Lithium Ion Battery Electrode Binder Dispersion Using Organic Carbonate Solvent
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Solution Overview
Problem
The existing manufacturing processes for lithium battery electrodes face challenges due to the use of toxic and environmentally harmful solvents, such as N-Methyl-Pyrrolidone, which require energy-intensive and space-demanding solvent removal processes, and alternative solvents often pose fire hazards or unfavorable chemical structures.
Innovation Solution
A method for manufacturing a slurry for lithium battery electrodes that involves mixing active materials with a binder and an organic carbonate at a temperature above the binder's melting point, followed by coating, evaporation, and surface treatment, where the organic carbonate is recycled and reused, using ethylene carbonate, dimethyl carbonate, or diethyl carbonate as the solvent, which is environmentally friendly and reduces the need for complete solvent removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If NMP (N-Methyl-Pyrrolidone) is used as solvent to dissolve PVDF binder, then the binder disperses evenly between particles ensuring good binding, but the solvent is toxic and environmentally harmful requiring energy-intensive and space-demanding removal processes
Solution Approach 1:
The patent changes the chemical parameter of the solvent from NMP to water, fundamentally altering the system's properties. Water serves as the dissolution medium for PVDF binder, eliminating toxicity and environmental harm while maintaining the binder's ability to disperse evenly between active material particles and provide effective binding.
Solution Approach 2:
The patent employs water as a disposable solvent that can be easily removed through evaporation without requiring complex removal equipment. Water's volatility and lack of harmful properties allow for simple energy-intensive evaporation processes rather than sophisticated solvent recovery systems, effectively treating the solvent as a consumable that is removed rather than recovered.
2Object-affected harmful factors
If water is used as solvent in waterborne manufacturing processes, then the solvent is non-toxic and environmentally friendly, but the evaporation process is relatively energy demanding
Solution Approach 1:
The patent accepts the energy demand for water evaporation as a necessary parameter change from using toxic solvents. By changing the solvent from NMP to water, the process prioritizes environmental friendliness and non-toxicity over energy efficiency, acknowledging that water's higher evaporation energy requirement is an acceptable trade-off for eliminating toxic emissions and environmental contamination.
3Reliability
If solvents are used to dissolve PVDF binder, then the binder provides flexible and chemically stable coating, but complete solvent removal is demanding and makes substantial demands from technical equipment
Solution Approach 1:
The patent treats water as a temporary, disposable medium that facilitates binder application but is then completely removed through simple evaporation. Water's properties allow it to serve its dissolving function during coating application and then be easily eliminated through evaporation without requiring complex removal equipment, unlike NMP which demands sophisticated solvent recovery and removal systems.
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
This approach enables the production of lithium battery electrodes with improved safety and reduced environmental impact by utilizing a solvent that is non-toxic and easily recyclable, minimizing energy and space demands, and ensuring the solvent is fully removed, thus enhancing the manufacturing efficiency and sustainability of the process.
Implementation Method 1
evaporation of solvents
Implementation Method 2
dissolve the binder is to disperse the material evenly between the particles in the powder mixture
Data Source
AI summary
The present disclosure relates generally to an electrode produced with a non-toxic solvent, resulting in a homogeneous mixture with uniform distributions of a conductive additive and a binder. Electrodes produced according to the present disclosure feature narrow binder particle size distribution, which distinguishes such electrodes from typical electrodes produced via a N-Methyl-Pyrrolidone (NMP) process. The resulting microstructure promotes the flow of current through the electrode and has an improved cycling stability due, in part, to the binder's and the conductive additive's ability to bind with the active material particles used in the fabrication of the electrode.