Polymers
·
2019
·Vol. 11
·期 5
·843
·
IF 3.164
Kangjun Xie,Zhen Dong,Yicheng Wang,Wei Qi,Maolin Zhai,Long Zhao
A novel amphoteric ion exchange membrane (AIEM) was successfully prepared by one-step radiation grafting of sodium styrene sulfonate (SSS) and dimethylaminoethyl methacrylate (DMAEMA) onto ethylene-vinylalcohol copolymer (EVOH) powder and sequent transferring into film by casting method. Fourier transform infrared spectrometry (FT-IR), thermal gravimetric analyzer (TGA) and elemental analysis testified SSS and DMAEMA were successfully grafted onto EVOH. The ion exchange capacity, water uptake and proton conductivity of the resulting AIEM increased with grafting yield (GY). At the GY of 40.9%, the permeability of vanadium ions of AIEM was 3.98 × 10−7cm2min−1, which was better than Nafion117 membrane. Furthermore, the cost of this AIEM is much lower than that of Nafion117 membrane. This work provided a low cost and simple method for fabrication of the ion exchange membrane for vanadium redox flow battery (VRFB). Meanwhile, it also provided a new direction for the application of EVOH.Keywords:radiation grafting;ion exchange membrane;EVOH;VRFB
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2026
·
IF 5.1
Miao Qin,Tao Liu,Yimin Zhang,Hong Liu,Ling Ge
H 2 SO 4 -HCl mixed-acid vanadium electrolytes broaden the operating window and allow higher vanadium concentrations, yet the negative V 3+ /V 2+ reaction can remain kinetically sluggish and impose substantial polarization. Here, a small amount of BiCl 3 is introduced directly into the mixed-acid negative electrolyte so that metallic bismuth forms and deposits in situ on graphite felt during cell operation, without electrode pretreatment. UV–vis spectra show that adding BiCl 3 does not measurably change the characteristic V 3+ absorption features, indicating that the bulk vanadium speciation remains unchanged. After charging, plate-like Bi 0 deposits are observed on the carbon fibers, and the V 3+ /V 2+ redox reaction is clearly accelerated. Electrochemical measurements show that 0.02 mol·L −1 Bi 3+ is most effective. The redox peak separation decreases from 535.19 mV to 212.35 mV, and the charge-transfer resistance is substantially reduced. The exchange current density increases from 0.195 mA·cm −2 to 0.324 mA·cm −2 , and the standard rate constant increases from 2.021 × 10 −9 cm·s −1 to 3.358 × 10 −9 cm·s −1 . By comparison, the double-layer capacitance increases only from 0.572 mF·cm −2 to 0.641 mF·cm −2 , suggesting that the gain mainly comes from faster interfacial charge transfer rather than a simple increase in electrochemically accessible area. In single-cell tests from 40 to 160 mA·cm −2 , the Bi-containing electrolyte shows lower polarization and improved voltage and energy efficiencies.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2026
·
IF 5.5
Xueyan Ma,Tianmei Xu,Xinmeng Li,Qingcui Liu,Siyi Jing,Yudai Huang,Juan Ding,Weiwei Meng
Abstract Vanadium redox flow batteries (VRFBs) have garnered distinguished attention for their feasibility to enable cost-effective large-scale energy storage. Nonetheless, the electrochemical activity of electrodes is constrained during vanadium redox reactions, posing a problem for accomplishing high-performance VRFBs. Herein, we prepare a defect-rich Fe-coal-based carbon nanofiber electrode (Fe-ECNFs-600) via electrospinning followed by high-temperature carbonization. The Fe-ECNFs-600 contains moderate oxygen defects, Fe3O4 nanoparticles, and oxygen-containing functional groups, which can regulate the electronic structure, improve electrical conductivity, electrolyte wettability, and catalytic activity for the VO2+/VO2+ and V3+/V2+ redox couples. The VRFB with the Fe-ECNFs-600 electrode exhibits improved discharge capacity and energy efficiency compared with ECNFs-600 at 100 mA cm–2. This work may provide a defect regulation strategy for developing self-supporting electrode materials for VRFBs.
✓ 已验证
DOI
高影响因子
IONICS
·
2020
·Vol. 26
·期 6
·3147-3159
·
IF 2.394
Wei Xianli,Liu Suqin,Wang Jue,He Zhen,Zhao Kuangmin,Yang Yuliang,Liu Bingjun,Huang Rongjiao,He Zhangxing
The electrolyte, one of the key components for the energy storage in the vanadium redox flow battery (VRFB), hinders the further commercial applications of the VRFB due to the poor thermal stability of the positive electrolyte at the elevated temperature and the inferior activity on the interface of electrode. To enhance the performance of the positive electrolyte, a zwitterion-type molecule pyridinium propyl sulphobetaine (PPS) with negatively charged sulfonic group and positively charged pyridine group is adopted as the additive for the positive electrolyte. In this study, we have proved that PPS can be adsorbed on the electrode through sulfonic group and pyridine group under both positive potential and negative potential, which can effectively modify the interface of electrode. Compared to other additives containing –NH 2 /–SO 3 H groups, PPS containing pyridine group may effectively eliminate the side effects of protonation (–NH 3 + ) and intermolecular hydrogen bonding (-SO 3 − --- + H 3 N-) in acidic electrolyte. Moreover, the PPS-containing V(V) electrolyte presents a better stability at 50 °C compared to the blank V(V) electrolyte. As a consequence, with the addition of 1% PPS in positive electrolyte, the VRFB exhibits higher efficiencies (80.78% VE and 78.17% EE compared to 78.95% VE and 76.87% EE of the blank VRFB at 100 mA cm −2 ) and 76.28% capacity retention after 100 cycles which is 5.22% higher than that of the pristine VRFB. Herein, the study of zwitterion molecules provides a meaningful reference for the further research on organic additives for VRFB.
研究领域:
电化学
·
能源材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）