Water-Soluble Sericin Protein Enabling Stable Solid-Electrolyte Interphase for Fast Charging High Voltage Battery...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Spinel lithium nickel manganese oxide (LNMO) offers high energy density for lithium-ion batteries due to its high operating voltage (≈4.75 V).
• High operating voltages cause electrolyte oxidation, leading to unstable solid-electrolyte interphase (SEI) layers, capacity fading, and poor rate performance in LNMO batteries.

Purpose of the Study:

• To investigate the use of silk sericin protein as a stabilizing agent for SEI layers in LNMO cathodes.
• To enhance the electrochemical performance and cycling stability of LNMO electrodes at high operating voltages.

Main Methods:

• Introduction of electrochemically stable silk sericin protein to the LNMO cathode.
• Analysis of SEI layer stabilization and self-discharge suppression.
• Evaluation of Li-ion diffusion energy barriers and high-rate performance using electrochemical techniques.

Main Results:

• Silk sericin effectively negates electrolyte oxidation and stabilizes the SEI layer on LNMO.
• Sericin coating suppresses self-discharge and provides mechanical support, maintaining structural integrity during cycling.
• Sericin-based LNMO electrodes exhibit a lower Li-ion diffusion energy barrier (26.1 kJ mol⁻¹) compared to polyvinylidene fluoride (PVDF)-based electrodes (37.5 kJ mol⁻¹), resulting in superior high-rate performance.

Conclusions:

• Silk sericin protein is a promising material for enhancing the interfacial chemistry of high-voltage cathode materials like LNMO.
• This approach offers a new strategy to overcome commercialization challenges for LNMO and other high-voltage (>4.5 V) cathode materials.
• The findings pave the way for developing next-generation lithium-ion batteries with improved energy density and faster charging capabilities.