bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mesoporous Sodium Vanadium Phosphate/Carbon As Efficient Cathode Materials for Rechargeable Sodium-Ion Batteries
Authors: Hung Tai-Feng , Cheng Wei-Jen , Chang Wen-Sheng , Yang Chang-Chung , Kuo Yu-Lin 
Published: February 2020

Rechargeable sodium-ion batteries (SIBs) have recently considered as alternative energy storage devices to lithium-ion batteries (LIBs) because of their benefits on material abundance, low cost and electrochemical similarities. In spite of the previously mentioned advantages for SIBs, there still remain challenges to realize the practicalities. In contrast to the smaller lithium cation, for example, the larger radius of sodium cation not only lowers its transportation ability but also causes the more severe structural impact and volume variation of electrode materials during the intercalation/de-intercalation processes. Therefore, searching the electrode materials with excellent structural stability, high reversible capacity, superior rate and cycling performances becomes one of the critical issues.
Among the developed cathode materials, sodium vanadium phosphate/carbon (Na3V2(PO4)3/C) nanocomposites with sodium superionic conductor (NASICON) structure have been regarded as one of the most promising candidates for SIBs owing to the high theoretical energy density (ca. 400 Wh/kg), good thermal stability (450°C) and highly covalent three-dimensional framework with large interstitial channels for fast sodium-ion migration. In the present study, mesoporous Na3V2(PO4)3 nanoparticles with highly sp2-coordinated carbon coatings (meso-Na3V2(PO4)3/C) were successfully synthesized by employing ascorbic acid as both of the reductant and carbon source, followed by calcination at 750°C in an argon atmosphere. The crystalline structure, morphology, surface area, carbon nature and amount were systematically identified by powder X-ray diffractometer, field-emission scanning electron microscope, transmission electron microscope, nitrogen adsorption-desorption technique, Raman microscope and thermogravimetric analyzer, respectively. Given their distinctive mesostructures and continuous sp2-coordinated carbon coatings, the remarkable reversible capacity (98 mAh/g@0.1 A/g), rate capability (63 mAh/g@1 A/g) and capacity retention (76 %@450 cycles@0.4 A/g) were achieved as demonstrated by galvanostatic testing. Consequently, the resultant meso-Na3V2(PO4)3/C were anticipated to function as efficient cathode materials for SIBs. More importantly, it appears to be a facile approach towards mass production of the electrode materials because the inexpensive chemicals and mild conditions were introduced to prepare the precursor powders.
Acknowledgements
We gratefully appreciate the financial support from the Bureau of Energy (BOE), Ministry of Economy Affair (MOEA), Taiwan.
Catalytic Activity Variation with the Crystal Structure Change of PdCu Nanocatalysts for Rechargeable Lithium-Oxygen Batteries
Authors: Park Mihui , Song Kyeongse , Kang Yong-Mook 
Published: February 2020

