Secondary Battery Tab Insulation Assembly for Compact Bend Fixation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary batteries face challenges in reducing tab space occupation and minimizing the risk of tab rupture and short-circuiting due to stress concentration and improper fixation during bending.
Innovation Solution
The implementation of a multi-layer insulation system comprising first, second, and third insulators, along with a prop member, to stabilize the connection and bend portions of the tab, dispersing stress and preventing insertion into the battery body, while ensuring secure fixation and reducing the risk of fracturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the tab is bent to occupy a smaller space, then the space occupation is reduced, but the risk of tab rupture increases due to stress concentration
Solution Approach 1:
The tab is divided into three distinct segments: connection portion, bend portion, and main body. This segmentation allows each part to be optimized independently - the connection portion is fixed to the cap plate for stability, the bend portion is left unfixed to allow stress release during bending, and the main body remains intact. This resolves the contradiction by enabling space reduction through bending while preventing rupture through strategic segmentation and differential fixation.
Solution Approach 2:
The cap plate serves as an intermediary element between the tab connection portion and the external environment. By fixing the connection portion to the cap plate, the stress during bending is transferred to and dispersed by the rigid cap plate structure, preventing stress concentration at the tab itself. This intermediary fixation allows the tab to be bent into a compact shape while maintaining structural integrity.
2Reliability
If the connection portion is fixed to reduce short-circuit risk, then safety is improved, but the bend portion may fracture due to stress during bending
Solution Approach 1:
Different parts of the tab have different fixation qualities: the connection portion is firmly fixed to the cap plate to prevent short-circuiting, while the bend portion is deliberately left unfixed to allow stress release during bending. This local differentiation of fixation quality resolves the contradiction by applying fixation only where needed for safety (connection portion) while avoiding it where it would cause damage (bend portion).
Solution Approach 2:
The tab is segmented into connection portion, bend portion, and main body, with only the connection portion being fixed to the cap plate. This segmentation allows the fixed connection portion to prevent short-circuits while the unfixed bend portion can flex without fracturing, as the stress is not transmitted to the fixed structure.
3Quantity of substance
If the tab is bent into a compact shape, then energy density is improved, but the structural integrity of the tab deteriorates
Solution Approach 1:
The tab is segmented into connection portion, bend portion, and main body, with selective fixation applied only to the connection portion on the cap plate. This allows the bend portion to be compacted into a small space while maintaining structural integrity through the fixed connection points, resolving the contradiction between compactness and structural stability.
Solution Approach 2:
The bend portion is extracted from the fixed structure and left as a free, unfixed element. This allows the bend portion to be compacted into a small space without being constrained by fixation, while the connection portion remains fixed to maintain overall structural integrity and prevent short-circuits.
Data Source
AI summary
Embodiments of this application provide a secondary battery, a battery module, and a device using a battery as a power supply. A secondary battery includes: a cap plate; electrode terminals, disposed on the cap plate; an electrode assembly, including a main body and tabs extending from the main body, where each of the tabs includes a connection portion and a bend portion, the connection portion is electrically connected to one of the electrode terminals, and the bend portion is bent against the connection portion and is connected between the connection portion and the main body; and a first insulation member, disposed at a side that is of the connection portion and that is away from the cap plate.