Electrode Bending Jig for Accurate Winding-Condition Tensile Testing
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Solution Overview
Problem
Current methods for evaluating the tensile strength of electrodes in secondary batteries, such as pencil hardness testers and nanoindenters, are inaccurate and costly, and fail to represent the properties of the entire electrode structure, including the active material layer and current collector, while existing bending tests do not measure tensile strength effectively.
Innovation Solution
A jig assembly and apparatus for measuring bending tensile strength, which simulates the winding process by bending the electrode around a core-like radius, using a bending jig and a tensile strength measuring device to apply force and calculate the tensile strength, ensuring accuracy and cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional evaluation methods (pencil hardness tester, nanoindenter) are used to measure tensile strength of electrodes, then measurement can be performed, but the measurement precision is inaccurate and the device complexity is costly
Solution Approach 1:
The patent replaces expensive, complex evaluation devices (pencil hardness testers, nanoindenters) with a simple, inexpensive jig assembly that can be easily manufactured and disposed of. The jig uses basic mechanical components like bending rods and fixing fixtures that are far cheaper than conventional sophisticated measurement equipment, while still providing accurate tensile strength measurements under winding conditions.
Solution Approach 2:
The patent substitutes complex mechanical measurement systems with a straightforward mechanical bending and tensile testing setup. Instead of using sophisticated instruments like nanoindenters that rely on complex mechanical and electronic systems, the invention uses a simple jig that applies controlled bending and tensile forces directly to the electrode, making the measurement process both simpler and more accurate for this specific application.
2Measurement precision
If conventional evaluation methods are used, then measurement can be performed, but they fail to represent the properties of the entire electrode structure including active material layer and current collector
Solution Approach 1:
The patent segments the electrode evaluation into two distinct phases: first bending the electrode to simulate winding conditions and create realistic stress distributions, then applying tensile force to measure strength. This segmentation allows the test to capture the combined properties of both the active material layer and current collector under conditions that mirror actual battery manufacturing, providing representative measurements that conventional single-step methods cannot achieve.
Solution Approach 2:
The patent performs a preliminary bending action on the electrode before applying tensile force. This preliminary bending pre-conditions the electrode by creating the same curvature and stress state that occurs during actual winding in battery manufacturing. By performing this action in advance, the subsequent tensile strength measurement accurately reflects the electrode's properties under realistic conditions, including the interaction between the active material layer and current collector.
3Strength
If existing bending tests are used, then bending can be tested, but tensile strength cannot be measured effectively
Solution Approach 1:
The patent merges two previously separate test functions into a single integrated jig assembly: bending testing and tensile strength measurement. The jig simultaneously performs both operations by first bending the electrode around a rod to simulate winding, then applying tensile force through the same fixture. This merging allows effective tensile strength measurement under bending conditions without complicating the operation, as both functions are achieved through a unified, simple mechanical system.
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 accurate measurement of tensile strength under conditions similar to real-world winding, reducing crack occurrence and optimizing winding radius and tension, thus improving battery performance and ease of specification.
Implementation Method 1
using a bending jig and a tensile strength measuring device to apply force and calculate the tensile strength
Implementation Method 2
a tensile strength measuring device to apply force and calculate the tensile strength
Data Source
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AI summary
Provided is a jig assembly for measuring the tensile strength of an electrode at a bend having a similar radius to a core, an apparatus for measuring bending tensile strength including the jig assembly, and a method for measuring bending tensile strength that measures the tensile strength of an electrode at a bend having a similar radius to a core using the apparatus for measuring bending tensile strength. The jig assembly of the present disclosure includes a fixing unit which fixes one end part of a sample, and a bending jig of plate shape which causes one point bend to a lengthwise direction cross section of the sample having one fixed end part and guides the other end part of the sample toward a tensile testing load unit. According to the present disclosure, it is possible to measure the tensile strength of the electrode under a similar condition to a winding process before the electrode is used in real winding applications.