Li_2.9Fe_0.9Zr_0.1Cl₆ as Redox-Active Catholyte for Solid-State Li-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Solid electrolytes are crucial for all-solid-state battery commercialization but present challenges.
• Development of redox-active catholytes is less explored than solid electrolytes for separators.
• High catholyte loading in composite cathodes reduces battery energy density.

Purpose of the Study:

• To introduce a novel redox-active catholyte material to improve all-solid-state battery energy density.
• To investigate the performance of Li_2.9Fe_0.9Zr_0.1Cl₆ as a catholyte in composite cathodes.
• To expand the design possibilities for lithium-ion conductors with redox-active elements.

Main Methods:

• Synthesized Li_2.9Fe_0.9Zr_0.1Cl₆ as a redox-active catholyte.
• Fabricated composite cathodes using uncoated LiCoO₂ and the synthesized catholyte.
• Tested solid-state cells for rate capability and long-term cycling performance.

Main Results:

• The Li_2.9Fe_0.9Zr_0.1Cl₆ catholyte demonstrated high ionic conductivity.
• Solid-state cells exhibited excellent rate capability and stable long-term cycling.
• Achieved a high cathode specific capacity of approximately 153 mAh·g^-1.

Conclusions:

• Li_2.9Fe_0.9Zr0.1Cl₆ offers a viable strategy to enhance all-solid-state battery energy density.
• The study broadens the scope of materials for lithium-ion conductors with redox-active elements.
• This work presents new avenues for cost reduction and energy density improvement in all-solid-state batteries.