In Situ X-ray Diffraction and X-ray Absorption Spectroscopic Studies of a Lithium-Rich Layered Positive Electrode Material: Comparison of Composite and Core-Shell Structures

Assessing the Performance of Al12N12 and Al12P12 Nanostructured Materials for Alkali Metal Ion (Li, Na, K) Batteries

This study focused on the potential of aluminum nitride (Al₁₂N₁₂) and aluminum phosphide (Al₁₂P₁₂) nanomaterials as anode electrodes of lithium-ion (Li-ion), sodium-ion (Na-ion), and potassium-ion (K-ion) batteries as investigated via density functional theory (DFT) calculations at PBE0-D3, M062X-D3, and DSDPBEP86 as the reference method. The results show that the Li-ion battery has a higher cell voltage with a binding energy of -1.210 eV and higher reduction potential of -6.791 kcal/mol compared to the sodium and potassium ion batteries with binding energies of -0.749 and -0.935 eV and reduction potentials of -6.414 and -6.513 kcal/mol, respectively, using Al₁₂N₁₂ material. However, in Al₁₂P₁₂, increases in the binding energy and reduction potential were observed in the K-ion battery with values -1.485 eV and -7.535 kcal/mol higher than the Li and Na ion batteries with binding energy and reduction potential -1.483, -1.311 eV and -7.071, -7.184 eV, respectively. Finally, Al₁₂N₁₂ and Al₁₂P₁₂ were both proposed as novel anode electrodes in Li-ion and K-ion batteries with the highest performances.

Operando analysis of electronic band structure in an all-solid-state thin-film battery

Material characterization that informs research and development of batteries is generally based on well-established ex situ and in situ experimental methods that do not consider the band structure. This is because experimental extraction of structural information for liquid-electrolyte batteries is extremely challenging. However, this hole in the available experimental data negatively affects the development of new battery systems. Herein, we determined the entire band structure of a model thin-film solid-state battery with respect to an absolute potential using operando hard X-ray photoelectron spectroscopy by treating the battery as a semiconductor device. We confirmed drastic changes in the band structure during charging, such as interfacial band bending, and determined the electrolyte potential window and overpotential location at high voltage. This enabled us to identify possible interfacial side reactions, for example, the formation of the decomposition layer and the space charge layer. Notably, this information can only be obtained by evaluating the battery band structure during operation. The obtained insights deepen our understanding of battery reactions and provide a novel protocol for battery design.

Boosting the Electrochemical Performance of a Spinel Cathode with the In Situ Transformed Allogenic Li-Rich Layered Phase

High-voltage spinel materials have attracted widespread attention because of their advantages such as good rate performance, low cost, abundant source, and easy preparation. However, the Mn dissolution and Jahn-Teller effect of spinel materials during cycling limit their practical application. In this paper, the allogenic composites (1 - x)Li(Ni_0.2Co_0.1Mn_0.7)₂ O₄·xLi_1.2(Ni_0.2Co_0.1Mn_0.7)_0.8O₂ (x = 0.05, 0.1, 0.2, 0.3, 0.4, and 0.5) are developed by the carbonate co-precipitation method combined with the high-temperature sintering method, which are certified by the X-ray diffraction (XRD) spectrum and transmission electron microscopy (TEM) image. The results show that the lithium-rich phase of the allogenic composites can effectively improve the initial discharge capacity, alleviate the side reaction between the spinel material and the electrolyte, and improve the cycle stability. This work reveals the relationship between the structure and electrochemical performance of the in situ transformed spinel@Li-rich allogenic composites and provide a new clue to design a high-performance spinel cathode for advanced Li-ion batteries.

Using In-Situ Laboratory and Synchrotron-Based X-ray Diffraction for Lithium-Ion Batteries Characterization: A Review on Recent Developments

Renewable technologies, and in particular the electric vehicle revolution, have generated tremendous pressure for the improvement of lithium ion battery performance. To meet the increasingly high market demand, challenges include improving the energy density, extending cycle life and enhancing safety. In order to address these issues, a deep understanding of both the physical and chemical changes of battery materials under working conditions is crucial for linking degradation processes to their origins in material properties and their electrochemical signatures. In situ and operando synchrotron-based X-ray techniques provide powerful tools for battery materials research, allowing a deep understanding of structural evolution, redox processes and transport properties during cycling. In this review, in situ synchrotron-based X-ray diffraction methods are discussed in detail with an emphasis on recent advancements in improving the spatial and temporal resolution. The experimental approaches reviewed here include cell designs and materials, as well as beamline experimental setup details. Finally, future challenges and opportunities for battery technologies are discussed.