Stereoisomeric engineering mediated zinc metal electrodeposition: Critical balance of solvation and adsorption capability

Abstract

The exceptional electrochemical performance of zinc anodes is frequently impeded by inadequate deposition kinetics and interfacial chemistry. Herein, we introduce the stereoisomerism to inform the balanced selection of electrolyte additives, taking into account their solvation and adsorption properties, to achieve the optimal deposition behaviors and electrochemical performance. The three-point coplanar adsorption configuration, in comparison to two-point adsorption, effectively mitigates the interference of water molecules and establishes a coplanar templating effect. This approach fosters a uniform distribution of charges, encourages the preferential orientation growth of (002) planes for uniform zinc deposition. Moreover, an appropriate level of solvation ability can modulate the solvation structure without substantially increasing the de-solvation energy barrier, thereby facilitating faster deposition kinetics than what is observed in cases of strong solvation. As a result, Zn//Zn cell can achieve an excellent performance of more than 3470 ​h at 2 ​mA ​cm −2 and 1 mAh cm −2 , and Zn//AC full cell can work for 50000 cycles at 3 ​A ​g −1 . Additionally, under practical conditions (N/P=4.37), the assembled Zn//I 2 full cell demonstrates stable lifespan for 710 cycles at 1 ​A ​g −1 . This work showcases the interplay between adsorption configuration of stereoisomeric additives on the cycling. A pair of stereoisomerisms is introduced to illustrate the balanced selection of electrolyte additives with their solvation and adsorption ability. It is precisely due to the structure-activity relationship between the two that the battery performance also exhibits differences. Stable cycling of the zinc anode has been accomplished under the synergistic influence of strong adsorption and weak solvation effects.

Topics & Concepts