Palladium-copper (Pd-Cu) alloys have two representative crystal structures; one is body-centered cubic (bcc), the other is face-centered cubic (fcc) even though both Pd and Cu originally have fcc crystal structures. The fcc Pd-Cu alloys have disordered structure within which Pd and Cu atoms are positioned randomly in fcc lattice, whereas the bcc Pd-Cu alloys have ordered structure which consists of alternative layers with either Pd or Cu atoms. In order to properly design the optimum Pd-Cu alloys, its physical and chemical characteristics have been extensively controlled.
Pd-Cu alloys have been widely utilized as a catalyst for the hydrogenation of carbonyl compounds, the reduction of nitrates and nitrites in water, the oxidation of formic acid in direct formic acid fuel cell, the membrane for hydrogen separation and so on. In particular, bcc Pd-Cu alloys have occasionally shown superior performance to fcc Pd-Cu alloys. As for the hydrogenation of acetylene, bcc Pd-Cu alloy have better ethylene selectivity than fcc Pd-Cu alloys, because isolated Pd atoms on the surface of bcc Pd-Cu alloys enhance selectivity. Most of bcc Pd-Cu alloys have been synthesized by annealing fcc Pd-Cu alloys for structural transformation and particle growth. Hence, the same size of fcc and bcc Pd-Cu alloys is quite difficult to be obtained because the crystallites larger than 20 nm favour the ordered bcc structure with lower symmetry. Thus, bcc Pd-Cu alloys in nanoscale have been rarely reported, and fcc and bcc Pd-Cu alloys have never been properly compared until now.
In this study, we successfully synthesized fcc and bcc Pd-Cu alloys in nanoscale through a simple polyol process. For the comparison between these in catalytic activity, we adopted fcc and bcc Pd-Cu alloys as cathode catalysts for lithium-oxygen batteries. This work would firstly report the comparison between the catalytic activities of fcc and bcc Pd-Cu alloys in nanoscale.
The Effect of the V2O5 Morphology on the Intercalation Behavior of Na+-Ions
Authors: Seidl Lukas , Martens Sladjana , Stimming Ulrich , Schneider Oliver 
Published: February 2020

Na-ion batteries (NIBs) are one of the most promising technologies to replace the costly Li-ion batteries (LIBs), since the latter suffer from a lower Li-abundance, which makes LIBs more expensive.1
,
2 Additionally to the higher Na-abundance, Na does not, in contrast to Li, form an Al-alloy during battery operation, which allows the use of Al-current collectors instead of the costly and heavy weight Cu used in LIBs.3 These advantages on the other hand are balanced by restrictions of the NIBs originating from the larger ionic radius and atomic weight of the Na+-ions.3
,
4

Since V2O5 is a suitable intercalation host material for Na+-ions and it can be structured in a wide morphological variety,5
,
6
,
7
,
8
,
9 the effect of structural properties of V2O5 electrodes on the Na+-intercalation has been studied. For this purpose different V2O5 morphologies, ranging from nanostructures, like single crystalline nanobelts, to microstructures, like solid, hollow or yolk-shell V2O5-spheres, were electrochemically tested as cathode material, considering the impact on e.g. phase transformations, capacity, rate capability, efficiency and cycling stability.

References

1. Yabuuchi, N., Kubota, K., Dahbi, M. & Komaba, S. Research Development on Sodium-Ion Batteries. Chem. Rev.
114, 11636–11682 (2014).
2. Palomares, V. et al. Na-ion batteries, recent advances and present challenges to become low cost energy storage systems. Energy Environ. Sci.
5, 5884 (2012).
3. Slater, M. D., Kim, D., Lee, E. & Johnson, C. S. Sodium-Ion Batteries. Adv. Funct. Mater.
23, 947–958 (2013).
4. Hong, S. Y. et al. Charge carriers in rechargeable batteries: Na ions vs. Li ions. Energy Environ. Sci.
6, 2067 (2013).
5. Tepavcevic, S. et al. Nanostructured bilayered vanadium oxide electrodes for rechargeable sodium-ion batteries. ACS Nano
6, 530–538 (2012).
6. Su, D. & Wang, G. Single Crystalline Bilayered V2O5 Nanobelts for High-Capacity Sodium-Ion Batteries. ACS Nano
7, 11218–11226 (2013).
7. Su, D. W., Dou, S. X. & Wang, G. X. Hierarchical orthorhombic V2O5 hollow nanospheres as high performance cathode materials for sodium-ion batteries. J. Mater. Chem. A
2, 11185 (2014).
8. Uchaker, E. et al. Better than crystalline: amorphous vanadium oxide for sodium-ion batteries. J. Mater. Chem. A
2, 18208–18214 (2014).
9. Kim, H., Kim, D. Y., Kim, Y., Lee, S.-S. & Park, K. Na Insertion Mechanisms in Vanadium Oxide Nanotubes for Na-Ion Batteries. ACS Appl. Mater. Interfaces
7, 1477–1485 (2015).
1D Structured Fe-Doped Tunnel Na0.44MnO2 Cathode Material with Excellent High Rate and Long Cycle Life Performance for Sodium Ion Battery Application
Authors: Amedzo-Adore Mawuse , Han Dong-Wook , Yang Junghoon , Kang Yong-Mook 
Published: February 2020

