Battery Electrode CNT Network for Uniform Conductive Dispersion
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Solution Overview
Problem
Existing conductive agents in secondary batteries, such as carbon nanotubes and graphene, face issues with uniform distribution, leading to poor electrical conductivity and reduced battery efficiency due to surface reactions and limited electrolyte mobility.
Innovation Solution
Incorporation of a carbon nanotube structure formed by bonding 2 to 5,000 single-walled carbon nanotube units, dispersed with polyvinylidene fluoride, to create a network structure within the electrode active material layer, enhancing electrical conductivity and adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If line-type conductive agents such as carbon nanotubes or carbon nanofibers are used to improve electrical conductivity, then electrical conductivity is enhanced, but dispersibility in slurry is low due to bundle type or entangled type growth, resulting in poor coatability and non-uniform distribution in the electrode active material layer
Solution Approach 1:
The carbon nanotubes are segmented into small bundles containing 2 to 500 individual nanotube units, rather than using large bundles or entangled structures. This segmentation improves dispersibility in the slurry while maintaining the electrical conductivity benefits of the nanotube structure, enabling uniform distribution in the electrode active material layer
Solution Approach 2:
The invention uses a composite structure where small bundles of carbon nanotubes are combined with electrode active material particles to form a conductive network. This composite approach maintains the excellent electrical conductivity of carbon nanotubes while achieving uniform distribution through the electrode structure
2Stability of the object's composition
If functional groups are introduced to improve dispersibility of line-type conductive agents, then dispersibility is enhanced, but surface side reactions occur, deteriorating electrochemical properties
Solution Approach 1:
Instead of using carbon nanotubes with functional groups that cause side reactions, the invention employs small bundles of unmodified carbon nanotubes. These simple structures provide sufficient dispersibility without introducing harmful functional groups, maintaining excellent electrochemical properties
Solution Approach 2:
The invention uses a small bundle structure as an intermediary form between individual nanotubes and large bundles. This intermediate structure achieves adequate dispersibility through its reduced size and controlled morphology without requiring functional group modification, thus avoiding surface side reactions
3Reliability
If thick graphene is used as plane-type conductive agent, then electrical conductivity is maintained, but it is difficult to prepare thin single layer graphene and battery efficiency is reduced
Solution Approach 1:
The invention segments the conductive structure into small bundles of nanotubes rather than using thick graphene layers. This segmentation enables better penetration into the electrode active material matrix, improving battery efficiency while maintaining electrical conductivity through the distributed nanotube network
Solution Approach 2:
The invention transitions from the two-dimensional planar structure of graphene to a three-dimensional network of small nanotube bundles. This dimensional change allows the conductive agent to distribute more effectively throughout the electrode volume, improving both conductivity and battery efficiency
4Reliability
If plane-type conductive agent such as graphene is used, then electrical conductivity is excellent, but electrolyte solution mobility is limited due to wide planar contact
Solution Approach 1:
The invention segments the conductive structure into small nanotube bundles rather than using continuous planar graphene. This segmentation creates numerous small contact points that do not block electrolyte pathways, maintaining fast ion mobility while providing sufficient electrical conductivity through the distributed conductive network
Solution Approach 2:
The small bundle structure creates a porous, three-dimensional conductive network that allows electrolyte to flow through the electrode matrix without being blocked by large planar structures. This maintains excellent ion mobility while providing effective electrical conductivity pathways
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 network structure improves electrical conductivity, reduces electrode resistance, and enhances electrochemical performance and battery life characteristics by maintaining the integrity of the carbon nanotube structure during battery operation.
Implementation Method 1
a carbon nanotube structure in which 2 to 5,000 single-walled carbon nanotube units are bonded to each other
Implementation Method 2
the conductive agent includes a carbon nanotube structure in which 2 to 5,000 single-walled carbon nanotube units are bonded to each other... dispersed with polyvinylidene fluoride
Implementation Method 3
enhancing electrical conductivity... The network structure improves electrical conductivity, reduces electrode resistance
Data Source
Figure 1(a)~1(d)
Figure 2
Figure 3~4
AI summary
An electrode includes an electrode active material, wherein the electrode active material layer includes an electrode active material, polyvinylidene fluoride, and a conductive agent, wherein the conductive agent includes a carbon nanotube structure in which 2 to 5,000 single-walled carbon nanotube units are bonded to each other. A secondary battery including the same, and a method of preparing the electrode are also provided.