Vent Channels in Battery Current Collectors

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Solution Overview

Problem

Lithium batteries face issues with air entrapment between current collectors and electrodes, leading to poor adhesion and uneven surfaces due to the lack of venting, which affects the battery's performance and efficiency.

Innovation Solution

Incorporating vent channels on the surfaces of current collectors, with different patterns on each side, to facilitate air escape and improve adhesion between the current collectors and active materials, thereby preventing air entrapment and ensuring even surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vent channels are added to the current collector, then air entrapment is reduced and adhesion is improved, but device complexity increases

Engineering Contradiction:

Improveadhesion qualityVSAvoidcurrent collector structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The current collector surface is segmented into multiple vent channels distributed across the surface, allowing air to escape at multiple locations simultaneously. This segmentation approach effectively reduces air entrapment throughout the electrode assembly while maintaining a manageable structural complexity through systematic distribution of the channels.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The current collector is designed with a porous structure featuring channels that extend through the substrate. This porous architecture provides dedicated pathways for air to escape during electrode assembly, improving adhesion by preventing air pockets from forming between the electrode and current collector, while the regular porous pattern maintains manufacturing feasibility.

Inventive Principle:

Principle #31Porous materials

2Ease of operation

If vent channels are created through etching processes, then air escape is enabled, but manufacturing complexity increases

Engineering Contradiction:

Improveair escape capabilityVSAvoidcurrent collector fabrication

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

A mask layer is deposited on the current collector before etching to define the vent channel patterns in advance. This preliminary masking action protects areas that should not be etched while allowing precise formation of vent channels in designated regions, enabling air escape functionality while maintaining control over the manufacturing process and reducing overall fabrication complexity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The mechanical process of creating vent channels is replaced by using a mask layer that defines the channel patterns, followed by an etching process that selectively removes material. This substitution approach enables precise vent channel formation without complex mechanical machining, improving air escape capability while maintaining ease of manufacture through standard semiconductor fabrication techniques.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS20230099946A1Current collector with vent channels

Publication Date: 2023.03.30 MEDTRONIC INC

AI summary

A battery includes a positive electrode. The positive electrode includes a first current collector and a first active material. A negative electrode includes a second current collector. The second current collector includes at least one vent channel on at least one surface of the second current collector. The negative electrode includes a second active material.