Composite Battery Electrolyte for Low Interface Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid electrolytes in lithium ion batteries face challenges with high interface resistance and difficulty in processability due to rigidity, which reduces the transport number of metal ions when complexed with conventional polymers.
Innovation Solution
An electrolyte composition comprising an ion conductive inorganic solid electrolyte, a polymer that preferentially conducts metal ions, and an organic solvent, with specific mass and volume percentages of the inorganic solid electrolyte, and the inclusion of functional groups to enhance metal ion transport.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a solid electrolyte is used, then ionic conductivity and safety are improved, but processability deteriorates due to rigidity and interface resistance increases
Solution Approach 1:
The patent uses a composite structure combining inorganic solid electrolyte particles (50-95 mass%) with a polymer electrolyte matrix (5-50 mass%). The inorganic particles provide high ionic conductivity and safety, while the polymer matrix provides flexibility and processability. This composite approach resolves the contradiction by integrating the advantages of both material types.
Solution Approach 2:
The patent optimizes the content ratio of inorganic solid electrolyte to polymer electrolyte, specifying that inorganic solid electrolyte content should be 50-95 mass% and polymer electrolyte 5-50 mass%. This parameter optimization ensures sufficient rigidity and ionic conductivity from the inorganic phase while maintaining flexibility and processability through the polymer phase.
2Reliability
If a solid electrolyte is used, then ionic conductivity is improved, but interface resistance increases
Solution Approach 1:
The polymer electrolyte acts as an intermediary between the inorganic solid electrolyte particles and the electrodes. It fills the spaces between particles and forms conductive pathways, reducing interface resistance while maintaining high ionic conductivity through the composite structure.
Solution Approach 2:
The composite electrolyte forms a porous network structure where inorganic solid electrolyte particles are distributed within the polymer matrix. This porous structure increases the surface area for ion transport and reduces interface resistance by providing multiple conduction pathways.
3Ease of operation
If complexed with a flexible polymer material, then flexibility is improved, but transport number of metal ions is significantly reduced
Solution Approach 1:
The patent creates a composite where inorganic solid electrolyte particles (providing high metal ion transport number) are embedded in a polymer electrolyte matrix (providing flexibility). The inorganic phase maintains high ion selectivity while the polymer phase provides mechanical flexibility, resolving the contradiction between these two properties.
Solution Approach 2:
The patent applies different material properties to different regions: inorganic solid electrolyte particles provide high metal ion transport number in specific locations, while the polymer matrix provides flexibility in the continuous phase. This local differentiation allows both properties to coexist without compromising overall performance.
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 electrolyte composition achieves a high transport number of metal ions, flexibility, and reduced interface resistance, suitable for use in batteries with improved performance.
Implementation Method 1
an ion conductive inorganic solid electrolyte
Implementation Method 2
a polymer having an ability to preferentially conduct metal ions... the polymer contains at least one of an anionic functional group having a metal ion as a counter cation
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An electrolyte composition contains an ion conductive inorganic solid electrolyte, a polymer having an ability to preferentially conduct metal ions, and an organic solvent, in which the electrolyte composition satisfies at least one of the following conditions: (1) a content of the ion conductive inorganic solid electrolyte is 50 mass% or more with respect to a total amount of the electrolyte composition; and (2) a content of the ion conductive inorganic solid electrolyte is 15 vol% or more with respect to the total amount of the electrolyte composition.