Hybrid Cathode Design for Rechargeable Alkaline Battery Capacity

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Solution Overview

Problem

Rechargeable alkaline batteries face limitations due to manganese dioxide's crystal structure and side reactions, leading to limited capacity and cycle life, while copper-zinc cells suffer from complex reaction mechanisms and material loss, resulting in low energy efficiency and short cycle life.

Innovation Solution

A secondary alkaline battery design incorporating a cathode mixture of manganese dioxide, copper, tin, iron, aluminum, vanadium, and bismuth, with a conductive carbon and copper-based structures, enabling high capacity and energy efficiency through a hybrid cathode approach and innovative electrode assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manganese dioxide is used as cathode material in rechargeable alkaline batteries, then the battery can be rechargeable, but the capacity and cycle life are limited due to crystal structure constraints and side reactions

Engineering Contradiction:

Improvecycle lifeVSAvoidcapacity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent uses composite cathode materials combining manganese dioxide with copper compounds and bismuth compounds. This composite structure allows the battery to achieve both high capacity (80-90% of second electron capacity) and long cycle life (over 500 cycles), resolving the contradiction between capacity and reliability by integrating multiple materials with complementary properties.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If copper-zinc cells are used to increase capacity, then the battery capacity improves, but energy efficiency decreases and cycle life shortens due to complex reaction mechanisms and material loss

Engineering Contradiction:

ImprovecapacityVSAvoidenergy efficiency

Core Design Contradiction:

Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent changes the chemical parameters by introducing bismuth compounds and copper compounds with specific ratios (e.g., MnO2:Cu:Bi = 1:0.1:0.05 to 1:0.5:0.2). These parameter changes optimize the reaction mechanisms to reduce material loss and improve energy efficiency while maintaining high capacity, achieving over 80% energy efficiency in rechargeable cycles.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If primary alkaline batteries are manufactured in high volume at low cost, then manufacturing cost decreases, but material wastage increases and environmental consequences worsen

Engineering Contradiction:

Improvemanufacturing costVSAvoidmaterial wastage

Core Design Contradiction:

Ease of manufactureVSLoss of substance

Solution Approach 1:

The patent transforms primary alkaline batteries into rechargeable batteries, enabling the recovery and reuse of electroactive materials (manganese dioxide, copper compounds, bismuth compounds) through multiple charge-discharge cycles. This eliminates the need to discard materials after single use, significantly reducing material wastage while maintaining ease of manufacture through scalable electrode fabrication processes.

Inventive Principle:

Principle #34Discarding and recovering

4Quantity of substance

If the battery achieves high depth of discharge, then energy capacity increases, but reliability and reproducibility decrease

Engineering Contradiction:

Improveenergy capacityVSAvoidreproducibility

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent employs feedback mechanisms through the synergistic interaction of copper compounds and bismuth compounds in the cathode structure. These compounds regulate the discharge process, maintaining stable voltage plateaus and consistent performance across cycles. The feedback control at the material level ensures that high depth of discharge (80-90% of second electron capacity) is achieved with improved reliability and reproducibility over 500 cycles.

Inventive Principle:

Principle #23Feedback

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 battery achieves high depth of discharge and energy efficiency for multiple cycles, surpassing previous rechargeable alkaline manganese dioxide batteries by delivering up to 80-90% of second electron capacity with improved reliability and reproducibility.

Implementation Method 1

manganese oxide (MnO2)

Methodology Applied

Scientific EffectOxidation: Oxidation

Implementation Method 2

copper compound comprising copper, a salt of copper

Methodology Applied

Scientific EffectReduction: Reduction

Implementation Method 3

a conductive carbon

Methodology Applied

Scientific EffectConduction (electrical): Conduction (electrical)

Implementation Method 4

an alkaline electrolyte

Methodology Applied

Scientific EffectIonic conduction: Conduction (electrical)

Data Source

PatentUS11152615B2Electrode designs for high energy density, efficiency, and capacity in rechargeable alkaline batteries

Publication Date: 2021.10.19 RES FOUND THE CITY UNIV OF NEW YORK

AI summary

A secondary alkaline battery includes an anode, a cathode, and an electrolyte. The cathode includes a current collector, a cathode mixture in electrical contact with the current collector. The cathode mixture comprises: manganese oxide, a copper compound comprising copper, a salt of copper, an alloy thereof, or any combination thereof, a bismuth compound comprising bismuth, a salt of bismuth, or any combination thereof, and a conductive carbon. The secondary alkaline battery can also include a first composition in contact with the current collector and disposed between the current collector and the cathode mixture that includes copper, a salt of copper, an alloy thereof, or a combination thereof.