Xu Haoyang, Wang Xinxiang, Tian Guilei, Fan Fengxia, Wen Xiaojuan, Liu Pengfei, Shu Chaozhu
College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, 1#, Dongsanlu, Erxianqiao, Chengdu 610059, Sichuan, P. R. China.
State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu 610059, Sichuan, P. R. China.
ACS Nano. 2024 Oct 8;18(40):27804-27816. doi: 10.1021/acsnano.4c11909. Epub 2024 Sep 30.
High-entropy perovskite oxides, in which the B-type metal site of perovskite oxides (ABO) is occupied by over five kinds of transition metal ions, show promising applications in energy storage and conversion fields. Herein, high-entropy perovskite oxides (LaSr(5TM)O) composed of Cr, Mn, Fe, Co, and Ni at the B-type metal site are prepared as oxygen electrocatalysts for Li-O batteries. The presence of compressive strain in LaSr(5TM)O effectively regulates the 3d orbit occupancy of the active Co site (Co → Co) and lifts the energy level of the Co d-band center, thus leading to enhanced adsorption toward the LiO intermediate on Co sites. Furthermore, the high electron-drawing capability of Cr sites ensures sufficient electron exchange and further strengthens the adsorption of LiO. As expected, the Li-O battery with a LaSr(5TM)O electrode delivers a low overpotential (0.79 V) and superior cyclability (226 cycles). This study provides a meaningful strain strategy to improve the electrocatalytic activity of multicomponent oxides via fabricating high-entropy materials.
高熵钙钛矿氧化物，即钙钛矿氧化物（ABO）的B型金属位点被五种以上的过渡金属离子占据，在能量存储和转换领域显示出有前景的应用。在此，制备了在B型金属位点由Cr、Mn、Fe、Co和Ni组成的高熵钙钛矿氧化物（LaSr(5TM)O）作为锂氧电池的氧电催化剂。LaSr(5TM)O中压缩应变的存在有效地调节了活性Co位点（Co→Co）的3d轨道占据情况，并提升了Co d带中心的能级，从而增强了Co位点对LiO中间体的吸附。此外，Cr位点的高吸电子能力确保了足够的电子交换，并进一步增强了对LiO的吸附。正如预期的那样，具有LaSr(5TM)O电极的锂氧电池具有低过电位（0.79 V）和优异的循环稳定性（226次循环）。本研究提供了一种有意义的应变策略，通过制备高熵材料来提高多组分氧化物的电催化活性。
