Air Battery Positive Electrode Projections Adhesion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing air battery positive electrodes formed using porous carbon and current collectors face challenges such as insufficient adhesion between the current collector and porous carbon, leading to unstable discharge voltage and reduced gravimetric energy density due to deformation during solvent evaporation in coating methods, and pore collapse during pressure-bonding, resulting in decreased discharge capacity.

Innovation Solution

A positive electrode design featuring a current collector with projections that extend into the porous layer, enhancing three-dimensional contact and adhesion, and reducing pressure-induced pore collapse, while maintaining high porosity for efficient oxygen diffusion and discharge product storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If porous carbon is coated onto the current collector using conventional coating methods, then the positive electrode structure is formed, but adhesion between the current collector and porous carbon is insufficient due to deformation during solvent evaporation

Engineering Contradiction:

Improveadhesion between current collector and porous carbonVSAvoidstructural stability during solvent evaporation

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

The current collector surface is pre-modified by forming oxide films and creating projections before coating the porous carbon layer. This preliminary surface preparation ensures proper adhesion and structural stability during subsequent solvent evaporation processes

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The current collector is designed with localized projections at specific positions rather than a uniformly modified surface. These projections create localized high-adhesion zones that anchor the porous carbon layer while maintaining overall structural integrity during coating and evaporation

Inventive Principle:

Principle #3Local quality

2Strength

If pressure-bonding is used to form the positive electrode, then adhesion is improved, but pore collapse occurs resulting in decreased discharge capacity

Engineering Contradiction:

Improveadhesion between current collector and porous layerVSAvoiddischarge capacity

Core Design Contradiction:

StrengthVSQuantity of substance

Solution Approach 1:

Projections are formed on the current collector surface before assembling the positive electrode. These pre-formed projections serve as mechanical anchors that provide adhesion without requiring high-pressure bonding, thereby preventing pore collapse and preserving discharge capacity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention replaces the conventional high-pressure mechanical bonding system with a projection-based mechanical interlocking system. The projections penetrate into the porous layer to provide adhesion through physical anchoring rather than compression, avoiding pore collapse

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If the current collector uses a planar surface design, then manufacturing is simple, but adhesion between the current collector and porous layer is insufficient

Engineering Contradiction:

Improvecurrent collector fabricationVSAvoidadhesion between current collector and porous layer

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The planar current collector surface is segmented into multiple projections distributed across the surface. This segmentation increases the total surface area and creates multiple anchoring points for the porous layer, significantly improving adhesion while maintaining manufacturing feasibility through standardized projection patterns

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The current collector surface is transformed from a two-dimensional planar structure to a three-dimensional projection structure. This dimensional change creates vertical anchoring features that mechanically interlock with the porous layer, providing superior adhesion compared to flat surfaces

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Productivity

If the porous layer has high porosity for oxygen diffusion, then electrochemical performance is improved, but adhesion to the current collector is reduced

Engineering Contradiction:

Improveoxygen diffusion efficiencyVSAvoidadhesion to current collector

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The porous layer is designed with localized high-porosity regions that maximize oxygen diffusion pathways while maintaining lower porosity zones near the current collector interface. The projections penetrate into these porous regions to provide mechanical anchoring, achieving both high oxygen diffusion and strong adhesion

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11276861B2Positive electrode for air battery

Publication Date: 2022.03.15 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A positive electrode for an air battery includes a current collector and a porous layer including an electroconductive material. The current collector includes a base having a first major surface, and a plurality of projections disposed on at least the first major surface of the base. The first major surface of the base is a planar surface. The porous layer is disposed on the first major surface of the base and is in direct contact with the first major surface. The projections are in direct contact with the porous layer in the interior of the porous layer.