NASICON Sodium Ion Conductor Composition for Room-Temperature Conductivity
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Solution Overview
Problem
Existing solid-state electrolytes for sodium batteries have lower conductivities than liquid electrolytes, limiting their practical application in solid-state batteries.
Innovation Solution
Development of a solid-state ion conductor comprising a compound of Formula 1: Na x M 1< 2-(y+z) M 3< z (AO 4 ) 3, where M 1<, M 2<, and M 3< are Hf, Sc, or Zr, and A is P or Si, with specific ranges for x, y, and z, exhibiting a NASICON structure and high sodium ion conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solid-state electrolytes are used instead of liquid electrolytes, then safety and energy density are improved, but ionic conductivity is reduced
Solution Approach 1:
The patent modifies the chemical composition parameters of the solid-state electrolyte by incorporating specific ratios of Na3Zr2Si2PO12 and Na3Sc2(PO4)3 compounds, adjusting the molecular structure to optimize ionic conductivity while maintaining the solid-state safety advantages
Solution Approach 2:
The invention creates a composite solid-state electrolyte material by combining Zr-based NASICON structure with Sc-doped components, leveraging the complementary properties of both materials to achieve high ionic conductivity (10^-2 to 50 mS/cm) while retaining the safety benefits of solid-state architecture
2Quantity of substance
If solid-state electrolytes are used instead of liquid electrolytes, then energy density is improved, but ionic conductivity is reduced
Solution Approach 1:
The patent optimizes the chemical composition parameters by controlling the molar ratios of Na, Zr, Sc, Si, and P elements, adjusting the crystal structure parameters to maximize sodium ion transport pathways while maintaining high energy density through compact solid-state architecture
3Stability of the object's composition
If conventional solid-state electrolyte compositions are used, then structural stability is maintained, but ionic conductivity is limited
Solution Approach 1:
The invention develops a composite NASICON-type electrolyte combining Na3Zr2Si2PO12 matrix with Na3Sc2(PO4)3 dopant phases, where the Zr-based framework provides structural stability while Sc doping creates additional ionic conduction pathways, achieving both stability and high conductivity (10^-2 to 50 mS/cm)
Solution Approach 2:
The patent introduces localized Sc doping at specific crystallographic sites within the NASICON structure, creating regions of enhanced ionic conductivity within the stable Zr-based framework, allowing different parts of the material to fulfill different functions (stability vs. conductivity)
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 new solid-state ion conductor achieves high room temperature ionic conductivity, ranging from 10 -2< to 50 mS/cm, enhancing the performance and safety of sodium batteries.
Implementation Method 1
The compound of Formula 1 may have a sodium ion conductivity of 10^-2 to 50 mS/cm
Data Source
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AI summary
A solid-state ion conductor includes a compound of the formula NaxM12-(y+z)M2yM3z(AO4)3 wherein M1, M2, and M3 are each independently Hf, Mg, Sc, In, Y, Ca, or Zr; A is P, Si, S, or a combination thereof; 3≤x≤3.5; 0.5≤y≤1; and 0≤z≤0.5. The solid-state ion conductor can be useful in various components of an electrochemical cell.