P-type NaxNi0.22Co0.11Mn0.66O2 materials: linking synthesis with structure and electrochemical performance

L. G. Chagas; D. Buchholz; C. Vaalma; L. Wu; S. Passerini

doi:10.1039/C4TA03946G

P-type Na_xNi_0.22Co_0.11Mn_0.66O₂ materials: linking synthesis with structure and electrochemical performance†

L. G. Chagas,^abc D. Buchholz,*^abc C. Vaalma,^abc L. Wu^abc and S. Passerini*^ac

Author affiliations

* Corresponding authors

^a Helmholtz Institute Ulm (HIU) Electrochemistry Ic, Helmholtzstrasse 11, 89081 Ulm, Germany

^b Institute of Physical Chemistry, University of Muenster, Corrensstrasse 28/30, Muenster, Germany

^c Karlsruhe Institute of Technology (KIT), PO Box 3640, 76021 Karlsruhe, Germany
E-mail: daniel.buchholz@kit.edu, stefano.passerini@kit.edu

Abstract

P-type layered oxides are promising cathode materials for sodium-ion batteries and a wide variety of compounds have been investigated so far. Nevertheless, detailed studies on how to link synthesis temperature, structure and electrochemistry are still rare. Herein, we present a study on P-type Na_xNi_0.22Co_0.11Mn_0.66O₂ materials, investigating the influence of synthesis temperature on their structure and electrochemical performance. The change of annealing temperature leads to various materials of different morphologies and either P3-type (700 °C), P3/P2-type (750 °C) or P2-type (800–900 °C) structure. Galvanostatic cycling of P3-type materials revealed high initial capacities but also a high capacity fade per cycle leading to a poor long-term cycling performance. In contrast, pure P2-type Na_xNi_0.22Co_0.11Mn_0.66O₂, synthesized at 800 °C, exhibits lower initial capacities but a stable cycling performance, underlined by a good rate capability, high coulombic efficiencies and high average discharge capacity (117 mA h g⁻¹) and discharge voltage (3.30 V vs. Na/Na⁺) for 200 cycles.

This article is part of the themed collection: 2014 Journal of Materials Chemistry A Hot Articles

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Article information

DOI: https://doi.org/10.1039/C4TA03946G
Article type: Paper
Submitted: 31 Jul 2014
Accepted: 29 Sep 2014
First published: 31 Oct 2014
This article is Open Access

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J. Mater. Chem. A, 2014,2, 20263-20270

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P-type Na_xNi_0.22Co_0.11Mn_0.66O₂ materials: linking synthesis with structure and electrochemical performance

L. G. Chagas, D. Buchholz, C. Vaalma, L. Wu and S. Passerini, J. Mater. Chem. A, 2014, 2, 20263 DOI: 10.1039/C4TA03946G

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Journal of Materials Chemistry A