Composite Current Collector for Lithium-Ion Battery Energy Density
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Solution Overview
Problem
Lithium-ion batteries face challenges in achieving high weight and volumetric energy density while maintaining good electrochemical performance and safety, particularly due to issues with current collectors such as metal burrs and short-circuit resistance during abnormal conditions like nail penetration.
Innovation Solution
The use of a composite current collector with a thin conductive layer and a polymer-based support layer, combined with a thermally conductive coating layer and a conductive primer coating layer, enhances energy density, safety, and electrochemical performance by improving heat dissipation and electron transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a plastic current collector with metal coating layer is used to reduce weight, then weight energy density is improved, but processing performance and electrochemical performance deteriorate
Solution Approach 1:
The patent uses a composite current collector structure consisting of a polymer support layer and a thin metal conductive layer. This composite structure combines the lightweight advantage of polymers with the electrical conductivity of metals, achieving both weight reduction and maintained electrochemical performance. The support layer provides mechanical strength while the conductive layer ensures electron transport.
Solution Approach 2:
The patent employs a thin metal coating layer (30 nm to 3 μm) on the polymer support layer. This thin film approach reduces the overall weight and thickness of the current collector while maintaining sufficient electrical conductivity through the optimized thickness range and material selection.
2Weight of moving object
If the conductive layer is made thinner to reduce weight, then weight energy density is improved, but heat dissipation and current flow capacity deteriorate
Solution Approach 1:
The composite structure of polymer support layer plus thin metal conductive layer creates a synergistic effect where the thin metal layer provides adequate electrical conductivity and the polymer layer provides thermal management capabilities, solving both weight reduction and heat dissipation requirements simultaneously.
Solution Approach 2:
The patent optimizes the thickness parameter of the metal conductive layer within the range of 30 nm to 3 μm. This parameter optimization ensures sufficient electrical conductivity and current flow capacity while maintaining the weight reduction benefits of a thin layer.
3Weight of moving object
If a thin conductive layer is used to reduce weight, then weight energy density is improved, but resistance to abnormal conditions like nail penetration deteriorates
Solution Approach 1:
The composite structure combines a polymer support layer with a metal conductive layer to create a current collector that is both lightweight and safety-resistant. The polymer layer provides structural integrity and resistance to nail penetration, while the thin metal layer maintains electrical conductivity.
Solution Approach 2:
The thin metal coating layer (30 nm to 3 μm) on the polymer support layer creates a protective structure that resists nail penetration while keeping the overall weight low. The polymer layer acts as a protective shell that prevents direct penetration.
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 significantly increases weight energy density, improves nail penetration safety, and maintains high electrochemical performance by reducing internal resistance and polarization, while also enhancing the battery's ability to withstand abnormal conditions.
Implementation Method 1
the electrode plate further includes a thermally conductive coating layer, and the thermally conductive coating layer covers at least a part of the electrical connection member in the adapting welding zone
Implementation Method 2
the current collector includes a support layer and a conductive layer provided on at least one surface of the support layer, single-sided thickness D2 of the conductive layer satisfies: 30 nm≤D2≤3 μm
Data Source
AI summary
This application relates to an electrode plate, an electrochemical apparatus, and an apparatus thereof. The electrode plate includes a current collector, an electrode active material layer provided on at least one surface of the current collector, and an electrical connection member electrically connected to the current collector. The electrode active material layer is provided at a zone referred to as a membrane zone on a main body portion of the current collector, the electrical connection member and the current collector are welded and connected at a welding zone referred to as an adapting welding zone at an edge of the current collector, and a transition zone is referred to as an extension zone, where the transition zone is of the current collector between the membrane zone and the adapting welding zone and coated with no electrode active material layer. The current collector is a composite current collector.