研究全钒液流电池的质子传导膜制备过程,提出高分子亲水/疏水相互作用诱导溶液相分离的成膜原理,进行制膜工艺放大,满足全钒液流电池的电堆制造与储能工程应用需要.突破现有＂离子交换＂传质机理的限制,利用电解液中不同价态钒离子与氢离子相比,存在体积和荷电量的差异,通过离子＂筛分＂和＂静电排斥＂效应进行离子选择性渗透.制成孔径分布在4~7 nm的聚偏氟乙烯质子传导膜,电导率为3.5×10-2S·cm-1,爆破强度高于0.3 MPa,面积800 mm×900 mm.利用扩散实验测定膜对H＋/VO2＋离子选择性,选择性系数达到306.利用该质子传导膜组装的15 k W电堆,充电/放电循环性能稳定,电流密度达到100 m A·cm-2,在700多个循环过程电流效率为93%,能量效率超过72%,具备产业化应用前景.
To reduce the energy consumption of the electrolytic hydrogen generation process, we propose a novel approach to generate hydrogen with acidic/alkaline amphoteric water electrolysis, wherein hydrogen is produced inside an acidic solution and oxygen evolved under alkaline condition, and a membrane is employed in the middle of the electrolyzer to restrain neutralization. The electrode polarization is greatly reduced due to the specific arrangement of the acidic/alkaline amphoteric electrolyzer. The rate of hydrogen production achieves over four times higher than that of the alkaline aqueous solution at 2.2 V, and the energy consumption is reduced approximately 30% under the current density of 200 m A/cm ^2. The investigation of transmembrane potential drop indicates water splitting on the membrane surfaces, which compensates for acid or alkaline loss on-site and maintains the concentration approximately constant during electrolysis process. The acidic/alkaline amphoteric water electrolysis is promising as an energy saving, clean and sustainable hydrogen production technology.
