Porous PVA skin-covered thin Zirfon-type separator as a new approach boosting high-rate alkaline water electrolysis beyond 1000 hours’ lifespan
Xi Luo,
Nengneng Xu,
Yongnan Zhou,
Xiaohui Yang,
Woochul Yang,
Guicheng Liu,
Joong Kee Lee,
Jinli Qiao
Affiliations
Xi Luo
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
Nengneng Xu
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
Yongnan Zhou
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
Xiaohui Yang
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China
Woochul Yang
Department of Physics, Dongguk University, Seoul 04620, Republic of Korea
Guicheng Liu
School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing 100096, China
Joong Kee Lee
Dept. of Chemical & Biochemical Eng, Gachon University, 1342 Seongnam-daero, Seongnam-si 13120, Republic of Korea
Jinli Qiao
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; Corresponding author.
Regulating the pore structure of a zirfon-based diaphragm is critical to promoting a high-rate alkaline electrolyzer, but it is still a big challenge to respond “trade-off” between the thickness of the diaphragm and the current density/gas barrier behavior. In this work, a porous hydrophilic skin layer with ∼μm thick of polyvinyl alcohol (PVA) has been successfully constructed and casted onto the thin zirfon-type separator composite (V-Zirfon-350 μm). The V-Zirfon-350 μm separator generates a high KOH uptake (> 90%), low area resistance (0.2026 Ω cm2) but a low electrolyte permeation flux density (5.2 × 10−4 mL cm−2 s−1 at 0.5 bar), which largely surpasses the state-of-the-art commercial Zirfon UTP-500 μm diaphragm. When coupled with Raney Ni cathode and NiCoMo-LDH anode catalysts, the V-Zirfon-350 μm separator offers a high current density over 1300 mA cm−2 @2.0 V (80 °C in 30% KOH) and a superior stability of 300 h under 800 mA cm−2 for alkaline water electrolysis (AWE). Specifically, the voltage is merely ∼3.5 V for two electrolytic cells connected in series, which can be even conducted for more than 1300 h at different operational conditions. This work provides a novel methodology for the practical application of a thin Zirfon-based diaphragm.
