Battery Binder Composition to Inhibit Crystallization and Hold Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional binder compositions for non-aqueous secondary batteries face challenges in achieving high process adhesiveness before electrolyte immersion and maintaining cycle characteristics due to crystallization of particulate block copolymers, leading to faults and reduced productivity.
Innovation Solution
Incorporating a specific saturated hydrocarbon, such as cyclohexane or n-pentane, in a particulate polymer binder composition formed from a block copolymer with aliphatic conjugated diene and aromatic vinyl monomer units, within a specific mass ratio, to enhance process adhesiveness and cycle stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a particulate block copolymer binder is used in conventional binder compositions, then the battery member can achieve basic adhesion and structural integrity, but the binder readily crystallizes leading to deteriorated cycle characteristics and reduced process adhesiveness
Solution Approach 1:
A hydrocarbon oil is introduced as an intermediary substance between the block copolymer binder and the functional particles. This hydrocarbon oil mediator prevents the block copolymer from crystallizing while maintaining adhesion properties, thereby resolving the contradiction between reliability and compositional stability.
Solution Approach 2:
The invention changes the physical state and compositional parameters of the binder system by adding hydrocarbon oil, which alters the crystallization behavior of the block copolymer. This parameter change enables the binder to maintain adhesion without crystallizing, improving cycle characteristics.
2Productivity
If conventional binder compositions are used to form functional layers, then the battery member can be manufactured with standard process adhesiveness, but misalignment occurs during cutting and transportation leading to faults and reduced productivity
Solution Approach 1:
The hydrocarbon oil is incorporated into the binder composition before functional layer formation, preliminarily establishing enhanced adhesion properties. This preliminary action ensures that the functional layer maintains high adhesion during subsequent cutting and transportation processes, preventing misalignment and faults.
3Reliability
If the block copolymer binder is used without hydrocarbon oil addition, then the binder composition maintains simplicity and ease of manufacture, but process adhesiveness is insufficient before electrolyte immersion
Solution Approach 1:
By changing the compositional parameter of the binder system through hydrocarbon oil addition, the invention achieves significantly improved process adhesiveness. The hydrocarbon oil modifies the binder's interaction with functional particles and substrate, enhancing adhesion without excessive complexity.
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 modified binder composition improves process adhesiveness and cycle characteristics of non-aqueous secondary batteries by inhibiting crystallization and maintaining adhesion, thus reducing faults and enhancing battery performance.
Implementation Method 1
the particulate block copolymer used as a binder readily crystallizes, and cycle characteristics of a secondary battery produced using the binder composition tend to deteriorate
Data Source
AI summary
Provided is a binder composition for a non-aqueous secondary battery containing: a particulate polymer formed of a block copolymer including an aliphatic conjugated diene monomer unit and a block region formed of an aromatic vinyl monomer unit; at least one saturated hydrocarbon selected from the group consisting of a chain alkane having a carbon number of not less than 5 and not more than 8 and a cycloalkane having a carbon number of not less than 5 and not more than 8; and water. The content of the saturated hydrocarbon is not less than 0.001 parts by mass and not more than 0.1 parts by mass per 100 parts by mass of the particulate polymer.