Stepped Busbar Assembly for Blocking Fire Spread in Battery Packs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional busbar assemblies in battery packs are prone to short circuits and fire spread due to melting cover members and exposure of busbars, leading to secondary damage from venting gas and fire.
Innovation Solution
A busbar assembly with a copper busbar and a refractory cover member, featuring a stepped design between first and second busbars, and protrusions on the second busbar to inhibit gas and fire movement, preventing contact with adjacent metals and maintaining the cover member's integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional flexible busbar assembly with a cover member is used to electrically connect adjacent battery modules, then ease of operation and adaptability are improved, but reliability deteriorates when fire breaks out because the cover member melts and exposes the busbar causing short circuit
Solution Approach 1:
The busbar structure is changed from a uniform design to a stepped design with different height levels. The first busbar portion has a higher height than the second busbar portion, creating a stepped configuration that prevents fire and venting gas from reaching the busbar while maintaining electrical connection functionality.
Solution Approach 2:
The problematic cover member is removed from the design. Instead of relying on a cover that can melt during fire, the invention uses the stepped busbar structure itself to provide fire resistance, eliminating the cover member entirely and its associated reliability issues.
2Ease of operation
If the busbar and cover member are spaced apart due to pressure from venting gas, then ease of operation is improved for assembly, but reliability deteriorates because fire and venting gas can transfer to neighboring battery modules causing secondary damage
Solution Approach 1:
The busbar height parameters are designed with a stepped configuration where the first portion extends higher than the second portion. This geometric parameter change creates a physical barrier that blocks fire and venting gas transfer while maintaining structural integrity under pressure.
Solution Approach 2:
The stepped portion of the busbar acts as an intermediary barrier between the battery module interior and the exterior environment. This intermediate structure prevents direct transfer of fire and venting gas to neighboring modules while allowing the busbar to maintain its electrical connection function.
3Ease of manufacture
If the cover member is made thin and flexible for ease of installation, then ease of manufacture and ease of operation are improved, but reliability deteriorates because the cover member melts during fire exposure
Solution Approach 1:
The cover member is completely removed from the design. The invention replaces the thin, fire-vulnerable cover with a stepped busbar structure that inherently provides fire resistance without requiring additional protective components.
Solution Approach 2:
The busbar is designed to serve multiple functions: electrical connection and fire protection. The stepped configuration of the busbar simultaneously provides electrical conductivity and acts as a fire barrier, eliminating the need for a separate cover member.
Data Source
AI summary
A busbar assembly includes a busbar made of a copper material and a cover member configured to wrap a part of the busbar. The busbar includes a first busbar protruding from each of opposite sides of the cover member and a second busbar wrapped by the cover member. The width of the second busbar is less than the width of the first busbar. A battery pack including the same is also provided.