Battery Cap Plate Protrusions for Lighter, Stiffer Cell Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary batteries face challenges in durability and weight reduction due to pressure from internal gas and structural deformation, with existing designs prone to alloy formation and ignition risks.
Innovation Solution
The design incorporates a cap plate with protrusions and a charging member made of conductive polymer and filler, which reduces the formation of alloys and enhances structural stiffness, while also reducing terminal thickness to minimize weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the terminal plate thickness is reduced to minimize weight, then the cell weight is reduced, but the structural stiffness and strength of the cap plate are compromised
Solution Approach 1:
The cap plate is segmented into multiple regions: a thin-weight reduction region for minimizing weight, and a thick-strengthening region with protrusions for enhancing structural stiffness. This segmentation allows different parts of the cap plate to have different thicknesses, optimizing both weight and strength requirements simultaneously
Solution Approach 2:
The cap plate employs local quality by varying the thickness in specific areas. The protrusions create localized thick regions that provide structural reinforcement exactly where needed (at the terminal coupling area), while other areas remain thin to minimize overall weight. This non-uniform thickness distribution optimizes the strength-to-weight ratio
2Ease of manufacture
If conventional terminal coupling structures are used, then the manufacturing process is simple, but alloy formation occurs on the case inner surface leading to reduced durability and ignition risks
Solution Approach 1:
The protrusion structure acts as an intermediary element between the terminal and the case. By positioning the terminal coupling interface away from the case inner surface and providing a dedicated protrusion structure for terminal attachment, the design prevents direct contact between the terminal and case, thereby eliminating the alloy formation issue while maintaining manufacturing simplicity
Solution Approach 2:
The terminal coupling function is extracted from the case structure and relocated to the protrusion structure on the cap plate. This separation removes the problematic interaction between the terminal and case inner surface, eliminating the source of alloy formation while keeping the manufacturing process straightforward
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 configuration increases durability by preventing alloy formation and ignition, while maintaining structural integrity and reducing cell weight through enhanced sealing and energy consumption during short-circuits.
Implementation Method 1
even when a negative electrode is short-circuited, the charging member may consume energy, thereby preventing ignition of the secondary battery
Implementation Method 2
since a case is charged to a positive electrode by a high-resistance charging member, an alloy (for example, lithium aluminum (LiAl) alloy) may not be formed on the inner surface of the case by an electrolyte
Data Source
AI summary
The present invention provides a secondary battery having enhanced durability, reinforced cap plate stiffness and reduced cell weight. Disclosed as an example is a secondary battery having: an electrode assembly; a case for accommodating the electrode assembly; a cap plate coupled to the case to seal the electrode assembly; a terminal connected to the electrode assembly and exposed through the cap plate; and a protrusion protruding toward the terminal in the area in which the terminal of the cap plate is coupled.