Band engineering in heterostructure catalysts to achieve High-Performance Lithium-Oxygen batteries

• Published in: Journal of colloid and interface science Vol. 635; pp. 138 - 147
• Main Authors: Pan, Yu, Zhao, Chuan, Hu, Anjun, Li, Runjing, Zhou, Bo, Fan, Yining, Chen, Jiahao, Yan, Zhongfu, Su, Chunbo, Long, Jianping
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2023
• Subjects: Built-in electric field; D-band center; Lithium-oxygen batteries; NiFe2O4/MoS2 heterostructure; D-band center; Built-in electric field; NiFe2O4/MoS2 heterostructure; Lithium-oxygen batteries; NiFeO/MoS heterostructure
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2022.12.121

The upper shift of the d-band level of Fe active sites was realized by regulating electronic structure of NiFe2O4/MoS2 heterostructure, fundamentally improving the electrocatalytic performance of NiFe2O4/MoS2. [Display omitted] The electronic structure of cathode catalysts dominates the electrochemistry reaction kinetics in lithium-oxygen batteries. However, conventional catalysts perform inferior intrinsic activity due to the low d-band level of the active sites makes it difficult to bond with the reaction intermediates, which results in poor electrochemical performance of lithium-oxygen batteries. Herein, NiFe2O4/MoS2 heterostructures are elaborately constructed to reach an electronic state balance for the active sites, which realizes the upper shift of the d-band level and enhanced adsorption of intermediates. Density functional theory calculation suggests that the d-band center of Fe active sites on the heterostructure moves toward the Fermi level, demonstrating the heterointerface engineering endows Fe active sites with high d-band level by the transfer and balance of electron. As a proof of concept, lithium-oxygen battery catalyzed by NiFe2O4/MoS2 exhibits a large specific capacity of 21526 mA h g−1 and an extended cycle performance for 268 cycles. Moreover, NiFe2O4/MoS2 with strong adsorption to intermediates promotes the uniform growth of discharge products, which is favor of the reversible decomposition during cycling. This work presents the energy band regulation of the active sites in heterostructure catalysts has great feasibility for enhancing catalytic activities.