Synthesis and Characteristic Valuation of a Thermoplastic Polyurethane Electrode Binder for In-Mold Coating

Area of Science:

• Polymer Science
• Materials Science
• Electrochemistry

Background:

• Polyurethanes (PUs) are versatile polymers with tunable properties.
• Developing advanced electrode binders is crucial for flexible electronics and energy storage devices.
• In-mold coating requires binders with high mechanical integrity and electrical conductivity.

Purpose of the Study:

• To synthesize and characterize a novel polyurethane series (PHEI-PU) using specific monomers.
• To evaluate the mechanical, thermal, and electrical properties of the synthesized PUs.
• To assess the suitability of PHEI-PU as an electrode binder for in-mold coating applications.

Main Methods:

• One-shot bulk polymerization of hexamethylene diisocyanate (HDI), polycarbonate diol (PCD), and isosorbide derivatives (ISBD).
• Mechanical testing using a universal testing machine (UTM).
• Thermal analysis via thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).
• Electrode fabrication with PU and silver flakes, followed by four-point probe electrical testing and scanning electron microscopy (SEM) for dispersion analysis.

Main Results:

• The PHEI-PU series demonstrated excellent mechanical properties, including an average tensile strength of 44.71 MPa and 190% elongation at break.
• Thermal analysis confirmed good heat resistance.
• Electrodes fabricated with PHEI-PU binders exhibited an electrical resistance change rate of less than 20% after 50% elongation, with well-dispersed silver flakes.

Conclusions:

• The synthesized PHEI-PU series possesses superior mechanical and thermal properties.
• The material demonstrates remarkable electrical stability and good dispersion characteristics when used as an electrode binder.
• PHEI-PU is a promising candidate for electrode binder applications in in-mold coating due to its comprehensive performance profile.