Mixed-Conducting Solid Electrolyte for All-Solid Battery Conductivity
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Solution Overview
Problem
Current all-solid batteries face limitations in energy density and lifetime due to the difficulty in simultaneously achieving ionic and electrical conductivity with commercially available solid electrolytes.
Innovation Solution
A solid electrolyte comprising a conducting polymer, such as PEDOT:PSS, combined with a lithium salt like LiTFSI, is developed, with controlled weight ratios and processing methods to form a matrix that enhances both ionic and electrical conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If commercially available solid electrolyte is used, then safety is improved compared to liquid electrolyte, but ionic conductivity and electrical conductivity cannot be simultaneously secured
Solution Approach 1:
The patent uses a composite material system consisting of conducting polymer (providing electrical conductivity), lithium salt (providing ionic conductivity), and plasticizer. This composite approach allows simultaneous achievement of both ionic conductivity and electrical conductivity while maintaining the safety advantages of solid electrolyte, directly resolving the technical contradiction.
Solution Approach 2:
The patent optimizes specific parameter ranges including lithium salt content (5-300 parts by weight per 100 parts conducting polymer), plasticizer content (5-200 parts by weight per 100 parts conducting polymer), and molecular weight of conducting polymer (10,000-1,000,000 g/mol). These parameter changes enable simultaneous securing of ionic conductivity (10^-7 to 10^-3 S/cm) and electrical conductivity (10^-9 to 10^-3 S/cm) while maintaining safety.
2Quantity of substance
If conducting polymer and lithium salt are combined, then both ionic conductivity and electrical conductivity can be achieved, but energy density and lifetime are limited without proper composition control
Solution Approach 1:
The patent specifies precise parameter ranges for conducting polymer molecular weight (10,000-1,000,000 g/mol), lithium salt content (5-300 parts by weight per 100 parts conducting polymer), and plasticizer content (5-200 parts by weight per 100 parts conducting polymer). These optimized parameters simultaneously achieve high ionic conductivity (10^-7 to 10^-3 S/cm) and electrical conductivity (10^-9 to 10^-3 S/cm) while improving battery lifetime and energy density.
Solution Approach 2:
The patent introduces plasticizer as an intermediary substance that mediates between conducting polymer and lithium salt, facilitating optimal interaction and distribution. The plasticizer content (5-200 parts by weight per 100 parts conducting polymer) is controlled to enhance both ionic and electrical conductivity while improving overall battery performance, lifetime, and energy density.
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 resulting solid electrolyte exhibits improved ionic and electrical conductivity, enabling enhanced energy density and extended battery life when used in all-solid batteries.
Implementation Method 1
mixing a conducting polymer, a lithium salt, and a solvent to prepare a mixed solution
Implementation Method 2
drying the coating layer
Implementation Method 3
a form of a matrix of the conducting polymer and the lithium salt dissociated inside the matrix
Data Source
AI summary
A solid electrolyte and a method for preparing the same are provided. The solid electrolyte includes a conducting polymer having mixed conducting characteristics; and a lithium salt, and the mixed conducting characteristics include ionic conductivity and electrical conductivity.