Vacancy Modulating Co₃Sn₂S₂ Topological Semimetal for Aqueous Zinc‐Ion Batteries

Abstract

Weyl semimetals (WSMs) with high electrical conductivity and suitable carrier density near the Fermi level are enticing candidates for aqueous Zn-ion batteries (AZIBs), meriting from topological surface states (TSSs). We propose aW SM Co 3 Sn 2 S 2 cathode for AZIBs showing ad ischarge plateau around 1.5 V. By introducing Sn vacancies,extra redox peaks from the Sn 4+ /Sn 2+ transition appear,w hichl eads to more Zn 2+ transfer channels and active sites promoting chargestorage kinetics and Zn 2+ storage capability.C o 3 Sn 1.8 S 2 achieves aspecific energy of 305 Wh kg À1 (0.2 Ag À1 )and aspecific power of 4900 Wkg À1 (5 Ag À1 ). Co 3 Sn 1.8 S 2 and Zn x Co 3 Sn 1.8 S 2 benefit from better conductivity at lower temperatures;t he quasi-solid Co 3 Sn 1.8 S 2 //Zn battery delivers 126 mAh g À1 (0.6 Ag À1 )a tÀ30 8 8Ca nd ac ycling stability over 3000 cycles (2 Ag À1 )with 85 %c apacity retention at À10 8 8C.

Improving the performance of a SnS2 cathode with interspace layer engineering using a Na+ insertion/extraction method for aqueous zinc ion batteries

“…In the context of ZIBs, the hydrated Zn 2+ ions (measuring 4.3 Å) in aqueous electrolytes face a considerable desolvation energy barrier when attempting to penetrate the interlayers of SnS 2 . 47 Despite their similar structures, layered metal dichalcogenides, such as MoS 2 and SnS 2 , can hold Na and Li; thus, they can be used in high-capacity SIBs and LIBs. [36][37][38][39] A layered metal dichalcogenide structure with van der Waals interactions dominates the migration behaviors of alkali ions.…”

“…In the context of ZIBs, the hydrated Zn 2+ ions (measuring 4.3 Å) in aqueous electrolytes face a considerable desolvation energy barrier when attempting to penetrate the interlayers of SnS 2 . 47…”

“…Zhao et al designed Weyl semimetal Co 3 Sn 2 S 2 cathodes for AZIBs. 47 Introducing Sn vacancies can improve the kinetics of charge storage and the diffusion rate of Zn 2+ by increasing the number of Zn 2+ active sites and transfer channels. With a high capacity of 195.7 mA h g −1 , the Co 3 Sn 1.8 S 2 //Zn battery offers exceptional performance over 2400 cycles due to its high capacity.…”

Recent advance and design strategies of chalcogenides for high-performance aqueous zinc-ion batteries

“…The MnS/rGO electrode demonstrated a reversible capacity of 289 mA h g −1 at 0.1 A g −1 and a rate capability of 62 mA h g −1 at 1 A g −1 (figure 14(a)). In another study, Zhao et al introduced Weyl semimetals Co 3 Sn 2 S 2 as a cathode material for AZIBs [138]. These semimetals have high electrical conductivity and a suitable carrier density near the Fermi level.…”

Unlatching the Additional Zinc Storage Ability of Vanadium Nitride Nanocrystallites

“…Furthermore, the density of states (DOS) of the as-designed models was studied and depicted in Figure 5i. Although, both the TiO 2 -VN and TiN-VN exhibited greater density of available electronic states near the Fermi level than VN, which implies improved electrical conductivity, TiN-VN is also much closer to the Fermi Level than TiO 2 -VN, indicating enhanced charge transfer between VN and Zn 2+ in the TiN-VN interface [66,67] We can conclude that the interaction between TiO 2 and VN enhances the adsorption energy, which TiN and VN enhances the conductivity, which do not only confirm the synergistic effect between the TiO 2 -VN and TiN-VN interfaces in the VNTONC electrode, but also justifies the reason why the VNTNC Zn 2+ storage performance is slightly inferior to the VNTONC owing to the presence of the TiO 2 -VN. Figure 5j-l depicts the charge density difference at the different TiO 2 -TiN, TiO 2 -VN, and TiN-VN interfaces.…”