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Page 24 of 31 Miao et al. Energy Mater 2023;3:300014 https://dx.doi.org/10.20517/energymater.2022.89

Figure 11. Schematic illustration of the future research on electrolyte design for high-performance Zn anodes.

Combinations and developments of characterization techniques
The key to providing guidelines for designing high-performance electrolytes is to understand the electrolyte
structure and properties. They can be analyzed using a variety of advanced characterization techniques. The
combined computational and experimental study can provide a more in-depth understanding of the
influence mechanism of the electrolyte structure on the performance of Zn anodes. However, most
characterization approaches can only perform static observation, making it impossible to understand
chemical reaction processes in real time. Hence the need for in-situ technologies. Additionally, it is unable
to directly observe the electrolyte structure either in the bulk phase or on the Zn anode surface at present. In
most cases, the electrolyte structure is only inferred from the signal generated by characterization
procedures. Therefore, in order to investigate the relationship between the electrolyte structure and the Zn
anode performance, it is important to develop and employ more advanced characterization techniques.

Synergistic impacts for enhancing Zn anode performance
Each electrolyte modification approach has merits and drawbacks. For instance, the Zn anode lifespan can
be prolonged without damaging the rate performance of the battery by altering the type of Zn salt in
electrolytes. However, this electrolyte regulation strategy is pricey. Particularly for the strategy to increase
salt concentrations, the cost increases significantly. Although adding organic cosolvents to electrolytes saves
cost, doing so will decrease ionic conductivity and increase voltage polarization. Moreover, the majority of
organic solvents are flammable, which presents security gaps for the battery. Currently, using additives to
stabilize Zn anodes appears to be the most promising approach. However, there is no clear advice on the
selection and design of additives. We speculate that the strategy of integrating the modification mechanism
of each electrolyte composition is a possible way to design optimal additives. In addition, the present
approaches for testing the Zn cycle life and CE have yet to be standardized, which poses an obstacle to
comparing the effectiveness of different electrolyte modification strategies. Thus, it is urgent to develop
universal testing standards.