Layered Negative Electrode Orientation for Thick Li-Ion Battery Anodes
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Solution Overview
Problem
Rechargeable lithium batteries face challenges with high electrical resistance and poor cycle-life characteristics due to the orientation and thickness of negative active material layers, which affect lithium ion transfer and battery performance.
Innovation Solution
A negative electrode design featuring a first and second negative active material layer with a peak intensity ratio (I(002)/I(110)) of 150 or less, achieved through magnetic field orientation and controlled thickness, enhances lithium ion transfer and reduces electrical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the negative active material layer is made thick to increase capacity, then the battery capacity increases, but the electrical resistance increases and cycle-life deteriorates
Solution Approach 1:
The negative active material layer is divided into multiple layers with different orientations. The first layer has particles oriented parallel to the current collector, while the second layer has particles oriented perpendicular to the current collector. This segmentation allows each layer to contribute differently to performance, enabling thick overall structure while maintaining good ion transfer and electrical conductivity.
2Quantity of substance
If the negative active material layer is made thick to increase capacity, then the battery capacity increases, but the electrical resistance increases
Solution Approach 1:
Different regions of the negative active material layer are given different local qualities through orientation control. The first layer has parallel orientation providing good electrical conductivity along the current collector, while the second layer has perpendicular orientation facilitating lithium ion transfer. This local quality differentiation allows the thick structure to maintain low electrical resistance while achieving high capacity.
3Ease of manufacture
If a single-layer structure is used to simplify manufacturing, then the manufacturing process is simpler, but the lithium ion transfer and electrical resistance characteristics are insufficient
Solution Approach 1:
The invention introduces dynamic orientation control in the particle arrangement within the negative active material layers. By controlling particles to have different orientations (parallel in first layer, perpendicular in second layer), the structure adapts to provide optimal lithium ion transfer pathways and electrical conductivity, achieving superior performance compared to static single-layer structures.
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 designed negative electrode exhibits reduced electrical resistance and improved cycle-life characteristics, enabling rapid charge and discharge even with thick layers, suitable for high-power applications.
Implementation Method 1
applying a magnetic field to the resulting product, and drying and compressing to prepare the first negative active material layer and the second negative active material layer
Data Source
AI summary
A negative electrode for a rechargeable lithium battery and a rechargeable lithium battery including the same are provided. The negative electrode includes: a current collector; a first negative active material layer on the current collector and including a first negative active material; and a second negative active material layer on the first negative active material layer and including a second negative active material, wherein the first negative active material layer and the second negative active material layer have a peak intensity ratio (I(002)/I(110)) of a peak intensity at a (002) plane relative to a peak intensity at a (110) plane of 150 or less when measured by X-ray powder diffraction (XRD) using a CuKα ray.