Preparation of intergrown P/O-type biphasic layered oxides as high-performance cathodes for sodium ion batteries

Abstract

This study reports on the solid-state synthesis and characterization of novel quaternary P/O intergrown biphasic Na0.8MnyNi0.8-yFe0.1Ti0.1O2 (y = 0.6, 0.55, 0.5, 0.45) cathode materials. Electrochemical test reveal superior performance of...

Transition metal oxides as a cathode for indispensable Na-ion batteries

“…Therefore, the Na 0.8 Mn 0.55 Ni 0.25 Fe 0.1 Ti 0.1 O 2 is most favourable two-phase material in this series. 90 The diffraction pattern of the Na 0.67 Mn 0.55 Ni 0.25 Fe 0.1 Ti 0.1 O 2 sample shows the existence of a pure P2 type phase, which fits nicely with the general P2 type structure for the synthesized sample. For O3-phase NaMn 0.55 Ni 0.25 Fe 0.1 Ti 0.1 O 2 , there are little peaks of impurity in the XRD pattern of material that might be the outcome of some impurities of TMOs or other layered type structures difficult to detect individually because of their low reaction concentrations.…”

“…Primarily, a distinct reduction of the reversible capacity of the O/P two phase sample is identified. 90…”

“…84 The stability is ascribed to the reversible migration of lithium while cycling and reduction of P2-O2 transformation. 85,90 The appropriate sodium content is important to achieve remarkable electrochemical performance. P2-type cathode-Na 0.85 Li 0.12 Ni 0.22 Mn 0.66 O 2 containing high sodium content exhibited plateau-free and fast Na + mobility with low volume expansion ($1.7%).…”

Research progress in O3-type phase Fe/Mn/Cu-based layered cathode materials for sodium ion batteries

“…Guo et al 148 synthesized the P2/O3-type layered oxide composite Na 0.66 Li 0.18 Mn 0.71 Ni 0.21 Co 0.08 O 2+ δ (Fig. 9a and b), which showed a high discharge capacity of 200 mA h g −1 (the mass loading density of the active material was approximately 2.0 mg cm −2 ) at 10 mA g −1 with the highest energy density of 640 W h kg −1 , and exhibited a superior cycling stability of 84% capacity retention after 50 cycles at 20 mA g −1 in the voltage range of 1.5–4.5 V. Wang et al 149 synthesized a series of quaternary P2/O3-type intergrowth layered oxides. Among them Na 0.8 Mn 0.55 Ni 0.25 Fe 0.1 Ti 0.1 O 2 showed a superior reversible capacity of 154.6 mA h g −1 with satisfying initial coulombic efficiency (∼100%) and an excellent capacity retention of 80.2% after 100 cycles at 20 mA g −1 between 1.5 and 4.3 V. Xie et al 59 synthesized the NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cathode material which was dominated by the O3-type and small fractions of the P3-type layer oxide.…”

Multiphase layered transition metal oxide positive electrodes for sodium ion batteries

“…A variety of LTMO materials have demonstrated the intergrowth of nanometer-scale domains of two or more phases in the bulk of individual primary particles. 58,[79][80][81][82][83][84]97,98,[128][129][130][131][132][133][134] Multiphasic intergrowth in the bulk of materials can arise in compositions known to form pure, single phases as a result of many different varied parameters, including Na content, 81,82 TM composiiton, 81,98,135 the addition of dopants, 58,79,80,83 varied calcination process (temperature, cooling procedure), 83,84 or combinations thereof.…”