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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.)

Aqueous zinc-bromine batteries (ZBBs) are highly promising because of the advantages of safety and cost. Compared with flow ZBBs, static ones without the assistance of pumping and tank components possess decreased cost and increased energy density and efficiency. Yet, the issues of Zn dendrites and shuttle effect of polybromide ions (Br n - ) are more serious in nonflow ZBBs. Meanwhile, the hydrogen evolution reaction (HER) and the sluggish kinetics of the Br 2 /Br - couple are also in-negligible. Herein, a compressive approach, the cation-exchange membrane (CEM) coating on Zn anodes and N-defect decoration toward carbon felt cathodes, is developed. The CEM with cation-only function can inhibit the formation of Zn dendrites via tuning the Zn 2+ flow at the interface, block the noncationic substances, and hence prevent the shuttle of Br 2 /Br n - and the water decomposition-concerned HER. The optimized nonflow ZBBs can deliver high Coulombic, voltage, and energy efficiencies of 94.1, 92.8, and 87.4%, respectively, which can be well remained in 1000 cycles. Meanwhile, the output voltage is as high as 1.7 V at 10 mA cm -2 with a high areal capacity of 2 mA h cm -2 , and a LED with a rated voltage of 1.6 V can be powered successfully, exhibiting high application value.

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.)

Herein, an efficient method to prepare sulfonated polyether ether ketone (SPEEK) based cation exchange membranes (CEMs) is developed, where polyethersulfone (PES) is used as an additive. The optimized membrane of 30 wt.%PES/SPEEK-M exhibits a rather low anion permeability and a high ionic conductivity of 9.52 mS cm -1 together with low volume swelling in water. Meanwhile, tensile strength of the membrane is as high as 31.4 MPa with a tensile strain of 162%. As separators for aqueous K-ion batteries (AKIBs) with decoupled gel electrolytes (Zn anode in alkaline and Prussian blue (FeHCF) cathode in neutral). Discharge voltage of the AKIB can reach 2.3 V. Meanwhile, Zn dendrites can be effectively suppressed in the gel anolyte. Specific capacities of the FeHCF cathode are 116.7 mAh g -1 at 0.3 A g -1 (close to its theoretical value), and 95.0 mAh g -1 at 1.0 A g -1 , indicating good rate performance. Capacity retention of the cathode is as high as 91.2% after 1000 cycles' cycling owing to the well remained neutral environment of the catholyte. There is almost no pH change for the catholyte after cycling, indicating good anion-blocking or cation-selecting ability of the 30 wt.%PES/SPEEK-M, much better than other membranes., (© 2022 Wiley-VCH GmbH.)

Alkaline nickel-zinc (Ni-Zn) batteries, as traditional rechargeable aqueous batteries, possess an obvious advantage in terms of energy density, but their development has been hindered by the anode-concerned problems, Zn dendrites, self-corrosion, passivation, deformation, and hydrogen evolution reaction (HER). Herein, to solve these problems, a dual protective strategy is proposed toward the anode using ZnO as an initial active material, including a C coating on ZnO (ZnO@C) and a thin poly(vinyl alcohol) (PVA) layer coating on the electrode (ZnO@C-PVA). In a three-electrode configuration, the reversible capacity can reach 600 mAh g -1 for the ZnO@C-PVA. Using excessive commercial Ni(OH) 2 as the cathode, the alkaline Ni-Zn cells exhibit good electrochemical performance: Discharge capacity can be as high as 640-650 mAh g -1 at 4 A g -1 with a Coulomb efficiency (CE) as high as 97-99% after activity, suggesting low self-corrosion and HER. Capacity retention is 97% after 1200 cycles, indicating rather good durability. The discharge capacity is even slightly increased with the increase of charge/discharge current density (≤8 A g -1 ), implying good rate performance. Additionally, the discharge voltage can reach 1.8 V (midpoint value) at various current densities, reflecting the fast reaction kinetics of the anode. Most importantly, no Zn dendrites and passivation are observed after long-term cycling. The strategy proposed here can solve the anode-concerned problems effectively, exhibiting a high application prospect.

Determination of phytate and phosphate by suppressed conductivity ion chromatography was investigated. Plant samples were extracted with 1% (mass fraction) trichloroacetic acid (TCA). After centrifugal settling, the supernatant was filtered with a 0.45 microm filter membrane before injected into the ion chromatographic system and detected by suppressed conductivity. The gradient eluent was composed of 0.22 mol/L sodium hydroxide solution, water and 50% (v/v) isopropyl alcohol solution. Phytate and phosphate were determined within 15 min, and no interference was found in the presence of fluorate, chlorate, nitrate, sulphate and TCA. Good linearities for phytate and phosphate were obtained in the ranges of 5-400 mg/L (r2 = 0.9994) and 5-500 mg/L (r2 = 0.9999), and the detection limits (S/N = 3) were 3.5 mg/L and 1.5 mg/L, respectively. The average recoveries for phytate and phosphate were 99.8% and 98.4%, and their relative standard deviations were 1.98% and 2.09%, respectively.