Pillar[5]quinone-Carbon Nanocomposites as High-Capacity Cathodes for Sodium-Ion Batteries

New organic cathodes to replace inorganic materials for the capacity enhancement of sodium-ion batteries (SIBs) are highly desirable. In this research, we described the investigation of pillar[5]quinone (P5Q), which we determined to have a theoretical capacity of 446 mAh g^-1, a value that makes it a very promising candidate as a cathode in rechargeable batteries. Inspired by this value, P5Q was encapsulated into CMK-3 to form a composite and then integrated with single-walled carbon nanotubes (SWCNTs) to generate a film that was used as the cathode in SIBs. The as-assembled SIBs showed an initial capacity up to 418 mAh g^-1 and maintained 290 mAh g^-1 after 300 cycles at 0.1 C. Even at 1 C, the capacity could still reach 201 mAh g^-1.