Advanced flame-retardant electrolyte for highly stabilized K-ion storage in graphite anode

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Graphite anodes are desirable for potassium-ion batteries due to their low potential.
• Severe capacity fading occurs because of reactive surfaces and lack of protective layers.
• Developing effective protection for graphite anodes is crucial for stable K-ion battery performance.

Purpose of the Study:

• To develop a protective strategy for graphite anodes in potassium-ion batteries.
• To enhance the stability and cycling life of graphite anodes.
• To overcome the limitations of conventional electrolytes in K-ion battery systems.

Main Methods:

• Introduction of a flame-retardant, localized high-concentration electrolyte.
• Tailoring a solid electrolyte interphase (SEI) with a balanced inorganic/organic composition.
• Utilizing a retentive solvation configuration with weakened anion-coordination and non-solvating fluorinated ether.

Main Results:

• The tailored SEI effectively prevented excessive solvent decomposition.
• Improved resistance to potassium-ion transport was achieved.
• Graphite anodes demonstrated prolonged cycling stability up to 1400 cycles with 92.4% capacity retention (245 mAh g⁻¹).
• Performance surpassed conventional and high-concentration electrolytes.

Conclusions:

• The optimized electrolyte with moderate salt concentration is highly compatible with graphite anodes.
• This approach offers a promising solution for stable and long-lasting potassium-ion batteries.
• The study highlights a potential pathway for the evolution of potassium-ion energy storage technology.