Low-Nickel Sodium-Ion Cathode Composition for Stable Cycling
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Solution Overview
Problem
Nickel-containing layered transition metal oxides for sodium ion battery cathode materials face issues of high cost, high residual alkali on the surface, and poor cycle stability, limiting their large-scale application.
Innovation Solution
A low-nickel layered oxide sodium ion battery cathode material is developed by regulating the composition and particle morphology of transition metal elements Fe and Mn, reducing free sodium ions on the surface, and incorporating a doping element, with a preparation method suitable for large-scale industrial production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If nickel-containing layered transition metal oxides are used as cathode material, then battery capacity can be improved, but cost increases and residual alkali on surface increases
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the inner core contains high-nickel content for high capacity, while the outer shell has reduced nickel content and adjusted Fe/Mn composition to minimize surface residual alkali. This spatial differentiation of composition allows simultaneous optimization of capacity (core) and surface stability (shell).
Solution Approach 2:
The patent uses composite materials by combining multiple transition metal elements (Ni, Fe, Mn) in a layered oxide structure with specific stoichiometric ratios. The composite nature of the material, with Ni providing capacity and Fe/Mn providing structural stability, resolves the contradiction between high capacity and low residual alkali.
2Quantity of substance
If nickel-containing layered transition metal oxides are used as cathode material, then battery capacity can be improved, but cycle stability deteriorates
Solution Approach 1:
The core-shell structure with differentiated Ni/Fe/Mn ratios creates local quality optimization where the core maximizes capacity while the shell provides structural stability for good cycling performance. The shell acts as a protective layer that maintains structural integrity during charge-discharge cycles.
Solution Approach 2:
The composite layered oxide structure combining Ni, Fe, and Mn elements with optimized ratios creates a material that balances capacity and stability. The synergistic effect of different metal elements provides both high capacity (from Ni) and good cycle stability (from Fe and Mn structural support).
3Quantity of substance
If high-nickel composition is used, then battery capacity increases, but manufacturing cost increases
Solution Approach 1:
The patent applies parameter changes by optimizing the stoichiometric ratios of Ni, Fe, and Mn elements to achieve a balance point where capacity is maximized while nickel content is controlled. By adjusting compositional parameters, the patent finds an optimal formulation that reduces expensive nickel content while maintaining acceptable capacity through enhanced Fe and Mn contributions.
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 approach results in a cathode material with high capacity, low residual alkali, and improved stability, while simplifying the preparation process and making it scalable for industrial use.
Implementation Method 1
preparing a precursor comprising a nickel source, an iron source and a manganese source with required stoichiometry by a co-precipitation method
Implementation Method 2
carrying out secondary sintering on the doped sodium ion battery cathode material
Data Source
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Figure 3~4
AI summary
Provided is a sodium ion battery cathode material and a preparation method therefor and application thereof. A chemical formula of the sodium ion battery cathode material is NamNixFeyMnzO2, where 0.1≤x≤0.25, 0.5≤y≤0.8, 0.1≤z≤0.25, 0.8≤m≤1.1, 0.95≤x/z≤1.05, and x+y+z=1, m, x, y and z are molar percentages of corresponding elements, respectively, and each component in the chemical formula satisfies charge conservation and stoichiometry conservation. The preparation method includes the following steps: preparing a precursor including a nickel source, an iron source and a manganese source with required stoichiometry by a co-precipitation method; mixing the precursor of the nickel source, iron source and manganese source with a sodium source according to a certain proportion, adding a doping element for primary sintering to a obtain a doped sodium ion battery cathode material; and carrying out secondary sintering on the doped sodium ion battery cathode material and a coating to obtain a final sodium ion battery cathode material. The sodium ion battery cathode material provided by the present disclosure has the advantages of high capacity, low residual alkali and high stability.