Segmented Electrode Assembly for Cylindrical Battery Heat Control

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Solution Overview

Problem

Conventional cylindrical batteries face issues with high resistance and heat generation due to concentrated current flow at electrode tabs, leading to potential ignition during rapid charging, especially in larger form factors, and poor electrolyte impregnation and increased fire risk from separator shrinkage in high temperature environments.

Innovation Solution

The electrode assembly structure comprises multiple electrode assemblies wound around a common axis with uncoated portions segmented and bent in opposite directions, separated by an insulating member, facilitating electrolyte impregnation and gas discharge, and reducing short-circuit risks through distributed current paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the form factor of cylindrical battery is increased to apply to electric vehicle, then the battery capacity and power output are improved, but resistance and heat generation around electrode tab increase during rapid charging

Engineering Contradiction:

Improvebattery capacityVSAvoidheat generation

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The electrode tab is divided into multiple segments along the winding direction, creating multiple current collection points instead of a single concentrated tab. This segmentation distributes the current flow across multiple contact points with the current collector, reducing current density and consequently reducing resistive heat generation at each individual contact point while maintaining overall current collection efficiency for the larger form factor battery

Inventive Principle:

Principle #1Segmentation

2Quantity of substance

If the form factor of cylindrical battery is increased, then the battery capacity is improved, but current collection efficiency deteriorates due to concentrated current on strip-shaped electrode tab

Engineering Contradiction:

Improvebattery capacityVSAvoidcurrent collection efficiency

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The electrode tab is divided into multiple segments that are distributed along the winding direction of the electrode assembly. Each segment serves as an independent current collection point that contacts the current collector at different locations. This segmentation increases the total surface area for current collection and distributes the current flow path, improving overall current collection efficiency in larger form factor batteries where the electrode diameter is increased

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The current collection structure transitions from a single-plane strip-shaped tab to a multi-dimensional segmented structure that extends along the winding direction. By adding the dimension of distribution along the winding axis, the current collection interface is expanded from a single contact line to multiple distributed contact points, improving current collection efficiency without increasing the radial or axial dimensions of the battery

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Quantity of substance

If electrolyte is injected into larger form factor battery, then the battery capacity is improved, but impregnability deteriorates as electrolyte cannot move to center or outermost area of electrode assembly

Engineering Contradiction:

Improvebattery capacityVSAvoidelectrolyte impregnation

Core Design Contradiction:

Quantity of substanceVSEase of operation

Solution Approach 1:

The electrode assembly is segmented into multiple sections along the winding direction, with each segment having its own uncoated portion that serves as an electrolyte entry point. This segmentation creates multiple pathways for electrolyte penetration, allowing electrolyte to reach the center and outermost areas of the electrode assembly more effectively through distributed entry points rather than relying on diffusion from a single location, thus improving impregnability in larger form factor batteries

Inventive Principle:

Principle #1Segmentation

4Duration of action of stationary object

If cylindrical battery is exposed to high temperature environment for long time, then the operating duration is improved, but fire risk increases due to separator shrinkage causing short circuit

Engineering Contradiction:

Improveoperating durationVSAvoidfire risk

Core Design Contradiction:

Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The electrode assembly is divided into multiple segments along the winding direction, with each segment independently surrounded by its own separator. This segmentation isolates potential short circuit paths, so that if separator shrinkage occurs in one segment due to high temperature exposure, the short circuit is confined to that local segment rather than affecting the entire electrode assembly. This reduces the overall fire risk while maintaining long operating duration in high temperature environments

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS20250385294A1Electrode assembly structure, and cylindrical battery, battery pack and vehicle comprising the same

Publication Date: 2025.12.18 LG ENERGY SOLUTION LTD

AI summary

The present disclosure discloses an electrode assembly structure that facilitates impregnation of electrolyte and discharge of gas, and reduces the risk of fire due to short circuit. The electrode assembly structure according to one aspect of the present disclosure includes a first electrode assembly wound around a winding axis, and a second electrode assembly wound around the winding axis, adjacent to the first electrode assembly, and located outer than the first electrode assembly in a radial direction.