bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical and Structural Characterizations of a Zinc-Ion Battery System Consisting of Zn2Mo6S8 As the Negative and Zn3[Fe(CN)6]2 As the Positive Material
Authors: Chae Munseok S , Hong Seung-Tae 
Published: February 2020

The rechargeable zinc-ion batteries have received attention as candidates for large-scale energy storage systems, being expected to give high performances in terms of the cost effectiveness due to the abundance of the elements, the safety, the energy density and the environmental friendliness.[1, 2] However, zinc metal has serious dendrite problems, resulting in low stability. Using intercalation-based anode materials could be a viable way to solve such problems.
In this work, we have constructed the prototype of such a zinc-ion battery system, employing Zn2Mo6S8 as the anode material since it intercalates zinc ions at low operating voltage of 0.35 V (vs. Zn2+/Zn),[3] and Zn3[Fe(CN)6]2 as the cathode material that also intercalates zinc ions at higher voltage of 1.75 V (vs. Zn2+/Zn) in ZnSO4 aqueous electrolytes (Fig. 1a and 1b). The negative and positive electrodes consisted of the active materials (Mo6S8 and Zn3[Fe(CN)6]2, respectively), the conductive carbon (Super P), and the binder [poly(vinylidene difluoride)] (8:1:1 w/w). The full-cell system was composed of the negative and the positive electrodes with a mass ratio of 5.5:1. The sufficiently high N/P loading ratio produced a positive-electrode limiting cell. Fig. 1b shows the discharge-charge profiles of each electrode measured with three-electrode system with zinc metal as the reference electrode. The negative electrode showed a flat profile at 0.35 V due to the high N/P ratio. The positive electrode was discharged to 1.10 V, displaying the capacity of 62.3 mAh g-1, and subsequently charged up to 2.05 V. The discharge-charge profile for the two-electrode full-cell showed a reversible cycle with the average discharge voltage at 1.40 V, demonstrating a successful zinc-ion battery system.
Detailed analyses with ICP-OES, EDX, XRD were performed to confirm the zinc intercalation chemistry. This result should be an important basis for understanding the electrochemical intercalation reaction of zinc as well as other divalent ions into various host materials.

References

[1] C. Xu, B. Li, H. Du, F. Kang, Angew. Chem., 2012, 124, 957–959.
[2] L. Zhang, L. Chen, X. Zhou, Z. Liu, Adv. Energy Mater., 2015, 5, 1400930.
[3] M. S. Chae, J. W. Heo, S. –C. Lim, S. –T. Hong, Inorg. Chem., 2016,
55, 3294–3301.

Figure 1
Compatibility Studies with New F-Free Electrolyte for Sodium Ion Batteries
Authors: Bitner-Michalska Anna , Trzeciak Tomasz , Poterala Marcin , Zukowska Grazyna Zofia , Niedzicki Leszek , Wieczorek Wladyslaw , Marcinek Marek 
Published: February 2020

Up to now sodium battery technology finds application for high temperature systems such as sodium-sulfur and sodium-metal chloride batteries. The challenge, which we took up was synthesis and investigation of the new F-free sodium salts as a base for electrolytes working at room-temperature batteries.
While the best conductivities have been shown by fluorinated salts, there is a paradigm shift in research and development. Since fluorinated salts may negatively affect electrolyte safety, cost and environmental friendliness, some researchers are looking for fluorine-free options [1]. Even partial elimination of the salts containing fluorine (both type YFX
n-or fluoro-organic) should lead to limiting production and emissions of toxic compounds to the environment. Use of a salt which doesn’t contain fluorine has also significant advantages such as stability of the electrode-electrolyte phase boundary in batteries or lack of formation of lithium fluoride layer at the solid-electrolyte interphase.
Three novel sodium salts: sodium pentacyanopropenide, sodium 2,3,4,5-tetracyanopirolate and sodium 2,4,5-tricyanoimidazolate were dissolved in organic solvents for sodium-ion batteries electrolytes. Salts were selected with respect to their fluorine-free composition and diffused negative charges. Due to the unique, non-covalent structural configurations of anions, improved electrolyte properties were observed [2]. Excellent dissociation of salts in carbonate such as PC or mixed carbonates EC/DMC results in high conductivity at room temperature. All presented salts showed high thermal stability and suitable width of electrochemical stability windows between 3 and 5 V.
For the very first time new type of electrolyte based on F-free sodium salts were studied versus electrode materials. Their superior electrochemical properties, compared to the reference systems will be presented.
[1] Scheers, J., et al. All fluorine-free lithium battery electrolytes. J. Power Sources
251,451-458 (2014)
[2] Plewa-Marczewska, A. et al., New Tailored Sodium Salts for Battery Applications, Chem. Mater., 26 (2014), 4908–4914
Improved Performance and Fabrication of Interlayer for Advanced Lithium-Sulfur Batteries
Authors: Kim Hee Min , Manthiram Arumugam , Sun Y.-K. 
Published: February 2020

