Nickel-Molybdenum Cathode for Galvanic Metal-Water Cells

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Solution Overview

Problem

Existing galvanic metal-water power sources face challenges with high hydrogen evolution reaction (HER) overpotential and fouling due to natural metal ions in seawater, and have high manufacturing costs for components like platinized titanium cathodes.

Innovation Solution

The development of a nickel-molybdenum coated cathode for galvanic metal-water cells, achieved through electrodeposition using a substrate in an aqueous solution with a complexing agent, where the nickel-molybdenum layer is deposited with varying current density and potentially annealed at high temperatures, offering a lower HER overpotential and reduced manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If platinized titanium cathodes are used, then hydrogen evolution reaction efficiency is improved, but manufacturing cost increases

Engineering Contradiction:

Improvehydrogen evolution reaction overpotentialVSAvoidmanufacturing cost

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The patent replaces expensive platinized titanium cathodes with a cheaper nickel-molybdenum coated substrate that can be manufactured at lower cost through electrodeposition processes, sacrificing the durability requirement for cost reduction in disposable or replaceable cathode applications

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the material composition parameters by using nickel-molybdenum alloy coating instead of platinum on titanium, and optimizes deposition parameters such as current density (5-800 mA/cm²) and annealing temperature (up to 1200°C) to achieve the desired catalytic performance at lower cost

Inventive Principle:

Principle #35Parameter changes

2Loss of energy

If platinized titanium cathodes are used, then hydrogen evolution reaction efficiency is improved, but device complexity increases

Engineering Contradiction:

Improvehydrogen evolution reaction overpotentialVSAvoidmanufacturing process complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical/physical process of platinum sputtering or electroplating onto titanium with a chemical electrodeposition process that directly forms nickel-molybdenum alloy coating on substrate, simplifying the manufacturing process

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses composite material approach by creating nickel-molybdenum alloy coating on a substrate (such as stainless steel or nickel foam), combining the catalytic activity of nickel-molybdenum with the structural integrity of the substrate, replacing the platinum-titanium composite

Inventive Principle:

Principle #40Composite materials

3Adaptability or versatility

If seawater is used as electrolyte, then availability is improved, but fouling occurs due to natural metal ions

Engineering Contradiction:

Improveelectrolyte availabilityVSAvoidfouling by metal ions

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary protective action by using nickel-molybdenum coating on the cathode surface that resists fouling by silicon, iron, calcium, and magnesium ions present in seawater, preventing the harmful effects before they can degrade performance

Inventive Principle:

Principle #9Preliminary anti-action

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 nickel-molybdenum coated cathodes exhibit a lower HER overpotential and lower manufacturing costs compared to platinized titanium, maintaining better performance and reducing fouling issues, making them a more efficient and cost-effective alternative for galvanic metal-water cells.

Implementation Method 1

depositing a layer comprising nickel-molybdenum on the substrate to provide a nickel-molybdenum coated positive electrode

Methodology Applied

Scientific EffectElectrodeposition: Electrodeposition

Implementation Method 2

leaching the sacrificial material by at least one of corrosion and an applied potential

Methodology Applied

Scientific EffectCorrosion:

Implementation Method 3

annealing the nickel-molybdenum coated positive electrode at a temperature up to 1,200 degrees Celsius in a controlled gas atmosphere

Methodology Applied

Scientific EffectAnnealing: Annealing

Implementation Method 4

a hydrogen evolving cathode that splits water according to the reaction 2H2O→H2+2OH−

Methodology Applied

Scientific EffectWater splitting: Electrolysis

Data Source

PatentUS11069883B2Galvanic metal-water cell with nickel-molybdenum cathode

Publication Date: 2021.07.20 L3HARRIS OPEN WATER POWER INC

AI summary

Galvanic metal-water cells and methods of manufacturing positive electrodes to be used in said galvanic metal-water cells. The galvanic metal-water cells in accordance with various embodiments include a cathode that includes a layer comprising nickel-molybdenum deposited thereon. The nickel-molybdenum coated cathodes exhibit favorable hydrogen evolution reaction overpotential compared with existing devices. In these galvanic metal-water cells, the metal is oxidized and water is reduced.