Preparation Of Bimetallic Alloy/Heteroatom Codoped Carbon Bifunctional Catalyst And Its Application In Zn-Air Battery

Zn-air batteries stand out among a series of energy storage system devices due to their high specific energy,low cost,non-polluting,safety and other advantages.The oxygen reduction reaction（ORR）and oxygen precipitation reaction（OER）are key electrochemical reactions in Zn-air batteries.The slow reaction kinetics of the ORR and OER impede their large-scale application.Therefore,it is urgently essential to develop inexpensive,efficient and stable bifunctional catalysts.According to literature reports,transition metal/heteroatom-doped carbon catalysts have excellent ORR/OER bifunctional catalytic activity,so the study of such catalyst is beneficial to the development of Zn-air batteries.Based on the above characteristics,this paper selects phenanthroline imidazole derivatives as ligands to coordinate with transition metals to obtain complex.The complex is mixed with the template to obtain a precursor.The precursor is pyrolyzed in two steps at high temperature to obtain the desired catalyst.In this paper,bifunctional electrocatalysts are preparation and studied.The main contents of this thesis are as follows:（1）Preparation and Zn-air battery performance of FeCo/N co-doped carbon bifunctional catalyst.1-hexyl-2-（3-aminophenyl）-1H-phenanthroline imidazole was used as a monomer to synthesize imidazolyl phenanthroline-containing polyaniline（PNIPA）by oxidative polymerization.The FeCo/N-C was prepared by the PNIPA with Co（OAc）₂·4H₂O and Fe（NO₃）₃·9H₂O,followed by mixing with melamine and ammonium carbonate then pyrolysis.The FeCo/N-C exhibited a higher ORR activity(E_o=0.975 V;E_1/2=0.87 V)and comparable OER activity(E_j=10=1.650 V).The FeCo/N-C based liquid Zn-air battery and flexible solid-state Zn-air battery exhibited high open-circuit voltage（1.52 V for liquid Zn-air battery;1.47 V for flexible solid-state Zn-air battery）,high power density(142 mW cm^-2 for liquid Zn-air battery;89 mW cm^-2 for flexible solid-state Zn-air battery),high specific capacity(813 mAh g_Zn^-1 at 5.0 mA cm^-2 for liquid Zn-air battery;609 mAh g_Zn^-1 at 2.0 mA cm^-2 for flexible solid-state Zn-air battery)and remarkable durability（900 h for liquid Zn-air battery;80 h for flexible solid-state Zn-air battery）,respectively.（2）Preparation and Zn-air battery performance of FeNi/N/S co-doped carbon bifunctional catalyst.1,4-bis（1-hexyl-1H-imidazole[4,5-f][1,10]phenanthroline-2-yl）benzene（HIPB）was synthesized by 1,10-phenanthroline-5,6-dione.The FeNi/NS-C was prepared by the HIPB with Ni（NO₃）₂·6H₂O and Fe（NO₃）₃·9H₂O,followed by mixing with trithiocyanuric acid then pyrolysis.The FeNi/NS-C showed comparable ORR activity to Pt/C(E_1/2=0.87 V)and excellent OER activity to Ir O₂(E_j=10=1.585V).The FeNi/NS-C based liquid Zn-air battery and flexible solid-state Zn-air battery exhibited high open-circuit voltage（1.49 V for liquid Zn-air battery,1.37 V for flexible solid-state Zn-air battery）,high power density(144 mW cm^-2 for liquid Zn-air battery;112 mW cm^-2 for flexible solid-state Zn-air battery),high specific capacity(821 mAh g_Zn^-1 at 5.0 mA cm^-2 for liquid Zn-air battery;722 mAh g_Zn^-1 at2.0 mA cm^-2 for flexible solid-state Zn-air battery)and remarkable durability（1010 h for liquid Zn-air battery;70 h for flexible solid-state Zn-air battery）,respectively.