Quantitative Chemistry in Electrolyte Solvation Design for Aqueous Batteries

Abstract

Aqueous electrolyte design is pivotal for boosting the energy density and lifespan of aqueous batteries, because it can expand the electrochemical stability window and also mitigate the parasitic side reactions. Until now, three main kinds of electrolytes, i.e., water-in-salt, eutectic, and additives-modified electrolytes, have been developed by which the activity of H2O can be lowered and/or the formed specific solid–electrolyte interphase (SEI) can mitigate the decomposition of H2O. However, there is still a lack of a universal model to elucidate the reason for the improved performance, especially as the SEI interpretation becomes ever more controversial. Herein, we present a quantitative and graphical model of the electrolyte solvation structure and metal-ion (de)­solvation process (i.e., interfacial model) to summarize a relationship between the electrolyte–electrode interfacial chemistry and electrode performance. This Focus Review extends the solvation structure and interfacial model into the field of aqueous electrolytes, revealing the essential influence of the solvation structure’s properties on electrolyte stability and electrode performance, by which electrode performance and electrolyte design can be more quantitatively and accurately understood.

Weak Solvent–Solvent Interaction Enables High Stability of Battery Electrolyte

“…were changed in different battery systems. Thus, our discovery may provide a new challenging direction which is to quantify the solvent–solvent interaction. − We believe more advanced techniques and simulations need to be developed to realize it, by which a certain critical value that the interaction intensity should surpass to stabilize the electrolytes could be estimated.…”

Reversible adsorption with oriented arrangement of a zwitterionic additive stabilizes electrodes for ultralong-life Zn-ion batteries

“…S20, ESI†), theoretically reflecting that this improvement can reduce the interfacial free energy and help practically in a uniform electric distribution for even Zn plating. 37…”

“…S20, ESI †), theoretically reflecting that this improvement can reduce the interfacial free energy and help practically in a uniform electric distribution for even Zn plating. 37 In addition, the Zn nucleation and growth behaviors were investigated via chronoamperometry (CA) test at a À150 mV overpotential (Fig. 3f).…”

Universality of Benzoquinone-based Anodes toward Various Metal Cations in Aqueous Rechargeable Batteries

“…wind, solar, and biomass energy) has become an urgent issue in the era of achieving carbon emission peak and carbon neutrality. However, their intermittence and scattered distribution properties trap the integration to public power systems. − It is essential to develop safe and affordable large-scale energy storage systems to integrate these renewable energy sources into the stable electric grid. ,,, Aqueous rechargeable batteries (ARBs) that employ aqueous electrolytes have the advantages of low cost, high safety, and production that can be easily scaled up, enabling them to be a promising candidate for grid energy storage. − …”