The generalization of the Local Density Approximation (LDA) method for the systems with strong Coulomb correlations is presented which gives a correct description of the Mott insulators. The LDA+U method is based on the model hamiltonian approach and allows to take into account the non-sphericity of the Coulomb and exchange interactions. parameters. Orbital-dependent LDA+U potential gives correct orbital polarization and corresponding Jahn-Teller distortion. To calculate the spectra of the strongly correlated systems the impurity Anderson model should be solved with a many-electron trial wave function. All parameters of the many-electron hamiltonian are taken from LDA+U calculations. The method was applied to NiO and has shown good agreement with experimental photoemission spectra and with the oxygen Kα X-ray emission spectrum.

http://absimage.aps.org/image/MAR06/MWS_MAR06-2005-007233.pdf

First-principles calculations of electronic structure and spectra of strongly correlated systems: the LDA+U method

Rechargeable zinc-ion batteries (RZIBs) utilizing aqueous electrolytes can offer high safety, low cost, and fast charge/discharge ratings for large-scale energy storage. The use of water as electro...

Undesired Reactions in Aqueous Rechargeable Zinc Ion Batteries

A Review of Degradation Mechanisms and Recent Achievements for Ni-Rich Cathode-Based Li-Ion Batteries

High-voltage lithium-ion batteries (LIBs) enabled by high-voltage electrolytes can effectively boost energy density and power density, which are critical requirements to achieve long travel distances, fast-charging, and reliable safety performance for electric vehicles. However, operating these batteries beyond the typical conditions of LIBs (4.3 V vs Li/Li+ ) leads to severe electrolyte decomposition, while interfacial side reactions remain elusive. These critical issues have become a bottleneck for developing electrolytes for applications in extreme conditions. Herein, an additive-free electrolyte is presented that affords high stability at high voltage (4.5 V vs Li/Li+ ), lithium-dendrite-free features upon fast-charging operations (e.g., 162 mAh g-1 at 3 C), and superior long-term battery performance at low temperature. More importantly, a new solvation structure-related interfacial model is presented, incorporating molecular-scale interactions between the lithium-ion, anion, and solvents at the electrolyte-electrode interfaces to help interpret battery performance. This report is a pioneering study that explores the dynamic mutual-interaction interfacial behaviors on the lithium layered oxide cathode and graphite anode simultaneously in the battery. This interfacial model enables new insights into electrode performances that differ from the known solid electrolyte interphase approach to be revealed, and sets new guidelines for the design of versatile electrolytes for metal-ion batteries.

/pdf/interfacial-model-deciphering-high-voltage-electrolytes-for-126mbnsxox.pdf

Interfacial Model Deciphering High-Voltage Electrolytes for High Energy Density, High Safety, and Fast-Charging Lithium-Ion Batteries

An advance review of solid-state battery: Challenges, progress and prospects

High-Voltage-Driven Surface Structuring and Electrochemical Stabilization of Ni-Rich Layered Cathode Materials for Li Rechargeable Batteries

New Insight on Open‐Structured Sodium Vanadium Oxide as High‐Capacity and Long Life Cathode for Zn–Ion Storage: Structure, Electrochemistry, and First‐Principles Calculation

In this study, a one-step process to fabricate "Janus"-structured nanocomposites with iron oxide (Fe3O4) nanoparticles (Fe3O4 NPs) and polydopamine (PDA) on each side of a graphene oxide (GO) nanosheet using the Langmuir-Schaefer technique has been proposed. The Fe3O4 NPs-GO hybrid is used as a high-capacity active material, while PDA is added as a binder due to its unique wet-resistant adhesive property. The transmission electron microscopy image shows a superlattice-like out-of-plane section of the multilayered nanocomposite, which maximizes the density of the composite materials. Grazing-incidence small-angle X-ray scattering results combined with scanning electron microscopy images confirm that the multilayered Janus composite exhibits an in-plane hexagonal array structure of closely packed Fe3O4 NPs. This Janus multilayered structure is expected to maximize the amount of active material in a specific volume and reduce volume changes caused by the conversion reaction of Fe3O4 NPs. According to the electrochemical results, the Janus multilayer electrode delivers an excellent capacity of ∼903 mAh g-1 at a current density of 200 mA g-1 and a reversible capacity of ∼639 mAh g-1 at 1 A g-1 up to the 1800th cycle, indicating that this Janus composite can be a promising anode for Li-ion batteries.

Janus Graphene Oxide Sheets with Fe3O4 Nanoparticles and Polydopamine as Anodes for Lithium-Ion Batteries.

In situ multiscale probing of the synthesis of a Ni-rich layered oxide cathode reveals reaction heterogeneity driven by competing kinetic pathways

Oxygen‐redox‐based cathode materials for sodium‐ion batteries (SIBs) have attracted considerable attention in recent years owing to the possibility of delivering additional capacity in the high‐voltage region. However, they still suffer from not only fast capacity fading but also poor rate capability. Herein, P2‐Na0.75[Li0.15Ni0.15Mn0.7]O2 is introduced, an oxygen‐redox‐based layered oxide cathode material for SIBs. The effect of Ni doping on the electrochemical performance is investigated by comparison with Ni‐free P2‐Na0.67[Li0.22Mn0.78]O2. The Na0.75[Li0.15Ni0.15Mn0.7]O2 delivers a specific capacity of ≈160 mAh g−1 in the voltage region of 1.5–4.6 V at 0.1 C in Na cells. Combined experiments (galvanostatic cycling, neutron powder diffraction, X‐ray absorption spectroscopy, X‐ray photoelectron spectroscopy, and nuclear magnetic resonance (7Li NMR)) and theoretical studies (density functional theory calculations) confirm that Ni substitution not only increases the operating voltage and decreases voltage hysteresis but also improves the cycling stability by reducing Li migration from transition metal to Na layers. This research demonstrates the effect of Li and Ni co‐doping in P2‐type layered materials and suggests a new strategy of using Mn‐rich cathode materials via oxygen redox with optimization of doping elements for SIBs.

Seok Hyun Song

Papers

High-Voltage-Driven Surface Structuring and Electrochemical Stabilization of Ni-Rich Layered Cathode Materials for Li Rechargeable Batteries

New Insight on Open‐Structured Sodium Vanadium Oxide as High‐Capacity and Long Life Cathode for Zn–Ion Storage: Structure, Electrochemistry, and First‐Principles Calculation

Janus Graphene Oxide Sheets with Fe3O4 Nanoparticles and Polydopamine as Anodes for Lithium-Ion Batteries.

In situ multiscale probing of the synthesis of a Ni-rich layered oxide cathode reveals reaction heterogeneity driven by competing kinetic pathways

Hysteresis‐Suppressed Reversible Oxygen‐Redox Cathodes for Sodium‐Ion Batteries