Lithium Potassium Element Oxide Solid Electrolytes for Safe Batteries
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Solution Overview
Problem
Conventional Li-ion batteries face safety risks due to flammable organic solvents and stability issues with existing solid-state lithium ion conductors, which limit their use in large-scale energy storage and metal batteries, as they degrade when in contact with lithium metal anodes.
Innovation Solution
Development of novel lithium potassium element oxide compounds, specifically compounds of formulae (I), (II), (III), and (IV), which exhibit high Li+ conductivity and stability, suitable as solid-state electrolytes or electrode coating layers for lithium ion and metal batteries, with Li+ conductivity ranging from 10−3 to 22 mS/cm and activation energy between 0.15 to 0.50 eV, ensuring compatibility and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flammable organic liquid electrolyte is used in Li-ion batteries, then high Li+ conductivity is achieved, but safety risk increases due to flammability
Solution Approach 1:
The patent transitions the electrolyte from liquid phase to solid phase by using lithium potassium element oxide compounds. This phase transition eliminates flammability while maintaining Li+ conductivity, as the solid-state compounds provide ion conduction pathways without the volatile organic components that cause fire hazards in liquid electrolytes.
Solution Approach 2:
The patent employs composite solid-state electrolyte materials combining lithium potassium element oxides with other components to achieve both safety and conductivity. The composite structure allows the material to block electron transport (improving safety) while providing sufficient Li+ ion conduction pathways (maintaining performance).
2Reliability
If conventional solid Li-ion conductors are used to replace liquid electrolyte, then safety is improved, but electrochemical stability deteriorates when in contact with lithium metal anodes
Solution Approach 1:
The patent modifies the chemical composition parameters of solid-state electrolytes by incorporating specific ratios of lithium, potassium, and element oxides (where element is Ir, Sb, I, Nb, or W). This compositional parameter change creates a stable interface with lithium metal anodes, preventing the degradation reactions that occur with conventional solid electrolytes while maintaining safety benefits.
Solution Approach 2:
The lithium potassium element oxide compounds act as an intermediary layer between the lithium metal anode and other battery components. This intermediary material is chemically stable with lithium metal, preventing direct harmful reactions, while still allowing efficient Li+ ion transport through its crystal structure.
3Stability of the object's composition
If solid Li-ion conductor is used, then mechanical and thermal stability are improved, but grain boundary resistance increases
Solution Approach 1:
The patent utilizes the controlled porous or defective structure within the solid-state electrolyte grains to facilitate ion transport. The lithium potassium element oxide compounds are synthesized with internal pathways or controlled porosity that reduce grain boundary resistance, allowing Li+ ions to move efficiently through the material while the overall solid structure maintains mechanical and thermal stability.
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 novel lithium potassium element oxide compounds provide enhanced mechanical and thermal stability, reduce grain boundary resistance, and maintain electrochemical stability with lithium metal anodes, facilitating the development of safer and more efficient all-solid-state lithium batteries with improved charge/discharge rates and power density.
Implementation Method 1
A primary function of the solid Li-conductive phase, usually called solid Li-ion conductor or solid state electrolyte, is to conduct Li+ ions from the anode side to the cathode side during discharge and from the cathode side to the anode side during charge
Data Source
AI summary
Solid-state lithium ion electrolytes of lithium potassium element oxide based compounds are provided which contain an anionic framework capable of conducting lithium ions. The element atoms are Ir, Sb, I Nb and W. An activation energy of the lithium potassium element oxide compounds is from 0.15 to 0.50 eV and conductivities are from 10−3 to 22 mS/cm at 300K. Compounds of specific formulae are provided and methods to alter the materials with inclusion of aliovalent ions shown. Lithium batteries containing the composite lithium ion electrolytes are also provided. Electrodes containing the lithium potassium element oxide based materials and batteries with such electrodes are also provided.