Alkaline Battery Leakage Control via Electrode Ratio

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Solution Overview

Problem

Alkaline primary batteries face challenges in suppressing leakage during overdischarge, especially when multiple batteries are connected in series, due to the formation of a high resistance coating on the zinc negative electrode, leading to unutilized zinc and increased gas generation.

Innovation Solution

The alkaline primary battery design includes a cylindrical positive electrode with manganese dioxide, a gel negative electrode containing zinc or zinc alloy, and a separator, with controlled electric capacity and height ratios between the positive and negative electrodes, specifically within the ranges 1.05 ≤ C2/C1 ≤ 1.25 and 0.85 ≤ L2/L1 ≤ -0.3058 × C2/C1 + 1.3153, to optimize discharge performance and reduce leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the electric capacity of the negative electrode is set larger than that of the positive electrode to improve heavy load discharge characteristics, then the discharge capacity and heavy load discharge characteristics are improved, but the amount of remaining zinc upon complete consumption of battery capacity is significantly increased

Engineering Contradiction:
Improvedischarge capacityVSAvoidremaining zinc
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent applies parameter changes by precisely controlling the electric capacity ratio (C2/C1) within 1.05-1.25 and the height ratio (L2/L1) within a specific range defined by formula (2). This dual parameter control optimizes zinc utilization while maintaining adequate discharge capacity, resolving the contradiction between productivity and substance loss.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic adjustment by establishing a relationship between the two ratios rather than fixing them independently. The height ratio adapts based on the electric capacity ratio through formula (2), allowing optimal performance across different operating conditions while minimizing remaining zinc.

Inventive Principle:
Principle #15Dynamics

2Power

If the electric capacity of the negative electrode is set larger than that of the positive electrode, then the heavy load discharge characteristics are improved, but the gas generation during overdischarge increases making leakage difficult to suppress

Engineering Contradiction:
Improveheavy load discharge characteristicsVSAvoidgas generation
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent changes the parameters of electric capacity ratio and height ratio to optimal ranges that balance power output with gas generation control. By constraining C2/C1 to 1.05-1.25 and L2/L1 to satisfy formula (2), the design achieves adequate heavy load performance while limiting excess zinc that would generate gas during overdischarge.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism through the interdependent relationship between the two ratios. The height ratio is determined by the electric capacity ratio via formula (2), creating a self-regulating system that prevents excessive zinc accumulation and associated gas generation while maintaining power characteristics.

Inventive Principle:
Principle #23Feedback

3Loss of substance

If zinc alloy particles with high reactivity are used to reduce remaining zinc, then the amount of remaining zinc is reduced, but the leakage resistance during overdischarge when multiple batteries are connected in series cannot be sufficiently improved

Engineering Contradiction:
Improveremaining zincVSAvoidleakage resistance
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent transitions from single-parameter optimization to two-dimensional optimization by simultaneously controlling both the electric capacity ratio and the height ratio. This dimensional expansion allows the design to address leakage resistance in series configurations while maintaining low remaining zinc levels, overcoming the limitations of previous single-parameter approaches.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent applies dynamics by establishing an adaptive relationship between the two ratios through formula (2). This dynamic adjustment enables the battery design to maintain optimal performance across different operating scenarios including series connections, where the interdependent ratios ensure both low remaining zinc and high leakage resistance.

Inventive Principle:
Principle #15Dynamics

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

This design effectively suppresses leakage during overdischarge by reducing the amount of remaining zinc and maximizing material utilization, even when multiple batteries are connected in series, ensuring reliable discharge performance and reduced gas generation.

Implementation Method 1

an alkaline electrolyte

Methodology Applied
Scientific EffectIonic conduction: Conduction (electrical)

Implementation Method 2

a high resistance coating containing a zinc oxide is formed on the surface of zinc serving as the negative electrode active material through the discharge reaction

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 3

a cylindrical positive electrode with manganese dioxide

Methodology Applied
Scientific EffectReduction: Reduction

Data Source

PatentEP2538476B1Alkaline primary battery
Publication Date: 2014.03.12 PANASONIC HOLDINGS CORP
  • EP2538476B1 patent drawingFigure 1
  • EP2538476B1 patent drawingFigure 2
  • EP2538476B1 patent drawingFigure 3

AI summary

Disclosed is an alkaline primary battery including: a bottomed cylindrical battery case; a cylindrical positive electrode having a hollow, being in contact with an inner wall of the battery case, and including manganese dioxide; a gel negative electrode being in the hollow of the positive electrode, and including zinc or a zinc alloy; a separator interposed between the positive electrode and the negative electrode; and an alkaline electrolyte. The positive electrode has an electric capacity C1 and a height L1, the negative electrode has an electric capacity C2 and a height L2, the electric capacity C1 and the electric capacity C2 satisfy the relational expression (1): 1.05≤C⁢2/C⁢1≤1.25 and the height L1 and the height L2 satisfy the relational expression (2): 0.85≤L⁢2/L⁢1≤fC⁢2/C⁢1 where fC⁢2/C⁢1=-0.3058×C⁢2/C⁢1+1.3153.