RESUMO
Designing a cost-effective and multifunctional separator that ensures dendrite-free and stable Zn metal anode remains a significant challenge. Herein, a multifunctional cellulose-based separator is presented consisting of industrial waste-fly ash particles and cellulose nanofiber using a facile solution-coating method. The resulting fly ash-cellulose (FACNF) separators enable a high ion conductivity (5.76 mS cm-1) and low desolvation energy barrier of hydrated Zn2+. These features facilitate fast ion transfer kinetics and inhibit water-induced side reactions. Furthermore, experimental results and theoretical simulations confirm that the presence of fly ash particles in FACNF separators effectively accommodate the preferential deposition of Zn(002) planes, due to the weak chemical affinity between Zn(002) plane and fly ash, to mitigate dendrite formation and growth. Consequently, the utilization of FACNF separators causes an impressive cycling performance in both Zn||Zn symmetric cells (1600 h at 2 mA cm-2/1 mAh cm-2) and Zn||(NH4)2V10O25 (NVO) full cells (4000 cycles with the capacity retention of 92.1% at 5 A g-1). Furthermore, the assembled pouch cells can steadily support digital thermometer over two months without generating gas and volume expansion. This work provides new insights for achieving crystallographic uniformity in Zn anodes and realizing cost-effective and long-lasting aqueous zinc-ion batteries (AZIBs).
RESUMO
Given their plentiful reserves, impressive safety features, and economical pricing, aqueous zinc - ion batteries (ZIBs) have positioned themselves as strong competitors to lithium - ion batteries. Yet, the scarcity of available cathode materials poses a challenge to their continued development. In this study, a V2O5/V6O13 heterostructure has been synthesized using a one - pot hydrothermal approach and employed as the cathode material for ZIBs. As evidenced by both experimental and theoretical findings, V2O5/V6O13 heterostructure delivers a rapid electrons and ions diffusion kinetics promoted by the stable interface and strong electronic coupling with significant charge transfer between V2O5 and V6O13, as well as a stable interface achieved by adjusting V - O bond length. Consequently, the optimized V2O5/V6O13 heterostructure cathode of ZIBs demonstrates exceptional capacity (338 mAh g-1 at 0.1 A g-1), remarkable cycling stability (92.96 % retained after 1400 cycles at 1 A g-1). Through comprehensive theoretical calculations and ex situ characterization, the kinetic analysis and storage mechanism of Zn2+ are thoroughly investigated, providing a solid theoretical foundation for the advancement of novel V - based cathode materials aimed at enhancing the performance of ZIBs.