Current Collector Aperture Variation for Uniform Ion Doping
Solution Overview
Problem
Existing electric storage devices face variations in ion doping due to uneven permeation of electrolyte solution, leading to potential variations in electrode potential and local overcharge or overdischarge, which deteriorate the device.
Innovation Solution
The electric storage device incorporates a current collector with varying aperture ratios in through-holes, adjusting the permeation state of the electrolyte solution to uniformly dope ions into the electrodes, enhancing durability by preventing potential variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If through-holes are formed in current collectors to facilitate ion permeation, then ion doping efficiency is improved, but uniformity of ion distribution deteriorates due to varying electrolyte solution permeation
Solution Approach 1:
The patent applies local quality by varying the aperture ratio of through-holes in different regions of the current collector. Specifically, the first region (closer to the ion source) has a smaller aperture ratio while the second region (farther from ion source) has a larger aperture ratio. This local differentiation compensates for the natural decay of electrolyte solution permeation distance, ensuring uniform ion distribution across the entire electrode area.
2Quantity of substance
If metal lithium foil is brought into contact with negative electrode to enhance energy density, then capacitance is improved, but potential variation and local overcharge deteriorate
Solution Approach 1:
The patent uses local quality by implementing region-specific aperture ratios in the current collector to address the non-uniform current density distribution that arises when metal lithium foil contacts the negative electrode. The varied aperture ratios ensure that ions are distributed more uniformly across different regions, preventing local overcharge and potential variation while maintaining high energy density.
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 solution ensures uniform ion doping, preventing local overcharge or overdischarge and maintaining consistent electrode potential, thereby enhancing the durability and capacity of the electric storage device.
Implementation Method 1
the permeation state of the electrolyte solution can be adjusted, whereby ions can uniformly be doped into the electrode
Implementation Method 2
The lithium ions emitted from the metal lithium foil move to the negative electrode via an electrolyte solution
Implementation Method 3
a small electric current flows to the metal lithium foil from the negative electrode when the lithium ions are doped, so that the lithium ions move from the metal lithium foil toward the negative electrode with the flow of the small electric current
Data Source
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AI summary
An electrode laminate unit (12) of an electric storage device (10) includes positive electrodes (13), negative electrodes (14) and a lithium electrode (16) connected to the negative electrode (14). When an electrolyte solution is injected into the electric storage device (10), lithium ions are emitted from the lithium electrode (16) to the negative electrode. A positive and a negative electrode current collector (20, 23) have through-holes (20a, 23a) that guide the lithium ions in the laminating direction. The aperture ratio of the through-holes (20a, 23a) at the edge parts (30a, 31a) where the electrolyte solution is easy to be permeated is set to be smaller than the aperture ratio at central parts (30b, 31b) in order to suppress the permeation. Thus, the distribution of the electrolyte solution is made uniform, whereby the doping amount is made uniform.