Yin Xunkai, Zhang Zichun, Yao Kequan, Xu Xinxin, Wang Yun
Department of Chemistry, College of Science, Northeastern University, 110819, Shenyang City, Liaoning Province, P. R. China.
Institute for Frontier Technologies of Low-Carbon Steelmaking, Northeastern University, 110819, Shenyang, Liaoning, P. R. China.
Chemistry. 2021 Jun 16;27(34):8774-8781. doi: 10.1002/chem.202100412. Epub 2021 May 13.
Zn-air batteriesare a perspective power source for grid-storage. But, after they are discharged at1.1 to 1.2 V, large overpotential is required for their charging (usually 2.5 V). This is due to a sluggish oxygen evolution reaction (OER). Incorporating organic pollutants into the cathode electrolyte is a feasible strategy for lowering the required charging potential. In the discharge process, the related oxygen reduction reaction, hydrophobic electrocatalysts are more popular than hydrophilic ones. Here, a hydrophobic bifunctional polyoxometalate electrocatalyst is synthesized by precise structural design. It shows excellent activities in both bisphenol A degradation and oxygen reduction reactions. In bisphenol A containing electrolyte, to achieve 100 mA ⋅ cm , its potential is only 1.32 V, which is 0.34 V lower than oxygen evolution reaction. In the oxygen reduction reaction, this electrocatalyst follows the four-electron mechanism. In both bisphenol A degradation and oxygen reduction reactions, it shows excellent stability. With this electrocatalyst as cathode material and bisphenol A containing KOH as electrolyte, a Zn-air battery was assembled. When "charged" at 85 mA ⋅ cm , it only requires 1.98 V. Peak power density of this Zn-air battery reaches 120.5 mW ⋅ cm . More importantly, in the "charge" process, bisphenol A is degraded, which achieves energy saving and pollutant removal simultaneously in one Zn-air battery.
锌空气电池是一种很有前景的电网储能电源。但是，在它们以1.1至1.2伏放电后，充电时需要很大的过电位（通常为2.5伏）。这是由于析氧反应（OER）缓慢所致。将有机污染物加入阴极电解液是降低所需充电电位的一种可行策略。在放电过程中，对于相关的氧还原反应，疏水电催化剂比亲水电催化剂更受欢迎。在此，通过精确的结构设计合成了一种疏水性双功能多金属氧酸盐电催化剂。它在双酚A降解和氧还原反应中均表现出优异的活性。在含有双酚A的电解液中，要达到100毫安·平方厘米，其电位仅为1.32伏，比析氧反应低0.34伏。在氧还原反应中，这种电催化剂遵循四电子机制。在双酚A降解和氧还原反应中，它都表现出优异的稳定性。以这种电催化剂作为阴极材料，以含有双酚A的氢氧化钾作为电解液，组装了一个锌空气电池。当以85毫安·平方厘米“充电”时，它仅需要1.98伏。这种锌空气电池的峰值功率密度达到120.5毫瓦·平方厘米。更重要的是，在“充电”过程中，双酚A被降解，这在一个锌空气电池中同时实现了节能和污染物去除。
