Lateral Cell Contact Assembly for Lower-Cost EV Battery Cooling

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Solution Overview

Problem

The existing cell contact-connection systems for electrical energy stores in motor vehicles require high manufacturing costs due to bond connections between cell connectors and terminals, and they often obstruct cooling mechanisms.

Innovation Solution

A cell contact-connection system with conductor tracks forming lateral pressure contacts that connect to cell terminals, allowing for a force fit and reducing contact resistance, while enabling cooling through a double-walled store housing with a support structure that includes an insulating material and punched comb conductor tracks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bond connections are used to connect cell connectors to cell terminals, then reliable electrical connection is achieved, but manufacturing costs increase significantly

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the bond wire connection system with a direct mechanical contact system. Conductor tracks with contact regions are pressed laterally against terminal regions of cell terminals, establishing electrical connection through force fit without requiring bond wires. This substitution eliminates the complex bonding process while maintaining reliable electrical connection.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The conductor tracks serve as an intermediary element between the support structure and cell terminals. The contact regions on the conductor tracks mediate the electrical connection by being pressed laterally against the terminal regions, providing a reliable electrical pathway without direct bonding between connectors and terminals.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If cell contact-connection system is disposed on the upper side of cell assembly, then cell terminals are easily accessible, but cooling mechanisms are obstructed

Engineering Contradiction:

Improvecell terminal accessibilityVSAvoidcooling efficiency

Core Design Contradiction:

Ease of operationVSTemperature

Solution Approach 1:

The patent transitions from vertical contact connection (top-down approach) to lateral contact connection. The contact regions are configured to press laterally against terminal regions that extend along the vertical axis, enabling electrical connection in a horizontal direction. This dimensional change allows cooling devices to be positioned on the upper side without interfering with the contact-connection system.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If lateral pressure contacts are used for contact-connection, then manufacturing costs are reduced and cooling is enabled, but contact resistance may increase

Engineering Contradiction:

Improvemanufacturing costVSAvoidcontact resistance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The conductor tracks are pre-configured with contact regions that are designed to exert a predetermined lateral force when pressed against the terminal regions. This preliminary design of the contact geometry and material properties ensures that the force fit connection achieves optimal contact pressure, minimizing contact resistance before the actual connection is made.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent optimizes parameters such as contact pressure, contact area, and material properties of the conductor tracks to minimize contact resistance. By carefully controlling these parameters in the lateral pressure contact system, the connection reliability is maintained at levels comparable to or better than bond connections, while achieving lower manufacturing costs.

Inventive Principle:

Principle #35Parameter changes

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 solution reduces manufacturing costs and allows for efficient cooling of energy storage cells by maintaining an open upper side for cooling devices, with low contact resistance and enhanced thermal management.

Implementation Method 1

The contact regions are at least partially in the form of lateral pressure contacts which in the course of the contact-connection exert a lateral force on the terminal regions that are to be contact-connected laterally

Methodology Applied

Scientific EffectLateral pressure contact: Mechanical Force

Implementation Method 2

a support structure that includes an insulating material and punched comb conductor tracks

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentUS20240063485A1Electrical Energy Store Having a Lateral Cell Contact System, and Motor Vehicle

Publication Date: 2024.02.22 BAYERISCHE MOTOREN WERKE AG

AI summary

An electrical energy store has a plurality of energy storage cells each having a cell housing and two cell terminals, and a cell contact system for connecting the energy storage cells which has a carrier and conductor tracks which are connected to the carrier and have conductor track portions forming contact regions for contacting the cell terminals of the energy storage cells. The cell terminals have terminal regions which are to be at least partially laterally contacted, and the contact regions are at least partially in the form of lateral pressure contacts which, during contact, exert a lateral force on the terminal regions which are to be laterally contacted.