Design of Solid Polycationic Electrolyte to Enable Durable Chloride-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Chloride-ion batteries (CIBs) offer high energy density and cost-effectiveness, posing an alternative to lithium-ion batteries.
• Development of CIBs is hindered by the absence of suitable electrolytes for economical anodes.
• Aluminum (Al) metal is a desirable anode material due to its cost and capacity, but requires compatible electrolytes.

Purpose of the Study:

• To design and synthesize a novel solid polycationic electrolyte (SPE) for room-temperature CIBs.
• To enable the use of aluminum metal as a cost-effective anode in CIBs.
• To improve the safety and stability of CIBs.

Main Methods:

• Rational design and synthesis of a solid polycationic electrolyte (SPE).
• Characterization of the SPE's ionic conductivity and structural properties.
• Assembly and electrochemical testing of Al|SPE|FeOCl CIBs at room temperature.

Main Results:

• The SPE exhibits high ionic conductivity (1.3×10^-2 S cm^-1 at 25 °C) due to its tailored coordination structure.
• The SPE ensures stable electrode-electrolyte interfaces, suppressing Al anode dendrite growth and FeOCl cathode degradation.
• Al|SPE|FeOCl CIBs demonstrate a high discharge capacity (~250 mAh g^-1) and an extended cycle lifespan.

Conclusions:

• The developed SPE facilitates stable and safe room-temperature chloride-ion batteries with aluminum anodes.
• This electrolyte design represents a significant advancement for low-cost and high-performance CIBs.
• The findings open new avenues for developing next-generation energy storage systems.