Li₂FeCl₄ as a Cost-Effective and Durable Cathode for Solid-State Li-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Development of next-generation solid-state Li-ion batteries (SSLIBs) requires low-cost cathode materials.
• High energy density and good rate performance are key requirements for these cathodes.

Purpose of the Study:

• To investigate Li₂FeCl₄ as a novel cathode material for SSLIBs.
• To evaluate its electrochemical performance, including intercalation/deintercalation, voltage, rate capability, and cycling stability.

Main Methods:

• Electrochemical testing of Li₂FeCl₄ as a cathode material in SSLIBs.
• Operando synchrotron X-ray diffraction (XRD) to study phase evolution during cycling.

Main Results:

• Li₂FeCl₄ exhibits highly reversible Li intercalation/deintercalation.
• Achieved a high operation voltage of 3.7 V vs Li⁺/Li.
• Demonstrated good rate capability and cycling stability with 86% capacity retention after 6000 cycles.
• Operando XRD revealed stable framework maintenance through solid-solution and two-phase reactions.

Conclusions:

• Li₂FeCl₄ is a promising low-cost cathode material for SSLIBs.
• Its stable framework and reversible electrochemical reactions contribute to excellent performance.
• The material shows potential for advancing high-performance solid-state battery technology.