五氧化二钒电解制备全钒液流电池V^(3+)电解液

Synthesis of V^(3+) Electrolyte by Electrochemical Reducing Vanadium Pentoxide

电解液的质量直接决定了全钒液流电池的储电能力。为了降低全钒液流电池的生产成本,在国内首次采用流动型电解槽电解还原法,研究了采用相对廉价的五氧化二钒(V2O5)代替价格昂贵的硫酸氧钒(VOSO4)为原料制备全钒液流电池电解液的制备技术;研究了阳极电极材料、电解电流密度等对制备电解液的影响因素;并通过循环伏安、交流阻抗和充放电测试分析和比较由两种原料制备的电解液的电化学性能。实验结果表明:以Ru Ir/Ti为阳极,多孔铅板为阴极,3 mol·L-1 H2SO4为阳极电解液,1.5 mol·L-1 V2O5+3 mol·L-1 H2SO4粉末混合溶液为阴极电解液,40 m A·cm-2恒流电解得到的电解液不但具有良好的电化学活性和可逆性,且电流效率高和电能损耗低,完全可以满足全钒液流电池的工作需求。

The storage capacity of all vanadium redox flow baterry （VFB） is determined by the quality of its electrolyte directly. In order to reduce the production costs of VFB, inexpensive raw materials should be used in the electrolyte preparation process. Compared with vanadyl sulfate （VOSO4）, Vanadium pentoxide（V2O5） is a cost-effective alternative. It was employed to prepare the VFB electrolyte using flow electrolyzer electrolytic reduction techniques. The influential factors on the electrolytic preparation, such as the anode electrode material and the electrolytic current density, were investigated in this paper. The electrolyte prepared from two different raw materials, respectively, was evaluated for its electrochemical performance by cyclic voltammetry, AC impedance and charge-discharge test. Experimental results indicate that： Ruthenium iridium coated titanium based electrode （Rulr/Ti） as an anode, regarding the porous lead plate as a cathode, 3 mol.L-1 H2804 as an anode electrolyte, and 1.5 mol.L-1 V205 ＋ 3 mol.L-1 H2SO4 mixed solution as a cathode electrolyte, 40 mA.cm-2 constant current electrolysis electrolyte has not only good electrochemical activity and reversibility, but also high current efficiency and low power loss. It can meet the needs of the VFB.