Fibrillated Binder Electrode for Lithium Battery Dry Manufacturing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium secondary battery electrodes face challenges in thickening due to drying issues and electrical short circuits caused by binder coverage in wet processes, and sulfide-based solid electrolytes are chemically vulnerable to solvents with polar functional groups.
Innovation Solution
A dry manufacturing method using a fibrillated binder, such as polytetrafluoroethylene (PTFE), which minimizes binder lifting and electrical blocking, allowing for thicker electrodes without solvents and protecting sulfide-based solid electrolytes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the electrode is thickened to increase energy density, then the energy density is improved, but the drying becomes difficult and binder lifting occurs
Solution Approach 1:
The patent removes the solvent from the electrode manufacturing process, extracting the harmful drying step entirely. This allows thick electrodes to be manufactured without encountering drying difficulties or binder lifting, as the slurry is applied and processed without requiring solvent evaporation.
Solution Approach 2:
The patent changes the fundamental parameter of the manufacturing process from wet to dry. By using a dry slurry composition and processing method, the electrode can be thickened without the constraints imposed by drying requirements, enabling both high energy density and manufacturing feasibility.
2Strength
If the binder is dissolved in solvent for wet process, then the adhesive force is improved, but electrical short circuits occur and performance degrades
Solution Approach 1:
The patent changes the binder's physical state from dissolved (wet process) to dispersed (dry process). The binder particles remain as discrete solid particles throughout processing, providing adhesion through particle-to-particle contact rather than through a continuous liquid phase, thereby preventing electrical short circuits while maintaining bonding strength.
Solution Approach 2:
The patent uses a minimal amount of binder (0.1-5 wt%) in a dry dispersed state, replacing the need for large amounts of binder dissolved in solvent. This small quantity of binder is sufficient to provide adhesion without creating continuous conductive paths that cause short circuits.
3Ease of manufacture
If solvent with polar functional group is used for wet process, then the process capability is improved, but sulfide-based solid electrolyte deteriorates chemically
Solution Approach 1:
The patent extracts the solvent entirely from the manufacturing process, eliminating the source of chemical vulnerability. By using a dry process, sulfide-based solid electrolytes are never exposed to polar solvents that would cause chemical deterioration, while the process remains capable through dry mixing and processing techniques.
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 enables the production of thick, high-quality lithium secondary battery electrodes with reduced electrical resistance and enhanced mechanical properties, preventing chemical deterioration of sulfide-based solid electrolytes and minimizing short circuits.
Implementation Method 1
applying shear stress to the mixture so that the mixture becomes clay
Data Source
AI summary
Proposed is an electrode for a lithium secondary battery including a fibrillated binder and a manufacturing method thereof.