首页|Engineering single-atom Mn on nitrogen-doped carbon to regulate lithium-peroxide reaction kinetics for rechargeable lithium-oxygen batteries

Engineering single-atom Mn on nitrogen-doped carbon to regulate lithium-peroxide reaction kinetics for rechargeable lithium-oxygen batteries

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Precision engineering of catalytic sites to guide more favorable pathways for Li2O2 nucleation and decom-position represents an enticing kinetic strategy for mitigating overpotential,enhancing discharge capac-ity,and improving recycling stability of Li-O2 batteries.In this work,we employ metal-organic frameworks(MOFs)derivation and ion substitution strategies to construct atomically dispersed Mn-N4 moieties on hierarchical porous nitrogen-doped carbon(Mn SAs-NC)with the aim of reducing the over-potential and improving the cycling stability of Li-O2 batteries.The porous structure provides more chan-nels for mass transfer and exposes more highly active sites for electrocatalytic reactions,thus promoting the formation and decomposition of Li2O2.The Li-O2 batteries with Mn SAs-NC cathode achieve lower overpotential,higher specific capacity(14290 mA h g-1 at 100 mA g-1),and superior cycle stability(＞100 cycles at 200 mA g-1)compared with the Mn NPs-NC and NC.Density functional theory(DFT)cal-culations reveal that the construction of Mn-N4 moiety tunes the charge distribution of the pyridinic N-rich vacancy and balances the affinity of the intermediates(LiO2 and Li2O2).The initial nucleation of Li2O2 on Mn SAs-NC favors the O2 → LiO2 → Li2O2 surface-adsorption pathway,which mitigates the overpoten-tials of the oxygen reduction(ORR)and oxygen evolution reaction(OER).As a result,Mn SAs-NC with Mn-N4 moiety effectively facilitates the Li2O2 nucleation and enables its reversible decomposition.This work establishes a methodology for constructing carbon-based electrocatalysts with high activity and selectivity for Li-O2 batteries.

Single-atom MnMOFs-oriented architectureRechargeable Li-O2 batteryN-doped carbonDensity functional theory calculation

Yaling Huang、Yong Liu、Yang Liu、Chenyang Zhang、Wenzhang Li、Jie Li

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School of Chemistry and Chemical Engineering,Central South University,Changsha 410083,Hunan,China

School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,Hunan,China

National Natural Science Foundation of ChinaHigh-Performance Computing Center of Central South University

21878340

2024

10.1016/j.jechem.2024.02.030

能源化学
中国科学院大连化学物理研究所 中国科学院成都有机化学研究所

能源化学

CSTPCDEI
影响因子：0.654
ISSN：2095-4956
年,卷(期)：2024.94(7)