Issue 36, 2016

Understanding the effect of an in situ generated and integrated spinel phase on a layered Li-rich cathode material using a non-stoichiometric strategy

Abstract

Recently, spinel-layered integrated Li-rich cathode materials have attracted great interest due to the large enhancement of their electrochemical performances. However, the modification mechanism and the effect of the integrated spinel phase on Li-rich layered cathode materials are still not very clear. Herein, we have successfully synthesized the spinel-layered integrated Li-rich cathode material using a facile non-stoichiometric strategy (NS-LNCMO). The rate capability (84 mA h g−1vs. 28 mA h g−1, 10 C), cycling stability (92.4% vs. 80.5%, 0.2 C), low temperature electrochemical capability (96.5 mA h g−1vs. 59 mA h g−1, −20 °C), initial coulomb efficiency (92% vs. 79%) and voltage fading (2.77 V vs. 3.02 V, 200 cycles@1 C) of spinel-layered integrated Li-rich cathode materials have been significantly improved compared with a pure Li-rich phase cathode. Some new insights into the effect of the integrated spinel phase on a layered Li-rich cathode have been proposed through a comparison of the structure evolution of the integrated and Li-rich only materials before and after cycling. The Li-ion diffusion coefficient of NS-LNCMO has been enlarged by about 3 times and almost does not change even after 100 cycles indicating an enhanced structure stability. The integration of the spinel phase not only enhances the structure stability of the layered Li-rich phase during charging–discharging but also expands the interslab spacing of the Li-ion diffusion layer, and elongates TM–O covalent bond lengths, which lowers the activation barrier of Li+-transportation, and alleviates the structure strain during the cycling procedure.

Graphical abstract: Understanding the effect of an in situ generated and integrated spinel phase on a layered Li-rich cathode material using a non-stoichiometric strategy

Article information

Article type
Paper
Submitted
28 May 2016
Accepted
19 Aug 2016
First published
19 Aug 2016

Phys. Chem. Chem. Phys., 2016,18, 25711-25720

Understanding the effect of an in situ generated and integrated spinel phase on a layered Li-rich cathode material using a non-stoichiometric strategy

J. Zhang, R. Gao, L. Sun, Z. Li, H. Zhang, Z. Hu and X. Liu, Phys. Chem. Chem. Phys., 2016, 18, 25711 DOI: 10.1039/C6CP03683J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements