Polysaccharide-Coated Positive Electrode for Stable Battery Slurry
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Solution Overview
Problem
The preparation of slurry containing guar gum for lithium-ion secondary battery positive electrodes can result in solidification issues due to alkalinity, leading to reduced productivity and potential deterioration of electrode characteristics.
Innovation Solution
A positive electrode mixture layer is formed on a current collector using a polysaccharide coating on the active material, conductive agent, and resin, preventing solidification and enhancing durability by stabilizing crystallinity and suppressing electrolyte decomposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If guar gum is used as a liquid binder in slurry for positive electrode production, then durability is improved, but the guar gum may solidify into gel due to alkalinity, reducing productivity
Solution Approach 1:
The patent uses a water-soluble polymer as an intermediary substance to replace guar gum in alkaline environments. This mediator maintains the binding function while avoiding gel solidification, enabling continuous slurry application and maintaining high productivity without sacrificing durability
Solution Approach 2:
The patent changes the chemical parameter of the binder from guar gum (which gels in alkaline conditions) to a water-soluble polymer that remains stable in alkaline pH. This parameter change allows the slurry to maintain proper viscosity and applyability, preventing productivity loss while preserving the durability benefits
2Quantity of substance
If high nickel content is used in positive electrode active material to achieve higher capacity, then energy density is improved, but electrode characteristics may deteriorate due to instability
Solution Approach 1:
The patent creates a composite structure by combining high-nickel positive electrode active material with a water-soluble polymer binder. This composite approach allows the high-capacity nickel material to function while the polymer matrix provides structural stability and prevents characteristic deterioration, achieving both high capacity and reliability
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 polysaccharide coating ensures stable production of secondary batteries with improved durability and low resistance, maintaining high crystallinity and cycle characteristics even with high nickel content active materials.
Implementation Method 1
stabilizing crystallinity
Implementation Method 2
suppressing electrolyte decomposition
Data Source
AI summary
A positive electrode for secondary batteries includes a positive electrode current collector, and a positive electrode mixture layer provided on a surface of the positive electrode current collector. The positive electrode mixture layer contains a positive electrode active material, a conductive agent, a polysaccharide, and a resin other than the polysaccharide, and at least part of surfaces of the positive electrode active material, the conductive agent, and the resin is coated with the polysaccharide.