Tapered Busbar Uniform Current Density Battery Module

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Solution Overview

Problem

Conventional battery modules for electric vehicles are large, heavy, and costly due to their design, which increases the risk of failure and reduces efficiency, and they lack effective impact resistance and thermal management.

Innovation Solution

A unified battery module design using structural foam, adhesive, and interconnecting carrier halves to provide impact resistance, thermal insulation, and dielectric barriers, with a tapered busbar for efficient current transfer and reduced material usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If conventional battery module design is used, then structural strength is sufficient, but weight and cost increase significantly

Engineering Contradiction:

Improvebattery module weightVSAvoidstructural strength

Core Design Contradiction:

Weight of moving objectVSStrength

Solution Approach 1:

The patent employs composite materials including structural foam, adhesive layers, and carrier halves to create a unified battery module design. The structural foam provides both mechanical strength and weight reduction compared to conventional solid metal structures, while the adhesive layers bond components together to maintain structural integrity. This composite approach resolves the contradiction by achieving sufficient strength with reduced weight.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The battery module is divided into separate carrier halves that are joined together with structural foam and adhesive. This segmentation allows for optimized design of each half, using lightweight materials where appropriate while maintaining overall structural strength. The modular approach enables weight reduction without sacrificing the necessary mechanical properties.

Inventive Principle:

Principle #1Segmentation

2Reliability

If more components and interconnections are added to battery modules, then electrical characteristics improve, but failure risk increases

Engineering Contradiction:

Improvefailure riskVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into the structural foam and adhesive system. The structural foam simultaneously provides structural support, thermal management, and electrical insulation, while the adhesive performs both bonding and sealing functions. This consolidation reduces the number of separate components and interconnections, thereby lowering failure risk while maintaining or improving electrical characteristics.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The structural foam serves multiple functions: mechanical support, thermal insulation, electrical dielectric barrier, and shock absorption. The adhesive layer provides both structural bonding and environmental sealing. This multi-functionality reduces the overall component count and simplifies the system architecture, directly addressing the reliability-complexity contradiction.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If uniform cross-sectional busbar is used, then manufacturing is simple, but current density is non-uniform causing inefficiency

Engineering Contradiction:

Improvecurrent transfer efficiencyVSAvoidbusbar manufacturing complexity

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The busbar is designed with a tapered cross-section where the width or height varies along its length. This local variation in geometry optimizes the current density distribution, providing larger cross-sectional area where higher current flows and smaller area where current is lower. This resolves the contradiction by achieving superior current transfer efficiency through localized geometric optimization while maintaining reasonable manufacturability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The busbar cross-sectional parameters (width, height, or area) are changed continuously or in steps along its length to match the current density requirements at different locations. This parameter optimization ensures uniform current density and maximizes electrical efficiency, accepting increased manufacturing complexity as a trade-off for significantly improved productivity.

Inventive Principle:

Principle #35Parameter changes

4Object-affected harmful factors

If conventional battery module design is used, then electrical connections are established, but thermal management and impact resistance are insufficient

Engineering Contradiction:

Improvethermal event riskVSAvoidthermal management

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The structural foam used in the unified battery module design provides inherent thermal insulation properties that conventional solid metal structures lack. This thermal insulation capability helps manage heat distribution within the battery module, reducing hot spots and thermal event risks while maintaining structural integrity. The composite material approach simultaneously addresses both mechanical and thermal requirements.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The structural foam acts as a cushioning material that provides shock absorption and impact resistance before thermal or mechanical failures can occur. This beforehand protection reduces the risk of thermal events by preventing mechanical damage to battery cells and maintaining proper spacing between components, thereby improving overall reliability and thermal management.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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

The solution results in a lighter, more cost-effective, and safer battery module with improved impact resistance and thermal management, reducing the risk of thermal events and enhancing the overall efficiency of electric vehicles.

Implementation Method 1

a tapered busbar for efficient current transfer

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

structural foam, adhesive, and interconnecting carrier halves to provide impact resistance, thermal insulation

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

provide impact resistance, thermal insulation, and dielectric barriers

Methodology Applied

Scientific EffectDielectric barrier: Dielectric

Data Source

PatentUS10784486B2Uniform current density tapered busbar

Publication Date: 2020.09.22 NIO TECH ANHUI CO LTD

AI summary

A tapered busbar for an energy storage device is provided. The tapered busbar is configured to interconnect with a first row of series-connected energy storage cells in a battery module at a first end of the busbar. As the busbar tapers from a first cross-sectional area at the first end to a larger second cross-sectional area at a second opposite end, the busbar is configured to interconnect with sequentially additional electrically-parallel rows of series-connected energy storage cells. The tapered cross-sectional area of the busbar provides a substantially uniform current density at any point along the length of the busbar regardless of the number of rows of energy storage cells connected before or after the point.