ZnPS3 Solid Electrolyte With Vacancy-Tuned Divalent Ion Conduction
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Solution Overview
Problem
There is a need for solid-state electrolyte materials that exhibit significant divalent ionic conductivity at room temperature while being electrically insulating, inexpensive, nontoxic, and electrochemically active, as current materials face challenges in achieving these properties simultaneously.
Innovation Solution
The development of solid-state electrolytes characterized by the formula MPS3, where M is one or more metal cations, including at least one divalent cation, with controlled vacancy and divalent ion concentrations to tune conductivity, using trivalent ions and specific metal cation concentrations to achieve divalent ion conductivity without electronic conduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If divalent cations (Mg2+, Zn2+) are used to replace monovalent Li+, then two-electron redox processes and volumetric capacity are improved, but solid-state ionic conductivity deteriorates due to increased mass and charge density
Solution Approach 1:
The patent modifies the crystal structure parameters of ZnPS3 by substituting Zn2+ with Al3+ ions, changing the lattice constants and creating vacancies that facilitate divalent ion conduction. This parameter change resolves the contradiction by optimizing the structure for both capacity and conductivity
Solution Approach 2:
The patent creates a composite solid electrolyte system combining ZnPS3 with Al3+ substituted phases, forming a composite material that exhibits both high volumetric capacity and improved solid-state ionic conductivity for divalent ions
2Reliability
If metal substitution and lattice softening strategies are used to maximize Li+ conductivity, then ionic conductivity is improved, but these approaches fail for M2+ due to difference in charge density
Solution Approach 1:
The patent specifically targets divalent ion conduction by modifying the crystal structure parameters of ZnPS3 through Al3+ substitution, creating a tailored structure that accommodates the higher charge density of M2+ ions while maintaining conductivity
Solution Approach 2:
The patent adapts the successful Li+ conduction structure of ZnPS3 and modifies it through Al3+ substitution to create a analogous structure optimized for M2+ conduction, copying the structural framework while adjusting parameters for divalent ions
3Quantity of substance
If solid-state electrolyte materials are developed for divalent ion conduction, then battery energy density is improved, but achieving room temperature conductivity with electrical insulation becomes difficult
Solution Approach 1:
The patent optimizes the crystal structure parameters of ZnPS3 through Al3+ substitution to achieve the right balance between ionic conductivity and electrical insulation at room temperature, enabling high energy density while maintaining safety
Solution Approach 2:
The patent introduces local structural modifications through Al3+ substitution at specific lattice sites, creating localized regions with enhanced divalent ion conduction pathways while maintaining overall electrical insulation of the bulk material
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 electrolytes demonstrate divalent ion conductivity at room temperature with low activation energy, maintaining electrical insulation, and are cost-effective and non-toxic, enabling improved performance in divalent ion batteries and electrochemical cells.
Implementation Method 1
First-principles calculations suggest that the barrier corresponds to vacancy-mediated diffusion
Implementation Method 2
the electrolyte is electrically insulating
Data Source
AI summary
In an aspect, an electrochemical cell comprises: a positive electrode; a negative electrode; and a solid state electrolyte in ionic communication with the positive electrode and the negative electrode; wherein: the electrolyte is characterized by formula (FX1): MPS3 (FX1); wherein M is one or more metal cations and optionally metal cation vacancies; and wherein at least one of said one or more metal cations is a divalent cation; the electrolyte is characterized by a divalent ion conductivity; and the electrolyte is electrically insulating. The solid state electrolyte is optionally not an electrocatalyst material or does not function as an electrocatalyst in the electrochemical cell during operation (e.g., charging and/or discharging) of the electrochemical cell. The solid state electrolyte is optionally not an electrode or does not function as an electrode in the electrochemical cell during operation (e.g., charging and/or discharging) of the electrochemical cell.