Seawater Battery Cathode Using Copper Sulfate Mixture

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Solution Overview

Problem

Conventional seawater batteries with insoluble cathode compounds face slow activation in water and inferior performance in fresh water, requiring inefficient mold-forming processes and difficult storage conditions.

Innovation Solution

A cathode made from a mixture of copper sulfate monohydrate and anhydrous copper sulfate with conductive carbon powder and carbon fiber, using polyethylene as a binding agent, and a metal titanium or nickel sheet electrode, processed to enhance solubility, conductivity, and storage stability, allowing for improved performance and production efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If insoluble compounds such as cuprous chloride, cuprous iodide, and silver chloride are used as the active substance of the cathode, then the battery can be manufactured with conventional processes, but the battery exhibits slow activation when meeting water and inferior performance in fresh water

Engineering Contradiction:
Improveconventional manufacturing processVSAvoidactivation speed and performance consistency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the chemical composition parameter of the cathode active substance from insoluble compounds (CuCl, CuI, AgCl) to water-soluble copper sulfate (CuSO4). This parameter change fundamentally alters the dissolution behavior and electrochemical performance, enabling fast activation in both seawater and fresh water while maintaining compatibility with conventional manufacturing processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite cathode material comprising copper sulfate as the active substance, graphite or conductive carbon as the conductive material, and binding agent. This composite structure combines the high solubility and electrochemical activity of copper sulfate with the conductivity of graphite and the structural integrity provided by the binding agent, resolving the contradiction between manufacturability and performance

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If conventional mold-forming processes are used for cathode production, then the manufacturing process is established, but the productivity is relatively inefficient

Engineering Contradiction:
Improveestablished manufacturing processVSAvoidbatch production efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent replaces the conventional mechanical mold-forming process with a chemical reaction-based forming method. Copper sulfate pentahydrate crystals are heated to transform into a porous mixture of copper sulfate monohydrate and anhydrous copper sulfate, which then naturally forms the cathode structure through controlled dissolution and precipitation reactions, eliminating the need for complex molding operations and significantly improving productivity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If conventional cathodes are stored under normal conditions, then storage is simple, but the batteries require drying, sealing and full isolation from moisture

Engineering Contradiction:
Improvestorage simplicityVSAvoidstorage preparation requirements
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent converts the typically harmful effect of moisture on battery components into a beneficial feature. The copper sulfate-based cathode is designed to utilize moisture from the environment to activate the electrochemical reactions. The cathode material is stable in dry conditions but automatically activates when exposed to moisture, eliminating the need for separate drying and sealing operations while improving ease of storage and operation

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 cathode enables faster activation and consistent performance in various water types, improving conductivity and physical strength, while allowing for normal storage conditions without drying or sealing, with a discharge difference of less than 30% between seawater and fresh water.

Implementation Method 1

heating copper sulfate pentahydrate for at least 3 hour at 150° C. to 250° C. so as to produce a mixture of copper sulfate monohydrate and anhydrous copper sulfate

Methodology Applied
Scientific EffectThermal decomposition: Pyrolysis

Implementation Method 2

copper sulfate is strong electrolyte and highly soluble to water

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 3

it not only helps to improve the electrolytic performance of the battery, but also chemically reacts well with metal magnesium in the anode to generate electricity effectively

Methodology Applied
Scientific EffectRedox reaction: Redox Reactions

Implementation Method 4

using conductive carbon powder and conductive carbon fiber as a conductive matter

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS9899679B2Cathode for seawater battery and method for making the same
Publication Date: 2018.02.20 XIAMEN LONAKO INDUSTRY & TRADE CO LTD

AI summary

A cathode for a seawater battery and a method for making the cathode are disclosed. The cathode is made using a mixture of copper sulfate monohydrate and anhydrous copper sulfate at a mass percentage of 70-92%, conductive carbon powder at a mass percentage of 1-10%, conductive carbon fiber at a mass percentage of 1-10%, polyethylene PE powder at a mass percentage of 3-15%, and polyethylene wax at a mass percentage of 3-12%; and using metal titanium sheet or nickel sheet as a current collecting electrode. The cathode prevents the battery from the problems of slow activation when meeting water and of inferior output in fresh water.