Fiber-Reinforced Sintered Electrode for Solid-State Battery Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion batteries with liquid electrolytes face limitations in maximum cell voltage, capacitance loss due to irreversible reactions, and fire hazards, while solid-state batteries struggle with mechanical stability and energy density due to volume shifts and porosity issues in sintered electrodes.
Innovation Solution
A sintered composite electrode with active material particles, inorganic lithium ion conductor particles, a conductive additive, and fibrous material, where the weight proportions prioritize active material content for improved mechanical stability and energy density, and a compact structure with minimal porosity is achieved through efficient volume filling and fiber reinforcement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid electrolyte is used in lithium ion batteries, then the battery can operate with high ion conductivity, but the maximum cell voltage is restricted to about 4.3 to 4.4 V and fire hazards occur
Solution Approach 1:
The patent changes the physical state of the electrolyte from liquid to solid, fundamentally altering the safety profile while maintaining lithium ion conductivity through careful selection of solid electrolyte materials and optimization of their microstructure
Solution Approach 2:
The patent converts the potential harm of electrolyte decomposition and fire into a benefit by using solid electrolytes that are inherently more stable and less flammable, while the sintered electrode structure ensures continued high ionic conductivity despite the phase change
2Reliability
If solid-state electrolytes are used to increase energy density and durability, then the mechanical stability deteriorates due to volume shifts and porosity issues in sintered electrodes
Solution Approach 1:
The patent creates a composite sintered electrode structure combining active material particles, solid electrolyte particles, conductive additives, and fibrous materials. This composite approach allows the solid electrolyte to provide high energy density while the fiber reinforcement and optimized porosity (10-30%) maintain mechanical stability and accommodate volume shifts during cycling
Solution Approach 2:
The patent applies different properties to different regions of the electrode: the bulk structure provides mechanical support through fiber reinforcement and controlled porosity, while the interstitial spaces between particles provide ion conduction pathways, creating local optimization of both mechanical and electrochemical properties
3Quantity of substance
If thick-layer electrodes are used for higher capacitance, then the energy density increases, but the electrical conductivity and lithium ion conductivity become limiting factors in the interior of the layer
Solution Approach 1:
The patent utilizes a porous sintered structure with controlled porosity of 10-30%, creating interconnected pathways for lithium ion transport throughout the thick electrode layer. The pores act as ion highways, maintaining high ionic conductivity even in thick electrodes with high active material content
Solution Approach 2:
The patent introduces a three-dimensional conductive network using fibrous materials and particulate conductive additives that extend throughout the thick electrode layer. This 3D conductive framework ensures electrical connectivity from the bulk active material to the current collector, overcoming the conductivity limitations of thick-layer electrodes
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 solution enhances mechanical stability and adhesion to current collectors, increasing the service life and energy density of lithium ion batteries by maintaining high active material content and reducing porosity, thus overcoming the limitations of traditional lithium ion batteries.
Implementation Method 1
a fibrous material... wherein for the weight proportions N(A) to N(D) of components (A) to (D) in the composite material, the following applies: N(A)>N(B)>N(C), N(D)
Implementation Method 2
solid-state electrolyte particles from an inorganic lithium ion conductor... lithium ion conductivity becomes a relevant factor in the interior
Implementation Method 3
a particulate conductivity additive from an electrically conductive material... the electrical conductivity and the lithium ion conductivity becomes a relevant factor
Implementation Method 4
fiber-reinforced sintered electrode... a sintered composite material... a compact structure with minimal porosity is achieved through efficient volume filling
Data Source
AI summary
A sintered electrode having a sintered composite material is provided. The composite material contains (A) active-material particles, (B) solid-state electrolyte particles from an inorganic lithium ion conductor, (C) a particulate conductivity additive from an electrically conductive material and (D) a fibrous material, with weight proportions N(A) to N(D) of components (A) to (D) in the composite material satisfy the following: N (A)>N (B)>N (C), N (D). A solid-state lithium-ion battery containing such sintered electrode is also provided.