Secondary Battery Case Structure for Compact Terminal Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary batteries face challenges in achieving high energy density, which affects their performance in portable devices and electric vehicles.
Innovation Solution
The design of a secondary battery with a case structure that includes a positive electrode terminal and an upper flange with specific dimensions, where the upper flange's length is shorter than the terminal's length, and the flange's edge regions are longer, along with a method of laser cutting the case to optimize the structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the upper flange length is reduced to increase energy density, then the battery volume decreases and energy density increases, but the welding quality may deteriorate
Solution Approach 1:
The upper flange is designed with non-uniform thickness, featuring a thicker terminal region and thinner edge regions. This local quality variation allows the terminal region to maintain adequate welding quality while reducing the overall flange volume through thinner edge regions that do not require high welding strength.
2Device complexity
If the case structure is simplified to reduce manufacturing complexity, then the manufacturing process is simplified, but the ability to protect electrode terminals may be compromised
Solution Approach 1:
The case structure employs local quality variation with thicker terminal regions for protection and thinner edge regions for weight reduction. This differentiated thickness distribution maintains adequate terminal protection while simplifying the overall structure by eliminating the need for complex reinforcement elements.
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
This design enhances energy density, reduces the battery's volume, improves welding quality, and simplifies the manufacturing process while minimizing damage to electrode terminals.
Implementation Method 1
a method of laser cutting the case to optimize the structure
Data Source
AI summary
A secondary battery includes: an electrode assembly including a positive electrode tab; and a case surrounding around the electrode assembly, and including: an accommodation portion accommodating the electrode assembly; a positive electrode terminal protruding from the accommodation portion in a first direction, and electrically connected to the positive electrode tab; and an upper flange extending from the accommodation portion in the first direction. A shortest length of the upper flange extending from the accommodation portion in the first direction is less than a length of the positive electrode terminal protruding from the accommodation portion in the first direction.