Alkaline Battery Negative Electrode Composition for Fe Elution Control
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Solution Overview
Problem
Conventional negative electrodes for alkaline secondary batteries fail to satisfactorily enhance discharge capacity and cycle characteristics.
Innovation Solution
A negative electrode comprising a hydrogen storage alloy with 200 to 900 mass ppm of Fe and carbon black with 1000 to 2800 mass ppm of Fe, with a content of 0.5% to 1% by mass of carbon black relative to the hydrogen storage alloy, is used to improve conductivity and reduce Fe elution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional carbon black with low Fe content is used as conductive aid, then the negative electrode mixture has insufficient conductivity, but using carbon black with high Fe content causes excessive Fe elution into electrolyte
Solution Approach 1:
The patent changes the Fe content parameter of carbon black from conventional low levels to specifically 1000-2800 mass ppm, and simultaneously adjusts the Fe content in hydrogen storage alloy to 200-900 mass ppm. This parameter optimization resolves the contradiction by achieving sufficient conductivity while controlling Fe elution through the specific compositional range.
Solution Approach 2:
The patent creates a composite system combining hydrogen storage alloy with specific Fe content and carbon black with specific Fe content in defined proportions (0.5-1% by mass). This composite approach allows the synergistic interaction between the two materials to achieve both high conductivity and reduced Fe elution, resolving the technical contradiction.
2Reliability
If carbon black content is increased to improve conductivity, then discharge capacity improves, but Fe elution into electrolyte increases
Solution Approach 1:
The patent optimizes the carbon black content parameter to specifically 0.5-1% by mass relative to hydrogen storage alloy, and controls Fe content in both carbon black (1000-2800 mass ppm) and hydrogen storage alloy (200-900 mass ppm). This multi-parameter optimization achieves the desired conductivity and discharge capacity while minimizing Fe loss through precise compositional control.
Data Source
AI summary
This negative electrode for alkaline secondary batteries comprises a negative electrode current collector and a negative electrode mixture that is supported by the negative electrode current collector. The negative electrode mixture contains a hydrogen storage alloy that has an Fe content of 200 to 900 ppm by mass, and a carbon black that has an Fe content of 1,000 to 2,800 ppm by mass.