Concentrated Electrolyte for High-Performance Ca-Ion Battery Based on Organic Anode and Graphite Cathode.

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Calcium-ion batteries (CIBs) are attractive for energy storage due to calcium's abundance and properties.
• Current CIB research is limited by poor cycling stability and capacity, primarily due to unsuitable electrolytes and electrode materials.

Purpose of the Study:

• To develop advanced electrolytes and electrode materials for improved CIB performance.
• To enhance the cycling stability and capacity of calcium-based dual-ion batteries (Ca-DIBs).

Main Methods:

• Development of a 3.5 m concentrated electrolyte using calcium bis(fluorosulfonyl)imide (Ca(FSI)2) in carbonate solvents.
• Utilizing a graphite cathode and an organic anode.
• Assembly and testing of the Ca-based dual-ion battery (Ca-DIB).

Main Results:

• The concentrated electrolyte improved anion intercalation in the graphite cathode and Ca2+ insertion in the organic anode.
• The assembled Ca-DIB demonstrated a specific discharge capacity of 75.4 mAh g-1 at 100 mA g-1.
• Achieved 84.7% capacity retention over 350 cycles, indicating enhanced cycling stability.

Conclusions:

• The developed concentrated electrolyte and electrode combination significantly advances CIB technology.
• This Ca-DIB system shows competitive performance, addressing key limitations in current CIB research.
• The findings pave the way for more stable and efficient calcium-ion energy storage solutions.