Metal-Air Cell Electrolyte Flow Layout for Lower Shunt Currents

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Aluminum-air batteries face inefficiencies due to corrosion and uneven energy distribution, leading to reduced reaction rates and electricity production, as the Al(OH)3 coating on the anode decreases the reaction rate and specific energy, and shunt currents consume energy rather than delivering it.

Innovation Solution

The design includes a structured flow of alkaline aqueous electrolyte solution with specific cross-sectional areas and flow directing elements to ensure even distribution across multiple anodes, reducing ohmic resistance and shunt currents, thereby maintaining consistent reaction rates and energy production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a constant flow of aqueous alkaline solution is used to remove Al(OH)3 from the anode surface, then the anode surface is kept clean and reaction rate is maintained, but the reaction rate of electricity production decreases and efficiency is reduced

Engineering Contradiction:
Improveanode surface cleanlinessVSAvoidelectricity production rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by providing different flow conditions to different regions of the anode. Flow directing elements create localized flow patterns that ensure adequate Al(OH)3 removal at critical areas while minimizing excessive flow in other regions, thus balancing surface cleanliness with electricity production efficiency

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses dynamics by making the flow distribution adaptive rather than uniform. Flow directing elements dynamically adjust the electrolyte flow based on local requirements, allowing the system to optimize between removing coating products and maintaining high reaction rates at different locations on the anode surface

Inventive Principle:
Principle #15Dynamics

2Quantity of substance

If multiple anodes with large surface area are used to increase capacity, then the energy storage increases, but the constant flow of electrolyte affects the reaction rate and electricity production efficiency

Engineering Contradiction:
Improvealuminum fuel capacityVSAvoidelectricity production efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent applies segmentation by dividing the electrolyte flow into multiple independent streams that can be distributed to multiple anodes. Flow directing elements create separate flow paths for each anode, allowing each to operate optimally without being constrained by the need for uniform constant flow across all anodes, thus maintaining high efficiency while supporting large total capacity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent ensures that each anode receives customized flow conditions appropriate to its specific requirements. By using flow directing elements, the system provides local quality control over electrolyte distribution, allowing multiple anodes of large surface area to maintain high reaction rates without excessive electrolyte flow affecting overall efficiency

Inventive Principle:
Principle #3Local quality

3Reliability

If electrolyte flow is increased to remove Al(OH)3 coating, then the anode surface is maintained, but voltage drops between cells increase and energy is lost to shunt currents

Engineering Contradiction:
Improveanode surface maintenanceVSAvoidenergy loss to shunt currents
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent reduces energy loss by applying flow only where needed. Flow directing elements create localized flow patterns that maintain anode surfaces without subjecting the entire electrolyte system to high flow rates, thus minimizing voltage drops and reducing energy lost to shunt currents while still effectively removing Al(OH)3 coating

Inventive Principle:
Principle #3Local quality

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

This approach enhances the energetic efficiency of aluminum-air batteries by maintaining consistent reaction rates, reducing voltage drops between cells, and evenly consuming anodes, resulting in higher specific energy and reduced energy losses from shunt currents.

Implementation Method 1

Al(OH)3 + KOH →K+ + Al(OH)-4. The salt K+ + Al(OH)-4 dissolves in water. This reaction allows removal of the Al(OH)3 from the surface of the anode

Methodology Applied
Scientific EffectChemical reaction (dissolution): Solvation

Implementation Method 2

The design includes a structured flow of alkaline aqueous electrolyte solution with specific cross-sectional areas and flow directing elements to ensure even distribution across multiple anodes, reducing ohmic resistance and shunt currents

Methodology Applied
Scientific EffectOhmic resistance reduction: Electrical Resistance

Implementation Method 3

Aluminum reacts with oxygen and water to produce aluminum-hydroxide according to the following reaction: 4Al + 6H2O + 3O2 → 4Al(OH)3 + 2.71v

Methodology Applied
Scientific EffectOxidation reaction: Oxidation

Implementation Method 4

Electricity production by metal-air batteries is based on the oxidation of metals, usually aluminum, in the presence of air (O2) and water

Methodology Applied
Scientific EffectElectrochemical reaction: Fuel Cell

Implementation Method 5

Some of the aluminum may react with the water to produce aluminum-hydroxide and hydrogen according to the following reaction: 2Al + 6H2O → 2Al(OH)3 + 3H2

Methodology Applied
Scientific EffectCorrosion reaction: Hydrolysis

Data Source

PatentEP2979320B1System and method for increasing electrical efficiency of metal-air cell
Publication Date: 2024.01.03 PHINERGY
  • EP2979320B1 patent drawingFigure 1A~2
  • EP2979320B1 patent drawingFigure 3
  • EP2979320B1 patent drawingFigure 4

AI summary

Flow directing element in a metal air cell is configured to cause evenly distributed flow of aqueous electrolyte solution electrolyte in it over the anode. Flow distributing element in a metal air cell is configured to lengthen the path of electrolyte flow from an inlet to the anode, thereby to increase ohmic resistance to shunt currents in the cell. A battery with these cells consumes the metal in the metal anodes evenly and with minimized shunt currents.