Super-Reversible CuF₂ Cathodes Enabled by Cu²⁺ -Coordinated Alginate.

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Copper fluoride (CuF2) exhibits high theoretical energy density for Li-ion batteries.
• CuF2 cathodes suffer from poor cycle stability due to Cu-ion dissolution.

Purpose of the Study:

• To suppress Cu-ion dissolution in CuF2 cathodes.
• To enhance the electrochemical performance and stability of CuF2-based batteries.

Main Methods:

• Fabrication of CuF2 electrodes using sodium alginate (SA) binder in water.
• Formation of a Cu2+-coordinated SA (Cu-SA) layer on CuF2 particles.
• Electrochemical testing in organic electrolyte.

Main Results:

• A conformal Cu-SA layer was formed in situ, acting as a Li-ion conductor and Cu2+ insulator.
• Cu-ion dissolution was effectively suppressed, significantly improving reversibility.
• CuF2 electrodes with SA binder achieved 420.4 mAh g-1 after 50 cycles at 0.05 C, with an energy density of 1009.1 Wh kg-1.

Conclusions:

• The Cu-SA coating strategy successfully stabilizes high-energy CuF2 cathodes.
• This approach offers a promising pathway for developing advanced Li-ion batteries.