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 singlewalled 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 .

Searching for new cheap encapsulating materials to decrease the solubility of organic small molecules as the cathode materials in electrolytes and improve the performance of organic lithium‐ion batteries (LIBs) is very important and highly desirable. In this research, we found that a novel cheap biomass carbon (named as PPL), prepared by pyrolyzing calyxes of Physalis Peruviana L, can efficiently encapsulate calix[4]quinone to form composites, which can be used as cathodes in LIBs. The initial discharge capacity of the as‐fabricated battery was 437 mAh g−1 and could maintain 228 mAh g−1 after 100 cycles. Even at 1 C, the discharge capacity was still 217 mAh g−1.

Calix[n]quinones, a class of cyclic oligomers composed of p-benzoquinone structures connected by methylene, have multi-conjugated carbonyl structures and adjustable cavities, which make their synthesis extremely attractive. In this minireview, synthetic methods of calix[n]quinones and recent synthetic experience of our group are summarized. The merits and demerits of various synthetic methods are briefly reviewed as well. When synthesizing calix[n]quinone (n � 6) with a larger ring, the reduction-oxidation method is considered to be the most recommended.

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