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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - High Voltage Mg-Doped Na 0.67 Ni 0.3– x Mg x Mn 0.7 O 2 ( x = 0.05, 0.1) Na-Ion Cathodes with Enhanced Stability and Rate Capability
AU - Singh, Gurpreet
AU - Tapia-Ruiz, Nuria
AU - Lopez del Amo, Juan Miguel
AU - Maitra, Urmimala
AU - Somerville, James W.
AU - Armstrong, A. Robert
AU - Martinez de Ilarduya, Jaione
AU - Rojo, Teófilo
AU - Bruce, Peter G.
PY - 2016/7/26
Y1 - 2016/7/26
N2 - Magnesium substituted P2-structure Na0.67Ni0.3Mn0.7O2 materials have been prepared by a facile solid-state method and investigated as cathodes in sodium-ion batteries. The Mg-doped materials described here were characterized by X-ray diffraction (XRD), 23Na solid-state nuclear magnetic resonance (SS-NMR), and scanning electron microscopy (SEM). The electrochemical performance of the samples was tested in half cells vs Na metal at room temperature. The Mg-doped materials operate at a high average voltage of ca. 3.3 V vs Na/Na+ delivering specific capacities of ∼120 mAh g–1, which remain stable up to 50 cycles. Mg doping suppresses the well-known P2–O2 phase transition observed in the undoped composition by stabilizing the reversible OP4 phase during charging (during Na removal). GITT measurements showed that the Na-ion mobility is improved by 2 orders of magnitude with respect to the parent P2–Na0.67Ni0.3Mn0.7O2 material. The fast Na-ion mobility may be the cause of the enhanced rate performance.
AB - Magnesium substituted P2-structure Na0.67Ni0.3Mn0.7O2 materials have been prepared by a facile solid-state method and investigated as cathodes in sodium-ion batteries. The Mg-doped materials described here were characterized by X-ray diffraction (XRD), 23Na solid-state nuclear magnetic resonance (SS-NMR), and scanning electron microscopy (SEM). The electrochemical performance of the samples was tested in half cells vs Na metal at room temperature. The Mg-doped materials operate at a high average voltage of ca. 3.3 V vs Na/Na+ delivering specific capacities of ∼120 mAh g–1, which remain stable up to 50 cycles. Mg doping suppresses the well-known P2–O2 phase transition observed in the undoped composition by stabilizing the reversible OP4 phase during charging (during Na removal). GITT measurements showed that the Na-ion mobility is improved by 2 orders of magnitude with respect to the parent P2–Na0.67Ni0.3Mn0.7O2 material. The fast Na-ion mobility may be the cause of the enhanced rate performance.
U2 - 10.1021/acs.chemmater.6b01935
DO - 10.1021/acs.chemmater.6b01935
M3 - Journal article
VL - 28
SP - 5087
EP - 5094
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 14
ER -