Expandable Battery Tabs for Electrode Stack Swelling

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Solution Overview

Problem

Electrode stacks in battery cells experience alternating expansion and contraction during charging and discharging, which can lead to mechanical stress and potential cell damage, as existing technologies lack effective mechanisms to absorb these volume changes.

Innovation Solution

The battery cell incorporates first and second electrically conductive tabs with expandable portions, mechanically connected to the battery terminals and fixedly connected to the anode and cathode elements, respectively. These expandable portions are configured to absorb the expansion and contraction of the electrode stacks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rigid tabs are used to connect electrodes, then electrical connection is maintained, but mechanical stress accumulates during electrode expansion and contraction

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidmechanical stress resistance

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The tab structure transitions from a rigid static design to a dynamic expandable design. The tab includes an expandable portion with multiple layers that can dynamically adjust its volume and shape to match the expansion and contraction of the electrode stacks during charging and discharging cycles, thereby maintaining reliable electrical connection while accommodating mechanical stress.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The tab's physical parameters (volume, shape, layer spacing) are designed to change in response to electrode volume changes. The expandable portion allows the tab to increase its volume and adjust its parameters during electrode expansion, and decrease during contraction, preventing mechanical stress accumulation while maintaining electrical connectivity.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If fixed tabs are used, then structural simplicity is maintained, but electrode expansion and contraction cause mechanical damage

Engineering Contradiction:

Improvetab structure simplicityVSAvoidcell durability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The tab is segmented into multiple functional portions: a first portion connected to the electrode stack, a second portion connected to the terminal, and an expandable portion connecting these two segments. This segmentation allows the expandable portion to independently deform and absorb mechanical stress, protecting the overall structure from damage while maintaining structural integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The expandable portion comprises multiple nested layers that can expand and contract like a nested doll structure. These layers are arranged concentrically, allowing them to expand outward or compress inward depending on the electrode volume, providing a compact yet adaptable connection structure that enhances durability without excessive complexity.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Strength

If expandable tabs are introduced, then mechanical stress is absorbed, but device complexity increases

Engineering Contradiction:

Improvemechanical stress absorptionVSAvoidtab structure complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The expandable portion utilizes a flexible multi-layer shell structure that can deform elastically to absorb mechanical stress. These thin film layers are designed with appropriate flexibility and elasticity, allowing them to expand and contract with the electrode stacks while maintaining structural integrity, providing stress absorption without excessive structural complexity.

Inventive Principle:

Principle #30Flexible shells and thin films

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 use of expandable conductive tabs effectively absorbs the alternating expansion and contraction of the electrode stacks, reducing mechanical stress and enhancing the durability and performance of the battery cell.

Implementation Method 1

Each of the first and second expandable portions is configured to absorb alternating expansion and contraction of the first and second electrode stacks when the battery cell is respectively charging and discharging

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS20250118837A1Expandable conductive tab for stacked electrode battery cell

Publication Date: 2025.04.10 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A battery cell includes a first electrode stack and a second electrode stack, each having at least one pair of anode and cathode elements. The cell also includes a container defining an internal chamber housing the first and second electrode stacks and having external first and second battery terminals. The cell additionally includes a first electrically conductive tab connected to the first battery terminal and to each anode element in the first and second electrode stacks and having a first expandable portion arranged between the first and second electrode stacks. The cell also includes a second electrically conductive tab connected to the second battery terminal and to each cathode element in the first and second electrode stacks and having a second expandable portion arranged between the first and second electrode stacks. The expandable portions absorb alternating expansion and contraction of the subject electrode stacks during cell charging and discharging.