Alkaline Battery Positive Electrode with Segmented Nickel Oxide Particles
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Solution Overview
Problem
Alkaline storage batteries face challenges in maintaining a high active material utilization rate while suppressing self-discharge, as high activity of nickel oxide leads to easy decomposition and reduced utilization due to increased particle diameter.
Innovation Solution
A positive electrode with a support and nickel oxide particles, where 15% or more of the particles have a diameter of 20 μm or more with cracks, and less than 20 μm without cracks, reducing specific surface area and allowing deeper electrolyte penetration for improved charge and discharge reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the particle diameter of nickel oxide is increased to suppress high activity and reduce self-discharge, then self-discharge is reduced, but the active material utilization rate decreases due to difficulty in utilizing the interior of particles for charge and discharge reactions
Solution Approach 1:
The nickel oxide particles are segmented into two distinct size groups: a first particle group with diameter of 20 μm or more (suppressing self-discharge) and a second particle group with diameter of less than 20 μm (improving utilization rate). This segmentation allows the battery to benefit from both large particle stability and small particle reactivity.
Solution Approach 2:
Different regions of the electrode are populated with different particle sizes according to their functional requirements. The first particle group (≥20 μm) is distributed to suppress self-discharge, while the second particle group (<20 μm) is distributed to enhance active material utilization. This local quality differentiation optimizes overall battery performance.
2Object-generated harmful factors
If the specific surface area of nickel oxide is reduced to suppress activity and self-discharge, then self-discharge is suppressed, but the active material utilization rate is reduced
Solution Approach 1:
The particle population is segmented into two groups with different surface area characteristics. The first particle group has larger diameter and smaller specific surface area (suppressing self-discharge), while the second particle group has smaller diameter and larger specific surface area (improving utilization). The combined distribution achieves both goals simultaneously.
3Object-generated harmful factors
If the proportion of large particles (≥20 μm) is increased to suppress self-discharge, then self-discharge is reduced, but the active material utilization rate decreases
Solution Approach 1:
The particle size parameter is changed and distributed across two ranges. By controlling the proportion of the first particle group (≥20 μm) at 15 vol% or more, the patent achieves optimal balance between self-discharge suppression and active material utilization, resolving the contradiction through parameter optimization.
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 configuration enhances active material utilization and cycle life while suppressing self-discharge, maintaining high activity and reducing deterioration during overcharge.
Implementation Method 1
during charge, the nickel hydroxide is converted to nickel oxyhydroxide; during discharge, the nickel oxyhydroxide is converted to nickel hydroxide
Implementation Method 2
allowing deeper electrolyte penetration for improved charge and discharge reactions
Data Source
AI summary
A positive electrode for alkaline storage batteries that enables to improve the active material utilization rate, while suppressing the self-discharge. The positive electrode for alkaline storage batteries includes a support having conductivity, and a positive electrode active material adhering to the support. The positive electrode active material includes particles of a nickel oxide. The particles of the nickel oxide include a first particle group having a particle diameter of 20 μm or more, and a second particle group having a particle diameter of less than 20 μm. The first particle group includes a first component with cracks, and a second component without cracks. The proportion of the first particle group in the particles of the nickel oxide is 15 vol % or more, and the proportion by number of the first component in the first particle group is 15% or more.