Enhanced Rate Capability and Cycle Performance of Titanium-Substituted P2-Type Na0.67Fe0.5Mn0.5O2 as a Cathode for Sodium-Ion Batteries

Park, Joon-ki; Park, Geun-gyung; Kwak, Hunho H.; Hong, Seung‐Tae; Lee, Jae-won

doi:10.1021/acsomega.7b01481

Cited by 69 publications

(55 citation statements)

References 50 publications

(136 reference statements)

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“…25 The capacity fade of NFMO is one of the lowest of Na x Fe y Mn 1-y O 2 cathode materials reported in literature. [25][26][27][28][29][30][31][32][33][34][35][36] The low capacity fade of the materials reported here can be attributed to the low Fe content and potentially lower sodium carbonate surface contamination. Fe in the TM layer has been reported to increase the sodium carbonate contamination on Na TM layered oxides, 28 however quantification of the sodium carbonate contamination is not commonly reported in cathode literature.…”

Section: Resultsmentioning

confidence: 83%

Meso-Structure Controlled Synthesis of Sodium Iron-Manganese Oxides Cathode for Low-Cost Na-Ion Batteries

Hirsh

Olguin

Chung

et al. 2019

J. Electrochem. Soc.

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A modified co-precipitation method is introduced to synthesize P2-type Na 0.67 Fe 1/4 Mn 3/4 O 2 cathode for low-cost Na-ion batteries. The meso-structure of the obtained material is well controlled through regulated cooling after a high temperature calcination process. The material via slow-cooling consists of sphere-like secondary particles with a uniform dispersion while the quenched material exhibits a hexagonal plate-like primary particle without meso-structure. Meso-structure is found to have a distinct effect upon the electrochemical performance of P2-type layered cathode. The slow-cooled sample exhibits a larger capacity and improved cyclability compared with the quenched sample, which is attributed to the larger surface area, reduced surface contamination, and surprisingly higher transition metal redox activity. This work demonstrates that cooling rate plays the key role in controlling the formation of spherical meso-structure for sodium iron-manganese oxides with enhanced electrochemical performance.

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Section: Resultsmentioning

confidence: 83%

Meso-Structure Controlled Synthesis of Sodium Iron-Manganese Oxides Cathode for Low-Cost Na-Ion Batteries

Hirsh

Olguin

Chung

et al. 2019

J. Electrochem. Soc.

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“…A larger crystal lattice enhances ionic transport of Na + , thus improving rate and cycle performance (As shown in Figure 3D). Normally, Ti-doping will lead to an increase in the alkalilayer distance of 1-3%, such as in NaCrO 2 (Li et al, 2019), Na 2/3 CoO 2 (Sabi et al, 2017) and Na 0.67 Fe 0.5 Mn 0.5 O 2 (Park et al, 2018). Recently, Lee et al reported enhanced rate capability and cycle performance by substitution of Ti for Fe in P2-Type Na 0.67 Fe 0.5 Mn 0.5 O 2 cathode for sodium-ion batteries (Park et al, 2018).…”

Section: Distance Between Layersmentioning

confidence: 99%

Roles of Ti in Electrode Materials for Sodium-Ion Batteries

et al. 2019

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Sodium-ion batteries offer a promising alternative to lithium-ion batteries due to their low cost, environmental friendliness, high abundance of sodium, and established electrochemical process. However, problems, such as low capacity, low storage voltage and capacity fade of electrode materials, must be resolved for the applications of sodium ion batteries. Many Ti-containing compounds were reported as cathode and anode materials, but very few studies focus on the role of Ti in electrodes used in sodium-ion batteries. This paper systemically reviews the roles of Ti in electrodes of sodium ion batteries. The Ti 4+ /Ti 3+ redox couple is a good choice for anodes due to its low potential and it exhibits different storage voltages in different structures. Although Ti 4+ does not participate in charge transfer in cathodes, it can indirectly enhance the capacity, cycling life and rate performance via structure change, cation order-disorder transition, and its interaction with the crystal lattice structure. This review will provide a new insight in designing and understanding novel high-performance electrodes. Keywords: sodium ion batteries, cathode, anode, titanium-based composite, order-disorder phase transition possibility of releasing fluorine gas becomes an environmental issue in large-scale production (Gover et al., 2006). Unlike LiFePO 4 , the olivine NaFePO 4 is thermally unstable in ambient environment and has to be produced (Kim et al., 2015) by the ion exchange of Li + in olivine LiFePO 4 with Na + , which complicates the production and increases cost (Oh et al., 2012). The commercial success of layered-LiCoO 2 in lithiumion batteries (Mizushima et al., 1980) has prompted extensive investigation of its sodium counterpart Na x TMO 2 (TM: Ni, Mn, Co, Ti) which crystallize into layered or tunneled structures depending on sodium content. The layered-structure consists of TM-O and Na-O layers. Compared to Li + , Na + has a larger radius and stronger interaction with O 2−. The sodiumlayered structure is further divided into O3, P3, P2, and O2. The O and P represent the octahedral and trigonal prismatic coordination environment of alkali ions, respectively; 3 and 2 describe the number of TM layers of repeated stacking (Delmas et al., 1980). The oxides P2/O3-Na x CoO 2 , Na x MnO 2 Na x VO 2 and Na x NiMnO 2 etc. are also investigated (Delmas et al.

