Hemimorphite /C interface layer with dual-effect methodically redistricted Zn2+ deposition behavior for dendrite-free zinc metal anodes

Abstract

The uneven distribution of Zn2+ gradient and electric fields at the electrolyte–anode interface are the two “pain points” that seriously limit the lifespan of AZIBs. Traditional artificial SEI layers targeted one single “pain points” cannot simultaneously balance the Zn2+ gradient and electric fields. Herein, hemimorphite/C interface layer, sandwich structure Zn4(Si2O7)(OH)2·H2O@rGO@Zn4(Si2O7)(OH)2·H2O (rGO@ZnSi) prepared by in-situ growth strategy is provided as “dual-effect” to modulate Zn2+ gradient and electric fields regulation. The rGO@ZnSi is demonstrated with the zincophilicity due to Zn-ion-conducive transport channel about 5Å and boosted electroconductibility properties by in situ growth rGO. The internal rGO acts as conductive core, facilitating the rapid transfer of electrons along the two-dimensional plane, thus significantly enhancing the conductivity of hemimorphite. Additionally, it opens up a new territory for Zn2+ reduction process, which would enhance the reversibility of Zn anode, mitigate the polarization and promote electrochemical performance. The Zn//Zn battery with the modified rGO@ZnSi SEI exhibits an ultra-long and outstanding cycling stability of up to 170 days. Benefitting from the rGO@ZnSi SEI, the rGO@ZnSi-Zn//V2O5 full battery delivers a high discharge capacity and long cycle performance. The “dual-effect” rGO@ZnSi SEI escorts for the dendrite-free zinc metal anodes with lifetime extension, ultra-high rate performance and cost-effectiveness.