3D Structure Electrode With CNT Network for Volume-Change Stability
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Solution Overview
Problem
Existing electrochemical devices face challenges with high-capacity active materials that exhibit low intrinsic electron conductivity and significant volume changes, leading to reduced battery life and energy density due to excessive conductive material usage.
Innovation Solution
A three-dimensional structure electrode is developed with a porous nonwoven fabric and carbon nanotubes forming an interconnected conductive network, sandwiching an active material layer to maintain electron conductivity and prevent material detachment, even with large volume changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-capacity active material is used, then capacity increases, but intrinsic electron conductivity decreases
Solution Approach 1:
The patent uses composite materials by combining high-capacity active material particles with carbon nanotubes to form a conductive network. The carbon nanotubes compensate for the low intrinsic electron conductivity of the high-capacity active material, creating a composite structure that achieves both high capacity and good electrical conductivity without requiring excessive conductive material additives.
Solution Approach 2:
The patent applies local quality by creating a conductive network specifically at the interfaces and around the active material particles using carbon nanotubes. Instead of uniformly distributing conductive material throughout the electrode, the conductive network is locally concentrated where it is most needed - at the particle surfaces and interparticle boundaries - thereby improving electron conductivity with minimal conductive material content.
2Quantity of substance
If high-capacity active material is used, then capacity increases, but volume change increases
Solution Approach 1:
The patent employs a flexible conductive network formed by carbon nanotubes that can accommodate the volume expansion and contraction of high-capacity active material during charge-discharge cycles. The carbon nanotube network acts as a flexible framework that maintains structural integrity despite the dynamic volume changes, preventing electrode disintegration and maintaining long-term stability.
Solution Approach 2:
The conductive network of carbon nanotubes serves as a pre-established cushioning framework that anticipates and absorbs the volume changes of the active material. This network is formed beforehand to provide mechanical support and stress distribution, preventing the electrode structure from collapsing during subsequent volume expansion and contraction cycles.
3Reliability
If excessive conductive material is added, then electron conductivity improves, but energy density decreases
Solution Approach 1:
The patent creates a composite conductive network using carbon nanotubes that provides high electron conductivity with minimal material content. The carbon nanotubes form an efficient conductive pathway that requires much less material compared to traditional conductive additives, thereby maintaining high energy density while achieving excellent electrical conductivity.
Solution Approach 2:
The patent concentrates conductive material locally at critical positions where electron transport is most needed - at the surfaces and interfaces of active material particles - rather than uniformly distributing it throughout the electrode. This localized approach maximizes conductivity efficiency and minimizes the total amount of conductive material required, preserving energy density.
4Quantity of substance
If three-dimensional structure is used, then capacity increases, but manufacturing complexity increases
Solution Approach 1:
The patent segments the electrode into distinct functional components: active material particles, carbon nanotube conductive network, and binder matrix. This segmentation allows each component to be optimized and processed independently, simplifying the overall manufacturing process while maintaining the benefits of the three-dimensional structure for high capacity.
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 design enhances the battery's capacity, energy density, and cycle performance by minimizing additives and using lightweight current collectors, while maintaining electron conductivity and preventing active material desorption.
Implementation Method 1
a porous nonwoven fabric including a plurality of polymer fibers and a plurality of carbon nanotubes are three-dimensionally connected and formed
Implementation Method 2
the electrode generates current through the exchange of ions
Data Source
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AI summary
The present invention relates to a three-dimensional structure electrode, a method for manufacturing same, and an electrochemical element including the electrode. The present invention is characterized by comprising: (a) an upper conductive layer and a lower conductive layer which have a structure constituting an assembly within which a conductive material and a porous nonwoven fabric including a plurality of polymeric fibers are three-dimensionally connected in an irregular and continuous manner, thereby forming a mutually connected porous structure; and (b) an active material layer forming the same assembly structure as the conductive layers and forming a three-dimensionally filled structure in which electrode active material particles are uniformly filled inside the mutually connected porous structure formed in the assembly structure, wherein the active material layer is formed between the upper conductive layer and the lower conductive layer.