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Controlling at Elevated Temperature the Sodium Intercalation Capacity and Rate Capability of P 3‐Na 2/3 Ni 1/2 Mn 1/2 O 2 through the Selective Substitution of Nickel with Magnesium
Author(s) -
Kalapsazova Mariya,
Markov Pavel,
Kostov Krassimir,
Zhecheva Ekaterina,
Nihtianova Diana,
Stoyanova Radostina
Publication year - 2020
Publication title -
batteries and supercaps
Language(s) - English
Resource type - Journals
ISSN - 2566-6223
DOI - 10.1002/batt.202000137
Subject(s) - electrolyte , intercalation (chemistry) , electrochemistry , oxide , ion , inorganic chemistry , sodium , materials science , ionic bonding , redox , oxygen , chemistry , electrode , metallurgy , organic chemistry
The integration of sodium‐ion batteries into large‐scale energy storage systems will become feasible in the case when their performance becomes less sensitive towards ambient temperature. Herein, we demonstrate the elaboration of the oxide‐based electrode material with an optimized layered structure and composition that is designed to work at elevated temperatures. Through selective substitution of Mg 2+ ions for Ni 2+ in the three‐layered oxide, P 3‐Na 2/3 Ni 1/2 Mn 1/2 O 2 , the oxidation state of Ni ions, the cationic distribution in the layers, the sodium intercalation capacity, and the rate capability is manipulated. The electrochemical behavior of P 3‐Na 2/3 Ni 1/3 Mg 1/6 Mn 1/2 O 2 is discussed on the basis of ex situ diffraction as well as microscopic and spectroscopic methods in terms of redox activity of the lattice oxygen, the reversible transfer of Mg 2+ and Ni 2+ ions between layers during Na + intercalation, thermal stability of cycled electrodes, and surface reactivity of the layered oxide towards the ionic liquid (IL) electrolyte. At 40 °C, the rate capability of the oxide is improved upon using an IL electrolyte rather than the carbonate‐based electrolyte.