Nano Lithium Sulfide Purification for Low-Agglomeration Solid Electrolytes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for preparing lithium sulfide result in low purity, large particle size, and severe agglomeration, making it difficult to achieve high-purity nano lithium sulfide suitable for solid-state batteries.
Innovation Solution
A method involving material purification, nano wet milling, homogeneous reaction, ball milling, and demagnetization to produce high-purity nano lithium sulfide with a particle size of <1,000 nm and a purity of ≥99.99%, while reducing magnetic material content to <50 ppb.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional preparation methods are used, then production process is simple, but product purity is low and particle size is large
Solution Approach 1:
The preparation process is divided into multiple sequential steps: material purification, nano wet milling, homogeneous reaction, ball milling, and demagnetization. Each step addresses specific quality requirements, transforming a single-step conventional process into a multi-stage refinement process that achieves >99.99% purity and nano particle size.
Solution Approach 2:
Material purification is performed before the main reaction to remove impurities from raw materials. This preliminary action prevents contamination during subsequent steps and ensures high purity of the final product, addressing the purity requirement at the source rather than relying solely on post-processing.
2Stability of the object's composition
If conventional preparation methods are used, then equipment requirements are simple, but product has severe agglomeration
Solution Approach 1:
A dispersant is introduced as an intermediary substance during the ball milling process. The dispersant prevents particle agglomeration by adsorbing onto particle surfaces and providing steric or electrostatic repulsion, enabling stable nano-dispersion that would otherwise be difficult to achieve with mechanical milling alone.
Solution Approach 2:
The process transforms material from conventional particle size to nano scale through controlled ball milling parameters (time, speed, ball-to-material ratio). This parameter optimization achieves fine dispersion without excessive energy input or equipment complexity, balancing manufacturing ease with product quality.
3Manufacturing precision
If vacuum defoaming is used, then product quality improves, but sealing requirements are strict and scale production is difficult
Solution Approach 1:
The harmful vacuum defoaming step is extracted and replaced with alternative quality assurance methods performed under atmospheric conditions. Quality control is achieved through material purification, controlled reaction conditions, and post-processing demagnetization, eliminating the need for complex vacuum sealing while maintaining product quality.
Solution Approach 2:
The quality assurance function of vacuum defoaming is copied through demagnetization processing. Instead of removing air bubbles via vacuum, the process uses magnetic field treatment to remove magnetic impurities and improve product quality, achieving similar quality outcomes with simpler equipment suitable for scale production.
4Productivity
If magnetic materials are present, then synthesis is facilitated, but solid electrolyte performance deteriorates
Solution Approach 1:
Magnetic impurities are removed through demagnetization processing in the final stage. The process discards magnetic contaminants that would otherwise degrade electrolyte performance, using magnetic separation to extract these unwanted components while preserving the non-magnetic lithium sulfide product.
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 method effectively produces high-purity nano lithium sulfide with improved performance, reducing electrical/ion resistance, increasing capacity, and minimizing mechanical stress associated with volume changes, while also simplifying the production process and reducing equipment sealing requirements.
Implementation Method 1
purify hydrazine hydrate, anhydrous hydrazine and/or hydramine and remove impurities to obtain a high-purity reducing agent
Implementation Method 2
Nano wet milling: take the high-purity reducing agent and high-purity lithium source in step a according to a mole ratio of 1:1-3 and blend the same
Implementation Method 3
drying: dry the lithium sulfide solution to obtain lithium sulfide
Data Source
AI summary
A solid-state lithium battery material. The method includes the following steps: material purification; nano wet milling; homogeneous reaction; and ball milling, to obtain high-purity nano lithium sulfide. The high-purity nano lithium sulfide of the present invention and a preparation method thereof can achieve high purity, excellent performance, simple operation, and good social and economic benefits.