Due to concern over the sustainability of Lithium ion battery (LIB) as energy storage system as a result of its limited resources, sodium ion battery (SIB) has been considered as an alternative energy storage system to supplement LIBs, due to the fact that, sodium is abundant and less expensive comparable to lithium. Concentration have been on obtaining the appropriate electrode materials for SIB application. NaxMnO2 has demonstrated its ability as a cathode material in SIB. There are different phases of these materials depending on the amount of Na present. Among these Mn-based cathode materials, tunnel Na0.44MnO2 structure, have received wide attention due to; its large channel which is considered to be suitable for ion insertion/extraction process as a cathode, and structural stability attributed to the formation of MnO5 pyramid and sheets of edge-shared MnO6 octahedral to form a large S-channel. However, these tunnel materials suffer from low initial charge and reversible capacities. Also, they are known to have drawbacks associated with lattice transformation which is attributed to Jahn-Teller distortion and Mn2+ dissolution as a result of disproportionation reaction of Mn3+ into Mn2+ and Mn4+ during repeated cycling. These disadvantages are considered to cause considerable strains in the crystal structure, leading to inferior rate and cycling performance.
To find remedy to the above drawbacks and to enhance electrochemical performance, 1D nanostructured Fe-doped Na0.44MnO2 was adopted. Fe substitution of Mn in the structure, helps to maintain material structural stability by suppressing Mn dissolution during cycling, and also give rise to increase in the operating voltage leading to increase in the energy density of the material. 1D nanostructured materials generally shows better performance as it improves the ion diffusion rate. The above adopted strategies provide improved electrochemical performance with excellent rate capability and long cycle life comparable to pristine tunnel Na0.44MnO2 for SIB application.
Mesoporous RuO2/Fe2O3 Nanofiber As Efficient Electrocatalyst for Lithium Oxygen Batteries
Authors: Huang Zhimei , Shen Yue , Huang Yunhui 
Published: February 2020

Recently, great attentions have been paid to the development of Lithium oxygen batteries (LOBs) as for its highest energy density up to 3505 Wh kg-1 than the conventional Lithium ion batteries1,2. However, there still have some obstacles to make it practical application in respect of its sluggish charge transfer between the insulating Li2O2 and electrode surface. Thus, many challenges like high overpotential, poor cycle stability, and low rate capacity exists and limits its applications in life. Many researches have made great progress in the development of the OER catalyst which can promote the dissolution of Li2O2. Among them, RuO2 has been widely investigated due to their high electronic conductivity and superior catalytic activity especially for OER3. Additionally, many metal oxides were also been studied in catalyzing the OER reactions, while Fe-based catalysts that exhibit electrocatalytic activities in fuel cells were seldom studied in Li-O2 batteries. Therefore, in this text, we synthesize mesoporous RuO2/Fe2O3 nanofibers by electrospinning as efficient and cost-effective OER catalyst. The synthetic mesoporous RuO2/Fe2O3 nanofibers has a high surface area which is benefit to the diffusion of oxygen and transfer of ions. The discharge and charge capacity in the first cycle are as high as 5600mAh/g and 5200mAh/g at a current density of 200mA/g with lower charging potential, respectively. In addition, a well cycling performance was achieved when limited capacity of 2000mAh/g due to the unique structure of cathode catalyst which has a high surface area with more reaction sites and enough space for Li2O2 deposition. In this way, the mesoporous RuO2/Fe2O3 nanofibers as a new cathode catalyst shows combined effect in catalyzed the dissolution of Li2O2. Reference:

1. Bruce, P. G.; Freunberger, S. A.; Hardwick, L. J.; Tarascon, J.-M. Nat. Mater.
2012, 11, (1), 19-29.
2. Luntz, A. C.; McCloskey, B. D. Chemical reviews. 2014, 114, (23), 11721-50.
3. Yoon, K. R.; Lee, G. Y.; Jung, J.-W.; Kim, N.-H.; Kim, S. O.; Kim, I.-D. Nano Letters. 2016, 16, (3), 2076-2083.

