硅酸盐学报2025，Vol.53Issue(7)：1816-1821,6.DOI:10.14062/j.issn.0454-5648.20240822
中性锌空气电池催化剂的理论设计
Theoretical Design of Catalysts for Neutral Zinc-Air Batteries
摘要
Abstract
Introduction Zinc-air batteries have a significant promise for next-generation energy storage due to their low cost,high safety,high theoretical capacity,and abundant availability.Recently,we reported a new rechargeable zinc-air battery based on zinc peroxide chemistry.Compared to conventional zinc-air batteries,this neutral zinc-air battery exhibits higher reversibility and stability,making it a more promising candidate for secondary zinc-air batteries.However,the low energy efficiency of neutral zinc-air batteries remains a challenge.And the mechanism of these neutral zinc-air battery reactions is still unclear.In this work,we systematically investigated the reaction pathways of neutral zinc-air reaction by first-principles calculations. Methods Density Functional Theory calculations based on a software package named VASP was employed with PAW potentials and the PBE functional.The vdW interactions were corrected by the Grimme's D3 method.The k-point mesh was generated by the Monkhorst-Pack scheme via Pymatgen with MPRelaxSet settings.A cutoff energy of 520 eV was utilized within a convergence criterion of 10-5 eV for self-consistent calculations.The convergence criterion for ionic relaxation was set to be 0.02 eV/Å.The calculations were performed by a slab model with a thickness of approximately 10 Å and a vacuum layer of greater than 15 Å. Results and discussion There is a clear linear scaling relationship among the adsorption strengths of O*,ZnO2*,and ZnO4* in neutral zinc-air reactions.This relationship constrains the freedom in catalyst design,making it difficult to optimize all intermediate adsorption strengths simultaneously.Breaking this linear scaling relationship will be a focus of future research.The rate-determined step for both the four-electron and two-electron reactions in Ag(111)is the first electron transfer.A weaker ZnO4* adsorption makes the first reaction barrier as high as 0.78 eV at 1.2 V(vs.Zn/Zn2+).This result indicates that even with this metal catalyst,the discharge voltage of neutral zinc-air batteries remains smaller than that of alkaline batteries due to the limitation of linear scaling relationships. Among various catalysts,Pt(111)exhibits a lowest reaction barrier,indicating that Pt maintains a high catalytic activity in Zn2+-involved ORR processes.Conversely,the surface reactivity of Ru(111)and Co(001)catalyst surfaces is significantly greater than that of Ag(111),where over-strong ZnO4* adsorption makes the second electron transfer the rate-determined step.Meanwhile,the energy barrier of four-electron pathway is notably lower than that of two-electron transfer pathway,showing that the Ru(111)and Co(001)catalyst can favor a four-electron transfer reaction and form ZnO discharge products. The optimal O*adsorption free energy is found to be around-6 eV based on the linear scaling relationships.And Ag(111)and Pt(111)have relatively appropriate O*adsorption strengths.The neutral zinc-air catalytic activity of Ag and Pt can be further improved via increasing the d-band center.In addition,the calculations also reveal that catalysts with a strong reactivity favor a four-electron transfer pathway. Conclusions The theoretical calculation results showed that linear scaling relationships still had true among various adsorption intermediates in neutral zinc-air reactions.Oxygen adsorption strength and overpotential followed the Sabatier principle,indicating that a moderate strength(i.e.,Δ Go*～-6 eV)yielded an optimal catalytic activity.Among numerous catalysts,Ag and Pt exhibited an optimal surface reactivity with a high theoretical catalytic activity.Furthermore,employing catalysts with a strong surface reactivity,such as Co and Ru,represented a potential approach to achieve non-protonic four-electron zinc-air batteries.关键词
中性锌空气电池/催化剂/描述符/第一性原理计算/线性标度关系Key words
neutral zinc-air batteries/catalysts/descriptors/first-principles calculations/linear scaling relationship分类
化学化工引用本文复制引用
孙中贤,张宝,孙威..中性锌空气电池催化剂的理论设计[J].硅酸盐学报,2025,53(7):1816-1821,6.基金项目
国家自然科学基金(52302221). （52302221）
