Quaternary phase diagrams of spinelLiy□1−yMnxNi2−xO4

Abstract

Core-shell coating structures and concentration gradient materials may enhance Li ion battery performance by integrating advantages of core and shell components without introducing unfavor-

Rechargeable Alkali-Ion Battery Materials: Theory and Computation

“…This study demonstrated a strong coupling between Li vacancy ordering tendencies and the degree of transition metal ordering. A similar study was performed by Hao et al for Li x (Mn y Ni 1– y ) 2 O 4 …”

“…First-principles statistical mechanics approaches have since been applied to a wide variety of other transition metal oxides and sulfides. These include O3 Li x NiO 2 and Li x (Ni 0.5 Mn 0.5 )­O 2 , O2 Li x CoO 2 , O1 and spinel forms of Li x TiS 2 , , spinel Li x Ti 2 O 4 , , and Li x (Mn y Ni 1– y ) 2 O 4 , as well as Li x TiO 2 in more complex crystal structures such as bronze B and anatase. , Similar investigations have been performed on Na, K, and Mg containing transition metal oxides such as O2/P2–Na x CoO 2 , , O3/P3–Na x CoO 2 , O3/P3–K x CoO 2 , Mg x TiS 2 , and spinel Mg x Cr 2 O 4 . The approach has become increasingly automated, enabling high-throughput studies of multiple electrode chemistries simultaneously, as was done in a recent investigation of the dependence of the voltage profile of the spinel crystal structure on host and guest ion chemistry …”

High-Throughput Description of Infinite Composition–Structure–Property–Performance Relationships of Lithium–Manganese Oxide Spinel Cathodes

“…Currently, most of the computational works focus on understanding the structure or property of electrode materials at an atomic scale. For instance, density functional theory (DFT) based ab initio calculations were performed to predict the fundamental properties (electronic structure, equilibrium voltage, thermal and electrochemical stability, lithium diffusivity) on thousands of potential electrode materials. − However, the pure ab initio calculations cannot be directly applied to describe the continuous properties of complete composition coverage for the electrode materials. Recently, the CALPHAD (Calculation of Phase Diagrams) approach has been proven to be a powerful tool to efficiently evaluate the phase diagrams and continuous properties in the lithium ion batteries. − The essence of this approach is to optimize the parameters of the sublattice model based on reliable experimental and theoretical data.…”

Nanoscale Voltage Enhancement at Cathode Interfaces in Li-Ion Batteries

“…The concentration gradient in Li­[Ni 1– x M x ]­O 2 creates multiple, diffuse interfaces between phases which contain different transition metal concentrations. Similar concentration gradient-induced interfaces occur in the spinel-structured Li y Va 1– y Mn x Ni 2‑x O 4 (Va = vacancy) cathode material with a compositional core–shell structure . Moreover, interfaces inevitably occur for cathode particles at their surface, with either a solid electrolyte interphase (SEI) or frequently a protective coating layer, the latter of which is typically comprised of insulating metal oxides or fluorides − or sometimes an electrochemically active material (e.g., Li–Ni–PO 4 coating layer) …”