Genetically evolved graphene encapsulated random alloy nanoparticles for Li-Air battery

We conducted an extensive investigation into graphene-encapsulated monometallic (Fe, Co, and Ni) and bime-tallic random alloy (FeCo, FeNi, and CoNi) systems for their potential application as highly efficient catalysts in Li-air battery technology. Through meticulous calculations and analyses, we identified the Co@C system as the most exceptional catalyst among the monometallic counterparts. This system exhibited particle-type growth of the discharging product along with a moderate intermediate binding energy. Furthermore, employing the powerful genetic algorithm (GA) method, we explored a vast array of approximately 800-1200 structures to unveil stable random alloy systems. Our investigation led us to the discovery of the remarkable FeCo@C catalyst, presenting a Co-rich surface, Despite the elemental dominance on the catalyst surfaces, we observed the binding of intermediates occurring at ensemble sites involving two elements. Notably, the FeCo@C system emerged as the superior catalyst among both monometallic and bimetallic systems. It displayed a pronounced preference for particle-type growth and showcased the weakest binding energy for Li3O4, thereby demonstrating exceptional catalytic activity. Additionally, we performed an in-depth analysis comparing the overall potential difference from the reaction energy diagram with the individual potential differences during the Li2O2 formation and decomposition sequence. We established the critical significance of comparing individual potential differences in Li-air battery studies to ensure the preservation of detailed information and maintain the predictive power necessary for suggesting novel and efficacious catalysts. In summary, our groundbreaking study provides invaluable insights into the remarkable performance of graphene-encapsulated monometallic and bimetallic catalysts in Li-air batteries. The Co@C catalyst excelled among the monometallic systems, while the FeCo@C catalyst showcased unparalleled activity within both monometallic and bimetallic systems. Our findings un-derscore the utmost importance of meticulously considering individual potential differences to drive forward the development of highly efficient catalysts for transformative Li-air battery applications.