Fabrication of a Cation Exchange Membrane with Largely Reduced Anion Permeability for Advanced Aqueous K‐ion Battery in an Alkaline‐Neutral Electrolyte Decoupling System

Abstract

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.

Sustainable Electrochemical Activation of Self-Generated Persulfate for the Degradation of Endocrine Disruptors: Kinetics, Performances, and Mechanisms

“…To provide further insight into the individual contributions of the anode and ca reactions in the BDD and ACF electrolysis system, we conducted additional investig on the degradation behavior of BPA in a divided cell configuration. The experimen up and electrode materials were identical to those used in the undivide configuration, with the exception of the incorporation of a cation exchange membr impede the migration of anions such as SO4 2− and S2O8 2− [37]. As illustrated in Figu the removal of BPA in the divided cell system was primarily attributed to anode oxi in the anode chamber, while adsorption and activation of reactive oxygen species o Prior research has demonstrated that BDD anodes have the capability to generate S 2 O 8 2− (Equation ( 2)) [38], while ACF cathodes are considered a promising candidate for both H 2 O 2 generation (Equation ( 3)) [39] and S 2 O 8 2− activation (Equation ( 4)) [40].…”

Achievement of Efficient and Stable Nonflow Zinc–Bromine Batteries Assisted by Rational Decoration upon the Two Electrodes

“…In our group, PES/SPPEK with good cation-selective ability and low volume variation has been optimized, which can block Br 2 / Br n − , H 2 O, and other noncations effectively. 37 Toward the issue of Zn dendrites, various strategies, such as anode structure modulation, anode/electrolyte interface engineering, and electrolyte additive tuning, have been tried in Zn-based aqueous systems, e.g., Zn||MnO 2 and Zn||V 2 O 5 cells. 38−42 Yet, few efforts have been made in NF-ZBBs.…”

“…Very recently, sulfonated polyether ether ketone (SPEEK)-based membranes famous for low cost, good mechanical properties, and rich polar functional groups have been developed as CEMs . Pure SPEEK or its composites (e.g., C/SPEEK, SiO 2 /SPEEK, and poly­(ether sulfone) (PES)/SPPEK) have been fabricated as CEMs. In our group, PES/SPPEK with good cation-selective ability and low volume variation has been optimized, which can block Br 2 /Br n – , H 2 O, and other noncations effectively …”

“…Pure SPEEK or its composites (e.g., C/SPEEK, SiO 2 /SPEEK, and poly­(ether sulfone) (PES)/SPPEK) have been fabricated as CEMs. In our group, PES/SPPEK with good cation-selective ability and low volume variation has been optimized, which can block Br 2 /Br n – , H 2 O, and other noncations effectively …”

Construction of Cation‐Sieving Function Layers Enabling Dendrite‐Free Zinc Metal Anodes for Durable Aqueous Systems

“…[1] Nevertheless, in some specific situations with strict requirements on safety, power density as well as eco-friendliness, LIBs are still far from satisfactory, wherein aqueous-based systems seem to possess much better application prospects. Among DOI: 10.1002/smtd.202300799 the state-of-the-art aqueous batteries, including those using NH 4+ , [2] K + , [3] Zn 2+ , [4] Ca 2+ , [5] Mg 2+ , [6] and Al 3+ , [7] etc. as carriers, aqueous Zn-ion batteries (ZIBs) are considered as the most promising candidates due to the advantages of Zn anodes, mainly including high theoretical specific capacity (820 mAh g −1 and 5855 mAh cm −3 ), low working potential (−0.76 V vs SHE), high overpotential for the hydrogen evolution reaction (HER), and abundant reserves.…”