Figure 1
High-Capacity Na-Excess Positive Electrode Materials; Na3NbO4-NaMnO2 Binary System
Authors: Sato Kei , Yabuuchi Naoaki 
Published: February 2020

The research interest for rechargeable sodium batteries is rapidly growing, especially for the large scale energy storage. Recently, we have reported a new Li-excess positive electrode material, Li3NbO4 – LiMnO2,[1] which effectively utilizes solid-state redox reaction of oxide ions, instead of classical redox of transition metals. The use of Na-excess materials and anion redox is important strategy to further increase the energy density of rechargeable sodium batteries.[2] In this study, Na3NbO4 is targeted as a model material and the possibility of new high-capacity electrode materials with the anion redox is examined. Our trials to synthesize Na3NbO4-NaMnO2 binary system by a conventional solid-state method were, however, failed, and therefore the materials were prepared via a non-equilibrium route.NaMnO2 was prepared by solid-state reaction from Na2CO3 (99.5 %, Wako Pure Chemical Industries, Ltd) and Mn2O3 and Na3NbO4 was prepared from Na2CO3 and Nb2O5 (99.9 %, Wako Pure Chemical Industries, Ltd). Both oxides were used as precursors. A mixture of Na3NbO4 and NaMnO2 was ball-milled using a ZrO2 pot and balls. Figure 1a shows X-ray diffraction patterns of the samples of x = 0.43 in x Na3NbO4 – (1–x) NaMnO2 binary system as a function of milling time. The chemical formula of the sample is reformulated as Na1.3Nb0.3Mn0.4O2. The mixture of Na3NbO4 and NaMnO2changes into cation-disordered rocksalt phase after the mechanical milling for 24 h. SEM images before and after ball-milling (24 h) are also compared in Figure 1b. Particle size are decreased to nano scale with spherical morphology. Moreover, thus prepared sample delivers large reversible capacity which cannot be explained on the basis of redox reaction of the transition metal ions.From these results, we will discuss the possibility of Na-excess positive electrode materials with anion redox for rechargeable Na batteries. References[1] N. Yabuuchi, M. Takeuchi, M. Nakayama, H. Shiiba, M. Ogawa, K. Nakayama, T. Ohta, D. Endo, T. Ozaki, T. Inamasu, K. Sato, and S. Komaba, PNAS, 112, 7650-7655 (2015).[2] P. Rozier, M. Sathiya, A.-R. Paulraj, D. Foix, T. Desaunay, P.-L. Taberna, P. Simon, J.-M. Tarascon, Electrochemistry Communications, 53, 29 (2015).

Figure 1
An Electrically Rechargeable Al-Air Battery with Aprotic Ionic Liquid Electrolyte
Authors: Bogolowski Nicky , Ngaleu Olivia , Drillet Jean-Francois 
Published: February 2020

Because of their higher theoretical energy density, lower toxicity, less expensive electrode materials and non-affinity to thermal runaway like e.g. Li-based systems, metal/air batteries such as Al/air (8040 vs. 2046 Ah L-1for Li) are potential candidates for sustainable energy storage applications. However, large scale commercialisation is hindered by some inherent drawbacks related to the metal electrode such as irreversibility (not electrochemically rechargeable), passivation and parasitic hydrogen evolution as well as low energy efficiency [1]. In this context, recent developments in aprotic room temperature ionic liquids (RTIL) based electrolytes such as 1-Ethyl-3-methylimidazolium (EMIm) chloride + aluminum chloride and 1-Butyl-1-methylpyrrolidinium (BMPyr) open new perspectives for Al deposition/dissolution, especially with respect to suppression of passive layer formation and self-discharge due to hydrogen evolution [2,3]. Most of the ILs, however, are highly viscous and consequently have a very low ionic conductivity that drastically limits reaction kinetics. Other crucial aspects are related to the low surface tension of pure ILs compared to water that commonly hinders 3-phase boundary formation at the gas-diffusion electrode. Development of highly active and stable bi-functional air electrode catalysts is still challenging as well. By nature some catalysts are poor electronic conductors or need distribution/support, requiring the addition of conductive materials such as carbon/graphite. For long-term stability of the gas diffusion electrode, highly corrosion-resistant carbon material is required.
In this work, commercial carbon materials have been tested regarding their stability by means of TGA and electrochemical accelerated degradation tests (ADT) in 7 M KOH. Carbon materials KS6L, C65 and Vulcan showed the highest both thermal and electrochemical stability. La0.7Ca0.3CoO3 (LCCO) and Ba0.5Sr0.5C00.8Fe0.2O3 (BSCF) were synthesized by a sol-gel process and characterized by XRD and SEM. GDE fabrication was performed by calendering a catalyst/carbon/PTFE mixture onto a Ni current collector. LCCO/C and BSCF/C activity and stability for oxygen reduction (ORR) and oxygen evolution (OER) reaction were first evaluated in 7 M KOH under half-cell conditions where 1750 and 2000h operation at 10 mA cm-2 was reached, respectively without any relevant cell potential decay. First experiments with ILs were conducted in a commercial El-Cell setup. Performance of as-prepared perovskite-based GDEs in different ILs was compared with that of a commercial Pt-C one. At a catalyst loading of 1 mg cm-2 for GDE, best results were obtained with Al foil // EMIMCl + ACl3 // Pt-C combination at 50 µAcm-2.
Literature:
[1] Pino, M.; Chacón, J.; Fatás, E.; Ocón, P., J. Power Sources 299 (2015) 195
[2] Zein El Abedin et al., Electrochemistry Communications 12 (2010) 1084
[3] Giridhar, P.; Zein El Abedin, S.; Endres, F., Electrochimica Acta 70 (2012) 210
An Inkjet-Printed Hydrogen Peroxide Sensor on Paper
Authors: Shamkhalichenar Hamed , Choi Jin-Woo 
Published: February 2020

This work presents a fully inkjet-printed electrochemical sensor on paper for non-enzymatic detection of hydrogen peroxide. A simple and low cost hydrogen peroxide (H2O2) sensing is desired in biomedical and environmental analysis. Enzyme-based sensors have widely been used but the possible chemical and thermal deformation of enzymes during the fabrication of the sensors may influence the stability and reliability of the sensors [1]. An alternative to enzymatic sensing could be electrocatalytic detection utilizing the electrocatalytic property of silver (Ag) nanoparticles in reducing H2O2[2].
In this work, we utilize the same principle for a fully printed sensor on paper. An ink solution containing multi-walled carbon nanotubes and silver nanoparticles has been developed before printing the electrode patterns on paper. Using an office inkjet printer and the developed ink, an electrochemical sensor has been designed and printed as shown in Figures 1(a) and 1(b). A total of 50 prints were applied to form the electrodes with high conductivity. A hydrophobic barrier formed by a wax has also been patterned to prevent a sample solution reaching from electrical contacts.
The developed sensor was tested with different concentrations of hydrogen peroxide samples. A custom-made potentiostat circuit was used for testing the sensor. Step voltammetry was used by measure the current response after applying -0.3 V to the working electrode. Figure 1(c) shows preliminary results of the sensor response demonstrating that the working electrode current increased with the concentration of H2O2.
In summary, a fully inkjet-printed hydrogen peroxide sensor has been demonstrated and its preliminary results have been obtained. The sensor design is currently under optimization to achieve a lower detection limit and high sensitivity.
References
[1] M. Song, S. Hwang, and D. Whang, “Non-enzymatic electrochemical CuO nanoflowers sensor for hydrogen peroxide detection,” Talanta, vol. 80, no. 5, pp. 1648-1652, 2010.
[2] W. Zhao, H. Wang, X. Qin, X. Wang, Z. Zhao, Z. Miao, L. Chen, M. Shan, Y. Fang, and Q. Chen, “A novel nonenzymatic hydrogen peroxide sensor based on multi-wall carbon nanotube/silver nanoparticle nanohybrids modified gold electrode,” Talanta, vol. 80, no. 2, pp. 1029-1033, 2009.
Figure 1. Inkjet-printed hydrogen peroxide sensor: (a) the sensor design with working, counter, and reference electrodes all formed with inkjet printing; (b) a picture of the printed sensor on paper, and (c) preliminary results of the developed sensor.

