Capacity Limitation and Ionic Transport Disruption in Li-Rich Cathodes under Practical High Active Material Fractions...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Lithium-rich layered oxide (LLO) cathodes offer high theoretical capacity for advanced batteries.
• Achieving high energy density in all-solid-state batteries (ASSBs) with LLOs is challenging due to void limitations.

Purpose of the Study:

• To investigate the impact of intra- and interparticle voids on Li+ transport in LLO cathodes.
• To develop a composite cathode strategy to overcome transport limitations and enhance ASSB performance.

Main Methods:

• Characterization of void formation in reduced-particle-size LLO cathodes.
• Design and implementation of a Li3InCl6 coating for improved interfacial contact and Li+ conduction.
• Electrochemical testing of the composite cathode in ASSBs.

Main Results:

• Sluggish Li+ transport, caused by intra- and interparticle voids, was identified as the primary performance limitation.
• The Li3InCl6 coating effectively improved interfacial contact and facilitated Li+ conduction pathways.
• The developed ASSB achieved high capacity (245.2 mAh/g at 0.1 C) and excellent cycling stability (80.9% retention after 250 cycles).

Conclusions:

• Void engineering and composite cathode design are crucial for high-energy-density LLO-based halide ASSBs.
• The Li3InCl6 coating presents a viable strategy to enhance electrochemical performance in LLO cathodes for ASSBs.