Patterned Lithium Anode for Dendrite-Controlled Secondary Batteries
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Solution Overview
Problem
The reversibility of lithium metal as a negative electrode in lithium secondary batteries is reduced due to irregular lithium dendrite formation during charging/discharging, leading to capacity drop and safety issues.
Innovation Solution
A method is developed to pattern the lithium metal on a current collector using a shadow mask, forming a lithium pattern layer to uniformly distribute current and inhibit dendrite growth, involving the deposition of a lithium-containing metal compound on the current collector and patterning with a shadow mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium metal is used as a negative electrode, then high energy density is achieved, but lithium dendrites form irregularly during charging/discharging causing capacity drop and safety issues
Solution Approach 1:
The lithium metal negative electrode is divided into multiple isolated lithium patterns arranged in an array, rather than using a continuous lithium foil. This segmentation distributes the lithium deposition sites uniformly across the electrode, preventing concentrated dendrite growth and improving charging/discharging reversibility while maintaining high energy density
Solution Approach 2:
Different regions of the negative electrode are given different properties through the patterned lithium arrangement. The lithium patterns are strategically positioned and sized to create uniform current density distribution across the electrode surface, ensuring each local region contributes effectively to reversible lithium insertion/extraction
2Use of energy by moving object
If lithium metal is used as a negative electrode, then high energy density is achieved, but lithium dendrites cause volumetric expansion of the cell
Solution Approach 1:
By segmenting the lithium metal into discrete patterns, the overall volume occupied by lithium is reduced compared to a continuous foil of equivalent capacity. The patterned arrangement creates void spaces between lithium regions that prevent dendrite-induced expansion while maintaining the required lithium content for high energy density
3Reliability
If shadow mask is used to pattern lithium metal, then current distribution is homogenized and dendrite growth is prevented, but manufacturing process complexity increases
Solution Approach 1:
A shadow mask is introduced as an intermediary tool during the lithium deposition process. The mask with precisely positioned openings controls the deposition of lithium metal to form the desired patterned structure. This intermediary approach enables uniform current distribution and dendrite prevention through simple geometric control rather than complex electrode design
Solution Approach 2:
The shadow mask method replaces complex mechanical or chemical patterning approaches with a simple deposition process controlled by mask geometry. Instead of using complex lithography or etching processes, the patent uses straightforward vapor deposition through a shadow mask to achieve precise lithium patterning
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 method improves the safety and performance of lithium secondary batteries by homogenizing electron distribution, preventing dendrite growth, and enhancing volumetric expansion resistance.
Implementation Method 1
forming a lithium pattern layer on the lithium substrate layer through the at least one opening of the shadow mask
Data Source
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AI summary
The present invention relates to a method for manufacturing an anode for a lithium secondary battery comprising a patterned lithium metal. An anode for a lithium secondary battery manufactured according to the present invention can prevent growth of lithium dendrite during an operation of the lithium secondary battery through a uniform distribution of electrons within a lithium electrode, and thus can improve safety of the lithium secondary battery. In addition, volume expansion of cells can be prevented as the formation of lithium dendrite is induced in an empty space formed by the patterning of the lithium metal.