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PolyanionNaNi1 − xCuxPO4 glass and glass-ceramic cathode network: Structure with improved electrochemical performance
(2024-07-01)
Grandhe, Radhika
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Katta, Vamsi Krishna
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Padala, Missak Swarup Raju
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Dutta, Dimple P.
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WisanuPecharapa
PolyanionNaNi<inf>1 − x</inf>Cu<inf>x</inf>PO<inf>4</inf> glass and glass-ceramic networks are prepared by Melt-quenching and after heat treated for 5 h at its T<inf>c</inf>, regarded as probable cathode composite material for Na-ion batteries (SIBs). The intensity variations arrived from XRD traces, revealed that the phases NaNi<inf>4</inf>(PO<inf>4</inf>)<inf>3</inf> (ICSD 60-964), NaCu(PO<inf>4</inf>) (ICSD 581-303), and Na<inf>2</inf>CuNi(PO<inf>4</inf>)<inf>2</inf> (ICSD 20-22594) which are precipitated during heat treatment is primarily caused by the partial substitution of tetrahedral PO<inf>4</inf> and CuO<inf>6</inf> sites with NiO<inf>6</inf> structural active sites in the glass-ceramic network resulting to accommodate sudden volume changes, and therefore diffusion of Na+ ions will be improved along with fast rate capability and voltage for longer durations as reflected in SEM image analysis. The cyclic voltammogram of half-cell of best conducting NaNi<inf>0.3</inf>Cu<inf>0.7</inf>PO<inf>4</inf> glass-ceramic cathode with a voltage range of 0.2 to 4 V and 100 V/S cycles noted to achieve lowest cell polarization (0.41 V) with best capacity retention of discharge (96%) up to 1000 cycles. Graphical abstract: (Figure presented.)
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Glass-Ceramic Na3+x[(Zr/Cr)x(Sc/Ti)2-x(PO4)3 Electrolyte Materials for Na-Ion Full-Cell Application
(2023-01-01)
Gandi, Shyam Sundar
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Katta, Vamsi Krishna
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Jayasankar, C. K.
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Pecharapa, Wisanu
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Ravuri, Balaji Rao
Na<inf>3+x</inf>[(Zr/Cr)<inf>x</inf>(Sc/Ti)<inf>2-x</inf>(PO<inf>4</inf>)<inf>3</inf>] glass-ceramic material compositions containing NASICON-type crystalline phases might be a good candidate as an efficient electrolyte exclusively for Na-ion batteries. All-solid-state Na-ion full cells are designed with the three-layered pellets (NaCo<inf>0.7</inf>(VO)<inf>0.3</inf>PO<inf>4</inf>/Na<inf>3.5</inf>Zr<inf>0.5</inf>Sc<inf>1.5</inf>(PO<inf>4</inf>)<inf>3</inf> (NZSP) and Na<inf>3.5</inf>Cr<inf>0.5</inf>Ti<inf>1.5</inf>(PO<inf>4</inf>)<inf>3</inf>) (NCTP)/Na-metal foil). The electrical conductivity of the NZSPglass-ceramic powder sample achieves to be highest (9.47 × 10−04 S/cm) due to its lower grain boundary resistance (R <inf>gb</inf>) as observed in SEM images and also exhibits best electrochemical stability against conductivity when the samples kept in ambient air for 60 d. The charge/discharge capacities for the initial cycle are 75/69 and 60/53 mAhg−1 to both NZSP and NCTP of two full cells, respectively. However, discharge capacities are boosted up for both these cells without much loss in coulombic efficiency even after 10 cycles.
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Synthesis of NaYF4:Yb,Er/AgInS2 nanoheterostructures
(2022-11-01)
Buatong, Nattha
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Ravuri, Balaji Rao
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Pecharapa, Wisanu
Multicomponent nanoheterostructure containing upconverting materials and semiconductor nanocrystals have been a growing interest in recent years. An interaction between these components can improve the existing and induce new materials and electronic properties. Here, we reported the synthesis of new nanoheterostructure consisting of NaYF<inf>4</inf>:Yb,Er decorated with AgInS<inf>2</inf> nanocrystal via a thermal decomposition reaction. The NaYF<inf>4</inf>:Yb,Er were used as seed crystal of the synthesis of NaYF<inf>4</inf>:Yb,Er/AgInS<inf>2</inf> nanoheterostructure. The results of combine upconverting and semiconducting materials indicate that the NaYF<inf>4</inf>:Yb,Er/AgInS<inf>2</inf> nanoheterostructure shows photoactivity under NIR irradiation. Compared with pure AgInS<inf>2</inf> nanocrystal, the nanoheterostructure of NaYF<inf>4</inf>:Yb,Er/AgInS<inf>2</inf> exhibits a strong light absorption characteristics in visible region, which more effective than that of pure AgInS<inf>2</inf> nanocrystal.
