Manganese Dioxide Cathode Additives for Reversible Capacity

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Solution Overview

Problem

Manganese dioxide electrodes in batteries suffer from irreversibility due to solid state proton insertion and dissolution-precipitation reactions in alkaline electrolytes, leading to inactive phase formation and reduced capacity utilization.

Innovation Solution

Incorporating additives such as bismuth, copper, and other metals into the manganese dioxide structure to enhance reversibility, allowing for complete utilization of the second electron capacity and stability through complexation and intercalation reactions, forming a layered birnessite phase that maintains electrode stability during charge and discharge cycles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If manganese dioxide undergoes solid state proton insertion and dissolution-precipitation reactions in alkaline electrolyte, then chemical reactions occur, but hausmannite and other inactive phases form that kill reversibility

Engineering Contradiction:

Improvechemical reaction activityVSAvoidelectrode reversibility

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent uses an intermediary substance (additive such as bismuth, copper, tin, lead, silver, cobalt, nickel, magnesium, aluminum, potassium, lithium, calcium, gold, antimony, iron, or zinc in elemental or salt form) that mediates between the manganese dioxide and the alkaline electrolyte. This intermediary prevents direct harmful reactions that lead to hausmannite formation while allowing beneficial chemical reactions to occur, thereby maintaining electrode reversibility during charge-discharge cycles

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical composition parameters of the electrode by incorporating additives in specific amounts (0.1-10 wt% of total cathode material weight). This parameter change modifies the reaction pathways and thermodynamic stability of phases formed during cycling, preventing irreversible hausmannite formation while maintaining active manganese dioxide phases

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If manganese dioxide is used in battery applications, then energy storage capacity is provided, but inactive phase formation reduces capacity utilization

Engineering Contradiction:

Improveenergy storage capacityVSAvoidcapacity utilization efficiency

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The additive acts as an intermediary that facilitates complete utilization of the second electron capacity of manganese dioxide by preventing formation of inactive hausmannite phase. The intermediary enables full capacity extraction during discharge while maintaining structural integrity during charge, thereby improving productivity without sacrificing energy storage quantity

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite cathode material combining manganese dioxide with small amounts of additive elements (0.1-10 wt%). This composite structure leverages the high capacity of manganese dioxide while the additive component prevents irreversible phase transformations, achieving both high energy storage capacity and high capacity utilization efficiency

Inventive Principle:

Principle #40Composite materials

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 method achieves complete reversibility and stability of manganese dioxide electrodes, enabling maximum capacity utilization in batteries, making primary manganese dioxide rechargeable and suitable for energy-dense applications with extended cycle life.

Implementation Method 1

allowing for complete utilization of the second electron capacity and stability through complexation and intercalation reactions

Methodology Applied

Scientific EffectComplexation:

Implementation Method 2

allowing for complete utilization of the second electron capacity and stability through complexation and intercalation reactions, forming a layered birnessite phase

Methodology Applied

Scientific EffectIntercalation:

Implementation Method 3

In alkaline electrolyte, manganese dioxides and its polymorphs undergo solid state proton insertion and dissolution-precipitation reactions

Methodology Applied

Scientific EffectSolid state proton insertion:

Implementation Method 4

In alkaline electrolyte, manganese dioxides and its polymorphs undergo solid state proton insertion and dissolution-precipitation reactions

Methodology Applied

Scientific EffectDissolution-precipitation: Precipitation

Data Source

PatentUS11302917B2Process for making manganese dioxide and its polymorphs reversible

Publication Date: 2022.04.12 RES FOUND THE CITY UNIV OF NEW YORK

AI summary

A method of forming a layered manganese dioxide for use in a cathode of a battery comprises disposing a cathode into a housing of an electrochemical cell, disposing an anode into the housing, disposing a polymeric separator between the anode and the cathode such that the anode and the cathode are electrically separated, adding an alkaline electrolyte to the housing, cycling the electrochemical cell into the 2nd electron capacity of the manganese dioxide, and forming a layered manganese dioxide having a layered manganese dioxide structure with the one or more additives incorporated into the layered manganese dioxide structure. The cathode comprising a cathode material comprising: a manganese dioxide compound, one or more additives selected from the group consisting of bismuth, copper, tin, lead, silver, cobalt, nickel, magnesium, aluminum, potassium, lithium, calcium, gold, antimony, iron, zinc, and combinations thereof, and a conductive carbon.