Ultrastable Potassium Storage Performance Realized by Highly Effective Solid Electrolyte Interphase Layer.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Potassium ion-batteries (PIBs) are gaining attention due to abundant potassium resources and low electrode potential.
• The solid-electrolyte interphase (SEI) in PIBs is crucial for security and cycling performance, but traditional organic SEI layers are unstable.
• Organic SEI layers react with air and water, leading to poor cycling and safety issues.

Purpose of the Study:

• To develop a highly stable and effective inorganic SEI layer for the anode in PIBs.
• To improve the cycling performance and safety of PIBs by addressing SEI instability.

Main Methods:

• Formation of a stable inorganic SEI layer in the anode.
• Optimization of the electrolyte composition for SEI formation.

Main Results:

• Achieved ultralong cycle performance exceeding 14,000 cycles at 2000 mA g^-1.
• Demonstrated an ultrahigh average coulombic efficiency of over 99.9%.
• The inorganic SEI layer provides enhanced stability compared to traditional organic SEI.

Conclusions:

• The optimized electrolyte successfully forms a stable inorganic SEI layer in PIBs.
• This inorganic SEI significantly improves the cycling stability and coulombic efficiency of PIBs.
• The findings pave the way for safer and more durable potassium ion-battery technology.