In the search for next-generation energy-storage materials, the lithium-sulfur battery has drawn much attention due to its immensely high theoretical specific capacity of 1675 mAh g-1 and energy density of 2600 Wh kg-1. Its added benefit of being a low-cost, copiously available, and environmentally benign material has also prioritized the Li-S battery as an auspicious candidate. Despite such auspiciousness, the lithium-sulfur battery has inherent disadvantages that hinder its commercialization: (i) elemental sulfur and Li2S suffer from poor electrical conductivity which makes the use of high-sulfur content electrodes challenging and (ii) polysulfide migration to and reverse reaction at the negative electrode during the charge/discharge process, known as shuttle effect, result in a loss of active material and degeneration of capacity and Coulombic efficiency.

A plethora of efforts has been made to resolve these issues. A traditional approach taken by researchers is the use of sulfur mixed with, confined by, and impregnated in all kinds of carbons to augment conductivity. However, polysulfide migration still occurs and cycle life is inadequate for practical applications. Previous papers introduced the use of carbon-paper interlayers in between the sulfur cathode and the polymer separator or carbon-coated membrane and demonstrated high sulfur utilization with better cycle life due to the suppression of polysulfide diffusion to the anode and the serving of the carbon-paper interlayer as a pseudo-upper current collector.
We present here the fabrication of an interlayer consisting of MWCNT and the electrolyte in a single fabrication process. Such MWCNT-electrolyte-paper interlayers are much more effective compared to the bare MWCNT-paper interlayer due to the fast ionic and electronic transport and a better interface between the sulfur cathode and the interlayer as well as between the separator and the interlayer.
Understanding the Mechanism of Two-Step Discharge Behavior in Lithium Air Batteries with Extremely High Capacity
Authors: Kim Won Keun , Kim Jin Soo , Jin Dae Gun , Kim Ji Na , Ryu Kyoung Han , Lee Ho-Teak 
Published: February 2020

A rechargeable lithium air battery holds promise as a high theoretical energy density battery system for electric vehicles. However, it requires various air management components other than the batterycells, and this can cause a significant loss in volumetric energy density.1) Many researchers often report specific capacity in the range of 1,000 ~ 3,000 mAh/gcarbon without any consideration of areal and/or volumetric capacity. Based on our estimation of system level energy density including balance of plant, the areal capacity should be around 20 mAh/cm2 for 500-mile ranged vehicle applications. On the path to higher areal capacity, we found abnormally high capacity with two distinct discharge plateaus called two-step discharge behavior as shown in Fig. 1. The first and second discharge appeared at approximately 2.6 and 2.4 V, respectively. This unknown property was frequently accompanied by limited charging capacity, which was under 50% of its full discharge capacity. Several efforts such as controlling the amount of electrolyte and oxygen flow/pressure were performed in an attempt to explain this abnormal behavior at this high discharge capacity.
In this presentation, we demonstrate reversible lithium air battery system with extremely high capacity over 20 mAh/cm2. The product analysis after each step of reaction confirmed that the main product is crystalline Li2O2 , and partially amorphous carbonates were formed as byproduct. From the result of in-situ DEMS analysis, the two-step discharge behavior had 70% oxygen efficiency (O2_OER/O2_ORR), and clearly exhibited two electron transfer reaction during charging/discharging cycle. Further results and detailed analysis will be discussed in this presentation.
1) K. G. Gallagher et. al., Energy Environ. Sci., 2014, 7

Figure 1
Carbon Coated Mesoporous CeO2 on Graphene Foam As Flexible Cathode in Lithium-Air Batteries
Authors: Jiang Yuexing , Cheng Junfang , Zou Lu , Chi Bo 
Published: February 2020

