Effect of Fe(III) on the positive electrolyte for vanadium redox flow battery
Effect of Fe(III) on the positive electrolyte for vanadium redox flow battery
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Fe(III)对全钒液流电池正极电解液的影响
DOI：
10.1098/rsos.181309
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发表时间：
2019-01-01
影响因子：
3.5
通讯作者：
Yuan, Yizhong
中科院分区：
文献类型：
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作者：
Ding, Muqing;Liu, Tao;Yuan, Yizhong
研究Fe（III）对正极电解液的影响，为钒电解液的制备和使用提供一些实用的指导意义。研究了Fe（III）对钒氧化还原液电池（VRFB）正电解质热稳定性和电化学行为的影响。当Fe（III）浓度高于0.0196 mol l−1时，V(V)电解质的热稳定性受到破坏，V（IV）物质的扩散系数从（2.06 ~ 3.33）× 10−6 cm2 s−1降低到（1.78 ~ 2.88）× 10−6 cm2 s−1，正极电解质表现出更高的电解质电阻和电荷转移电阻。此外，Fe（III）可能导致副反应和容量衰退，这将对电池的应用产生不利影响。随着Fe（III）含量的增加，钒离子与Fe（III）的碰撞概率和与氧化还原反应的竞争加剧，会干扰电极反应，影响钒离子的扩散，影响VRFB的性能。因此，本研究为钒电解液制备和使用过程中，将Fe（III）杂质控制在0.0196 mol l−1以下提供了一定的实践指导。
It is important to study the effect of Fe(III) on the positive electrolyte, in order to provide some practical guidance for the preparation and use of vanadium electrolyte. The effect of Fe(III) on the thermal stability and electrochemical behaviour of the positive electrolyte for the vanadium redox flow battery (VRFB) was investigated. When the Fe(III) concentration was above 0.0196 mol l−1, the thermal stability of V(V) electrolyte was impaired, the diffusion coefficient of V(IV) species decreased from (2.06–3.33) × 10−6 cm2 s−1 to (1.78–2.88) × 10−6 cm2 s−1, and the positive electrolyte exhibited a higher electrolyte resistance and a charge transfer resistance. Furthermore, Fe(III) could result in the side reaction and capacity fading, which would have a detrimental effect on battery application. With the increase of Fe(III), the collision probability of vanadium ions with Fe(III) and the competition with the redox reaction was aggravated, which would interfere with the electrode reaction, the diffusion of vanadium ions and the performance of VRFB. Therefore, this study provides some practical guidance that it is best to bring the impurity of Fe(III) below 0.0196 mol l−1 during the preparation and use of vanadium electrolyte.