Lithium Battery Electrode Assembly With Integrated Composite Separator
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Solution Overview
Problem
Rechargeable lithium batteries face challenges in reducing electrical resistance and achieving economical production, particularly in the integration of electrode assemblies that effectively manage lithium ion intercalation and electrolyte impregnation, leading to issues with high-rate charge capabilities and cycle life.
Innovation Solution
The electrode assembly incorporates a negative electrode with a current collector, a negative active material layer, and an organic-inorganic composite layer, where the negative active material layer is structured with a first carbon-based layer and a second carbon-based layer having specific Degree of Divergence (DD) values, and an organic-inorganic composite layer acts as a separator, reducing electrical resistance and eliminating the need for additional separators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional electrode assembly with separate separator is used, then safety and isolation between electrodes are ensured, but electrical resistance increases and manufacturing complexity increases
Solution Approach 1:
The patent combines the separator function and negative active material layer into a single integrated component. The organic-inorganic composite layer serves dual purposes: as the separator that isolates positive and negative electrodes, and as the negative active material layer that enables lithium ion intercalation. This merging eliminates the need for separate separator and negative electrode components, reducing electrical resistance at interfaces and simplifying the overall electrode assembly structure.
Solution Approach 2:
The organic-inorganic composite layer performs multiple functions simultaneously: it acts as the separator providing electrical isolation, as the negative active material enabling lithium storage, and as the structural framework for the electrode assembly. This multi-functionality reduces the number of components needed and eliminates additional manufacturing steps for assembling separate separator and electrode layers.
2Ease of manufacture
If multiple separate components (separator, negative electrode, positive electrode) are assembled, then functional separation is achieved, but manufacturing process becomes more complex and costly
Solution Approach 1:
The invention merges the separator and negative active material layer into one integrated organic-inorganic composite layer. This eliminates the need for separate manufacturing and assembly processes for these components, reducing manufacturing complexity and cost while maintaining the functional separation between positive and negative electrodes.
Solution Approach 2:
The organic-inorganic composite layer is designed to perform multiple functions within a single component structure. It provides both the separator function for electrical isolation and the negative active material function for lithium ion intercalation, thereby reducing the total number of components and simplifying the manufacturing process.
3Productivity
If traditional electrode assembly structure is used, then manufacturing is straightforward, but electrolyte impregnation efficiency is reduced and ionic transportation resistance increases
Solution Approach 1:
The patent employs an organic-inorganic composite material structure where the organic component provides porosity and flexibility for electrolyte penetration, while the inorganic component provides structural stability and lithium ion conduction pathways. This composite structure enhances electrolyte impregnation efficiency and reduces ionic transportation resistance compared to traditional single-material electrode structures.
Solution Approach 2:
The organic-inorganic composite layer is designed with specific local properties: the organic phase creates porous structures that facilitate electrolyte penetration, while the inorganic phase provides conductive pathways for lithium ions. This localized functional differentiation within the composite layer simultaneously improves electrolyte impregnation and reduces ionic transportation resistance.
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
This configuration enhances electrolyte impregnation, reduces ionic transportation resistance, and improves high-rate charge capabilities and cycle life, while also simplifying the battery manufacturing process by integrating the organic-inorganic composite layer with the negative active material layer, thus achieving a more economical and efficient rechargeable lithium battery design.
Implementation Method 1
an organic-inorganic composite layer integrated with the negative active material layer... the organic-inorganic composite layer acts as a separator
Implementation Method 2
oxides including lithium and a transition metal with a structure capable of intercalating/deintercalating lithium ions... a first layer including a first carbon-based negative material that physically contacts the current collector, and a second layer including a second carbon-based material, on the first layer
Implementation Method 3
Ia is a sum of peak intensities at non-planar angles measured by X-ray diffraction (XRD) using a CuKα ray, and Itotal is a sum of peak intensities at all angles measured by an XRD using a CuKα ray
Data Source
AI summary
An electrode assembly for a rechargeable lithium battery and a rechargeable lithium battery including the same are disclosed. The electrode assembly for the rechargeable lithium battery includes: a negative electrode including a current collector; a negative active material layer; an organic-inorganic composite layer integrated with the negative active material layer, the negative active material layer including an organic layer and an inorganic layer; and a positive electrode, the negative active material layer including a first layer physically contacting the current collector, the first layer including a first carbon-based negative active material, and a second layer on the first layer, including a second carbon-based negative active material, wherein a DD value of the first layer is about 30% to about 90% of a DD value of the negative active material layer, and the DD values are defined by Equation 1.DD(Degree of Divergence)=(Ia/Itotal)*100 Equation 1