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Improved Na+ ion storage capacity of Na2O-Bi2O3 glass anode network: effect of TiO2 nanocrystals
(2022-01-01)
Yerranuka, Saritha Kumari
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Katta, Vamsi Krishna
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Mekprasart, Wanichaya
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Pecharapa, Wisanu
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Dutta, Dimple P.
This investigation highlights the influence of nanosized amorphous intermediate domains such as Na<inf>3</inf>Bi and Na<inf>2</inf>Ti on the electrochemical characteristics of the new Na<inf>2</inf>O-Bi<inf>2</inf>O<inf>3</inf> glass anode network mixed with TiO<inf>2</inf> nanocrystals. Amorphous domains (h-Na<inf>3</inf>Bi and h-Na<inf>2</inf>Ti) are indexed with hexagonal structures precipitated during the charging and discharging process, which might improve the high electrochemical performance of the glass anode network to a greater extent. The first discharge and charge capacities are recorded as 700 and 1060 mAh/g, respectively. Moreover, the Coulombic efficiency achieved is between 66 and 98% as the current rate varies from 0.1 C to 5 C. The value of R<inf>ct</inf> in the EIS spectra gradually decreases up to 500 cycles, indicating an increase in the electronic conductivity, eventually boosting the ionic conductivity. These results will create a potential interest to design and develop various glass and glass–ceramic anode networks to realize Na-ion technology for large-scale energy storage applications.
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Characterization, X-ray absorption spectroscopic analysis and photocatalytic activity of Co/Zn co-doped TiO2 nanoparticles synthesized by one-step sonochemical process
(2021-10-01)
Mekprasart, Wanichaya
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Pavasupree, Sorapong
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Jayasankar, C. K.
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Ravuri, Balaji Rao
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Wattanawikkam, Chakkaphan
A novel one-step preparation of sonochemical method was applied to synthesize Co/Zn co-doped TiO<inf>2</inf> nanoparticles using a sonicator of 750 W, 20 kHz for 30 min at room temperature. The formation of the anatase TiO<inf>2</inf> phase for all as-prepared samples was observed from XRD results with a crystalline size in nanoscale. The use of ultrasound allowed for the successful doping of both Co and Zn into the TiO<inf>2</inf> lattice, which was confirmed by Synchrotron light including X-ray near edge structure (XANES) and Extended X-ray absorption fine structure (EXAFS) spectroscopy. Ti K-edge, Co K-edge, and Zn K-edge XANES spectra exhibited the dominating +4, +2, and +2 valence state of Ti, Co, and Zn in as-prepared samples, respectively. A detailed XANES and EXAFS data analysis give strong evidence that the Co/Zn dopants partially replace the Ti atom of the TiO<inf>2</inf> host. The Co/Zn co-doping extends the light absorption of the host to the visible region and restricts the e+/h+ recombination. The photocatalytic activity of samples was tested for degradation of Rhodamine B dye solution under visible light irradiation. The as-synthesized of the co-doped catalyst was presented as highly efficient, with 2.5 and 5 times dye degradation compared with single-doped and bare TiO<inf>2</inf>.
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Mixed Polyanion Na-Mn-V-P Glass–Ceramic Cathode Network: Improved Electrochemical Performance and Stability
(2021-02-01)
Katta, Vamsi Krishna
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Gandi, Suman
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Katari, Naresh Kumar
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Mekprasart, Wanichaya
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Pecharapa, Wisanu
This investigation demonstrates the electrochemical performance of glass and glass–ceramic NaMn<inf>1−x</inf>(VO)<inf>x</inf>PO<inf>4</inf> (x = 0.1, 0.3, 05, 0.7 mol%, and labeled as NM<inf>1−x</inf>V<inf>x</inf>P) cathode material system via phase details, structural illustration, electronic conductivity, and reversible capacity, etc. Pro-crystal calculation analysis is used to monitor Na+ ion pathways’ migration for as-precipitated NaMnPO<inf>4</inf>, Na<inf>2</inf>MnP<inf>2</inf>O<inf>7</inf>, and NaVO<inf>3</inf> phases. The highest conductivity is achieved (≈5.92 × 10−7 S cm−1) for the glass–ceramic sample having x = 0.3 mol% (NM<inf>0.7</inf>V<inf>0.3</inf>P) due to the lowest charge transfer resistance (R<inf>ct</inf>). Electrochemical measurements of the best conducting sample using coin half-cell exhibit two distinct voltage plateaus at 2 and 2.9 V versus Na/Na+, facilitating the active centers in two directions. The cyclability test of best-conducting NM<inf>0.7</inf>V<inf>0.3</inf>P glass–ceramic network exhibits adequate reversible capacity up to 97% of the specific capacity even up to 50 cycles, which satisfies its superior stability for longer durations.
