Cylindrical Battery Current Interruption Under Internal Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary batteries face challenges in safely managing internal pressure increases, which can lead to current flow disruptions and potential explosions, and require a stable welding area for effective connection with busbars.
Innovation Solution
A secondary battery design featuring a variable connection part that blocks current flow in response to increased internal pressure, comprising a fixed body and a variable body that moves away from the inner terminal, with insulating spacers and notches to manage pressure and ensure a stable welding area with the terminal cover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rigid connection structure is used between inner terminal and terminal cover, then electrical connection is stable, but current flow cannot be blocked when internal pressure increases
Solution Approach 1:
The connection structure transitions from a static rigid connection to a dynamic variable connection. The variable connection part includes a variable body that can change its connection state between the inner terminal and terminal cover based on internal pressure conditions, enabling automatic current flow blocking without complex control systems
Solution Approach 2:
The variable connection part automatically responds to internal pressure changes and blocks current flow without external intervention. The structure uses the pressure differential itself as the actuating force, with the variable body moving to open or close the electrical connection based on whether internal pressure exceeds external pressure
2Reliability
If the variable body is fixed rigidly to the inner terminal, then electrical connection is stable, but the variable body cannot move to block current flow during pressure increase
Solution Approach 1:
The variable body is connected to the inner terminal through a dynamic connection that allows movement. The connection maintains electrical contact during normal operation but permits the variable body to move away from the inner terminal when pressure differential acts upon it, thereby blocking current flow
Solution Approach 2:
The system uses pressure differential (pneumatic principle) as the actuating force. When internal pressure exceeds external pressure, the pressure differential pushes the variable body to move away from the inner terminal, automatically blocking current flow without mechanical actuators or complex mechanisms
3Reliability
If the welding area between terminal cover and busbar is small, then the battery structure is compact, but the welding connection is unstable
Solution Approach 1:
The terminal cover is segmented into functional zones: a welding area specifically designed for busbar connection and an extension area that provides structural support and current flow blocking functionality. This segmentation allows the welding area to be optimized for connection stability while the extension body provides additional safety functions
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 effectively prevents current flow during pressure increases, reducing the risk of explosion and ensures a stable welding area for secure connection with busbars, enhancing safety and performance.
Implementation Method 1
configured to move away from the inner terminal in response to a pressure of a gas passing through the inner terminal
Data Source
AI summary
A secondary battery configured to block a supply of current in response to a pressure within the secondary battery increasing. A secondary battery includes a cylindrical can accommodating an electrode assembly, a positive electrode current collector plate electrically connected to the electrode assembly and inside the cylindrical can, an inner terminal electrically connected to the positive electrode current collector plate and having a connection hole, a variable connection part fixed to the cylindrical can in contact with the inner terminal and spaced apart from the inner terminal to block a flow of current in response to an internal pressure of the cylindrical can increasing, a terminal cover electrically connected to the variable connection part and outside the cylindrical can, and a spacer between the variable connection part and the terminal cover and configured to define an inner space for movement of the variable connection part.