Li3AB6 Halide Electrolytes for Stable Nickel-Rich Solid-State Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid-state batteries with nickel-rich electroactive materials face challenges due to poor interfacial compatibility and stability with sulfide electrolytes, particularly at elevated temperatures, leading to reduced performance and safety concerns.
Innovation Solution
The development of all-solid-state electrochemical cells with reduced porosity using Li3AB6 as a solid-state electrolyte material, where A is yttrium, indium, or erbium, and B is chloride or bromide, along with nickel-rich electroactive materials like NMC or NCMA, to enhance compatibility and stability, and a hot press process to form the electrodes and electrolyte layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If nickel-rich electroactive materials are used to improve capacity capability, then energy density is improved, but interfacial compatibility and stability with solid-state electrolytes deteriorates
Solution Approach 1:
A buffer layer comprising Li3YCl6, Li3InCl6, Li3ScCl6, Li3ErCl6, or mixtures thereof is introduced between the nickel-rich electroactive material and the solid-state electrolyte. This intermediary buffer layer prevents direct negative reactions at the interface while maintaining ionic conductivity, thereby resolving the compatibility issue between high-capacity nickel-rich materials and solid-state electrolytes.
Solution Approach 2:
The electrode structure is designed as a composite system combining nickel-rich electroactive materials (NMC or NCMA with specific compositions) with a buffer layer of Li3AB6 halide material. This composite approach allows the system to benefit from the high capacity of nickel-rich materials while the buffer layer provides interfacial protection and stability.
2Manufacturing precision
If hot pressing is used to reduce porosity and improve density, then manufacturing precision is improved, but negative reactions between sulfide electrolyte and nickel-rich materials at elevated temperatures worsen
Solution Approach 1:
The Li3AB6 buffer layer serves as a thermal and chemical barrier during hot pressing. It protects the sulfide electrolyte from direct contact with nickel-rich materials at elevated temperatures, preventing negative reactions while still allowing the application of pressure and heat to reduce porosity and improve density of the overall structure.
Solution Approach 2:
The hot pressing parameters (temperature, pressure, time) are optimized to be sufficient for densification but controlled to minimize thermal degradation. The buffer layer enables this parameter optimization by providing thermal protection, allowing higher temperatures to be applied without causing harmful reactions.
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
This approach results in improved temperature tolerance, safety, and superior power and life performance of lithium-ion batteries, with reduced porosity and increased active material loading, addressing the compatibility and stability issues with nickel-rich materials.
Implementation Method 1
The electrolyte is suitable for conducting lithium ions between the electrodes
Implementation Method 2
Hot pressing processes can be used during the formation of solid-state electrolyte layers, and also, solid-state electrodes
Data Source
AI summary
The present disclosure provides an all-solid-state electrochemical battery that includes a positive electrode, a negative electrode, and a solid-state electrolyte layer disposed between and separating the positive electrode and the negative electrode. The positive electrode includes a positive electroactive material and a solid-state electrolyte material. The solid-state electrolyte material may be represented by Li3AB6, where A is selected from the group consisting of: yttrium (Y), indium (In), scandium (Sc), erbium (Er), and combinations thereof, and B is selected from the group consisting of: chloride (Cl), bromide (Br), ClxBr(x−1) (where 0<x<1), and combinations thereof. In certain variations, the positive electroactive material includes a nickel-rich electroactive material, and the solid state electrolyte layer includes a sulfide-based electrolyte material. The solid-state electrolyte layer can also include the solid-state electrolyte material may be represented by Li3AB6.