An inorganic-organic nanocomposite calix[4] quinone (C4Q)/CMK-3 as a cathode material for high-capacity sodium batteries

Based on the concept of grid-scale energy storage systems (ESSs), organic sodium-ion batteries (OSIBs), combining the merits of SIBs and the advantages of organic materials, are promising candidates for the new stage of commercial batteries. Organic cathode materials of calix[4] quinone (C4Q) in LIBs have delivered a high initial discharge capacity of 422 mA h g(-1). However, its sodium storage property remains unclear. Here, a series of C4Q/ordered mesoporous carbon (CMK-3) nanocomposites have been firstly prepared by simple perfusion methods and employed as cathode materials for rechargeable sodium batteries. Systematic characterization including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) analysis has been carried out, which demonstrated that C4Q was almost completely infused in the nano-pores of CMK-3 when its content was lower than 66 wt%. The optimized nanocomposite with 33 wt% C4Q exhibits a superior initial discharge capacity up to 438 mA h g(-1) at 0.1C rate and a capacity retention of 219.2 mA h g(-1) after 50 cycles. The enhanced cycling stability and high-rate capability are attributed to the nanosize effect and the good conduction of CMK-3. This constrains the dissolution of the embedded active materials. Our results enrich the family of inorganic-organic nanoconfinement cathode materials for high capacity sodium batteries.