Wound Energy Storage Cell Current Collector Layout for Shorter Current Paths

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Solution Overview

Problem

Conventional electrochemical energy storage cells, particularly button cells, do not optimize the utilization of electrochemical potential due to suboptimal electrical connections in their coil-shaped electrode-separator composite design.

Innovation Solution

The design incorporates at least two metallic conductor strips fixed at different positions on the band-shaped current collectors of the electrodes, with these strips emerging from the winding end faces and being angled to lie flat, allowing for improved electrical contact by being welded to the housing bases, thereby optimizing current dissipation and preventing short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single conductor strip is used in conventional button cells, then the structure is simple, but the current dissipation is suboptimal and electrochemical potential is not fully utilized

Engineering Contradiction:
Improvecurrent dissipationVSAvoidconductor strip configuration
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The single conductor strip is segmented into multiple conductor strips (at least two) that are distributed over the length of the band-shaped current collector. This segmentation allows current to be collected from multiple positions along the electrode, reducing current path length and improving current dissipation while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The conductor strips are arranged in a distributed pattern along the length of the current collector, transitioning from a single-point collection to a distributed linear arrangement. This dimensional distribution along the electrode length optimizes electrical connection without significantly increasing structural complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If conductor strips are positioned to optimize current dissipation, then current consumption improves, but the risk of short circuits increases

Engineering Contradiction:
Improvecurrent consumptionVSAvoidshort circuit prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

Electrically insulating elements are introduced as intermediaries between adjacent conductor strips. These insulating elements prevent electrical contact between strips of opposite polarity while allowing both strips to maintain their optimized positions for current collection, thus preventing short circuits without compromising current dissipation performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If multiple conductor strips are distributed over the electrode length, then current path length is reduced, but the device volume utilization may be compromised

Engineering Contradiction:
Improvecurrent path lengthVSAvoidinternal volume utilization
Core Design Contradiction:
ProductivityVSVolume of moving object

Solution Approach 1:

The conductor strips are positioned at specific locations along the current collector where they can effectively collect current without requiring excessive space. The distributed arrangement allows each strip to serve its local function efficiently, optimizing current collection while maintaining compact overall dimensions and good volume utilization.

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 configuration enhances the performance of the energy storage cell by reducing the current path length, improving current consumption, and ensuring optimal utilization of internal volume without creating unused cavities or causing short circuits.

Implementation Method 1

at least two metallic current collector strips are provided for the electrical connection of at least one of the electrodes

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

The current collector strips of one electrode all protrude from one of the winding end faces and comprise a first section outside and a second section inside the winding

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP4329083A1Electrochemical energy storage cell and method of manufacturing the same
Publication Date: 2024.02.28 VARTA MICROBATTERY GMBH
  • EP4329083A1 patent drawingFigure 1
  • EP4329083A1 patent drawingFigure 2A~2B
  • EP4329083A1 patent drawingFigure 3A~3C

AI summary

An electrochemical energy storage cell (100) comprises a housing with a circumferential housing shell and a first and a second housing base (110, 120). A cylindrical electrode-separator assembly (150) is provided in the housing, comprising at least one ribbon-shaped negative electrode (151), at least one ribbon-shaped positive electrode (152), and at least one ribbon-shaped separator (153). The electrodes (151, 152) each comprise a ribbon-shaped metallic current collector (171, 172), which is preferably coated on both sides with an electrode material (181, 182). The electrode-separator assembly (150) is a winding in which the electrodes (151, 152) and the at least one separator (153) are wound spirally. The cylindrical electrode-separator assembly (150) comprises a first winding end face, a second winding end face, and a circumferential shell.The cylindrical electrode-separator assembly (150) is axially aligned within the housing so that the winding ends face the housing bottoms (110, 120). The electrochemical energy storage cell is further characterized in that it comprises at least two metallic current collector strips (1510, 1520) which are fixed at different positions on the ribbon-shaped current collector (171, 172) of at least one of the electrodes (151, 152). The current collector strips (1510, 1520) of each electrode (151, 152) extend from one of the winding ends and comprise a first section (1511, 1521) outside and a second section inside the winding. The first sections (1511, 1521) of the current collector strips are angled such that they lie flat against the respective winding end.Furthermore, the first sections (1511, 1521) of the electrode's discharge strips are connected by welding to each of the housing bottoms (110, 120), wherein the dimensions of the discharge strips (1510, 1520) and/or the positions at which they are fixed to the ribbon-shaped current collector are chosen such that the first sections lying on the respective winding end face do not overlap each other.