Binder Composition for Non-Aqueous Battery Electrodes
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Solution Overview
Problem
Current non-aqueous secondary battery electrodes face challenges in achieving high close adherence between components, suppressing metal precipitation during charging, and maintaining stable discharge capacity preservation.
Innovation Solution
A binder composition with a particulate polymer of specific particle diameter and surfactant content, combined with a water-soluble polymer, is used to enhance adherence and prevent metal precipitation, improving storage characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a particulate polymer with a small particle diameter is used to improve close adherence and suppress dusting, then mixing uniformity and surface coverage improve, but metal precipitation during charging increases
Solution Approach 1:
The patent changes the particle diameter parameter of the particulate polymer to a specific range (0.01 μm or more and 0.1 μm or less) and controls the surfactant content (0.1 parts by mass or more and 1.0 parts by mass or less relative to 100 parts by mass of particulate polymer). This parameter optimization resolves the contradiction by finding the optimal balance point where small enough particles provide good adherence but not so small that they cause metal precipitation.
Solution Approach 2:
The patent creates a composite binder composition combining particulate polymer with a water-soluble polymer in specific ratios. This composite structure allows the particulate polymer to provide adhesion while the water-soluble polymer component helps prevent metal precipitation, thus resolving the contradiction between adherence and precipitation suppression.
2Stability of the object's composition
If the particle diameter of the particulate polymer is decreased to improve mixing uniformity, then surface coverage improves, but storage characteristics (discharge capacity preservation) deteriorate
Solution Approach 1:
The patent optimizes the particle diameter parameter to a specific range (0.01 μm or more and 0.1 μm or less) rather than using the smallest possible particles. This controlled parameter change ensures sufficient mixing uniformity while maintaining storage characteristics by preventing particles from being too fine.
Solution Approach 2:
The patent applies different properties to different components: the particulate polymer provides local adhesion quality with optimized particle size, while the water-soluble polymer provides local stability quality. This local differentiation allows each component to excel at its specific function without compromising the other.
3Stability of the object's composition
If surfactant amount is increased to reduce particle diameter, then mixing uniformity improves, but close adherence and storage characteristics worsen
Solution Approach 1:
The patent controls the surfactant content parameter within a specific range (0.1-1.0 parts by mass relative to 100 parts by mass of particulate polymer). This parameter optimization ensures sufficient mixing uniformity while preventing excessive surfactant that would harm close adherence and storage characteristics.
Solution Approach 2:
The patent uses a limited, controlled amount of surfactant (partial action) rather than large amounts. This sufficient but not excessive surfactant content achieves the needed mixing uniformity without the harmful effects of excess surfactant on adherence and storage.
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 results in electrodes with excellent close adherence and reduced metal precipitation, leading to improved storage characteristics and discharge capacity stability in non-aqueous secondary batteries.
Implementation Method 1
An electrode produced using the particulate polymer with a small particle diameter can suppress the detachment (dusting) of the electrode active material, the particulate polymer, and the like from the electrode mixed material layer and achieve high close adherence between the components in the electrode mixed material layer and between the electrode mixed material layer and the current collector
Implementation Method 2
in the case of producing the particulate polymer by emulsion polymerization, it is typically known that the particle diameter of the particulate polymer can be decreased by increasing the amount of the surfactant used
Data Source
AI summary
A binder composition from which an electrode for a non-aqueous secondary battery having excellent close adherence and a non-aqueous secondary battery that suppresses metal precipitation onto the electrode during charging and has excellent discharge capacity storage characteristics can be produced is provided. A binder composition for a non-aqueous secondary battery electrode comprises: a particulate polymer; and a surfactant, wherein a volume-average particle diameter of the particulate polymer is 0.01 µm or more and 0.1 µm or less, and a content of the surfactant is 0.1 parts by mass or more and 1.0 parts by mass or less relative to 100 parts by mass of the particulate polymer.