Oxide Solid-State Lithium-Ion Conductor for Safe High Conductivity
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Solution Overview
Problem
Current solid-state lithium-ion conductors face challenges such as low ionic conductivity, high cost due to the use of rare-earth elements or noble metals, and safety concerns associated with sulfide electrolytes, limiting their practical application in batteries for electric vehicles and grid-based energy storage.
Innovation Solution
A solid-state ion conductor with a sodalite-type structure, represented by compounds like Li5Al4Si2O12BH4, is developed, offering high ionic conductivity and stability, and is synthesized using a wet method involving precursor compounds and hydrothermal or microwave synthesis, avoiding the use of rare-earth elements and noble metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sulfide solid-state electrolytes are used, then lithium conductivity is improved, but toxicity and safety concerns increase due to reaction with air or water to evolve hydrogen sulfide
Solution Approach 1:
The patent replaces expensive and hazardous sulfide electrolytes with oxide-based solid-state electrolytes that are less toxic and safer. The oxide electrolyte layer serves as a protective barrier between the sulfur-containing cathode material and the lithium metal anode, preventing direct contact and harmful reactions while maintaining ionic conductivity.
Solution Approach 2:
The oxide solid-state electrolyte acts as an intermediary layer between the sulfur-containing cathode and lithium metal anode. This intermediate oxide layer prevents direct interaction between sulfur and lithium, blocking the formation of toxic lithium sulfide and hydrogen sulfide gas, while still allowing lithium ion transport.
2Object-affected harmful factors
If oxide solid-state electrolytes are used, then toxicity is reduced and air stability is improved, but ionic conductivity is limited
Solution Approach 1:
The patent modifies the oxide electrolyte composition by incorporating specific metal oxides and controlling stoichiometry to enhance ionic conductivity. The oxide electrolyte layer is designed with specific chemical composition and structure to optimize lithium ion transport while maintaining air stability and low toxicity.
Solution Approach 2:
The patent uses composite structures combining oxide electrolyte with sulfur-containing cathode materials. The composite design allows the oxide to provide stability and safety while the sulfur-containing materials contribute to high voltage and energy density, achieving a balance between conductivity, safety, and performance.
3Reliability
If rare-earth elements or noble metals are used in solid-state electrolytes, then ionic conductivity is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive rare-earth elements and noble metals with abundant and cost-effective oxide materials. The oxide solid-state electrolyte composition is designed to achieve adequate ionic conductivity using common metals, significantly reducing material costs while maintaining safety and performance.
Solution Approach 2:
The patent optimizes the chemical composition and structural parameters of oxide-based electrolytes to enhance ionic conductivity without relying on expensive rare-earth elements. By adjusting stoichiometry and incorporating specific metal oxides, the patent achieves improved conductivity using cost-effective materials.
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 ionic conductivity of up to 25 mS/cm at room temperature, is kinetically stable with lithium transition metal oxides and phosphates, and does not form alloys with lithium metal, enhancing the performance and safety of solid-state batteries.
Implementation Method 1
the solid-state ion conductor achieves ionic conductivity of up to 25 mS/cm at room temperature
Implementation Method 2
synthesized using a wet method involving precursor compounds and hydrothermal or microwave synthesis
Implementation Method 3
synthesized using a wet method involving precursor compounds and hydrothermal or microwave synthesis
Data Source
AI summary
A solid-state ion conductor includes a compound of Formula (I):Li4+(b−a)y+cδ+(a−γ)xM13+x+yM23−yM″xO12X1cX21−c Formula (I)wherein, M1 is a cationic element having an oxidation state of +2 or +3; M2 is a cationic element having an oxidation state of +4 or +5; M″ is a cationic element having an oxidation state of γ, wherein γ is less than b; X1 is a cluster anion having an oxidation state of (−1-δ), wherein δ is 0 or 1; X2 is a halogen; 0<c≤1; 0≤x≤1; and 0≤y≤2.