Composite Active Material Coating via Dew-Point Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for producing composite active materials using the sol-gel method for all solid state batteries often result in insufficient output characteristics due to active material deterioration and impurities in the coat layer, which are influenced by dew-point temperature during the producing processes.
Innovation Solution
A producing method involving an applied film forming step under a lower dew-point temperature to prevent active material deterioration, a hydrolysis promoting step under a higher dew-point temperature to promote alkoxide compound hydrolysis, and a heat-treating step to form the coat layer, while controlling dew-point temperatures to minimize impurity carbon formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sol-gel method is used to form a coat layer on the active material surface, then the ion conductive oxide coat layer can be formed, but the active material deteriorates and impurities are generated in the coat layer
Solution Approach 1:
The patent divides the coat layer formation process into three distinct stages: (1) applied film forming step under low dew-point temperature to prevent active material deterioration, (2) hydrolysis promoting step under high dew-point temperature to promote alkoxide hydrolysis, and (3) heat-treating step to form the final coat layer. This segmentation allows each stage to optimize for its specific purpose, preventing deterioration while ensuring complete hydrolysis and coat layer formation.
Solution Approach 2:
The patent applies the coating liquid to form an applied film on the active material surface before hydrolysis occurs. This preliminary action creates a protective layer that prevents direct contact between moisture and the active material during subsequent hydrolysis, thereby preventing active material deterioration while still allowing hydrolysis to proceed in the applied film.
2Productivity
If the alkoxide compound is hydrolyzed by exposing under high dew-point temperature atmosphere, then the hydrolysis is promoted, but the active material deteriorates due to moisture
Solution Approach 1:
The patent separates the hydrolysis promotion step from the active material exposure step by first forming an applied film under low dew-point temperature, then exposing only the applied film to high dew-point temperature atmosphere for hydrolysis. This segmentation ensures that the active material is never exposed to high moisture conditions that would cause deterioration, while still achieving complete hydrolysis of the alkoxide compound in the applied film.
Solution Approach 2:
The applied film acts as an intermediary layer between the alkoxide compound and the high moisture atmosphere. During the hydrolysis promoting step, the applied film undergoes hydrolysis while protecting the underlying active material from direct contact with moisture, thus enabling high hydrolysis rate without active material deterioration.
3Object-affected harmful factors
If the coating liquid is applied under low dew-point temperature to prevent deterioration, then the active material is protected, but the hydrolysis of alkoxide compound is insufficient
Solution Approach 1:
The patent divides the process into two separate environmental conditions: first, the coating liquid is applied under low dew-point temperature to form an applied film while protecting the active material; second, the applied film is exposed under high dew-point temperature atmosphere to promote complete hydrolysis of the alkoxide compound. This temporal and environmental segmentation allows both objectives to be achieved sequentially without conflict.
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 method produces composite active materials with reduced deterioration and lower impurity carbon content in the coat layer, leading to improved output characteristics and lower reaction resistance in all solid state batteries.
Implementation Method 1
hydrolysis promoting step of promoting hydrolysis of the alkoxide compound by exposing the applied film under an atmosphere of higher dew-point temperature than dew-point temperature in the applied film forming step
Implementation Method 2
heat-treating step of forming the coat layer by heat-treating the applied film after the hydrolysis promoting step
Data Source
AI summary
A method of producing a composite active material having an active material and a coat layer containing an ion conductive oxide and formed on a surface of the active material, including: applied film forming step of forming an applied film by applying a coating liquid for coat layer, containing an alkoxide compound as a raw material of the ion conductive oxide, on a surface of the active material under an atmosphere of lower dew-point temperature than dew-point temperature where the active material deteriorates; hydrolysis promoting step of promoting hydrolysis of the alkoxide compound by exposing the applied film under an atmosphere of higher dew-point temperature than dew-point temperature in the applied film forming step; and heat-treating step of forming the coat layer by heat-treating the applied film after the hydrolysis promoting step.