Poly(Anthraquinonyl Sulfide)/CNT Composites as High‐Rate‐Performance Cathodes for Nonaqueous Rechargeable Calcium‐Ion Batteries

Abstract

Calcium-ion batteries (CIBs) are considered as promising alternatives in large-scale energy storage due to their divalent electron redox properties, low cost, and high volumetric/gravimetric capacity. However, the high charge density of Ca 2+ contributes to strong electrostatic interaction between divalent Ca 2+ and hosting lattice, leading to sluggish kinetics and poor rate performance. Here, in situ formed poly(anthraquinonyl sulfide) (PAQS)@CNT composite is reported as nonaqueous calcium-ion battery cathode. The enolization redox chemistry of organics has fast redox kinetics, and the introduction of carbon nanotube (CNT) accelerates electron transportation, which contributes to fast ionic diffusion. As the conductivity of the PAQS is enhanced by the increasing content of CNT, the voltage gap is significantly reduced. The PAQS@CNT electrode exhibits specific capacity (116 mAh g −1 at 0.05 A g −1 ), high rate capacity (60 mAh g −1 at 4 A g −1 ), and an initial capacity of 82 mAh g −1 at 1 A g −1 (83% capacity retention after 500 cycles). The electrochemical mechanism is proved to be that the PAQS undergoes reduction reaction of their carbonyl bond during discharge and becomes coordinated by Ca 2+ and Ca(TFSI) + species. Computational simulation also suggests that the construction of Ca 2+ and Ca(TFSI) + co-intercalation in the PAQS is the most reasonable pathway.

Topological Insulator Bi2Se3‐Assisted Heterostructure for Ultrafast Charging Sodium‐Ion Batteries

“…The equation i = av b is used to describe the relationship between current (i) and scan rate (v), where a and b are adjustable parameters and b represents the charge storage behavior. [56] NDC, [57] CuSe, [58] FeSe 2 @C, [59] and In 2 Se 3 @CoSe 2 . [48] e) Normalized ratio of diffusion or capacity controlled at various scan rates of BZSC.…”

Advances in organic cathode materials for aqueous multivalent metal-ion storage

“…4). 52 The incorporation of carbon nanotubes boosted electron transportation of the cathode material and reduced the voltage gaps between the reduction and oxidation state of poly(anthraquinonyl sulfide). The as-obtained composite cathode showed competitive Ca-ion storage ability including a high-rate capacity of 60 mA h g À1 @ 4 A g À1 as well as 83% retention after 500 cycles.…”

“…23 Yao's group investigated the Mg 2+ -storage (Reproduced with permission. 52 Copyright 2022, Wiley-VCH.) ability of three carbonyl compounds in Mg metal-compatible electrolytes for the purpose of high-energy Mg-organic batteries (Fig.…”

“…(b and c) FTIR and (d-f) XPS spectra of the poly(anthraquinonyl sulfide)-based cathode material. (Reproduced with permission 52. Copyright 2022, Wiley-VCH.…”

Cathode materials for calcium‐ion batteries: Current status and prospects

“…[88] Until now, the developed organic CIB cathode materials have been very limited. Poly(anthraquinonyl sulfide) (PAQS) was reported as a nonaqueous CIB cathode by Zhang et al [43] To accelerate electron transportation, carbon nanotubes F I G U R E 9 Organic materials for CIB cathodes. (a) Schematic illustration of the synthesis of PAQS@CNT composites.…”