Rejoinable Bus Bar Module for Reusable Battery Cell Assembly

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Solution Overview

Problem

The increasing number of electric vehicles has led to a growing need for reusable battery modules, as existing bus bar configurations do not efficiently allow for the reuse of battery cells without discarding materials, especially when welding failures occur.

Innovation Solution

A bus bar module with a rejoinable design, featuring electrode joining parts, a coupling part that can be cut to separate the bus bars, and rejoinable parts that can be connected using a joining member, allowing for the reuse of battery cells by separating and reconnecting them without welding traces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bus bars are designed with permanent welding connections for battery cells, then electrical connectivity and structural strength are ensured, but the ability to reuse and reconfigure battery modules is lost when welding failures occur

Engineering Contradiction:
Improveelectrical connectivityVSAvoidreusability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The bus bar is divided into multiple detachable sections with rejoinable parts that can be separated and reconnected. Each section can be independently joined to battery cells, allowing the bus bar to be segmented for easier replacement and reuse of battery modules without discarding the entire bus bar structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bus bar transitions from a static welded structure to a dynamic configuration where connections can be made and broken. The rejoinable parts enable the bus bar to adapt its configuration by allowing detachment and reattachment to different battery cell arrangements, providing flexibility for module reuse.

Inventive Principle:
Principle #15Dynamics

2Ease of manufacture

If bus bars are designed as integrated permanent structures, then manufacturing simplicity is maintained, but material waste increases when battery cells need replacement

Engineering Contradiction:
Improvestructural simplicityVSAvoidmaterial waste
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

By segmenting the bus bar into detachable sections with standardized rejoinable parts, the design maintains manufacturing simplicity through modular components while enabling selective replacement. Only the necessary bus bar sections connected to replaced battery cells need to be removed, minimizing material waste.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rejoinable bus bar design enables recovery and reuse of bus bar materials. When battery cells are replaced, the bus bar sections can be detached and reused with new battery cells, preventing material waste and reducing the need to discard entire bus bar structures.

Inventive Principle:
Principle #34Discarding and recovering

3Strength

If welding is used to connect bus bars to battery cells, then strong electrical connection is achieved, but repairability is reduced when welding failures occur

Engineering Contradiction:
Improveconnection strengthVSAvoidrepairability
Core Design Contradiction:
StrengthVSEase of repair

Solution Approach 1:

The connection method transitions from permanent welding to a dynamic system where mechanical or reversible connections are used. The rejoinable parts allow connections to be made and broken multiple times while maintaining sufficient electrical and mechanical strength, greatly improving repairability when connection failures occur.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Rejoinable parts serve as intermediary components between bus bars and battery cells, providing a connection mechanism that achieves sufficient electrical and mechanical strength while allowing for easy disconnection and reconnection. This intermediary structure replaces direct welding with a more repairable interface.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4135116B1Bus bar module, battery module, and manufacturing method for reused battery module
Publication Date: 2024.05.15 YAZAKI CORP
  • EP4135116B1 patent drawingFigure 1
  • EP4135116B1 patent drawingFigure 2
  • EP4135116B1 patent drawingFigure 3

AI summary

A bus bar module (1) includes a bus bar (10) electrically connect electrode terminals (114) respectively included in a plurality of battery cells (112), and a detection conductor (30) electrically connected to the bus bar (10). The bus bar (10) includes: a pair of electrode joining parts (11) respectively joined to the different electrode terminals (114); a coupling part (12) coupling the pair of electrode joining parts (11) to each other, and capable of being cut between the pair of electrode joining parts (11) where the pair of electrode joining parts (11) is respectively joined to the electrode terminals (114); and a pair of rejoinable parts (13) respectively extending from the pair of electrode joining parts (11). The electrode joining parts (11) and the coupling part (12) constitute a conductive connection part (14) for primary use disposed across the different electrode terminals (114) to electrically connect the different electrode terminals (114) to each other.