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Antibacterial activity of yellow zinc oxide prepared by high-energy ball milling technique
(2020-10-26)
Mekprasart, Wanichaya
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Chutipaijit, Sutee
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Ravuri, Balaji Rao
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Pecharapa, Wisanu
Size reduction in nanoscale of commercial zinc oxide (ZnO) powder is required to enhance its promising properties. Therefore, milling technique is one of an effective method to produce ultrafine ZnO powder. Milling speed is the important parameter that affected on size reduction of the particles. In this work, commercial ZnO powder was milled at 0, 200, 400 and 600rpm by high energy ball milling process during 10min. Surface morphology of milled ZnO powder was monitored by scanning electron microscopy (SEM). Meanwhile, crystalline structure of all samples was investigated by X-ray diffractometer (XRD). Moreover, the defect in the samples after milling process at different speed was analyzed by photoluminescence emission spectra (PL). XRD result showed that ZnO diffracted patterns was identically in hexagonal crystalline phase at different milling speed. ZnO particle size was distinctly decreased approximately 200nm according to the increase of milling speed as affirmed by SEM images. However, yellow ZnO powder was obviously occurred at the highest milling speed (600rpm). This phenomenon is originated from the deep defect levels of oxygen vacancies as identified and interpreted by PL spectra at green emission. Additionally, ZnO powders in white and yellow status at different milling speed were monitored by antibacterial application compared with commercial grade. The efficiency of yellow ZnO powder after milling at 600rpm in antibacterial property still showed its excellent properties as considering in the largest clear zone in the experiment.
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Improvement in fast Na-ion conduction in Na3+xCr xTi2−x(PO4)3 glass–ceramic electrolyte material for Na-ion batteries
(2020-10-01)
Gandi, Shyam Sundar
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Gandi, Suman
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Katari, Naresh Kumar
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Mekprasart, Wanichaya
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Pecharapa, Wisanu
Abstract: In this report, efforts were made to investigate and characterize a variety of compositions in a glass system of general formula Na<inf>3+x</inf>Cr<inf>x</inf>Ti<inf>2−x</inf>(PO<inf>4</inf>)<inf>3</inf> (x = 0, 0.25, 0.5 and 0.75 mol%, designated as NCTP<inf>x</inf>) to optimize their properties for use in Na-ion batteries. Several crystalline phases such as Na<inf>3</inf>Ti<inf>2</inf>(PO<inf>4</inf>)<inf>3</inf> (COD-4106515) (NASICON), Cr<inf>2</inf>O<inf>3</inf> (ICSD-25781) and Cr(PO<inf>3</inf>)<inf>3</inf> (ICSD-39410) are precipitated during the process of crystallization. The microstructures of all the glass and glass–ceramic samples are analyzed using SEM and are correlated with powder XRD to explain the ionic conductivity for a given glass–ceramic sample. Single semicircle in the complex impedance plots clearly suggests that the present NCTP<inf>x</inf> glass samples exhibit a predominantly single-ion conduction mechanism. Electrical conductivity data follow the Arrhenius equation. The power-law exponent ‘s’ is observed to be the lowest (0.70) for the best conducting glass–ceramic sample NTCP<inf>0.5</inf> (4.24 × 10−4 S/cm). The electrical modulus study proves that the conductivity relaxation of NCTP<inf>x</inf> glass–ceramic samples is temperature independent. Scaling behavior in the normalized spectra indicates that frequency-dependent relaxation behavior is unaffected by the temperature. Graphic abstract: [Figure not available: see fulltext.].
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Na–Ge glass anode network mixed with bismuth oxide nanocrystallites: A high capacity anode material for use in advanced sodium-ion battery design
(2020-02-15)
Gandi, Suman
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Mekprasart, Wanichaya
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Pecharapa, Wisanu
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Dutta, Dimple P.
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Jayasankar, C. K.
Exploring the growing phenomenon of amorphous intermediate domains at nanoscale and its application as flexible active centres in a glass anode network is decisively significant to enhance sodium-ion battery performance. The outstanding stability of nanosized h-Na<inf>3</inf>Bi and NaGe domains in the glass anode network makes it more electrochemically efficient and increases its ionic conductivity. Subsequently, improved cycle stability and rate capability of glass anode half-cell have been achieved due to optimum void space between domains and open glass network. It also exhibits enhanced ability to withstand extensive volume variations during the repetitive sodiation/de-sodiation process. The size of the amorphous intermediate domains, structure, and lattice planes separation has been estimated based on the HRTEM and SAED images. The advantages gained by the growth of amorphous domains in the sodium-germanate glass network highlights its potential application as high-performance anode components for the advancement of Na-ion battery (NIB) efficiency.
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