Composite Cathode Current Collector for Short-Circuit Crack Response
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Solution Overview
Problem
Lithium-ion batteries face safety hazards due to internal short circuits caused by lithium precipitation and mechanical damage, which existing designs fail to adequately prevent or mitigate.
Innovation Solution
A positive electrode current collector with an organic support layer and an aluminum-based conductive layer, doped with oxygen, nitrogen, or fluorine, featuring specific X-ray photoelectron spectroscopy peaks, which facilitates rapid cracking or pulverization under stress, reducing the risk of thermal runaway.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional current collector structure is used, then the battery can maintain good electrical conductivity, but the battery is prone to internal short circuits under mechanical damage or high power operation
Solution Approach 1:
The current collector is divided into multiple layers: an organic support layer and an aluminum-based conductive layer. This segmentation allows each layer to perform its specific function - the organic layer provides mechanical strength and structural integrity, while the aluminum layer provides electrical conductivity. The segmented structure prevents complete short circuit by isolating the conductive aluminum from direct mechanical damage.
Solution Approach 2:
The invention uses a composite current collector structure combining organic material (support layer) with aluminum-based material (conductive layer). This composite structure leverages the advantages of both materials: the organic material's mechanical properties and the aluminum's electrical properties, creating a current collector that is both mechanically robust and electrically conductive, thereby preventing internal short circuits.
2Reliability
If the aluminum-based conductive layer is made thicker to improve conductivity, then electrical performance improves, but the layer becomes more resistant to cracking under stress
Solution Approach 1:
The invention optimizes the thickness parameter of the aluminum-based conductive layer to a specific range (30nm to 3μm). This parameter optimization ensures the layer is thin enough to crack rapidly under stress (improving safety response) but thick enough to maintain adequate electrical conductivity. The precise control of this dimensional parameter resolves the contradiction between conductivity and crack resistance.
3Reliability
If modifiers are added to the aluminum-based conductive layer to improve safety, then thermal runaway resistance improves, but the manufacturing complexity increases
Solution Approach 1:
The invention introduces modifiers (oxygen, nitrogen, or fluorine) into the aluminum-based conductive layer to create local regions with enhanced safety properties. These modifiers are incorporated into the aluminum layer's structure, creating localized zones that resist thermal runaway. This local quality approach improves safety without requiring complete structural redesign of the entire current collector system.
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 significantly enhances battery safety by minimizing thermal runaway risk during mechanical damage, improving response speed and reducing short-circuit temperature rise.
Implementation Method 1
the aluminum-based conductive layer, having a relatively thin thickness, is prone to rapid cracking or even pulverization at a stress site
Implementation Method 2
including an organic support layer and an aluminum-based conductive layer disposed on at least one surface of the organic support layer
Data Source
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AI summary
The present application relates to a positive electrode current collector, and a positive electrode plate, a battery, a battery module, a battery pack and an apparatus comprising the positive electrode current collector. Specifically, the present application discloses a positive electrode current collector, comprising an organic support layer and an aluminum-based conductive layer provided on at least one surface of the organic support layer; the aluminum-based conductive layer contains aluminum (Al) and at least one modifier element selected from oxygen (O), nitrogen (N), fluorine (F), boron (B), sulfur (S), and phosphorus (P); and after a surface passivation layer is removed by etching, the aluminum-based conductive layer has, in an X-ray photoelectron spectroscopy (XPS) spectrum obtained from XPS, at least a first peak in the range from 70 eV to 73.5 eV and a second peak in the range from 73.5 eV to 78 eV, and the ratio x of the intensity of the second peak to the intensity of the first peak satisfies 0<x≤3.0. The positive electrode current collector can greatly reduce, in usage of a battery, the possibility of thermal runaway caused by a short circuit occurring when a cell is subjected to anomalous mechanical damage such as piercing, compression, and falling, increasing a thermal runaway response speed, and greatly improving the safety performance of a battery.