Synthesis and application of Calix[6]quinone as a high-capacity organic cathode for plastic crystal electrolyte-based lithium-ion batteries

Conventional lithium-ion batteries (LIBs) utilizing inorganic cathode materials do not meet the increasing demand for high-capacity and green energy storage technologies, which have drawn increasing attention to the use of carbonyl compounds as high-capacity electrode materials. Herein, we describe the synthesis and application of an organic three-dimensional cyclic oligomer, calix[6]quinone (C6Q), as a high-capacity cathode material for rechargeable LIBs. Ex-situ UV–vis spectroscopy was used to compare the cycling-induced dissolution of calix[4]quinone with that of C6Q. Operando infrared spectroscopy was applied to uncover the discharge-charge mechanism of C6Q. An all-solid-state battery containing C6Q and a plastic crystal electrolyte (5 ​mol% solution of lithium bis(trifluoromethane)sulfonimide in succinonitrile) exhibits a specific initial capacity of 425 mAh g−1 and maintains at a stable value of 405 mAh g−1 after 500 cycles at 0.1 ​C. Thus, this study demonstrates the prospects of organic materials in high-power rechargeable devices.