Synthesis, structural and electrochemical study of O3–NaNi_0.4Mn_0.4Co_0.2O₂ as a cathode material for Na-ion batteries

Abstract

Hexagonal layered O3-NaNi 0.4 Mn 0.4 Co 0.2 O 2 is prepared by mixed hydroxide solid state reaction method at an optimum temperature of 800 °C. Rietveld refined PXRD pattern reveals single phase formation with space group R-3m. Galvanostatic electrochemical studies reveal reversible sodium de-insertion/insertion with concomitant structural phase transitions. In the voltage window of 2.2 -3.8 V, the first discharge capacities are 150 and 135 mAh g -1 at C/20 and C/6.5 current rates, respectively. The capacity retention is 80% after 33 discharge cycle at C/20 rate and 78% after 40 discharge cycle at C/6.5 rate. When the voltage window is increased to 1.6 -4.5 V, the initial discharge capacity is 173 mAh g -1 at C/10 rate and a capacity retention of 63% is observed after 10 discharge cycle. The O3 phase undergoes a series of structural transformations from O3, O'3, P3, P'3 and P3'' during charging and reverts to O3 phase upon deinsertion of Na during discharge. Structural stability is evident from ex-situ XRD studies even after 33 cycles, when cycled in the voltage window of 2.2 -3.8 V at C/20 rate.

Synthesis and Electrochemical Study of New P3 Type Layered Na0.6Ni0.25Mn0.5Co0.25O2 for Sodium‐Ion Batteries

“…The high capacity and stability of this material at voltage window of 2.0‐4.0 and 2.0‐4.4 V may be due to the presence of Co in the structure compared to without cobalt substituted materials like Na x Ni 0.5 Mn 0.5 O 2 , NaFeO 2 ,. The retention capacity 64 % of 2 nd discharge capacity is obtained with coloumbic efficiency of 98 % up to 35 cycles (Figure c) ,. The high capacity fade on charged to above 4 V may be due to the electrolyte instability and oxygen evolution from lattice.…”

“…The structural and electrochemical properties of this phase material studied at different current rates in the voltage range between 1.5 and 4.4 V vs. Na + /Na. We have shown the existence of stable P3 phase at higher cutoff voltages than converted to other phases as observed for O3 phases with good electrochemical performance ,…”

“…The Na analog of high capacity and more stable compound, LiNi 1/3 Co 1/3 Mn 1/3 O 2 shows the discharge capacity of 120 mAh/g at C/10 rate in the voltage window of 2.0‐3.75 V vs. Na + /Na . We have studied Na analog of high capacity LiNi 0.4 Co 0.2 Mn 0.4 O 2 and shows the stable discharge capacity of 120 mAh/g at C/6.5 rate in the voltage window of 2.2‐3.8 V . These materials show high irreversible capacity loss on charged to high voltages with irreversible structural changes.…”

Co-Substitution Enhances the Rate Capability and Stabilizes the Cyclic Performance of O3-Type Cathode NaNi0.45–xMn0.25Ti0.3CoxO2 for Sodium-Ion Storage at High Voltage

“…The comparisons indicate that co-substitution enhances the rate capability of NMTCo x . The energy density of NMTCo 0.05 is outstanding even compared with those of other reported O3-type cathode materials (Figure c). ,,− The cycling performance of NMTCo x ( x = 0, 0.05, and 0.1) at 0.5 C is shown in Figure d. NMTCo 0.05 exhibits a reversible capacity of 152 mA h g –1 in the first cycle and maintains 91.4 mA h g –1 even after 180 cycles, with a capacity retention of 60%.…”

Air-Stable NaxTMO2 Cathodes for Sodium Storage

“…In Na x TMO 2 compounds, TM layers are usually occupied by Ti, (Senguttuvan et al, 2011; Wu D. et al, 2015) V, (Hamani et al, 2011; Guignard et al, 2013; Wang et al, 2018d) Cr, (Braconnier et al, 1982; Yu et al, 2015) Mn, (Ma et al, 2011) Fe, (Blesa et al, 1993; Yabuuchi et al, 2012b) Co, (Berthelot et al, 2011; Rai et al, 2014) Ni, (Vassilaras et al, 2013; Wang et al, 2018b) Cu, (Ono et al, 2014; Jiang et al, 2018; Ono, 2018) a mixture of two (Saadoune et al, 1996; Yabuuchi et al, 2012a; Mortemard de Boisse et al, 2013; Gonzalo et al, 2014; Guo et al, 2014; Kalluri et al, 2014; Zhu et al, 2014, 2016; Chen et al, 2015; Jiang et al, 2015; Kang et al, 2015; Wang et al, 2015, 2016d; Bucher et al, 2016; Kee et al, 2016; Liu et al, 2016; Manikandan et al, 2017; Sabi et al, 2017; Song et al, 2017) or more elements (Lu and Dahn, 2001b; Buchholz et al, 2014; Li et al, 2014; Liu et al, 2015; Li Y. et al, 2015; Li Z.-Y. et al, 2015; Yue et al, 2015; Han et al, 2016a; Kang et al, 2016; Qi et al, 2016; Satyanarayana et al, 2016; Sun et al, 2016; Wang et al, 2016b; Zhang X.-H. et al, 2016; Wang L. et al, 2017; Zheng and Obrovac, 2017) The corresponding redox potential ranges of these TM are presented in Figure 2. Na x TiO 2 compound is usually used as anode material due to its low redox potential range.…”