Synthetic Control of Electronic Property and Porosity in Anthraquinone-Based Conjugated Polymer Cathodes for High-Rate and Long-Cycle-Life Na–Organic Batteries

Abstract

Redox-active carbonyl-containing compounds have received extensive attention as cathode materials for sodium-ion batteries (SIBs) because of their excellent attributes, including elemental sustainability, high theoretical capacity, diverse structures, and tunable properties. However, the storage of Na+ in most carbonyl-based cathode materials is plagued by the low capacity, unsatisfying rate performance, and short cycling life. Herein, we develop a series of anthraquinone-based conjugated polymer cathodes consisting of anthraquinone and benzene with different linking patterns. It reveals that the linkage sites on benzene ring could affect the electronic structures of the resulting polymers and thus their charge-storage capabilities. The 1,2,4,5-linkage on benzene leads to a high surface area, a narrow band gap, and the lowest unoccupied molecular orbital for the resulting polymer PBAQ-3. As a cathode for SIBs, it delivers a high capacity of around 200 mAh g–1 and excellent rate performance (105 mAh g–1 at 200 C) as well as stable cycling with a capacity retention of 95.8% after 1000 cycles at 0.05 A g–1 and 83.1% after 40000 cycles at 3 A g–1. Our findings highlight the influence of linking patterns of the building blocks on the electrochemical performance of organic electrodes.

Construction of Naphthalene Diimide Derived Nanostructured Cathodes through Self-Assembly for High-Performance Sodium–Organic Batteries

“…This could be attributed to the efficient π–π stacking in the self-assembled structure, consistent with the XRD results. The ion diffusion abilities were further analyzed by both EIS − and galvanostatic intermittent titration (GITT) techniques. ,, Detailed calculation methodologies are described in the Supporting Information (Figures S10 and S11). Based on EIS experiments, the Na + diffusion coefficient ( D Na + ) values of NDI-ONa (SA) were calculated to be 1.80 × 10 –11 cm 2 s –1 , which is up to an order of magnitude higher than that of NDI-ONa (PVDF) (1.82 × 10 –12 cm 2 s –1 ).…”

Atomistic structural engineering of conjugated organic polymer cathodes for high-performance Li-organic batteries

“…3f, the σ -value of the PTO-Py electrode is slightly larger than that of the PTO-Bz , PTO-Pm , and PTO-Tz electrodes, and the corresponding D Li + values are calculated to be 0.68 × 10 −13 , 1.50 × 10 −13 , 0.70 × 10 −13 , and 2.80 × 10 −13 cm 2 S −1 , respectively, suggesting that there is not a simple linear relationship between the Li + diffusivity and electrochemical capabilities for the four electrodes. 40 Meanwhile, the D Li + of the four electrodes was further investigated by the galvanostatic intermittent titration technique (GITT) test at a current pulse of 0.05 A g −1 for 20 min followed by an open-circuit relaxation for 2 h (Fig. 3g).…”

Low-Cost Organodisulfide Polymer for Ultrafast High-Capacity Cathode Materials

“…In addition, organic electrode materials usually have relatively low intrinsic conductivity, thus resulting in poor rate performance . This issue has been approached by using conjugated polymers with large π bonds . Even more effective is to combine polymers with conductive components that have lightweight and high specific surface, such as graphene and carbon nanotubes. ,,, Although significant achievements have been made, especially in improving cycle stability and high power performance, large-scale production of organic electrode materials is limited due to expensive raw materials and complicated synthetic processes.…”