Wound Electrode Assembly Porous Layer for Battery Electrolyte Infiltration

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Solution Overview

Problem

Cylindrical batteries with all-tab structures face limitations in electrolyte infiltration due to the absence of a mechanism to ensure uniform distribution of electrolytic solution, leading to insufficient solution content in local regions and reduced cycle life.

Innovation Solution

Incorporation of a porous layer on the current collector, made from materials like polymer or ceramic, which facilitates capillary action to enhance electrolyte transfer to the active material layer, improving the distribution and retention of electrolyte within the battery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an all-tab structure is used with tightly welded current collectors, then structural integrity is improved, but electrolyte infiltration is limited

Engineering Contradiction:

Improvestructural integrityVSAvoidelectrolyte content

Core Design Contradiction:

StrengthVSQuantity of substance

Solution Approach 1:

A porous layer is disposed on the current collector to provide capillary action that draws electrolyte into the electrode assembly. The porous structure allows electrolyte infiltration while maintaining structural integrity, resolving the contradiction between tight welding and electrolyte access.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The porous layer acts as an intermediary between the tightly welded current collector and the electrolyte. It mediates the conflict by providing a pathway for electrolyte infiltration while allowing the current collector to maintain its strong structural connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If current collectors are tightly welded to current collection plates, then electrical connection reliability is improved, but electrolyte distribution uniformity deteriorates

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidelectrolyte distribution uniformity

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The porous layer compensates for the non-uniform electrolyte distribution caused by tight welding. Its capillary action ensures uniform electrolyte penetration throughout the electrode assembly, maintaining composition stability while preserving electrical connection reliability.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The porous layer is disposed specifically on the current collector where electrolyte infiltration is needed, while the current collector itself maintains tight welding for electrical connection. This local differentiation resolves the contradiction between uniform electrolyte distribution and reliable electrical connection.

Inventive Principle:

Principle #3Local quality

3Quantity of substance

If free electrolytic solution is present in the device, then electrolyte availability is improved, but local insufficient content occurs

Engineering Contradiction:

Improveelectrolyte availabilityVSAvoidlocal electrolyte content

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The porous layer provides self-service by automatically drawing free electrolyte through capillary action to regions where it is needed. This self-regulating mechanism ensures uniform electrolyte distribution without external intervention, resolving the contradiction between overall availability and local sufficiency.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The porous layer mediates between the bulk electrolyte reservoir and the local electrode regions. It transports electrolyte from areas of high concentration to areas of low concentration, ensuring uniform distribution while maintaining overall electrolyte availability.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 porous layer effectively increases the electrolyte content in the active material layer during cycling, alleviating the issue of insufficient electrolyte and enhancing the cycle life of the electrochemical device.

Implementation Method 1

Under the capillary action of the porous layer, free electrolytic solution in the electrochemical device can be easily transferred to the first active material layer through the porous layer

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Data Source

PatentUS12191455B2Electrochemical device and electronic device that applies same

Publication Date: 2025.01.07 NINGDE AMPEREX TECHNOLOGY LTD

AI summary

An electrochemical device includes an electrolytic solution, an electrode assembly, and a housing accommodating the electrolytic solution and the electrode assembly. The electrode assembly includes a first electrode plate, a second electrode plate, and a separator disposed there between, which are stacked and wound. In a direction of a winding central axis, the electrochemical device includes a first end and a second end that are opposite to each other. The first electrode plate includes a first current collector and a first active material layer disposed on the first current collector. The first current collector includes a first part. In the direction of the winding central axis, the first part is located at an end of the first current collector and is closer to the first end than the second end. A porous layer is disposed on the first part.