Ultrafast Nucleation Reverses Dissolution of Transition Metal Ions for Robust Aqueous Batteries

摘要

The dissolution of transition metal ions causes the notoriouspeelingof active substances and attenuates electrochemical capacity. Frustratedby the ceaseless task of pushing a boulder up a mountain, Sisyphusof the Greek myth yearned for a treasure to be unearthed that couldbolster his efforts. Inspirationally, by using ferricyanide ions (Fe-(CN)(6) (3-)) in an electrolyte as a driving forceand taking advantage of the fast nucleation rate of copper hexacyanoferrate(CuHCF), we successfully reversed the dissolution of Fe and Cu ionsthat typically occurs during cycling. The capacity retention increasedfrom 5.7% to 99.4% at 0.5 A g(-1) after 10,000 cycles,and extreme stability of 99.8% at 1 A g(-1) after40,000 cycles was achieved. Fe-(CN)(6) (3-) enables atom-by-atom substitution during the electrochemical process,enhancing conductivity and reducing volume change. Moreover, we demonstratethat this approach is applicable to various aqueous batteries (i.e.,NH4 (+), Li+, Na+, K+, Mg2+, Ca2+, and Al3+).

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