Cosolvent electrolyte chemistries for high-voltage potassium-ion battery

Area of Science:

• Energy Storage
• Materials Science
• Electrochemistry

Background:

• Traditional electrolytes limit high-voltage potassium-ion battery development due to poor oxidation resistance.
• Developing stable electrolytes is crucial for advancing potassium-ion battery technology.

Purpose of the Study:

• To design a cosolvent electrolyte overcoming high-voltage limitations in potassium-ion batteries.
• To enhance the stability and performance of potassium-ion battery electrolytes.

Main Methods:

• Utilized a cosolvent electrolyte design strategy.
• Investigated ion-dipole interactions to modify solvation clusters.
• Employed *in situ* synchrotron-based wide-angle X-ray scattering for structural analysis.
• Tested K||Prussian blue cells at high voltage (2-4.5 V).

Main Results:

• Cosolvent electrolyte breaks salt dissolution limitations via ion-dipole interactions.
• Significantly enlarged anion-rich solvation clusters were observed.
• Effective electrode-electrolyte interphase formation was facilitated.
• K||Prussian blue cells demonstrated over 700 cycles with 91.9% capacity retention.

Conclusions:

• The cosolvent electrolyte design strategy enables stable high-voltage potassium-ion battery operation.
• This approach enhances compatibility with high-voltage electrodes.
• Paves new avenues for developing advanced potassium-ion batteries and beyond.