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Zn metal as a promising anode of aqueous batteries faces severe challenges from dendrite growth and side reactions. Here, tetraphenylporphyrin tetrasulfonic acid (TPPS) is explored as an electrolyte additive for advanced Zn anodes. It is interesting to note that TPPS spontaneously assembles into unique aggregates. As they adsorb on the Zn anode, the aggregates enhance the resistance to electrolyte percolation and dendrite growth compared to single molecules. Meanwhile, TPPS facilitates anion association in the solvation sheath of Zn2+, and boosts the transference number of Zn2+ up to 0.95. Therefore, anion‐related side reactions and anion‐induced electrode overpotentials are reduced accordingly. In this context, the electrolyte containing TPPS exhibits excellent electrochemical performance. Even under a high loading of MnO2 (25 mg cm−2), a limited Zn supply (N/P ratio=1.7), and a lean electrolyte (15 μL mAh−1), the full cells still represent a higher cumulative capacity compared to the reported data. The advantages of this electrolyte are also adapted to other cathode materials. The pouch cells of Zn||NaV3O8 ⋅ 1.5H2O realize a capacity of ~0.35 Ah at 0.4 C under harsh conditions. [ABSTRACT FROM AUTHOR]

Zn metal as a promising anode of aqueous batteries faces severe challenges from dendrite growth and side reactions. Here, tetraphenylporphyrin tetrasulfonic acid (TPPS) is explored as an electrolyte additive for advanced Zn anodes. It is interesting to note that TPPS spontaneously assembles into unique aggregates. As they adsorb on the Zn anode, the aggregates enhance the resistance to electrolyte percolation and dendrite growth compared to single molecules. Meanwhile, TPPS facilitates anion association in the solvation sheath of Zn 2+ , and boosts the transference number of Zn 2+ up to 0.95. Therefore, anion-related side reactions and anion-induced electrode overpotentials are reduced accordingly. In this context, the electrolyte containing TPPS exhibits excellent electrochemical performance. Even under a high loading of MnO 2 (25 mg cm -2 ), a limited Zn supply (N/P ratio=1.7), and a lean electrolyte (15 μL mAh -1 ), the full cells still represent a higher cumulative capacity compared to the reported data. The advantages of this electrolyte are also adapted to other cathode materials. The pouch cells of Zn||NaV 3 O 8  ⋅ 1.5H 2 O realize a capacity of ~0.35 Ah at 0.4 C under harsh conditions., (© 2024 Wiley-VCH GmbH.)

Clever and rational design of structural hierarchy, along with precise component adjustment, holds profound significance for the construction of high-performance supercapacitor electrode materials. In this study, a binder-free self-supported CCO@N 0.5 C 0.5 OH/NF cathode material is constructed with hierarchical hetero-core-shell honeycomb nanostructure by first growing CuCo 2 O 4 (CCO) nanopin arrays uniformly on highly conductive nickel foam (NF) substrate, and then anchoring Ni 0.5 Co 0.5 (OH) 2 (N 0.5 C 0.5 OH) bimetallic hydroxide nanosheet arrays on the CCO nanopin arrays by adjusting the molar ratio of Ni(OH) 2 and Co(OH) 2 . The constructed CCO@N 0.5 C 0.5 OH/NF electrode material showcases a wealth of multivalent metal ions and mesopores, along with good electrical conductivity, excellent electrochemical reaction rates, and robust long-term performance (capacitance retention rate of 87.2%). The CCO@N 0.5 C 0.5 OH/NF electrode, benefiting from the hierarchical structure of the material and the exceptional synergy between multiple components, demonstrates an excellent specific capacitance (2553.6 F g -1 at 1 A g -1 ). Furthermore, the assembled asymmetric CCO@N 0.5 C 0.5 OH/NF//AC/NF supercapacitor demonstrates a high energy density (70.1 Wh kg -1 at 850 W kg -1 ), and maintains robust capacitance cycling stability performance (83.7%) after undergoing 10 000 successive charges and discharges. It is noteworthy that the assembled supercapacitor exhibits an operating voltage (1.7 V) that is well above the theoretical value (1.5 V)., (© 2023 Wiley-VCH GmbH.)