Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.



High-energy O3-Na1−2xCax[Ni0.5Mn0.5]O2 cathodes for long-life sodium-ion batteries

Author affiliations

Abstract

To facilitate the practical realization of sodium-ion batteries, the energy density, determined by the output operating voltage and/or capacity, needs to be improved to the level of commercial Li-ion batteries. Herein, O3-type Na0.98Ca0.01[Ni0.5Mn0.5]O2 is synthesized by incorporating Ca2+ into the NaO6 octahedron of Na[Ni0.5Mn0.5]O2 and its potential use as a cathode material for high energy density SIBs is demonstrated. The ionic radius of calcium (≈1.00 Å) is similar to that of sodium (≈1.02 Å); hence, it is energetically favorable for calcium to occupy sites in the sodium layers. Within a wide operating voltage range of 2.0–4.3 V, O3-type Na0.98Ca0.01[Ni0.5Mn0.5]O2 exhibits a reversible O3–P3–O3 phase transition with small volume changes compared to Ca-free Na[Ni0.5Mn0.5]O2 because of the strong interaction between Ca2+ and O2− and delivers a high reversible capacity of 209 mA h g−1 at 15 mA g−1 with improved cycling stability. Moreover, Ca substitution improves the practically useful aspects such as thermal and air stability. A prototype pouch full cell with a hard carbon anode shows an excellent capacity retention of 67% over 300 cycles. Thus, this study provides an efficient and simple method to boost the performance and applicability of layered oxide cathode materials for practical applications.

Graphical abstract: High-energy O3-Na1−2xCax[Ni0.5Mn0.5]O2 cathodes for long-life sodium-ion batteries

Back to tab navigation

Supplementary files

Article information


Submitted
11 May 2020
Accepted
21 Jun 2020
First published
22 Jun 2020

J. Mater. Chem. A, 2020, Advance Article
Article type
Paper

High-energy O3-Na1−2xCax[Ni0.5Mn0.5]O2 cathodes for long-life sodium-ion batteries

T. Yu, J. Kim, J. Hwang, H. Kim, G. Han, H. Jung and Y. Sun, J. Mater. Chem. A, 2020, Advance Article , DOI: 10.1039/D0TA04847J

Social activity

Search articles by author

Spotlight

Advertisements