Figure 1
a Study on Degradation of Ni-YSZ Anode Materials in Terms of Redox Stability for Solid Oxide Fuel Cells
Authors: Park Jae-Woo , Park Yoon-Tae , Lee Sang-Hun , Lee Ki-Tae 
Published: February 2020

▪
Introduction

Solid oxide fuel cells (SOFCs) have lately attracted considerable attention as the source of new energy considering environmental pollution and exhaustion of underground resources. Nickel-yttria stabilized zirconia (Ni-YSZ) cermet has been used as an anode material for SOFCs for more than 20 years. Although Ni-YSZ has various advantages such as high catalytic activity for H2 oxidation and methane reforming, stability in reducing atmosphere, high electrical conductivity, it exhibits various types of degradations such as poor redox stability, sulfur poisoning, carbon deposition. Ni-YSZ anode still suffers from exposure to oxidizing condition caused by sudden interruption of fuel or sealing problem like leakage. When exposed in oxidizing atmosphere, Ni-YSZ experiences significant volume change due to the oxidation of Ni to NiO, which causes internal cracks and consequent destruction of the cell. In this study, the redox stability of Ni-YSZ cermet according to various conditions such as porosity, pore size distribution, and composition has been studied systematically.

▪
Experimental

NiO-YSZ composite powders have been prepared by mixing of commercial NiO (High purity chemicals, 99.97%), 8YSZ (TZ-8YS: 8 mol% Y2O3-stabilized ZrO2, 99.9% Tosoh, Japan) and PMMA as a pore former. The NiO-YSZ bulk samples were fabricated by the typical die compaction method and sintering at 1450 °C for 4 h in air. The sintered NiO-YSZ samples were reduced at 800 °C for 3 h in H2 in order to make Ni-YSZ. The phase change was confirmed by the X-ray diffraction (XRD). The morphology of Ni-YSZ was investigated by scanning electron microscopy (SEM). Degree of oxidation (D.o.O) of Ni was calculated from thermogravimetric analysis (TGA) data. The amount of volume change of Ni powders during oxidation was measured using a helium pycnometer. The both porosity and pore size distribution of Ni-YSZ bulk samples were analyzed with mercury porosimeter. The linear length change of Ni-YZ during oxidation was measured using dilatometer.

▪
Results and Discussion

If we know both temperature and time of exposure in oxidizing atmosphere, we can predict the D.o.O of Ni at a certain condition using the D.o.O equation obtained from TGA data. The percentage weight gain per specific surface area can explain the oxidation kinetics of the Ni-YSZ anode supports, which obeys a multi-stage parabolic law expressed by Kp. Kp can be expressed by Kp1 and Kp2. Kp1 and Kp2 correspond to fast oxidation reaction at early oxidation stage and slow oxidation reaction at the next oxidation stage, respectively. The volume change of Ni-YSZ caused by oxidation can be the result of two competing factors: expansion caused by NiO formation and shrinkage caused by continuous sintering of both Ni and NiO. Ni-YSZ cermet with high porosity showed higher tolerance to the cumulative length change due to providing the more relaxation space.