摘要
高效耐用的双功能氧电催化剂对于先进的可充电锌空气电池至关重要.然而,发展氧还原反应(ORR)/析氧反应(OER)双功能电催化剂的障碍在于ORR和OER对催化材料的要求不同.本工作通过合理筛选目标ORR/OER组分并精确控制其电子结构,制备了La_(0.75)Sr_(0.25)Mn0.5X0.5-O_(3)(X=Co、Ni和Fe)钙钛矿纳米颗粒,其中La_(0.75)Sr_(0.25)Mn0.5Fe0.5O_(3)(LSFMO)具有优异的ORR性能(Eonset=0.932 V,n=3.59),同时表现出了显著增强的OER电催化活性(Ej=10=1.658 V,过电位=428 mV),实现了出色的双功能特性(ΔE=0.94 V).此外,密度泛函理论计算表明,部分取代后产生的Mn和Fe双位点对电催化过程具有显着的协同作用.可充锌空气电池展现出前所未有的小充放电电压极化(0.76 V)、高度可逆性和长充放电循环稳定性(60 h).如此优异的结果表明,掺杂铁的锰基钙钛矿无疑是用于可充电锌空气电池非常有前途的双功能电催化剂.
Efficient and durable bifunctional oxygen electrocatalysts are critical for advanced rechargeable zinc-air(Zn-air) batteries.However,the obstacle to the development of bifunctional electrocatalysts for the oxygen reduction reaction(ORR)/oxygen evolution reaction(OER) lies in the different requirements of the ORR and OER for catalytic materials.Herein,La_(0.75)Sr_(0.25)Mn0.5X0.5O_(3)(X=Co,Ni,and Fe) perovskite nanoparticles were created by rationally screening targeted ORR/OER components and precisely controlling their electronic structures to achieve bifunctional oxygen electrocatalysis,in which La_(0.75)Sr_(0.25)Mn0.5Fe0.5O_(3)(LSFMO) displayed superior ORR performance(Eonsetof 0.932 V and n of 3.59)and significantly enhanced electrocatalytic activity in the OER process(an Ej=10 of 1.658 V and overpotential of 428 mV),corresponding to excellent bifunctional properties(ΔE=0.94 V).Furthermore,density functional theory(DFT) calculations demonstrated that Mn and Fe dual sites generated by partial substitution had a significant synergistic effect on the electrocatalytic process.The rechargeable Zn-air batteries delivered an unprecedented small charge-discharge voltage polarization(0.76 V),high reversibility and stability over many charge-discharge cycles(60 h).These excellent results demonstrate that Mn-based perovskites with Fe doping are undoubtedly promising bifunctional electrocatalysts for rechargeable Zn-air batteries.
作者
税子怡
田慧英
于思乐
肖航
赵炜
陈曦
Ziyi Shui;Huiying Tian;Sile Yu;Hang Xiao;Wei Zhao;Xi Chen(School of Chemical Engineering,Northwest University,Xi’an 710069,China;Earth Engineering Center,Center for Advanced Materials for Energy and Environment,Department of Earth and Environmental Engineering,Columbia University,New York NY10027,USA)
基金
supported by the Earth Engineering Center and Center for Advanced Materials for Energy and Environment at Columbia University,the School of Chemical Engineering,Northwest University,the National Natural Science Foundation of China(11872302)
the Natural Science Project of Shaanxi Provincial Department of Education(20JK0927).
