Pouch Cell Lug Coating Layout for Short-Circuit-Safe Stacking

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Solution Overview

Problem

Pouch cells in mass production processes face challenges due to close proximity of contact lugs, leading to potential short-circuiting and difficulty in resistance-welding for electrical contact, resulting in high technical and financial expenditure for automated installations.

Innovation Solution

The pouch cells are designed with a conductive coating on one side and an insulating coating on the opposite side for the positive and negative contact lugs, respectively, allowing for secure and simple contact connection through overlapping complementary lugs in a stack, using materials like aluminum, nickel, and ceramic, with coatings applied via soldering paste or self-adhesive carriers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If contact lugs are positioned close together to reduce space, then area is reduced, but short-circuit risk increases

Engineering Contradiction:

Improvepouch cell areaVSAvoidshort-circuit risk

Core Design Contradiction:

Area of stationary objectVSReliability

Solution Approach 1:

The patent applies different coatings to different sides of contact lugs: conductive coating on one side for electrical connection and insulating coating on the other side to prevent short-circuits. This local differentiation of properties allows close positioning of contact lugs while maintaining safety.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The insulating coating acts as an intermediary that prevents direct electrical contact between adjacent contact lugs of opposite polarity, enabling compact arrangement without short-circuit risk.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If conventional contact lugs are used without differentiated coatings, then manufacturing is simpler, but resistance-welding becomes difficult and requires expensive automated installations

Engineering Contradiction:

Improvecoating application simplicityVSAvoidautomated installation complexity

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent changes the electrical properties (conductive/insulating) of contact lug surfaces through coating application. This parameter change enables resistance-welding by providing appropriate surface characteristics for welding while preventing short-circuits, thereby simplifying automated assembly installations.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The contact lugs are formed as composite structures with multiple coatings (conductive and insulating layers) applied to different surfaces. This composite approach enables both easy manufacturing through standard coating processes and simplified welding operations.

Inventive Principle:

Principle #40Composite materials

3Reliability

If conductive coating is applied to both sides of contact lugs, then electrical connection is improved, but short-circuit risk increases

Engineering Contradiction:

Improveelectrical contact qualityVSAvoidshort-circuit hazard

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies conductive coating only on the sides of contact lugs that require electrical connection, while applying insulating coating on sides that would otherwise be exposed to adjacent opposite-polarity lugs. This localized application of conductive properties ensures good electrical contact where needed while preventing short-circuits elsewhere.

Inventive Principle:

Principle #3Local quality

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 facilitates secure and efficient electrical contact-connection of pouch cells in stacks, reducing the risk of short-circuiting and enabling cost-effective automated assembly, allowing for series and parallel connections in battery packs.

Implementation Method 1

the positive contact lug has a conductive coating on the cell top side and an insulating coating on the cell bottom side and the negative contact lug has an insulating coating on the cell top side and a conductive coating on the cell bottom side

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

Methodology Applied

Scientific EffectElectrical insulation: Conduction (electrical)

Implementation Method 3

the conductive coating is provided on a self-adhesive carrier material which is preferably applied or to be applied to a contact lug. The insulating coating can be provided on a self-adhesive carrier material

Methodology Applied

Scientific EffectAdhesive bonding: Adhesive

Data Source

PatentUS20230327302A1Pouch cell and stack

Publication Date: 2023.10.12 HILTI AG

AI summary

Pouch cell having a positive contact lug and a negative contact lug, by means of which contact lugs electrical contact can be made with the pouch cell and the pouch cell can be charged and discharged in this way, wherein the pouch cell is of planar design and has a cell top side as well as a cell bottom side which is situated opposite the cell top side, wherein the positive contact lug has a conductive coating on the cell top side and an insulating coating on the cell bottom side and the negative contact lug has an insulating coating on the cell top side and a conductive coating on the cell bottom side, or vice versa, wherein the positive contact lug has an insulating coating on the cell top side and a conductive coating on the cell bottom side and the negative contact lug has a conductive coating on the cell top side and an insulating coating on the cell bottom side.