All-Solid-State Battery Can Structure for Low-Resistance Crimping
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Solution Overview
Problem
Conventional lithium-ion secondary batteries face issues with internal resistance due to electrically conductive elastic bodies and lack of protection against pressing forces during crimping, which can damage the cathode or anode layers in all-solid-state batteries.
Innovation Solution
An all-solid-state battery design featuring a recessed exterior can, a seal can with a flat portion, and recoverable conductive sheets between the power generation element and the cans to ensure electric contact and mitigate pressing forces, preventing damage to the layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If elastic bodies with conductor surfaces are used to ensure contact area and mitigate stress, then contact reliability is improved, but internal resistance increases due to the resistance component
Solution Approach 1:
The patent extracts the conductor material from the elastic body structure, placing the conductor separately at the bottom of the recessed portion rather than coating the elastic body. This separation eliminates the resistance component while maintaining the elastic body's stress-mitigating function, thereby reducing internal resistance while preserving contact reliability.
Solution Approach 2:
The patent introduces a conductor as an intermediary element positioned at the bottom of the recessed portion, which mediates between the elastic body and the external circuit. This conductor provides a low-resistance electrical pathway while the elastic body maintains mechanical contact and stress absorption, resolving the contradiction between contact reliability and internal resistance.
2Reliability
If a recessed portion is provided in the bottom wall to contain the power generation element, then sealability is improved, but pressing forces during crimping may damage the cathode or anode layers
Solution Approach 1:
The patent places an elastic body at the bottom of the recessed portion before crimping occurs. This elastic body acts as a cushioning element that absorbs and distributes the pressing forces generated during the crimping process, preventing direct transmission of harmful forces to the cathode and anode layers while maintaining the sealability provided by the recessed portion structure.
3Reliability
If the battery is crimped to ensure sealability, then sealing performance is improved, but stress generated during crimping may crack the positive and negative electrodes
Solution Approach 1:
The elastic body is positioned in advance at the bottom of the recessed portion to provide cushioning during crimping. This pre-positioned cushioning element absorbs the stress generated during the crimping process, protecting the electrodes from cracking while allowing the crimping operation to proceed for achieving sealability.
Solution Approach 2:
The patent employs an elastic body (flexible element) at the bottom of the recessed portion that can deform under crimping stress. This flexible element absorbs and distributes the mechanical stress, preventing stress concentration that would otherwise lead to electrode cracking, thereby maintaining both sealing performance and electrode integrity.
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 design maintains good conductivity and prevents damage to the cathode or anode layers by absorbing pressing forces during crimping, ensuring reliable sealability and battery performance.
Implementation Method 1
at least one of a first recoverable conductive sheet located between the inner bottom surface of the recessed portion and the power generation element, and a second recoverable conductive sheet located between the flat portion of the seal can and the power generation element
Data Source
AI summary
An all-solid-state battery 1 includes: an exterior can 2 having a bottom 21 and a cylindrical side wall 22; a negative-electrode can 3 having a flat portion 31 and a peripheral wall 32; a power generation element 4 located between the exterior can 2 and the negative-electrode can 3; a gasket 6 positioned between the cylindrical side wall 22 and peripheral wall 32; and recoverable conductive sheets 5. The bottom 21 of the exterior can 2 includes a recessed portion 211 recessed toward the outside. A recoverable conductive sheet 5 is located between the power generation element 4 and the inner bottom surface of the recessed portion 211, and another recoverable conductive sheet is located between the power generation element 4 and the flat portion 31 of the seal can 3.