Battery Module Bus Bar Assembly for Stable Lead Welding

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current battery module assembly processes face challenges in maintaining stable electric connections between electrode leads and bus bars due to elastic recovery of metal materials, leading to poor weldability and increased defects, especially in large-sized battery packs.

Innovation Solution

A battery module design featuring a bus bar assembly with connection and sensing bus bars accommodated in recessed portions of bus bar frames, along with a sensing assembly that includes a circuit board and sensing frame, allows for easy and reliable electrical connections without the need for bending electrode leads, enhancing manufacturing efficiency and reducing defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrode leads are bent to contact the bus bar surface, then electric connection is achieved, but elastic recovery causes poor adhesion and low weldability

Engineering Contradiction:
Improveelectric connection reliabilityVSAvoidweldability
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

Instead of bending the electrode lead to contact the bus bar, the invention inverts the approach by making the bus bar conform to the electrode lead. The bus bar is bent to match the curvature of the electrode lead surface, ensuring stable contact without relying on the elastic properties of the electrode lead. This resolves the contradiction by eliminating the need for electrode lead bending while maintaining reliable electric connection and improving weldability.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If multiple manual operations are performed to maintain bent shape, then electrode leads can contact bus bar, but productivity decreases and assembly complexity increases

Engineering Contradiction:
Improvecontact stabilityVSAvoidassembly efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention applies preliminary action by pre-bending the bus bar to match the electrode lead curvature before assembly. This preparation is done in advance during bus bar manufacturing, so that during final assembly, no manual bending operations are needed. The bus bar is already in the correct shape to conform to the electrode lead, ensuring stable contact while dramatically improving productivity and reducing assembly complexity.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If electrode leads are bent manually, then connection is possible, but maintaining overlap state for welding becomes difficult

Engineering Contradiction:
Improveconnection feasibilityVSAvoidoverlap alignment
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention inverts the bending operation from the electrode lead to the bus bar. By bending the bus bar to conform to the electrode lead surface, the electrode lead maintains its straight, stable shape while the bus bar adapts to it. This ensures perfect overlap alignment at the contact point, making welding straightforward and precise without the alignment difficulties caused by manually bending multiple electrode leads.

Inventive Principle:
Principle #13The other way round (Inversion)

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 improves the reliability of electrical connections, reduces defects, and simplifies the assembly process by eliminating the need for bending electrode leads, thereby enhancing the productivity and efficiency of battery module manufacturing.

Implementation Method 1

it is difficult to maintain an adhered state between the electrode leads and the bus bar due to elastic recovery of the electrode leads of a metal material

Methodology Applied
Scientific EffectElastic recovery: Elasticity

Data Source

PatentEP3671937B1Battery module including sensing assembly and bus bar assembly
Publication Date: 2024.06.12 LG ENERGY SOLUTION LTD
  • EP3671937B1 patent drawingFigure 1
  • EP3671937B1 patent drawingFigure 2
  • EP3671937B1 patent drawingFigure 3

AI summary

Provided is a battery module including: a cell stack formed as a plurality of battery cells each including at least one of a sensing negative electrode lead and a sensing positive electrode lead together with a positive electrode lead and a negative electrode; a bas bar assembly including a plurality of connection bus bars electrically connected to one of the positive electrode lead and the negative electrode lead, a plurality of sensing bus bars electrically connected to the sensing negative electrode lead or the sensing positive electrode lead, and a plurality of bus bar frames including a connection accommodating portion where the plurality of connection bus bars are accommodated and a sensing accommodating portion where the plurality of sensing bus bars are accommodated; and a sensing assembly including a circuit board electrically connected to the plurality of connection bus bars and the plurality of sensing bus bars, and a sensing frame mounted on a front surface of the bus bar assembly and where a board embedding portion accommodating the circuit board therein is formed.