Composite Electrode Binder for Low-Temperature Battery Cycling
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Solution Overview
Problem
Conventional binder compositions for non-aqueous secondary battery electrodes fail to adequately enhance low-temperature output characteristics and cycle characteristics of non-aqueous secondary batteries.
Innovation Solution
A binder composition comprising a particulate polymer A, a block copolymer with an aromatic vinyl monomer unit and an aliphatic conjugated diene monomer unit, and a particulate polymer B, a random copolymer with a (meth)acrylic acid ester monomer unit, is used to form a slurry composition that improves electrode stability and prevents aggregation of active materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional binder compositions are used, then electrode formation is achieved, but low-temperature output characteristics and cycle characteristics are insufficient
Solution Approach 1:
The patent uses a composite binder system combining particulate polymer A (block copolymer with aromatic vinyl and aliphatic conjugated diene units) and particulate polymer B (random copolymer with (meth)acrylic acid ester units). This composite approach leverages the mechanical strength and structural stability of polymer A with the flexibility and low-temperature performance of polymer B, achieving both excellent low-temperature output characteristics and cycle characteristics that neither polymer could achieve alone.
Solution Approach 2:
The patent specifies precise compositional parameters for the binder composition, including the proportion of (meth)acrylic acid ester monomer units in polymer B (not less than 20 mass% and not more than 80 mass%), and the specific monomer unit compositions of both polymers. By optimizing these chemical composition parameters, the binder achieves enhanced performance across different temperature conditions while maintaining electrode stability.
2Reliability
If binder composition is optimized for performance, then low-temperature output characteristics improve, but electrode stability may be compromised
Solution Approach 1:
The composite binder system balances performance and stability through complementary polymer properties. Particulate polymer A with its block copolymer structure (aromatic vinyl and aliphatic conjugated diene units) provides structural integrity and electrode stability, while particulate polymer B with (meth)acrylic acid ester units contributes flexibility and low-temperature output characteristics. The synergistic combination maintains both electrode stability and enhanced low-temperature performance.
3Ease of manufacture
If single polymer binder is used, then manufacturing is simple, but battery performance is limited
Solution Approach 1:
While the binder composition uses two different particulate polymers, the manufacturing process remains relatively simple by utilizing commercially available polymer particles with specified compositional ranges. The patent specifies clear criteria for selecting polymer A and polymer B based on their monomer unit compositions, making the composite approach feasible for industrial production while achieving superior battery performance including excellent low-temperature output characteristics and cycle characteristics.
Data Source
AI summary
A binder composition for a non-aqueous secondary battery electrode contains a particulate polymer A and a particulate polymer B. The particulate polymer A is a block copolymer including an aromatic vinyl monomer unit and an aliphatic conjugated diene monomer unit having a carbon number of 4 or more. The particulate polymer B is a random copolymer including a (meth)acrylic acid ester monomer unit in a proportion of not less than 20.0 mass % and not more than 80.0 mass %.