Magnetically Oriented Battery Anode for Shorter Lithium-Ion Paths
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Solution Overview
Problem
The orientation of anode active materials in secondary batteries, primarily graphite, in a horizontal direction increases the migration path of lithium ions, leading to higher resistance and reduced charging/discharging efficiency, especially at high C-rates, resulting in capacity degradation and safety concerns due to lithium plating.
Innovation Solution
The anode active materials are oriented vertically with respect to the current collector, with a magnetic field applied to the anode mixture layer to achieve a colorimetric value of 42.5 or greater and a Z-tensor value of 0.25 or greater, shortening the lithium ion migration path and improving pore orientation, thereby enhancing charging/discharging efficiency and reducing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If anode active materials are oriented horizontally parallel to the current collector, then the electrode structure is simple and easy to manufacture, but the lithium ion migration path becomes significantly longer, increasing resistance and reducing charging/discharging efficiency
Solution Approach 1:
The patent applies a magnetic field to reorient anode active materials from horizontal to vertical orientation, changing the dimensional arrangement of particles. This vertical orientation shortens the lithium ion migration path from the electrode surface into the bulk, reducing resistance and improving charging/discharging efficiency while maintaining manufacturing simplicity through the use of magnetic field application during the coating process
2Quantity of substance
If the loading amount of electrodes is increased to achieve higher battery capacity, then the battery capacity increases, but the lithium ion movement distance significantly increases, causing increased resistance and longer charging/discharging time
Solution Approach 1:
By vertically orienting anode active materials using a magnetic field, the patent creates shorter lithium ion diffusion paths that scale better with increased electrode loading. The vertical pore structure allows lithium ions to reach active materials more quickly even when the electrode is thicker or has higher loading, thereby maintaining fast charging/discharging performance at higher capacities
3Power
If charging/discharging is performed at high C-rate, then the power output increases, but lithium salt precipitates on the electrode surface causing capacity degradation and safety issues
Solution Approach 1:
The vertical orientation of anode active materials and pores created by magnetic field application provides direct, short pathways for lithium ion transport to the electrode surface. This reduces concentration gradients and prevents lithium salt precipitation during high C-rate charging, thereby maintaining both high power output and battery safety without capacity degradation
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 improves the charging/discharging efficiency at high rates, suppresses lithium plating, and extends the battery's cycle life by reducing diffusion resistance and maintaining capacity retention.
Implementation Method 1
a magnetic field applied to the anode mixture layer to achieve a colorimetric value of 42.5 or greater and a Z-tensor value of 0.25 or greater
Data Source
AI summary
An anode for a secondary battery, a method for preparing the same, and a secondary battery including the anode are provided. The anode for a secondary battery includes an anode current collector and an anode mixture layer including an anode active material formed on at least one surface of the anode current collector. The anode mixture layer has a colorimetric value of 42.5 or greater, and a Z-tensor value of an internal pore of the anode mixture layer is 0.25 or greater.