Alpha-Phase Nickel Hydroxide Electrode for Low-Temperature Discharge
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Solution Overview
Problem
Alkaline secondary batteries using β-phase Ni(OH)2 as positive electrode active material face limitations in discharge capacity and low temperature performance, as they primarily undergo one-electron reactions, whereas batteries employing α-phase Ni(OH)2 and γ-NiOOH can achieve higher capacities but still struggle with temperature-dependent discharge characteristics.
Innovation Solution
A positive electrode for alkaline secondary batteries is developed using nickel hydroxide with α-phase single-phase crystal structure and additives like yttrium oxide, which enhances the electroconductivity and improves discharge capacity, particularly at low temperatures, by incorporating yttrium oxide and other compounds such as niobium, titanium, or ytterbium oxides as additives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If β-phase Ni(OH)2 is used as positive electrode active material, then the battery structure is simple and easy to manufacture, but the discharge capacity is limited and low temperature performance is poor
Solution Approach 1:
The patent changes the crystal phase parameter of nickel hydroxide from β-phase to α-phase, which fundamentally alters the electrochemical properties. The α-phase structure enables multi-electron reactions and significantly improves discharge capacity and low temperature performance while maintaining manufacturing feasibility through controlled synthesis conditions
Solution Approach 2:
The patent creates a composite positive electrode material consisting of α-phase nickel hydroxide combined with specific additives (0.1-5 mass% of compounds containing Y, Nb, Ti, or Yb). This composite structure leverages the high capacity of α-phase Ni(OH)2 while the additives enhance electroconductivity and stabilize the crystal structure, resolving the contradiction between capacity and manufacturability
2Ease of manufacture
If β-phase Ni(OH)2 is used as positive electrode active material, then the manufacturing process is simple, but the low temperature discharge characteristics are poor
Solution Approach 1:
The patent changes the crystal phase parameter of nickel hydroxide from β-phase to α-phase, which fundamentally alters the electrochemical properties. The α-phase structure enables multi-electron reactions and significantly improves discharge capacity and low temperature performance while maintaining manufacturing feasibility through controlled synthesis conditions
Solution Approach 2:
The patent creates a composite positive electrode material consisting of α-phase nickel hydroxide combined with specific additives (0.1-5 mass% of compounds containing Y, Nb, Ti, or Yb). This composite structure leverages the high capacity of α-phase Ni(OH)2 while the additives enhance electroconductivity and stabilize the crystal structure, resolving the contradiction between capacity and manufacturability
3Quantity of substance
If α-phase Ni(OH)2 and γ-NiOOH are used to achieve 1.5 electron reaction, then the discharge capacity increases, but the temperature-dependent discharge characteristics remain problematic
Solution Approach 1:
The patent creates a composite positive electrode material consisting of α-phase nickel hydroxide combined with specific additives (0.1-5 mass% of compounds containing Y, Nb, Ti, or Yb). This composite structure leverages the high capacity of α-phase Ni(OH)2 while the additives enhance electroconductivity and stabilize the crystal structure, resolving the contradiction between capacity and manufacturability
Solution Approach 2:
The patent optimizes the additive content parameter within 0.1-5 mass% to achieve the best balance between capacity and temperature performance. This parameter optimization ensures that the multi-electron reaction capability is maximized while temperature-dependent characteristics are minimized
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 use of α-phase nickel hydroxide with yttrium oxide and other additives significantly improves low temperature discharge characteristics and high temperature charge characteristics, achieving higher discharge capacities and better performance in extreme temperatures compared to batteries using β-phase nickel hydroxide.
Implementation Method 1
enhances the electroconductivity and improves discharge capacity, particularly at low temperatures
Implementation Method 2
During battery charge, the active material is oxidized from β-Ni(OH)2 to nickel oxyhydroxide β-NiOOH. During discharge, the nickel oxyhydroxide β-NiOOH is reduced to the original β-Ni(OH)2
Data Source
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AI summary
A positive electrode for an alkaline secondary battery has high discharge capacity in a low temperature environment. The positive electrode included in the alkaline secondary battery has a positive electrode active material including 100 parts by mass of nickel hydroxide, and an additive including yttrium oxide. The nickel hydroxide includes an α-phase single phase.