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Rechargeable aqueous zinc-ion batteries are considered as promising candidates for safe and green energy storage. Yet, Zn anodes still suffer from serious challenges. Herein, an effective cation-sieve of polyethersulfone-modified sulfonated polyether ether ketone is developed as protective coating layer of the Zn anodes. Cation-only transmission and dense property of the layer can protect the Zn from active water and anions, inhibiting corrosion, hydrogen evolution reaction (HER), and passivation. Zincophilic property of the layer can homogenize Zn 2+ flow, and promote uniform plating of Zn. Therefore, protected symmetric Zn||Zn cell can maintain as long as 5600 h with a low polarization at 1.0 mA cm -2 and 0.5 mAh cm -2 , and still long as 800 h at 5.0 mA cm -2 and 5.0 mAh cm -2 . It is found that not only the dendrites but also the popular existed passivation product of Zn 4 SO 4 (OH) 6 ·5H 2 O can be inhibited effectively. In asymmetric Zn||Ti cells, average Coulombic efficiency can reach 98.2%, suggesting corrosion and HER are restrained effectively. Matched with MnO 2 cathode, full cells using coated Zn exhibit much better cycling performance than that using bare Zn. Moreover, Zn 4 O 3 (SO 4 )·7H 2 O (ZSH)-assisted reversible conversion mechanism between the ZSH and Zn x H y MnO 2 is revealed through operando Raman., (© 2023 Wiley‐VCH GmbH.)

Non-flow aqueous zinc-bromine batteries (AZBBs) are highly attractive owing to their lightweight construction and largely reduced cost compared with the flow ones. Yet, their development is restricted by the sluggish reaction kinetics of Br 2 /Br - , the shuttle of soluble polybromide species (Br n - , n is odd), and the poor stability of Zn-based anode. Herein, an effective alkaline-neutral electrolyte decoupling system is constructed to mitigate these issues, where nitrogen-doped carbon felt with high catalytic activity to Br 2 /Br - reaction is developed for cathode, a cost-effective cation exchange membrane (CEM) of polyethersulfone/sulfonated polyether ether ketone (PES/SPEEK-M) that can stop Br n - is used as separator, and glucose that can inhibit dendrites is introduced as anolyte additive. The constructed flowless AZBB mainly consists of two separate redox couples, including Zn/Zn(OH) 4 2- in alkaline anolyte and Br 2 /Br - in neutral media, where non-cations (e.g. OH - , Zn(OH) 4 2- , H 2 O,  and Br n - ) can be restricted to their respective chamber by the PES/SPEEK-M while cations can pass by. In the optimized system, good electrochemical performance is achieved, mainly including a surprising discharge voltage of 2.01 V, a high average Coulombic efficiency of 96.7%, and a good cycling life of ≈1000 cycles without obvious capacity decay at a fixed charge capacity of 2 mAh cm -2 ., (© 2024 Wiley‐VCH GmbH.)