With the rapid development of foldable electronics in recent years, flexible energy storages have received extensive attention. As the key component, several prototypes such as flexible supercapacitors, li-ion batteries, and solar cells have been developed for practical application. However, low theoretical energy density of these power storages will limit their application in new flexible device. Therefore, non-aqueous lithium-air batteries have been developed for their extremely high theoretical specific energy density about 3600 Wh·kg-1, 3-5 times higher than that of the current lithium-ion batteries1, 2. When used in ambient air as flexible batteries, several problems must be overcome: (1) lithium anode should be protected from CO2 and H2O, (2) catalyst of high activity towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) should be introduced at lower oxygen partial pressure3. Thus the structure of the air cathode should be optimized. Macroporous along with mesoporous with high specific surface area should be introduced for the effective adsorption of O2 on the active sites, as well as the enhanced transportation of the reactants and intermediate species on the catalyst4. In our studies, mesoporous CeO2 microspheres were synthesized through hydrothermal process on 3D macrospores graphene foam as flexible cathode. CeO2 microspheres with the size of ~ 300 nm are distributed uniformly on the surface of 3D graphene foam with carbon coated for enhanced electrical conductivity. With the macroporous provided by 3D graphene foam for O2 diffusion and the mesoporous CeO2for enhanced catalytic activity towards ORR and OER, the LABs show better reversible capacity. And the detailed morphological and electrochemical analysis will be discussed in the presentation.
References
[1] P. G. Bruce, S. A. Freunberger, L. J. Hardwick and J. M. Tarascon, Nat. Mater., 11, 19 (2012).
[2] A. C. Luntz and B. D. McCloskey, Chem. Rev., 114, 11721 (2014).
[3] J. Yi, X. Liu, S. Guo, K. Zhu, H. Xue, H. Zhou, ACS Appl. Mater. Inter., 7, 23798 (2015).
[4] J.-J. Xu, Z.-L. Wang, D. Xu, F.-Z. Meng and X.-B. Zhang, Energy Environ. Sci., 7, 2213 (2014).
Honeycomb Compound Na3Ni2BiO6 As Positive Electrode Material for Na-Ion Battery
Authors: Zheng Lituo , Obrovac Mark N 
Published: February 2020

Introduction

Layered sodium transition metal oxide materials are promising candidates as positive electrode for sodium ion batteries. Partial substitution of the transition metal with other metal could modify the crystal structure and electrochemistry of the materials. Honeycomb oxides such as Na3Ni2SbO6 have been studied and showed high energy density.1,2 In this study, honeycomb compound Na3Ni2BiO6 was synthesized and characterized in Na cells.

Experimental

Stoichiometric amounts of NiO, NaBiO3 and Na2CO3 powders were mixed by ball milling and pelletized. The pellets were heated at 700 ºC for 8 hours first then 750 ºC for 12 hours under oxygen to obtain Na3Ni2BiO6. Heated samples were transferred to Ar-filled glovebox immediately. Electrodes were made with active material, PVDF binder, carbon black at a ratio of 8:1:1 and dried under vacuum at 120 ℃ overnight. 1M NaPF6 in a solution of EC, DEC, FEC (volume ratio 3:6:1) was used as electrolyte and Na foil was used as counter/reference electrode. X-ray diffraction (XRD) patterns were measured with a Rigaku Ultima IV X-ray diffractometer equipped with a Cu anode X-ray tube and a diffracted beam monochromator.

Results and discussion

Figure 1 shows the XRD pattern of synthesized Na3Ni2BiO6. The structure resembles that of Rm α-NaFeO2 (space group 166), except for the honeycomb ordering at low angles not described by the Rm α-NaFeO2 structure (indicated by stars). The honeycomb structure is generated by the 2:1 ordering of edge sharing NiO6 and BiO6 in the a-b plane. An impurity phase of NiO was present (indicated by solid circles).
Figure 2 shows the voltage curve of Na3Ni2BiO6 for the first 2 cycles in the voltage range of 1.5 V – 3.8 V and 1.5 V – 4.5 V. Na3Ni2BiO6 was found to have a reversible capacity of ~80 mAh/g, corresponding to the reversible removal of ~0.5 Na per NaNi2/3Bi1/3O2. It should be noted that the heavy atomic weight of Bi lowers the gravimetric capacity. The voltage curve is characterized by two flat plateaus located at ~3.3 V and ~3.5 V during charging, which is typical for Ni-compounds. The two plateaus are both reversible during discharging with a hysteresis of ~0.2 V. When the cell was cycled between 1.5 V – 4.5 V, another plateau with a capacity of ~20 mAh/g appears at ~4.3 V upon charging. However this plateau is not reversible, as can be seen by the similar discharge curve to that of cycled between 1.5 V – 3.8 V. The cycling performance, rate capability and structural changes during charge/discharge will also be discussed.

