Metal-Doped NVPF/NVP Composite Cathode for Lower-Cost Sodium-Ion Storage
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Solution Overview
Problem
Sodium-ion batteries face challenges with high vanadium content, which increases production costs due to vanadium's high price, limiting their commercialization, and they exhibit low output power and energy storage density compared to lithium-ion batteries.
Innovation Solution
A sodium-ion storage material composed of Na3V2-xMx(PO4)2F3/Na3V2-xMx(PO4)3, where M is a transition metal such as Fe, Zn, Cr, Mn, or Cu, is developed, reducing vanadium content and improving discharge capacity and cycle stability by incorporating a binder and electrically conductive carbon to enhance electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high vanadium content materials (Na3V2(PO4)2F3, Na3V2(PO4)3) are used to achieve high energy density and power density, then excellent electrochemical performance is obtained, but production cost increases significantly due to expensive vanadium
Solution Approach 1:
The patent changes the compositional parameters by doping transition metals (Fe, Mn, Zn, Cu, Cr) into the vanadium phosphate structure, creating Na3V2-xMx(PO4)2F3/Na3V2-xMx(PO4)3 composite materials. This substitution reduces vanadium content (x value) while maintaining the crystal structure and electrochemical performance through the dopant elements' contribution to electronic and ionic conductivity.
Solution Approach 2:
The patent creates composite materials by combining doped vanadium fluorophosphate (NVPF) and vanadium phosphate (NVP) phases with transition metal elements. The composite structure Na3V2-xMx(PO4)2F3/Na3V2-xMx(PO4)3 leverages the advantages of both phases while reducing reliance on pure vanadium, thereby lowering cost while preserving performance.
2Ease of manufacture
If sodium-ion batteries are developed as low-cost alternatives to lithium-ion batteries, then production cost decreases, but output power and energy storage density are reduced
Solution Approach 1:
The patent optimizes the compositional parameters of sodium vanadium fluorophosphate by introducing transition metal dopants at controlled concentrations (x in Na3V2-xMx(PO4)2F3). This parameter adjustment enhances the material's electrical conductivity and sodium ion diffusion rate, thereby improving output power while maintaining the cost advantage of sodium-ion systems.
Solution Approach 2:
The patent introduces local quality changes through transition metal doping at specific lattice positions within the vanadium phosphate structure. The dopant elements create localized regions with enhanced electronic conductivity and modified electrochemical properties, improving overall battery power output without requiring uniform composition changes throughout the material.
3Ease of manufacture
If sodium-ion batteries are developed as low-cost alternatives to lithium-ion batteries, then production cost decreases, but energy storage density is reduced
Solution Approach 1:
The patent develops composite materials combining doped NVPF and NVP phases, where the transition metal-doped structure provides enhanced capacity for sodium ion insertion and extraction. The composite architecture maximizes the utilization of sodium ions while maintaining structural stability, thereby increasing energy storage density while preserving the cost benefits of sodium-ion battery technology.
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 solution achieves excellent charge/discharge cycle characteristics and high discharge capacity while reducing vanadium content, making sodium-ion batteries more cost-effective and competitive with lithium-ion batteries.
Implementation Method 1
Na3V2-xMx(PO4)2F3/Na3V2-xMx(PO4)3 (M=Fe, Zn, Cr, Mn, Cu or Zn, and 0< x≤ 1)
Implementation Method 2
incorporating a binder and electrically conductive carbon to enhance electrical conductivity
Implementation Method 3
exhibiting excellent charge/discharge cycle characteristics
Data Source
AI summary
The present disclosure relates to a sodium-ion storage material including a doped compound, and an electrode material for a sodium-ion battery, an electrode for a sodium-ion battery, and a sodium-ion battery, which include the sodium-ion storage material. Specifically, the sodium-ion storage material may include a compound consisting of an Na3V2-xMx(PO4)2F3/Na3V2-yMy(PO4)3 composite (M=Fe, Mn, Cr, Cu, Zn or Ti, 0<x,y≤2). When the sodium-ion storage material according to the present disclosure is used, it may maintain high discharge capacity while reducing the vanadium content, and when the sodium-ion storage material is applied to a sodium-ion secondary battery or a sodium-magnesium hybrid-ion battery, the battery may exhibit excellent charge/discharge cycle characteristics.