LAUSR

Zn metal has shown promise as an anode material for grid-level energy storage yet is challenged by dendritic growth and low coulombic efficiency. Herein, we developed an ultrafast, stable, and high-loading polymer anode for aqueous Zn-ion batteries and capacitors (ZIBs and ZICs) by engineering both the electrode and electrolyte. The anode polymer was rationally prepared to have a suitable electronic structure and a large π-conjugated structure, whereas the electrolyte was manufactured based on the superiority of triflate anions over sulfate anions, as analyzed and confirmed via experiments and simulations. This dual engineering resulted in an optimal polymer anode with a low discharge potential, near-theoretical capacity, ultrahigh-loading capability (∼50 mg cm-2 ), ultrafast rate (100 A g-1 ), and ultralong lifespan (one million cycles). Its mechanism involves reversible Zn2+ /proton co-storage at the carbonyl site. When the polymer anode was coupled with cathodes for both ZIB and ZIC applications, the devices demonstrated ultrahigh power densities and ultralong lifespans, far surpassing those of corresponding Zn-metal-based devices. This article is protected by copyright. All rights reserved.