Acknowledgments

The authors acknowledge funding from NSERC and 3M Canada under the auspices of the Industrial Research Chair and Discovery grant programs.

References

1. D. Yuan et al., Adv. Mater., 26, 6301-6306 (2014)
2. J. Ma et al., Chem. Mater., 27, 2387-2399 (2015)

Figure 1
{001} Facets Exposed Anatase TiO2 Nanosheets and Reduced Graphene Oxide Composite Anodes for High Performance Na-Ion Batteries
Authors: Mei Yueni , Huang Yunhui , Hu Xianluo 
Published: February 2020

Lithium ion batteries (LIBs) have been widely applied in energy storage applications such as electric vehicles and portable devices, pushing up the price of lithium compounds and making lithium resources more limited. Owing to the high abundance, low cost and similar redox potential compared to lithium, sodium becomes a suitable candidate. Up to now, a variety of cathode materials have been investigated for sodium ion batteries (NIBs). However, finding suitable anode materials remains a huge challenge. Graphite, which has been employed as commercialized anode in LIBs, exhibits poor performance in NIBs (less than 35 mAh g−1). Recently, titanium dioxide (TiO2) has been proposed as anode materials for NIBs1. TiO2 has the advantages of low cost and structural stability, which hold great promise for application in NIBs.
Here, we report a composite electrode that consists of rGO and anatase TiO2 nanosheets with exposed high-energy facets as anodes for NIBs. The thin anatase nanosheets with {001} facets exposed were synthesized via a simple hydrothermal route2. The as-obtained electrode shows enhanced cycling performance and rate capability. This composite electrode exhibits a specific capacity of ~110 mAh g−1 after 500 cycles at 5C rate. Overall, anatase nanosheets/rGO composite electrode was produced and could provide a possible choice for energy storage applications.
1. C. Chen, Y. Wen, X. Hu, X. Ji, M. Yan, L. Mai, P. Hu, B. Shan and Y. Huang, Nature communications, 2015, 6, 6929.
2. C. H. Sun, X. H. Yang, J. S. Chen, Z. Li, X. W. Lou, C. Li, S. C. Smith, G. Q. Lu and H. G. Yang, Chemical communications, 2010, 46, 6129-6131.

Figure 1
Towards All Solid State Batteries Using Perovskite Solid Electrolytes
Authors: Bibienne Thomas , Alvares Pauline , Castro Laurent , Bardé Fanny , Rosciano Fabio , Dollé Mickael 
Published: February 2020

Safety and environmental concerns are some of the main issues when considering lithium batteries technology. All Solid State Batteries (ASSB) may give a fundamental solution to solve those concerns. These solvent-free ASSB show major advantages: thermal stability, possibility of multicell assembly, possibility to use high potential electrode materials. We recently reported the approach to assemble ASSB in one step by Spark Plasma Sintering (SPS) using phosphate materials [1, 2]. Investigations on oxide electrolytes were considered. These electrolytes require not only being chemically stable towards electrode materials, but should also provide a good electrochemical stability over a wide potential range. Candidate materials (e.g. perovskite materials) should be relatively low cost, environmentally benign and easy to produce at an industrial scale. Several perovskite electrolytes (covering most of these requirements) were synthesized and characterized by XRD and impedance spectroscopy after sintering by SPS. Their thermal stability towards well-known electrode materials was also investigated, as well as electrodes and electrolyte interfaces using SEM and EDS. This presentation will focus on the required steps to develop ASSB using perovskite solid electrolytes.
[1] A. Aboulaich et al,Advanced Energy Materials, 1, 179-183 (2011).
[2] G. Delaizir et al, Adv. Funct.
Mat., 22, 2140-2147 (2012).
Porous Carbon Nanofibers Decorated with Cobalt Nanoparticles As Binder-Free Efficient Cathode for Lithium-Oxygen Batteries
Authors: Singhal Richa , Kalra Vibha 
Published: February 2020