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“…[12,[16][17][18][19][20][21][22][23] Among these findings, recent studies have shown that increasing the ionicity of the crystal lattice with Ti 4+ substitution, apart from increasing the redox potential, also helps in reducing number of phase transitions, hence enabling a better cyclability over a larger voltage window. They show greater rate capabilities than Li-ion via the least number of phase transitions so as to ensure long cycle life while being able to utilize their total capacity in Na-ion full cells.…”

Section: Introductionmentioning

confidence: 99%

Reaching the Energy Density Limit of Layered O3‐NaNi_0.5Mn_0.5O₂ Electrodes via Dual Cu and Ti Substitution

Wang

Mariyappan

Vergnet

et al. 2019

Advanced Energy Materials

137

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counterparts, hence offering practical interest for grid applications where capabilities for smoothening fluctuations and low cost are the overriding factors. [1][2][3][4][5][6][7] Most of the Na-ion systems demonstrated till now use hard carbon (HC) as common negative electrode and either sodium layered oxides (Na x TMO 2 , 0 < x ≤ 1, TM = transition metals) or polyanionic compounds (Na 3 V 2 (PO 4 ) 2 F 3 ) as positive electrodes. [8][9][10][11] We have recently benchmarked such Na-ion full cells having sodium layered oxide electrodes with either O3 or P2 structures and TM/TM′ of different nature against Na 3 V 2 (PO 4 ) 2 F 3 /HC cells. [12] Whatever the figures of merit we have checked, such as specific energy, cyclability as well as rate capability, the 3D Na 3 V 2 (PO 4 ) 2 F 3 (NVPF) phase outperforms the layered phases, irrespective of its high molecular weight and modest capacity (128 mAh g −1 , equivalent to 2 Na + exchange). [13] Moreover, sodium based layered oxides reported so far, whatever O or P-type structures, suffer from low redox potential, limited reversible capacity versus carbon in Na-ion full cells (hardly 50% of their theoretical capacity), Na-driven structural instability and moisture sensitivity. [14,15] So how long will this supremacy of NVPF last?To compete with NVPF, it is important to design sodium layered oxides, which can reversibly release and uptake Na + ions Although being less competitive energy density-wise, Na-ion batteries are serious alternatives to Li-ion ones for applications where cost and sustainability dominate. O3-type sodium layered oxides could partially overcome the energy limitation, but their practical use is plagued by a reaction process that enlists numerous phase changes and volume variations while additionally being moisture sensitive. Here, it is shown that the double substitution of Ti for Mn and Cu for Ni in O3-NaNi 0.5 − y Cu y Mn 0.5 − z Ti z O 2 can alleviate most of these issues. Among this series, electrodes with specific compositions are identified that can reversibly release and uptake ≈0.9 sodium per formula unit via a smooth voltage-composition profile enlisting minor lattice volume changes upon cycling as opposed to ΔV/V≈23% in the parent NaNi 0.5 Mn 0.5 O 2 while showing a greater resistance against moisture. The positive attributes of substitution are rationalized by structure considerations supported by density functional theory (DFT) calculations. Electrodes with sustained capacities of ≈180 mAh g −1 are successfully implemented into 18 650 Na-ion cells having greater performances, energy density-wise (≈250 Wh L −1 ), than today's Na 3 V 2 (PO 4 ) 2 F 3 /HC Na-ion technology which excels in rate capabilities. These results constitute a step forward in increasing the practicality of Na-ion technology with additional opportunities for applications in which energy density prevails over rate capability.

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Enhanced Rate Capability and Cycle Performance of Titanium-Substituted P2-Type Na_0.67Fe_0.5Mn_0.5O₂ as a Cathode for Sodium-Ion Batteries

Cited by 69 publications

References 50 publications

Meso-Structure Controlled Synthesis of Sodium Iron-Manganese Oxides Cathode for Low-Cost Na-Ion Batteries

Meso-Structure Controlled Synthesis of Sodium Iron-Manganese Oxides Cathode for Low-Cost Na-Ion Batteries

Roles of Ti in Electrode Materials for Sodium-Ion Batteries

Reaching the Energy Density Limit of Layered O3‐NaNi_0.5Mn_0.5O₂ Electrodes via Dual Cu and Ti Substitution

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Enhanced Rate Capability and Cycle Performance of Titanium-Substituted P2-Type Na0.67Fe0.5Mn0.5O2 as a Cathode for Sodium-Ion Batteries

Cited by 69 publications

References 50 publications

Meso-Structure Controlled Synthesis of Sodium Iron-Manganese Oxides Cathode for Low-Cost Na-Ion Batteries

Meso-Structure Controlled Synthesis of Sodium Iron-Manganese Oxides Cathode for Low-Cost Na-Ion Batteries

Roles of Ti in Electrode Materials for Sodium-Ion Batteries

Reaching the Energy Density Limit of Layered O3‐NaNi0.5Mn0.5O2 Electrodes via Dual Cu and Ti Substitution

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Product

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Enhanced Rate Capability and Cycle Performance of Titanium-Substituted P2-Type Na_0.67Fe_0.5Mn_0.5O₂ as a Cathode for Sodium-Ion Batteries

Reaching the Energy Density Limit of Layered O3‐NaNi_0.5Mn_0.5O₂ Electrodes via Dual Cu and Ti Substitution