Battery Binder Composition for Low-Resistance Solid-State Sheets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-aqueous secondary batteries face issues with increased interface resistance and deteriorated cycle characteristics due to inadequate interfacial contact and dispersion stability of solid particles in the electrode layers, leading to poor storage stability and ion conductivity.
Innovation Solution
A binder composition for secondary batteries is developed, containing a polymer binder dissolved in an organic solvent with a low-boiling point organic solvent (A) and a high-boiling point organic solvent (B), along with functional groups like ester, carboxy, or amide groups, which enhances dispersion characteristics and handleability, ensuring firm adhesion of solid particles and reduced resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If solid particles are used to form electrode layers and constitutional layers, then the battery structure can be simplified and energy density increased, but the interfacial contact between solid particles and collector is restricted, leading to increased interface resistance
Solution Approach 1:
The patent introduces a binder composition as an intermediary substance between solid particles and the collector. This binder composition contains a polymer binder dissolved in an organic solvent, which improves the interfacial contact and reduces interface resistance while maintaining the solid-state battery structure that enables high energy density.
Solution Approach 2:
The patent changes the physical and chemical parameters of the binder composition, specifically using a polymer binder with a glass transition temperature of -50°C or lower dissolved in an organic solvent. This parameter optimization enables the binder to effectively reduce interface resistance without compromising the solid-state structure's energy density advantages.
2Strength
If a polymer binder is used to bind solid particles, then adhesion between particles can be improved, but the dispersion stability of solid particles may deteriorate, leading to poor storage stability
Solution Approach 1:
The patent optimizes the parameters of the binder composition by selecting a polymer binder with specific glass transition temperature (-50°C or lower) and using an organic solvent as the dispersing medium. This parameter selection enables the composition to simultaneously achieve strong adhesion between solid particles and maintain excellent dispersion stability during storage.
Solution Approach 2:
The patent creates a composite binder composition system combining a polymer binder with specific thermal properties and an organic solvent. This composite material approach allows the system to exhibit both strong adhesive properties for binding solid particles and stable dispersion characteristics for long-term storage stability.
3Temperature
If the binder composition uses a polymer with high glass transition temperature, then thermal stability is improved, but the flexibility and ability to maintain good interfacial contact at operating temperatures deteriorates
Solution Approach 1:
The patent changes the glass transition temperature parameter of the polymer binder to -50°C or lower. This parameter optimization ensures the binder remains flexible and maintains good interfacial contact quality at battery operating temperatures while still providing adequate thermal stability for the application.
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 binder composition achieves excellent storage stability, improved dispersion characteristics, and low resistance in non-aqueous secondary batteries, resulting in enhanced cycle performance and ion conductivity, enabling the production of sheets and all-solid state secondary batteries with improved reliability.
Implementation Method 1
a binder composition for a secondary battery, comprising: an organic solvent; and a polymer binder dissolved in the organic solvent
Implementation Method 2
contains 3 to 1.0×105 ppm of a low-boiling point organic solvent (A) having a boiling point of lower than 120° C.
Data Source
AI summary
There is provided a binder composition for a secondary battery, containing an organic solvent and a polymer binder dissolved in the organic solvent, in which the binder composition for a secondary battery contains 3 to 1.0×105 ppm of a low-boiling point organic solvent (A) having a boiling point of lower than 120°° C. in the binder composition. There are also provided a composition for a non-aqueous secondary battery, which contains the binder composition for a secondary battery as well as a sheet for an all-solid state secondary battery and an all-solid state secondary battery, which use the composition for a non-aqueous secondary battery, and manufacturing methods of these.