缺陷钴氧化物中选择性锚定Pd单原子用于高效锂氧电池
Selectively anchoring Pd single atoms on specific sites in defective cobalt oxides for efficient lithium-oxygen batteries
郑健 1张文静 1李泰广 1陈步天 1柳冲 1张天然 1刘向峰1
作者信息
- 1. Center of Materials Science and Optoelectronics Engineering,College of Materials Science and Optoelectronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China
- 折叠
摘要
非质子锂氧电池基于锂金属与氧的可逆反应生成Li2O2,可提供极高的理论能量密度.然而,Li2O2的成核/消除机制仍然不清楚.因此,构建能在原子水平上深入了解催化机理的催化剂体系,是开发高性能锂氧电池的关键.在此,我们报道了一种在富氧空位的Co3O4(Pd1-Co3O4-x)中实现Pd单原子选择性锚定的策略.原子水平表征技术揭示了Pd原子优先地结合到缺陷Co3O4的四面体位点.理论计算表明,选择性锚定的Pd单原子与氧空位的耦合引起了明显的电荷重分布,这可以有效地提高Pd 4d轨道在费米能级附近的能带占用率,促进电子转移,有利于中间体的吸附.这种双重相互作用不仅可以调节放电过程中Li2O2的成核生长过程,而且有利于Li2O2上的电子云的离域,减弱Li-O键的强度,从而促进Li2O2在充电过程中的分解.本研究对锂氧电池在原子水平上的催化机理和高效催化剂的合理设计提出了一些见解.
Abstract
Aprotic Li-O2 batteries,based on the reversible formation of Li2O2 by the reaction between Li metal and oxygen,afford extremely high theoretical energy density.However,the nucleation/delithiation mechanisms of Li2O2 remain ambiguous.Therefore,it is an important issue for developing high performance Li-O2 batteries to construct a catalyst system and deeply understand the catalytic mechan-ism at the atomic level.Herein,we report a strategy for achieving the site-selectively anchoring of Pd single atoms in oxygen vacancy-rich Co3O4(PdI-Co3O4-x).Atomic-level char-acterization techniques unravel that the Pd atoms are pre-ferably incorporated into the tetrahedral site of defective Co3O4.Theoretical calculations manifest the obvious charge redistribution induced by the selective-anchored Pd single atom coupled with oxygen vacancies can effectively increase the energy band occupancy of Pd 4d orbitals near the Fermi level,which promotes electron transfer and facilitates the adsorption of intermediates.This dual interaction can not only regulate the nucleation-growth procedures of Li2O2 during discharging,but also benefit the delocalization of the electron cloud on Li2O2 and weaken the strength of the Li-O bond,which promotes the decomposition of Li2O2 during charging.This work proposes some insights into the catalytic mechanism at the atomic level and facilitates the rational de-sign of highly efficient catalysts for Li-O2 batteries.
关键词
Pt single-atom catalyst/tetrahedral sites/oxygen va-cancies/catalytic mechanism/Li-O2 batteriesKey words
Pt single-atom catalyst/tetrahedral sites/oxygen va-cancies/catalytic mechanism/Li-O2 batteries引用本文复制引用
基金项目
National Natural Science Foundation of China(11975238)
National Natural Science Foundation of China(11575192)
Scientific Instrument Developing Project(ZDKYYQ20170001)
Strategic Priority Research Program(XDB28000000)
International Partnership Program of the Chinese Academy of Sciences and the University of the Chinese Academy of Sciences(211211KYSB20170060)
International Partnership Program of the Chinese Academy of Sciences and the University of the Chinese Academy of Sciences(211211KYSB20180020)
Fundamental Research Funds for the Central Universities()
出版年
2024
NETL
NSTL
万方数据