parts or the first and second negative electrode contact parts with respect to the battery cell. The first terminal for current is disposed opposite to the first terminal for voltage, and the second terminal for current is disposed opposite to the second terminal for voltage.