Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Aqueous rechargeable zinc metal batteries promise attractive advantages including safety, high volumetric energy density, and low cost; however, such benefits cannot be unlocked unless Zn reversibility meets stringent commercial viability. Herein, we report remarkable improvements on Zn reversibility in aqueous electrolytes when phosphonium‐based cations are used to reshape interfacial structures and interphasial chemistries, particularly when their ligands contain an ether linkage. This novel aqueous electrolyte supports unprecedented Zn reversibility by showing dendrite‐free Zn plating/stripping for over 6400 h at 0.5 mA cm−2, or over 280 h at 2.5 mA cm−2, with coulombic efficiency above 99 % even with 20 % Zn utilization per cycle. Excellent full cell performance is demonstrated with Na2V6O16⋅1.63 H2O cathode, which cycles for 2000 times at 300 mA g−1. The microscopic characterization and modeling identify the mechanism of unique interphase chemistry from phosphonium and its functionalities as the key factors responsible for dictating reversible Zn chemistry
The addition of phosphonium‐based supporting salts and a subtle difference in their ligand chemistry remarkably improves the reversibility of aqueous Zn electrolytes. By promoting interphase formation, P444(2O1)‐TFSI supports a Zn coulombic efficiency above 99 % even at 1.17 mA cm−2 with 20 % Zn utilization per cycle, and a stable Zn∥Na2V6O16⋅1.63 H2O cell cycling.