Multilayer Ceramic Separator with Plastic Reinforcement
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Solution Overview
Problem
Conventional lithium-ion batteries with liquid or gelled electrolytes and porous plastic separators face issues with dendrite growth and mechanical fragility, particularly at lower temperatures, leading to short circuits and potential explosions, while existing solid-state electrolyte solutions are not cost-effective or defect-free.
Innovation Solution
A multilayer separator comprising a first solid electrolyte layer, a porous plastic separator film impregnated with a liquid or gel electrolyte, and a second solid electrolyte layer, which provides mechanical reinforcement and seals the electrolyte, preventing leakage and enhancing rupture strength, similar to bulletproof glass structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a porous plastic separator is used in conventional lithium-ion batteries, then flexibility is improved, but dendrite growth and short circuits occur
Solution Approach 1:
The patent uses a composite structure combining a porous plastic separator film with solid electrolyte layers on both sides. The plastic film provides flexibility while the solid electrolyte layers block dendrite growth, creating a composite material system that resolves the contradiction between flexibility and dendrite prevention.
Solution Approach 2:
The separator is divided into multiple functional layers: a porous plastic separator film for flexibility and ion transport, and solid electrolyte layers for dendrite blocking. This segmentation allows each layer to perform its specific function, combining the advantages of both materials.
2Reliability
If a pure ceramic separator is used, then dendrite growth is prevented, but mechanical fragility and susceptibility to breakage increase
Solution Approach 1:
The patent combines fragile solid electrolyte layers with a flexible porous plastic separator film to create a composite structure. The plastic film reinforces the ceramic layers, preventing breakage while the solid electrolyte layers maintain dendrite blocking capability.
Solution Approach 2:
The porous plastic separator film acts as an intermediary between the solid electrolyte layers, providing mechanical support and preventing the fragile ceramic layers from breaking during handling and operation.
3Reliability
If solid-state electrolyte layers are used to prevent dendrite growth, then reliability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The separator is segmented into a standard porous plastic separator (easy to manufacture) and solid electrolyte layers (applied as coatings). This allows the bulk of the separator to be produced using conventional, cost-effective methods while adding dendrite-blocking functionality through thinner, applied layers.
Solution Approach 2:
The solid electrolyte layers are applied locally on the surfaces of the porous plastic separator, providing dendrite protection only where needed at the electrode interfaces, rather than requiring the entire separator to be made of expensive solid electrolyte material.
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 effectively prevents dendrite growth and short circuits by shielding the electrolyte, allowing the use of metallic lithium anodes and reducing the risk of cell damage, while maintaining flexibility and cost efficiency, even at elevated temperatures.
Implementation Method 1
the polymer layer can also conduct lithium ions
Implementation Method 2
a porous plastic separator film impregnated with a liquid or gel electrolyte
Data Source
AI summary
A separator for an electric battery includes a first solid electrolyte layer; a plastic separator film impregnated with a liquid or gel electrolyte; and a second solid electrolyte layer, the first and second electrolyte layers sealing the liquid or gel electrolyte in the plastic separator. Also disclosed is a separator where first and second electrolyte layers sealing a plastic separator film and have a porosity less than 5%. A method for manufacturing a separator, an electric battery and a vehicle are also provided.