Battery Electrode Paste Using Carbon Nanotubes for Low Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional secondary battery pastes and electrodes face challenges in reducing internal resistance while maintaining excellent cycle characteristics.
Innovation Solution
A paste for secondary batteries using surface-treated carbon nanotubes with specific surface area, surface base content, and surface acid content, combined with a polymer containing nitrile and conjugated diene monomer units, is used to form an electrode mixed material layer, reducing internal resistance and improving cycle characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional dispersants are used to form electrode mixed material layers, then the paste can be produced and applied, but the internal resistance of the secondary battery remains high and cycle characteristics are insufficient
Solution Approach 1:
The patent changes the chemical parameters of the dispersant by specifying a polymer with particular functional groups (carboxyl, hydroxyl, or amine groups with specific content ranges). This parameter change in the dispersant's chemical composition enables it to effectively disperse carbon nanotubes while reducing internal resistance and improving cycle characteristics, without complicating the manufacturing process.
Solution Approach 2:
The patent employs a composite approach by combining carbon nanotubes with specific polymers that have defined functional group compositions. This composite material system creates an effective dispersion medium that simultaneously achieves good dispersion, low internal resistance, and excellent cycle characteristics, resolving the contradiction between performance improvement and manufacturing simplicity.
2Object-generated harmful factors
If carbon nanotubes are used as conductive additive, then internal resistance can be reduced, but dispersion stability and adhesion require optimization
Solution Approach 1:
The patent introduces a polymer dispersant as an intermediary substance between carbon nanotubes and the electrode mixture. This dispersant, characterized by specific functional groups and molecular weight parameters, mediates the interaction between carbon nanotubes and the electrode components, ensuring stable dispersion and good adhesion while maintaining low internal resistance.
Solution Approach 2:
The patent optimizes the molecular weight and functional group content of the polymer dispersant to achieve the right balance between dispersion stability and conductivity. By controlling these parameters within specific ranges, the dispersant effectively stabilizes carbon nanotube dispersion while allowing sufficient electrical conductivity, thus reducing internal resistance.
3Ease of manufacture
If electrode mixed material layer is formed with conventional methods, then electrode can be produced, but adhesion and flexibility need improvement
Solution Approach 1:
The patent modifies the chemical parameters of the binder polymer by specifying functional groups (carboxyl, hydroxyl, or amine) with particular content ranges. These parameter changes enhance the chemical interaction between the binder and electrode components, improving adhesion strength while maintaining flexibility and not complicating the electrode production process.
Solution Approach 2:
The patent uses a composite binder system combining polymers with specific functional groups that work synergistically with the carbon nanotube-polymer dispersant. This composite material approach improves adhesion and flexibility of the electrode while maintaining ease of manufacture through a unified paste formulation.
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 solution effectively reduces internal resistance and enhances cycle characteristics of secondary batteries by ensuring good dispersion and adhesion of carbon nanotubes, forming a stable electrode layer with improved conductivity and flexibility.
Implementation Method 1
the conductive additive includes one or more surface-treated carbon nanotubes
Implementation Method 2
one or more surface-treated carbon nanotubes having a surface base content of not less than 0.01 mmol/g and not more than 0.10 mmol/g and a ratio of surface acid content relative to the surface base content of not less than 0.1 and not more than 1.0
Data Source
AI summary
Provided are a paste for a secondary battery, and method of producing the same, with which it is possible to produce an electrode that can reduce internal resistance of a secondary battery and that can cause the secondary battery to display excellent cycle characteristics. The paste for a secondary battery contains a conductive additive, a polymer, and a dispersion medium. The conductive additive includes one or more carbon nanotubes having a surface base content of not less than 0.01 mmol/g and not more than 0.10 mmol/g and a ratio of surface acid content relative to the surface base content of not less than 0.1 and not more than 1.0.