Doped Solid-State Electrolytes for Lower-Temperature Potassium Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The development of potassium batteries is hindered by the limitations of liquid electrolytes, including low ionic conductivity and safety concerns, necessitating the search for high ionic conductivity solid-state electrolytes that are also cost-effective and can withstand high sintering temperatures.
Innovation Solution
A solid-state electrolyte with the formula A(3-x)MyBwCz is developed, where A is a metal cation (Na+, Li+, or K+), B is O2- or S2-, and C is an anion (F-, Cl-, Br-, I-, or CN-), with x varying from 0 to 1, and M being a monovalent or divalent metal cation, to enhance ionic conductivity and stability, specifically optimized for potassium-ion batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If commercial K-beta''-Al2O3 is used as solid-state electrolyte, then ionic conductivity is improved (8×10^-4 S cm^-1 at room temperature), but sintering temperature becomes excessively high (1200-1500°C) and cost increases
Solution Approach 1:
The patent modifies the chemical composition parameters of the electrolyte by introducing dopants (Li, Na, K, Rb, Cs) at controlled concentrations (x=0.01 to 0.1) into the beta''-alumina structure. This compositional parameter change enables achieving high ionic conductivity (≥8×10^-4 S cm^-1 at room temperature) at significantly reduced sintering temperatures (900-1100°C) compared to undoped commercial K-beta''-Al2O3 which requires 1200-1500°C
Solution Approach 2:
The patent creates composite electrolyte materials by combining beta''-alumina base structure with various alkali metal dopants (Li, Na, K, Rb, Cs) to form doped beta''-alumina compounds. This composite approach allows optimization of both ionic conductivity and sintering temperature by selecting appropriate dopant combinations and ratios, achieving high performance at lower processing temperatures
2Ease of manufacture
If liquid electrolytes are used in potassium batteries, then battery assembly is simplified, but safety deteriorates due to dendritic metal plating and oxygen/sulfur crossover
Solution Approach 1:
The patent transitions the electrolyte from liquid phase to solid phase (phase change), fundamentally changing the physical state parameter. This solid-state configuration inherently prevents dendritic metal plating by providing a rigid structure that blocks uneven metal deposition, and prevents oxygen/sulfur crossover through the dense solid matrix, thereby improving safety while maintaining manufacturability
Solution Approach 2:
The patent employs a solid electrolyte layer that serves as a permanent structural component replacing consumable liquid electrolyte, eliminating the need for complex sealing and safety mechanisms required for liquid electrolytes, thus simplifying overall battery assembly while enhancing safety
3Ease of manufacture
If other potassium-ion solid-state electrolytes are used, then cost is reduced compared to commercial K-beta''-Al2O3, but ionic conductivity deteriorates (low conductivity at room temperature)
Solution Approach 1:
The patent optimizes compositional parameters by controlling dopant concentration (x=0.01 to 0.1) and ratio, achieving the optimal balance between ionic conductivity and processing cost. This parameter optimization enables room temperature ionic conductivity ≥8×10^-4 S cm^-1 while using lower-cost dopants and reduced sintering temperatures (900-1100°C), making the electrolyte more cost-effective than commercial K-beta''-Al2O3
Solution Approach 2:
The patent introduces localized dopant atoms at specific sites within the beta''-alumina crystal structure (substituting at Al sites in the conduction plane), creating local regions of enhanced ionic conductivity. This local modification approach achieves high overall conductivity without requiring uniform high-cost materials throughout the entire electrolyte structure
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 electrolyte exhibits significantly higher ionic conductivity, improved safety by preventing oxygen or sulfur crossover, and reduced production costs, making it suitable for practical application in potassium batteries.
Implementation Method 1
The new electrolyte exhibits significantly higher ionic conductivity
Data Source
AI summary
Disclosed are solid-state electrolytes having high ionic conductivity and adapted for use in alkaline batteries. Batteries comprising such electrolytes are also disclosed. Also disclosed are methods of making solid-state electrolytes.