Achieving efficient and inexpensive vanadium flow battery by combining CexZr1-xO2 electrocatalyst and hydrocarbon membrane
Achieving efficient and inexpensive vanadium flow battery by combining CexZr1-xO2 electrocatalyst and hydrocarbon membrane
复制标题
CexZr1-xO2电催化剂与碳氢化合物膜相结合实现高效、廉价的钒液流电池
DOI：
10.1016/j.cej.2018.09.069
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发表时间：
2019
影响因子：
15.1
通讯作者：
Xi Jingyu
中科院分区：
文献类型：
--
作者：
Yu Lihong;Un Feng;Xiao Wangdong;Xu Ling;Xi Jingyu
钒液流电池（VFB）具有无限容量和超长寿命的特点，是最有前途的电网规模储能技术之一。提高能效和降低成本是VFB技术实际应用的关键。VFB的效率和成本主要取决于电极和质子传导膜等关键材料。在此，我们报告了使用高活性氧化铈-氧化锆混合氧化物修饰的石墨毡（CexZr 1 − xO 2/GF）电极与高质子选择性磺化聚醚醚酮（SPEEK）膜相结合，以实现高效和廉价的VFB。CexZr 1 − xO 2电催化剂可以改善GF电极对电解液的润湿性和对VO 2 +/VO 2+和V2+/V3+氧化还原电对的电化学活性，从而显著提高VFB的电压效率（VE）。另一方面，SPEEK膜可以有效地抑制钒离子的渗透，从而大大提高VFB的库仑效率（CE）。因此，CexZr 1 − xO 2/GF-SPEEK组合显示出比传统GF-Nafion组合更优越的上级电池效率（CE、VE和EE）和循环稳定性。同时，由于碳氢化合物基SPEEK膜比商业Nafion膜便宜得多，VFB的成本也显著降低。
Vanadium flow battery (VFB) is one of the most promising technologies for grid scale energy storage because of its unlimited capacity and ultralong lifespan. Improving energy efficiency (EE) and reducing cost are critical to the practical application of VFB. The efficiency and cost of VFB mainly depend on its key materials such as electrode and proton-conducting membrane. Herein, we report the use of highly active ceria–zirconia mixed oxide decorated graphite felt (CexZr1−xO2/GF) electrodes in combination with a high proton-selective sulfonated poly(ether ether ketone) (SPEEK) membrane to achieve efficient and inexpensive VFB. CexZr1−xO2electrocatalysts can improve the electrolyte wettability and electrochemical activity of the GF electrode towards VO2+/VO2+and V2+/V3+redox couples, leading to remarkably enhanced voltage efficiency (VE) of VFB. On the other hand, SPEEK membrane can effectively suppress the crossover of vanadium ions, resulting in greatly improved coulombic efficiency (CE) of VFB. As a result, the CexZr1−xO2/GF-SPEEK combination demonstrates superior battery efficiencies (CE, VE and EE) and cycling stability to the traditional GF-Nafion combination. Meanwhile, since hydrocarbon-based SPEEK membrane is much cheaper than commercial Nafion membrane, the cost of VFB is also significantly reduced.