Fast Reaction Kinetics and Commendable Low‐Temperature Adaptability of Zinc Batteries Enabled by Aprotic Water‐Acetamide Symbiotic Solvation Sheath

Aqueous zinc‐ion batteries (AZIBs) exhibit significant potential for grid energy storage due to their low cost and safety. However, the commercial applications of AZIBs face challenges, particularly in the anode, such as zinc dendrites, hydrogen evolution reaction (HER), and zinc corrosion. In this study, a protonated triglycine (ggg) as a multifunctional electrolyte additive for AZIBs is employed. This ggg molecule can dissociate as zwitterion (both anion and cation) in mildly acidic ZnSO4 electrolytes. The NH3+ cation in ggg molecule can adsorb on the surface of the zinc anode, regulating the deposition of Zn2+ and slowing down the side reactions, and the spontaneously dissociated ggg anions will combine with Zn2+ to regulate the solvated Zn2+ chemistry in the electrolyte, establishing the electrostatic interaction via the strong adsorption ability to Zn2+. Theoretical calculations indicate that ggg molecule demonstrates a strong affinity toward Zn2+, enabling the reconstruction of Zn(H2O)62+ and facilitating subsequent de‐solvation processes. As a result, Zn||Zn symmetric cells in ZnSO4/0.2 mM ggg electrolyte exhibited an extended cycling lifetime of ≈4500 h. Furthermore, the Zn||MnO2 full battery demonstrated enhanced capacity and cycling performance with the addition of ggg molecule. This study provides valuable insights into constructing a highly reversible electrolyte for AZIBs.

Zwitterionic Organic Multifunctional Additive Stabilizes Electrodes for Reversible Aqueous Zn‐Ion Batteries

Zhang,

Liu,

Wang

et al. 2024

Design Strategies for Anti‐Freeze Electrolytes in Aqueous Energy Storage Devices at Low Temperatures

You,

Fan,

Xiong

et al. 2024

With the continuous development of electrochemical energy storage technology, especially in the current pursuit of environmental sustainability and safety, aqueous energy storage devices, due to their high safety, environmental friendliness, and cost‐effectiveness, are becoming an important direction of development in the field of energy storage. Diverse application scenarios require that energy storage systems be capable of continuous power supply under low temperature conditions. However, conventional aqueous electrolytes freeze at extremely low temperatures, causing limited ion transport and slow reaction kinetics, degrading the performance of the energy storage system. The design of low‐temperature anti‐freeze aqueous electrolytes has become an effective way to address this issue. In this review, the deep connection between hydrogen bonds (HBs) interactions in aqueous electrolytes and the liquid‐to‐solid conversion process, and the fundamental principles of the anti‐freeze mechanism is first explored. Subsequently, a systematic categorization and discussion of the design strategies for low‐temperature anti‐freeze aqueous electrolytes are conducted. Finally, potential directions are proposed. This review aims to provide comprehensive scientific guidance and technical reference for the development of anti‐freeze aqueous electrolytes with excellent low‐temperature performance, thereby promoting the application and innovation of aqueous energy storage devices in low‐temperature environments.

Boosting the Anode and Cathode Stability Simultaneously by Interfacial Engineering via Electrolyte Solvation Structure Regulation Toward Practical Aqueous Zn‐ion Battery

Wang,

Zhong,

Wang

et al. 2024

The application of zinc‐ion batteries (ZIBs) is seriously challenged by the poor stability of Zn anode and cathode in aqueous solution, which is closely associated with electrolyte structure and water reactivity. Herein, the stability issues both for the cathode and anode can be simultaneously addressed via tuning the electrolyte solvation structure in hybrid electrolyte with tripropyl phosphate (TPP) as co‐solvent. On the Zn anode, a robust poly‐inorganic solid electrolyte interphase (SEI) layer comprised of Zn3(PO4)2‐ZnS‐ZnF2 species is in situ formed, effectively suppressing parasitic reaction and dendrite evolution. For V2O5 cathode, the notorious vanadium dissolution is effectively restricted with improved structure stability achieved. The optimized electrolyte facilitates the reversible redox kinetics both at the cathode and Zn anode. Consequently, Zn||Zn cells display extended cycling lifespans over 3000 h at 1 mA cm−2, 1 mAh cm−2. Zn||V2O5 full cells deliver a high reversible capacity of 261.8 mAh g−1 and hold retention of 73.6% upon 500 cycles even operated in harsh conditions with thin Zn anode (10 µm) and low negative/positive (N/P) ratio of ≈4.3, which also showcase impressive performance with regard to rate and storage performance, further emphasizing the potential of electrolyte regulation tactics in advancing the commercialization of ZIBs.