Tailoring Electronic Structure to Achieve Maximum Utilization of Transition Metal Redox for High-Entropy Na Layered Oxide Cathodes.

Charge compensation from cationic and anionic redox couples accompanying Na (de)intercalation in layered oxide cathodes contributes to high specific capacity. However, the engagement level of different redox couples remains unclear and their relationship with Na content is less studied. Here we discover that it is possible to take full advantage of the high-voltage transition metal (TM) redox reaction through low-valence cation substitution to tailor the electronic structure, which involves an increased ratio of Na content to available charge transfer number of TMs.

Conversion of Surface Residual Alkali to Solid Electrolyte to Enable Na-Ion Full Cells with Robust Interfaces.

The deposition of volatilized Na on the surface of the cathode during sintering results in the formation of surface residual alkali (NaOH/Na CO NaHCO ) in layered cathode materials, leading to serious interfacial reactions and performance degradation. This phenomenon is particularly evident in O3-NaNi Cu Mn Ti O (NCMT). In this study, a strategy is proposed to transform waste into treasure by converting residual alkali into a solid electrolyte.

A comprehensive study of the multiple effects of Y/Al substitution on O3-type NaNiMnFeO with improved cycling stability and rate capability for Na-ion battery applications.

O3-NaNi0.33Mn0.33Fe0.

In situ synthesis of a nickel concentration gradient structure of Ni-rich LiNiCoAlO with promising superior electrochemical properties at high cut-off voltage.

Nickel-rich layered cathode materials have aroused widespread interest due to their high discharge capacity, which is a basic requirement for next-generation high energy density lithium batteries. However, with the increase of nickel content, cathode materials face the serious challenge of capacity degradation, which is attributed to the formation of rock salt-type oxides such as NiO on the surface of cathode particles. To overcome this shortcoming, a novel Ni concentration gradient LiNi0.

Na-Conductive NaTiO-Modified P2-type NaNiMnO via a Smart in Situ Coating Approach: Suppressing Na/Vacancy Ordering and P2-O2 Phase Transition.

Sodium-ion batteries (SIBs) have shown great superiority for grid-scale storage applications because of their low cost and the abundance of sodium. P2-type NaNiMnO cathode materials have attracted much attention for their high capacities and operating voltages as well as their simple synthesis processes. However, Na/vacancy ordering and the P2-O2 phase transition are unavoidable during Na insertion/extraction, leading to undesired voltage plateaus and deficient battery performances.

CuO-Coated and Cu-doped Co-modified P2-type Na[NiMn]O for sodium-ion batteries.

Layered P2-type CuO-coated Na2/3[Ni1/3Mn2/3]O2 (NNMO@CuO) with excellent rate capability and cycling performance was investigated as a sodium-ion battery cathode material for the first time. The NNMO@CuO cathode material combines the advantages of CuO coating and Cu2+ doping. Transmission electron microscopy (TEM) images, TEM elemental line scan analysis and ex situ scanning electron microscopy (SEM) images show that CuO has been successfully coated on the particle surface uniformly, and that this CuO layer effectively suppresses the exfoliation of the metal oxide layers and unfavorable side reactions.

Synthesis Method for Long Cycle Life Lithium-Ion Cathode Material: Nickel-Rich Core-Shell LiNiCoMnO.

High-nickel materials with core-shell structures, whose bulk is rich in nickel content and the outer shell is rich in manganese content, have been demonstrated to improve cycle stability. The high-nickel cathode material LiNiCoMnO is a very promising material for lithium-ion batteries; however, its low rate performance and especially cycle performance currently hamper further commercialization. This study presents a new synthesis method to prepare this core-shell material (LiNiCoMnO@ x[Li-Mn-O], x = 0.