Gaseous Nitrogen Oxides Catholyte for Rechargeable Redox Flow Batteries
Gaseous Nitrogen Oxides Catholyte for Rechargeable Redox Flow Batteries
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用于可充电氧化还原液流电池的气态氮氧化物阴极电解液
DOI：
10.1002/anie.202216889
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Zhang, Shiyu
中科院分区：
文献类型：
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作者：
Zhang, Weiyao;Yang, Xin;Zhang, Shiyu
寻找易溶的氧化还原化合物来提高氧化还原液流电池(RFB)的能量密度一直是人们研究的热点。然而，高溶质浓度往往会对电解液的性能产生负面影响。在这里，我们设计了一种高电位(0.5 V对Ag/Ag+)的RFBS阴极，其中充电和放电的物种都是气态氮氧化物(NOx)。这些物种可以从液体电解液中释放出来并储存在单独的气体容器中，从而在不增加电解液的浓度和体积的情况下扩大存储容量。在NO_3-−存在下，NO的氧化生成N_2O_3，而N_2O_3的还原生成NO和NO_3-−，共同提供电化学反应：NO_3-−+3- -NO-⇌-2- -N_2O_3+e-−，其低质量/电荷比为152 克/摩尔储存电子。概念验证NOx对称型H电池在400 小时内表现出200个稳定的循环，库仑效率为97 %，容量衰减可以忽略不计。
There is a strong interest in finding highly soluble redox compounds to improve the energy density of redox flow batteries (RFBs). However, the performance of electrolytes is often negatively influenced by high solute concentration. Herein, we designed a high‐potential (0.5 V vs. Ag/Ag+) catholyte for RFBs, where the charged and discharged species are both gaseous nitrogen oxides (NOx). These species can be liberated from the liquid electrolyte and stored in a separate gas container, allowing scale‐up of storage capacity without increasing the concentration and volume of the electrolyte. The oxidation of NO in the presence of NO3−affords N2O3, and the reduction of N2O3regenerates NO and NO3−, together affording the electrochemical reaction: NO3−+3 NO⇌2 N2O3+e−with a low mass/charge ratio of 152 grams per mole of stored electron. A proof‐of‐concept NOxsymmetric H‐cell shows 200 stable cycles over 400 hours with >97 % Coulombic efficiency and negligible capacity decay.