Thin-Film Battery Encapsulation System for Moisture Barrier
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Solution Overview
Problem
Lithium-ion batteries face challenges with encapsulation systems that are not sufficiently impervious to air and moisture, leading to reduced lifespan and increased self-discharge rates, especially when exposed to high temperatures, which limits their application in demanding environments.
Innovation Solution
A stiff encapsulation system using a combination of parylene, ceramic materials, and low melting point glass layers, along with metal foils, is deposited in a vacuum to create a hermetically sealed barrier that prevents moisture and air ingress, ensuring the integrity of the battery and reducing self-discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional encapsulation systems are used for thin-film lithium-ion batteries, then the batteries can be protected to some extent, but the encapsulation is not sufficiently impervious to air and moisture, leading to reduced lifespan and increased self-discharge rates
Solution Approach 1:
The patent applies composite materials by creating a multi-layer encapsulation system combining parylene (organic polymer), ceramic materials (inorganic), and low melting point glass. This composite structure leverages the complementary properties of each material: parylene provides baseline protection and flexibility, ceramic materials provide superior moisture and gas barrier properties, and glass layers provide hermetic sealing. The combination achieves imperviousness to air and moisture that no single material could provide alone, directly resolving the contradiction between encapsulation quality and battery lifespan.
Solution Approach 2:
The patent implements the nesting principle by depositing multiple encapsulation layers in sequence, with each layer nested within or upon the previous layer. The structure typically includes parylene as a base layer, followed by ceramic material layers, and then glass layers, creating a nested multi-layer barrier system. This nested architecture ensures that each layer contributes to the overall protection, with inner layers providing specific functions and outer layers providing additional barriers, thereby achieving superior imperviousness and extended battery lifespan.
2Duration of action of stationary object
If the encapsulation system is made more impervious using multiple layers, then battery lifespan is extended, but the device complexity increases
Solution Approach 1:
The patent applies parameter changes by carefully controlling the thickness, composition, and deposition parameters of each encapsulation layer. Rather than simply adding many thick layers, the invention optimizes the parameters of each layer (e.g., ceramic layer thickness of a few micrometers, glass layer composition and thickness) to achieve maximum protection with minimum complexity. The low melting point glass parameter enables sealing at moderate temperatures, simplifying the overall manufacturing process despite the multi-layer structure.
Solution Approach 2:
The patent utilizes inert atmosphere principles by conducting the vacuum deposition process in a controlled vacuum environment, preventing contamination during layer formation. The encapsulation system itself creates an inert barrier environment around the battery, isolating the sensitive lithium-ion components from reactive atmospheric elements. This dual application of inert atmosphere principles simplifies manufacturing while ensuring long-term battery protection.
3Reliability
If vacuum deposition is used to deposit the encapsulation layers, then hermetic sealing is achieved, but the manufacturing process becomes more complex
Solution Approach 1:
The patent applies merging by combining multiple deposition steps into a continuous vacuum deposition process. Rather than separating the deposition of parylene, ceramic, and glass layers into distinct manufacturing operations, the invention integrates them into a single vacuum chamber process sequence. This merging approach maintains hermetic sealing quality while simplifying manufacturing by eliminating intermediate handling steps and reducing the number of separate equipment systems required.
Solution Approach 2:
The patent utilizes phase transitions, particularly the low melting point characteristic of the glass material, to achieve hermetic sealing. The glass layer is deposited and then subjected to a controlled heating process that melts the low melting point glass, allowing it to flow and seal micro-defects in the encapsulation structure. This phase transition approach achieves superior hermetic sealing without requiring excessively complex high-pressure or high-temperature processing equipment.
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 encapsulation system significantly extends the lifespan of lithium-ion batteries by preventing moisture and air exposure, reducing self-discharge rates, and maintaining performance even under high temperature conditions, thereby meeting the demand for longer-lasting battery solutions.
Implementation Method 1
A stiff encapsulation system using a combination of parylene, ceramic materials, and low melting point glass layers, along with metal foils, is deposited in a vacuum to create a hermetically sealed barrier that prevents moisture and air ingress
Implementation Method 2
A stiff encapsulation system using a combination of parylene, ceramic materials, and low melting point glass layers, along with metal foils, is deposited in a vacuum
Data Source
AI summary
Thin-film batteries that include a novel encapsulation system.