Johansen Morten, Ravnsbæk Dorthe B
Center for Integrated Materials Research, Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark.
ACS Omega. 2024 Aug 14;9(34):36291-36298. doi: 10.1021/acsomega.4c02839. eCollection 2024 Aug 27.
Transition metal oxides are widely employed as electrode materials in Li-ion batteries. During battery operation, Li ions are intercalated and extracted from the framework of the electrode structure, causing structural transitions. In some materials, the process can drive order-disorder transitions; however, insights into such processes are generally lacking, although they are essential for our understanding of battery aging and in the design of new sustainable battery chemistries. Herein, we investigate the intercalation-induced order-disorder transition in rutile VO(M) electrodes by means of galvanostatic charge/discharge cycling, powder X-ray diffraction, and total X-ray scattering with pair distribution function analysis. The study reveals that the rutile structure transforms irreversibly into a highly disordered layered Li VO structure, which is capable of reversibly intercalating Li ions. Our findings point out general trends for the intercalation-driven transitions in rutile oxides.
过渡金属氧化物在锂离子电池中被广泛用作电极材料。在电池运行过程中，锂离子嵌入并从电极结构框架中脱出，导致结构转变。在某些材料中，该过程可驱动有序-无序转变；然而，尽管这些过程对于我们理解电池老化和设计新的可持续电池化学至关重要，但对此类过程的深入了解普遍不足。在此，我们通过恒电流充/放电循环、粉末X射线衍射以及利用对分布函数分析的全X射线散射，研究了金红石型VO₂电极中嵌入诱导的有序-无序转变。研究表明，金红石结构不可逆地转变为高度无序的层状LiₓVO₂结构，该结构能够可逆地嵌入锂离子。我们的研究结果指出了金红石氧化物中嵌入驱动转变的一般趋势。
