Heteroatom-Substituted P2–Na_2/3Ni_1/4Mg_1/12Mn_2/3O₂ Cathode with {010} Exposing Facets Boost Anionic Activity and High-Rate Performance for Na-Ion Batteries

Abstract

As an attractive cathode candidate for sodium-ion batteries, P2-type Na 2/3 Ni 1/3 Mn 2/3 O 2 is famous for its high stability in humid air, attractive capacity, and high operating voltage. However, the low Na + transport kinetics, oxygen-redox reactions, and irreversible structural evolution at high-voltage areas hinder its practical application. Herein, a comprehensive study of a microbar P2-type Ni 2/3 Ni 1/4 Mg 1/12 Mn 2/3 O 2 material with {010} facets is presented, which exhibits high reversibility of structural evolution and anionic redox activity, leading to outstanding rate capability and cyclability. The notable rate performance (53 mA h g −1 at 20 C, 2.0− 4.3 V) contributed to the high exposure of {010} facets via controlling the growth orientation of the precursor, which is certified by density functional theory calculation and lattice structural analysis. Mg substitution strengthens the reversibility of anionic oxygen redox and structural evolution in high-voltage areas that was confirmed by the in situ X-ray diffraction and ex situ X-ray photoelectron spectroscopy tests, leading to outstanding cyclic reversibility (68.9% after 1000 cycles at 5 C) and slowing down the voltage fading. This work provides new insights into constructing electrochemically active planes combined with heteroatom substitution to improve the Na + transport kinetics and structural stability of layered oxide cathodes for sodium storage.

Dual Modification of P3-Type Layered Cathodes to Achieve High Capacity and Long Cyclability for Sodium-Ion Batteries

“…It has been reported that ethanol molecules in the solvent have a lower adsorption energy on the {001} facet than on the {010} facet of the precursor, leading to the preferential growth of the {010} facet and the formation of the one-dimensional microrod structure. 39 Thereby, the fully exposed {010} facet provides sufficient channels for the transport of Na + , leading to improved rate performance of the cathodes. 40,41 As for the hollow structure observed in the TEM image (Figure 1e), it is probably attributed to the release of CO 2 during the hightemperature calcination process.…”

Quasi‐Zero Volume Strain Cathode Materials for Sodium Ion Battery through Synergetic Substitution Effect of Li and Mg

“…As shown in Figure 3d, the volume change rate of LMNM is at a much lower level (0.49%) compared to the Ni-Mn cathode materials reported in the literature. [15,17,31,32,[42][43][44][45] As a sharp contrast, we also performed in situ XRD characterization of NM (Figure S7, Supporting Information). The results show that the characteristic peak of O2 phase starts to appear in NM material when it is charged to 4.2 V. The calculated volume change of the phase change fraction reaches 22.2%.…”

O3-Type Na0.95Ni0.40Fe0.15Mn0.3Ti0.15O2 Cathode Materials with Enhanced Storage Stability for High-Energy Na-Ion Batteries

“…The unsustainable consumption of fossil fuels accelerates energy transition to renewable energy such as wind energy and solar energy. , However, achieving efficient utilization of these clean energy sources requires large-scale energy storage devices. , Due to the abundant sodium resources and low cost, Na-ion batteries (NIBs) are considered as one of the most promising candidate materials for low-cost and large-scale energy storage. − …”