Ionically Conductive Elastic Polymer Binder for Ultrahigh Loading Electrode in High-Energy-Density Lithium Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• High-energy-density lithium batteries are crucial but face challenges with structural instability and poor charge transfer in high-mass-loading electrodes.
• Developing advanced binders is essential for fabricating stable and efficient electrodes for next-generation batteries.

Purpose of the Study:

• To introduce an ionically conductive elastic polymer (ICEP) binder for fabricating ultrahigh mass-loading Ni-rich layered cathodes (NCM811).
• To address structural instability, poor charge transfer, and solvent-drying-induced cracking in high-mass-loading electrodes.

Main Methods:

• Design and synthesis of an ICEP binder with integrated mechanical elasticity, adhesion, and ionic conductivity.
• Fabrication of ultrahigh mass-loading NCM811 electrodes using the ICEP binder.
• Electrochemical characterization of electrodes and full cells, including cycling performance and energy density measurements.

Main Results:

• Successfully fabricated high-mass-loading electrodes (62.4 mg cm⁻², 12.5 mAh cm⁻²) with 94.6% capacity retention.
• ICEP binder ensured uniform electrode morphology, stable cathode-electrolyte interphase (CEI), and suppressed NCM811 phase transitions.
• Achieved high energy densities of 377.6 Wh kg⁻¹ and 1016.8 Wh L⁻¹ in a double-stacked pouch-type lithium metal full cell.

Conclusions:

• The ICEP binder is a highly effective solution for next-generation high-energy-density batteries.
• It offers a scalable and commercially viable approach for ultrahigh-loading cathodes, enhancing electrochemical stability and performance.
• The developed binder sets new benchmarks for lithium metal batteries by enabling superior energy density and long-term cycling stability.