Rechargeable lithium-oxygen (Li-O2) batteries have received much attention because of their ultra-high theoretical energy density, about ten-times higher than that of current lithium-ion batteries.[1-4] However, the development of these batteries is still at its initial stage, owing to various technical challenges such as high overpotentials, low round-trip efficiency, poor rate capability, and low cycle life. Among various issues affecting Li-O2 battery performance, the low performance of the oxygen cathode has been identified as the dominating factor.[5, 6] The development of efficient cathode with nano-architectures, large accessible surface area, and bifunctional catalytic activity is a great challenge for high-performance lithium-air batteries.[7]
In the present study, binder-free high surface area porous carbon nanofibers modified with cobalt nanoparticles (Co-PCNF) are presented as efficient cathodes for Li-O2 batteries. The macroporous inter-connected structure of carbon nanofibers with effective dispersion of cobalt nanoparticles serve as an efficient cathode with high electrocatalytic activity. Co-PCNF demonstrated much better performance as cathodes in Li-O2 batteries, with high discharge capacity, rechargeability, and rate capability, compared to non-cobalt-carbon cathodes. Li-air cells with Co-PCNF as cathode exhibit a high initial discharge capacity of 8800 mAhg-1 at the current density of 100 mA g-1, and can be recharged for more than 50 cycles with limited discharge capacity of 500 mAh g-1. Moreover, the synergistic role of N-and F- doped carbon defects and cobalt nanoparticles leads to faster electronic transfer and stabilize carbon surface, enhancing the reversibility.

References:

[1] M. Armand, J.M. Tarascon, Nature, 451 (2008) 652-657.
[2] G. Girishkumar, B. McCloskey, A.C. Luntz, S. Swanson, W. Wilcke, J. Phys. Chem. Lett., 1 (2010) 2193-2203.
[3] P.G. Bruce, S.A. Freunberger, L.J. Hardwick, J.-M. Tarascon, Nat. Mater., 11 (2012) 172-172.
[4] N. Imanishi, O. Yamamoto, Materials Today, 17 (2014) 24-30.
[5] L. Mai, X. Tian, X. Xu, L. Chang, L. Xu, Chem. Rev., 114 (2014) 11828-11862.
[6] Z. Ma, X. Yuan, L. Li, Z.-F. Ma, D.P. Wilkinson, L. Zhang, J. Zhang, Energy Environ. Sci., 8 (2015) 2144-2198.
[7] J. Wang, Y. Li, X. Sun, Nano Energy, 2 (2013) 443-467.
Correctly Evaluating the Performance of Lithium-Oxygen Battery
Authors: Shen Yue 
Published: February 2020

The lithium-oxygen battery (LOB) is quite a controversial topic. A lot of people believe it will have a brilliant future because it has the highest theoretic energy density. But there are also other people believing it is largely overestimated. Some papers have reported LOB cathodes with specific capacity of several thousand mAh g-1, and cycle life longer than 100 cycles. But is the state-of-art LOB really that good? We looked into the conventional limited capacity cycling tests with unlimited lithium anode, and found the testing result may be misleading due to the following reasons:
1. The electrochemically active reactant at the cathode side is oxygen, which is unlimited. The active material at the anode side is lithium, also unlimited. In such a test, we are actually testing the reusability of the catalyst instead of the cyclability of the active electrode material.
2. The LOB cathode discharge and charge is accompanied with irreversible formation of side-products such as LiOH, Li2CO3, HCOOLi, Li2SO4, et al. But as long as these side-products are dissolved or simply accumulated away from the cathode and do not hinder the discharge, the cycling can still go on.
3. The cathode/electrolyte weight ratio is usually extremely small, which makes the cathodic weight based specific capacity meaningless.
Because of the above reasons, we propose a novel Li2O2-graphite set-up to evaluate the cathodic cyclability. Unlike the conventional set-up with unlimited lithium metal anode, the total amount of lithium ion in the Li2O2-graphite battery is limited. If any side reactions consumed the lithium-ion, the capacity lose would be objectively reflected to the charge/discharge curves. Based on this set-up, several electrolyte recipes were compared and we found the positive effect of redox mediates to improve the cycling performance is very obvious. On the whole, the LOB still has a future, but we must face the challenge before overcome it.