Silver Oxide Positive Electrode Composition for Low-Resistance Cycling

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Solution Overview

Problem

Alkaline batteries using silver oxide as a positive electrode active material face challenges in improving charge-discharge cycle characteristics and reducing internal resistance, while avoiding the environmental burden of cadmium usage.

Innovation Solution

A positive electrode containing silver oxide with a compound of tellurium, where the tellurium content is 0.4 parts by mass or more relative to silver, and free of cadmium, is used, along with an alkaline electrolyte solution containing tellurium, to enhance the battery's performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If cadmium component is added to silver peroxide to suppress oxygen generation, then oxygen generation is suppressed, but environmental burden increases

Engineering Contradiction:
Improveoxygen generationVSAvoidenvironmental burden
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing cadmium with tellurium at a specific ratio (0.03 to 0.1 mass%). This substitution maintains the oxygen suppression function while eliminating the environmental toxicity associated with cadmium, thus resolving the contradiction between suppressing harmful oxygen generation and avoiding environmental burden

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses tellurium as a substitute for cadmium, creating a composition that is environmentally friendly while maintaining functional effectiveness. The tellurium-based composition serves as a sustainable alternative that achieves the same oxygen suppression goal without the long-term environmental damage caused by cadmium

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Reliability

If silver oxide is used as positive electrode active material, then battery performance is achieved, but charge-discharge cycle characteristics need improvement

Engineering Contradiction:
Improvecharge-discharge cycle characteristicsVSAvoidbattery performance
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The patent creates a composite material system by combining silver oxide with tellurium at a specific ratio (0.03 to 0.1 mass%). This composite structure improves charge-discharge cycle characteristics while maintaining the electrochemical performance of silver oxide, resolving the contradiction between reliability and power

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent introduces tellurium as a localized additive within the silver oxide matrix, creating regions with enhanced properties. The tellurium distributes at specific concentrations to locally improve cycle stability without compromising the overall electrochemical performance of the silver oxide active material

Inventive Principle:
Principle #3Local quality

3Power

If silver oxide is used as positive electrode active material, then battery operation is enabled, but internal resistance needs reduction

Engineering Contradiction:
Improveinternal resistanceVSAvoidbattery operation
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent changes the compositional parameters by incorporating tellurium at optimized concentrations (0.03 to 0.1 mass% relative to silver oxide). This parameter adjustment reduces internal resistance by modifying the electrochemical properties of the positive electrode, while maintaining reliable battery operation through the stable silver oxide base structure

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4068412B1Positive electrode for alkaline batteries, and alkaline battery, and method for producing the same
Publication Date: 2025.09.17 MAXELL LTD
  • EP4068412B1 patent drawingFigure 1~2

AI summary

The alkaline battery of the present invention includes, as power generation components, a positive electrode containing silver oxide as a positive electrode active material, a negative electrode, a separator, and an alkaline electrolyte solution. At least one of the power generation components contains tellurium or a compound of tellurium. The total content of tellurium element contained in components housed in the battery is 0.4 parts by mass or more with respect to 100 parts by mass of the total amount of silver element in the positive electrode active material. The positive electrode is substantially free of cadmium.