Alkaline Cell Anode and Separator Structure for Low-Zinc Reliability

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Solution Overview

Problem

Alkaline cells face reliability issues at low zinc loadings below 65% due to inadequate particle contact and increased cell gassing, leading to failures in abuse tests like drop and vibration discharge.

Innovation Solution

Incorporating anode active material with optimized particle size distribution and a separator with an integrated bottom cup design, using high fines zinc powder and a unitary cylinder-type separator to enhance particle contact and reduce gassing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If zinc loading is decreased below 65%, then production cost is reduced, but particle contact becomes inadequate and cell reliability deteriorates

Engineering Contradiction:

Improveproduction costVSAvoidcell reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the particle size parameter of zinc powder, using finer particles (average diameter 40-100 μm) to improve packing density and particle contact at low zinc loadings, thereby maintaining reliability while reducing cost

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite zinc alloys containing zinc with alloying elements (indium 10-50 ppm, bismuth 10-50 ppm) to enhance particle properties and maintain electrical contact and reliability even at reduced zinc loadings

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If zinc loading is increased above 72%, then cell capacity is improved, but cell gassing increases

Engineering Contradiction:

Improvecell capacityVSAvoidcell gassing

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent changes the particle size parameter to finer zinc powder (40-100 μm) which improves packing density and allows achieving higher cell capacity at lower zinc loadings, thereby reducing cell gassing while maintaining or improving capacity

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If zinc loading is decreased below 65%, then production cost is reduced, but particle-to-particle contact becomes inadequate

Engineering Contradiction:

Improveproduction costVSAvoidparticle contact

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent changes the particle size parameter to finer zinc powder with average diameter 40-100 μm, which increases packing density and improves particle-to-particle contact even at low zinc loadings, maintaining electrical connectivity while reducing cost

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250309239A1Alkaline electrochemical cell with improved anode and separator components

Publication Date: 2025.10.02 ENERGIZER BRANDS LLC

AI summary

An alkaline electrochemical cell includes a cathode, an anode which includes an anode active material, and a non-conductive separator disposed between the cathode and the anode, wherein from about 20% to about 50% by weight of the anode active material relative to a total amount of anode active material has a particle size of less than about 75 μm, and wherein the separator includes a unitary, cylindrical configuration having an open end, a side wall, and integrally formed closed end disposed distally to the open end.