Notably enhanced proton conductivity by thermally-induced phase-separation transition of Nafion/ Poly(vinylidene fluoride) blend membranes

TY - JOUR

T1 - Notably enhanced proton conductivity by thermally-induced phase-separation transition of Nafion/ Poly(vinylidene fluoride) blend membranes

AU - Yang, Xueqi

AU - Zhu, Haijin

AU - Jiang, Fengjing

AU - Zhou, Xinjie

N1 - Publisher Copyright: © 2020 Elsevier B.V.

PY - 2020/10/15

Y1 - 2020/10/15

N2 - Blending perfluorosulfonic acid (e.g. Nafion) with other polymers is an effective approach to reduce the cost and adjust the properties of durable proton conducting membranes. In particular, poly(vinylidene fluoride) (PVDF) composites have attracted much attention because of its outstanding chemical/thermal stability and it can enhance the barrier property, mechanical strength and processibility of the membranes. One of the major issues with this approach, however, is that the proton conductivity of the Nafion/PVDF composite drops rapidly with increasing PVDF content. In this work, we demonstrate for the first time that through a simple and facile annealing process at 180 °C, the proton conductivity of the Nafion/PVDF blend membrane can be boosted by more than 200%, and the annealed membrane with 60 wt% Nafion shows proton conductivity as high as 45.2 mS cm−1. The barrier properties of the blend membranes are significantly superior to the neat Nafion as indicated by the vanadium ion permeability of approximately one third of the Nafion. In the single cell test of vanadium redox flow battery, the energy efficiency of the annealed membrane with 60 wt% Nafion reaches 83.6% at 100 mA cm−2, which is comparable to Nafion membranes. The annealed blend membranes possess a high chemical and dimensional stability, which makes them promising for practical applications in redox flow batteries or fuel cells.

AB - Blending perfluorosulfonic acid (e.g. Nafion) with other polymers is an effective approach to reduce the cost and adjust the properties of durable proton conducting membranes. In particular, poly(vinylidene fluoride) (PVDF) composites have attracted much attention because of its outstanding chemical/thermal stability and it can enhance the barrier property, mechanical strength and processibility of the membranes. One of the major issues with this approach, however, is that the proton conductivity of the Nafion/PVDF composite drops rapidly with increasing PVDF content. In this work, we demonstrate for the first time that through a simple and facile annealing process at 180 °C, the proton conductivity of the Nafion/PVDF blend membrane can be boosted by more than 200%, and the annealed membrane with 60 wt% Nafion shows proton conductivity as high as 45.2 mS cm−1. The barrier properties of the blend membranes are significantly superior to the neat Nafion as indicated by the vanadium ion permeability of approximately one third of the Nafion. In the single cell test of vanadium redox flow battery, the energy efficiency of the annealed membrane with 60 wt% Nafion reaches 83.6% at 100 mA cm−2, which is comparable to Nafion membranes. The annealed blend membranes possess a high chemical and dimensional stability, which makes them promising for practical applications in redox flow batteries or fuel cells.

KW - Blend membrane

KW - Fuel cell

KW - Phase separation

KW - Proton exchange membrane

KW - Vanadium redox flow battery

UR - http://www.scopus.com/inward/record.url?scp=85088319259&partnerID=8YFLogxK

U2 - 10.1016/j.jpowsour.2020.228586

DO - 10.1016/j.jpowsour.2020.228586

M3 - 文章

AN - SCOPUS:85088319259

SN - 0378-7753

VL - 473

JO - Journal of Power Sources

JF - Journal of Power Sources

M1 - 228586

ER -