FeOCl Nanoparticle-Embedded Mesocellular Carbon Foam as a Cathode Material with Improve d Electrochemical Performance for Chloride-Ion Batteries

Chloride-ion batteries (CIBs) have been regarded as a promising alternative battery technology to lithium-ion batteries because of their abundant resources, high theoretical volumetric energy density, and high safety. However, the research on chloride-ion batteries is still in its infancy. Exploring appropriate cathode materials with desirable electrochemical performance is in high demand for CIBs. Herein, the FeOCl nanocrystal embedded in a mesocellular carbon foam (MCF) has been prepared and developed as a high-performance cathode material for CIBs. The MCF with uniform and large mesocells (15.7-31.2 nm) interconnected through uniform windows (15.2-21.5 nm) can provide high-speed pathways for electron and chloride-ion transport and accommodate the strain caused by the volume change of FeOCl during cycling. As a result, the optimized FeOCl@MCF cathode exhibits the highest discharge capacity of 235 mAh g-1 (94% of the theoretical capacity) among those of the previously reported metal (oxy)chloride cathodes for CIBs. A reversible capacity of 140 mAh g-1 after 100 cycles is retained. In contrast, only 18 mAh g-1 was kept for the FeOCl cathode.

Automated summary

Chloride-ion batteries (CIBs) are considered as a promising alternative to lithium-ion batteries due to their abundant resources, high theoretical volumetric energy density, and high safety. This study focuses on exploring suitable cathode materials for CIBs and presents FeOCl nanocrystals embedded in a mesocellular carbon foam (MCF) as a high-performance cathode material. The optimized FeOCl@MCF cathode exhibits a high discharge capacity of 235 mAh g-1 (94% of the theoretical capacity) and retains a reversible capacity of 140 mAh g-1 after 100 cycles, outperforming previous metal (oxy)chloride cathodes.