Cylindrical Battery Current Collector for Emergency Electrode Withdrawal
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Solution Overview
Problem
Existing cylindrical secondary batteries face difficulties in withdrawing the electrode assembly during a fire due to the second current collector being integrated within the cylindrical can, making it challenging to remove the internal heat source.
Innovation Solution
The negative electrode current collector is designed with a notch groove or cutting hole that allows it to deform and facilitate easy withdrawal of the electrode assembly upon increased pressure or fire, comprising a body portion, extension portions, and wing portions that are easily separable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the negative electrode current collector is integrated within the cylindrical can to ensure electrical connection, then electrical reliability is improved, but ease of withdrawal of electrode assembly during fire deteriorates
Solution Approach 1:
The negative electrode current collector is divided into multiple parts (first current collector connected to electrode assembly, second current collector connected to cylindrical can) that can separate from each other. This segmentation allows the current collector to maintain electrical connection during normal operation while enabling easy separation during emergency withdrawal scenarios.
Solution Approach 2:
The notched groove or cutting hole is pre-formed in the negative electrode current collector before any emergency occurs. This preliminary structural feature ensures that when separation is needed, the current collector can be quickly and easily divided along the pre-formed weak point, eliminating the need for complex separation mechanisms during emergency response.
2Strength
If the negative electrode current collector is made as a single integrated piece to ensure structural strength, then mechanical strength is improved, but ease of deformation upon fire deteriorates
Solution Approach 1:
The current collector is designed as an assembly of multiple parts connected through a connection portion, with notched grooves or cutting holes positioned to allow separation. This structure maintains overall strength during normal operation while enabling easy deformation and separation when needed.
Solution Approach 2:
The notched groove or cutting hole creates a localized weak point in the current collector structure. This local modification allows the majority of the current collector to maintain its structural strength while providing a specific location that deforms easily under thermal stress or applied force during fire conditions.
3Ease of operation
If the negative electrode current collector is designed as an assembly of parts to facilitate deformation, then ease of withdrawal is improved, but device complexity increases
Solution Approach 1:
The current collector is divided into simple components (first current collector, second current collector, and connection portion) that can be easily manufactured and assembled. The segmentation is achieved through simple notched grooves or cutting holes rather than complex mechanisms, maintaining manufacturing simplicity while enabling easy separation.
Solution Approach 2:
The notched groove or cutting hole is pre-formed during manufacturing, eliminating the need for complex separation mechanisms or tools during emergency withdrawal. This preliminary preparation simplifies the overall device complexity by providing a passive, pre-configured separation path that requires no active control or complex mechanisms during operation.
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 quick and efficient withdrawal of the electrode assembly by allowing the negative electrode current collector to separate, thereby mitigating the risk of further damage and facilitating safer handling of the battery during a fire.
Implementation Method 1
a notch groove or a cutting hole formed therein so as to be cut in response to an increase in pressure in the cylindrical can
Data Source
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AI summary
A cylindrical secondary battery including an electrode assembly including a negative electrode plate and a positive electrode plate; a cylindrical can accommodating the electrode assembly and including a terminal hole in one side of the cylindrical can and an open inlet in another side of the cylindrical can; a terminal coupled to the cylindrical can through the terminal hole; and a negative electrode current collector in the cylindrical can and electrically connecting the cylindrical can to the negative electrode plate. The negative electrode current collector includes a notch groove or a cutting hole configured to be cut in response to an increase in pressure in the cylindrical can.