bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study and Development of Al-Air Battery Applying Room Temperature Ionic Liquid Electrolyte
Authors: Gelman Danny , Shvartsev Boris , Wallwater Itamar , Ein-Eli Yair 
Published: February 2020

Metal – air battery chemistry defers by the electrolyte of choice. Zn – Air, Al – Air and Fe – Air batteries were already reported utilizing aqueous alkaline and brine solutions as electrolytes. The main advantage of these specific electrolyte of choice is theirs high ionic conductivity and the ability to efficiently reduce oxygen into hydroxide anions. Nevertheless, such batteries systems suffers from major drawbacks, such as comparably low voltage and specific energy, for Zn and Fe, and extremely high corrosion rates under open circuit condition, for Al.
To deal with such challenges a fairly new approach has been taken. The approach is based on Room Temperature Ionic Liquids (RTIL) utilization as electrolyte in Metal – air batteries research. Among these, one could find Na –and Si – air battery systems. RTILs offer unique properties, while serving as electrolytic media. Among the properties one can count their low vapor pressure, even at considerably elevated temperatures, the high intrinsic ionic conductivity, non-flammability, thermal and chemical stability with considerably large electrochemical windows (in some cases as much as 5 V) what makes them remarkable electrolytes for high-end electrochemical applications. In our recent report[1], a new Al – air battery was presented applying 1-ethyl-3-methylimidazolium oligoflourohydrogenat (EMIm(HF)2.3F) RTIL. The specific conductivity of this exact stoichiometry is 100 mS cm-1 at 298 K, one the highest of all RTIL family, comparable to that of 0.5 M KCl aqueous solution. The presented novel Al – air battery can sustain current densities up to 1.5 mA cm-2, producing capacities above 140 mA h cm-2, and thus utilizing above 70% of the theoretical Al capacity. This is equivalent to outstanding energy densities of 2300 W h kg-1 and 6200 W h L-1.
In the current work a further investigation of the RTIL based Al – air battery is presented. Combining surface characterization with electrochemical experiments, both in half cell and also a full battery discharge, an ongoing progress in the study of this unique battery is shown. One of the main achievements in the study is related to the understanding of the operation voltage drop (deep). Conditions for elimination of this voltage deep were established and will be reported.

[1] D. Gelman, B. Shvartsev, Y. Ein-Eli, J. Mater. Chem. A. 2.47 (2014) 20237-20242.
Comparison of Amorphous TiO2 with Anatase Thin-Films Grown By ALD in Terms of Rate Performance and Capacity for Li+-Insertion
Authors: Moitzheim Sebastien , Deng Shaoren , Detavernier Christophe , De Gendt Stefan , Vereecken Philippe M 
Published: February 2020

In this work we compare amorphous TiO2 to anatase thin-films for their Li+ insertion/extraction properties. For this, we deposited ultra-thin (35 nm) amorphous TiO2 and anatase films by atomic layer deposition on a TiN current collector. Such thin films are interesting since they have the same length scale as nanostructured particles or other nanostructures, e.g. nanotubes, but with the additional benefit of offering a well-defined geometry that allows for a more precise determination of the underlying lithium insertion/extraction kinetics. Furthermore, such ultra-thin electrodes might find application in 3D (micro-)batteries.
The amorphous and anatase films were characterized using cyclic voltammetry and galvanostatic charging/discharging. The electrochemical properties of 35 nm amorphous TiO2 and anatase films are shown in figure 1. The cyclic voltammograms (CV, see figure 1a) performed at 10 mV/s shows distinction between lithium insertion/extraction of the amorphous and anatase films. The average of the insertion and extraction peak potentials is 1.65 V vs Li+/Li and 1.99 V vs Li+/Li for amorphous and anatase, respectively. Also, the peaks in the CV for amorphous TiO2 are less sharp compared to anatase, suggesting a different intercalation mechanism.
Galvanostatic charge/discharge experiments show a significantly increased capacity for amorphous compared to anatase (see figure 1b). At 1C, the amorphous TiO2 film has a capacity of 1.9 µAh/cm2 compared to 1.2 µAh/cm2 for the anatase film. Also, at higher C-rates the amorphous TiO2 film shows high retention of the capacity. For example, at 20C, 63% of the capacity at 1C is retained, compared to 30% for anatase. These results show the potential benefits of using amorphous TiO2 compared to anatase thin-films due to its significantly higher capacity and superior rate performance.

Figure 1
Electrochemical Studies of Vanadium-Based Polyoxometalate Molecular-Cluster Batteries
Authors: Chen Han-Yi , Friedl Jochen , Al-Oweini Rami , Pan Chun-Jern , Hwang Bing-Joe , Kortz Ulrich , Srinivasan Madhavi , Stimming Ulrich 
Published: February 2020

The lithium ion battery (LIB) is a promising energy storage technology for electric vehicles [1]. The most commonly used cathode material in LIBs is LiCoO2. Lithium ion intercalation/de-intercalation into the layer-structured LixCoO2 can result in fast capacity fading. Besides, the kinetic rate of lithium ion intercalation/de-intercalation in the lattice structure is slow which causes low power density.[2] Polyoxometalates (POMs) are transition metal oxide molecular clusters with various structures and have been reported as promising cathode active material for energy storage applications. Due to their multiple redox centers they can undergo fast and reversible redox reactions.[3-5] POMs are expected to undergo redox process as a molecular cluster, thus the stability of the POMs is not depended on the recoverability of its long-term crystal structure. The most commonly used POMs in Li ion Molecular-Cluster Batteries (MCBs) are Mo-based POMs which can achieve a capacity of 270 mAh g-1. However, the cycling stability of Mo-based POMs is poor because of the instability of molecular cluster ions [PMo12O40]3- in the reduced state and high solubility in the electrolytes. Vanadium based POMs have been reported to possess a high capacity of up to 200 mAh g-1, and higher cycling stability than Mo-based POMs. However, the valence and fine structural changes of V-based POMs MBCs during charging/discharging have not yet been investigated. Thus, we performed in-situ V K-edge XAFS measurements for V-based POM molecular cluster batteries, and determined the oxidation states and inner structure changes of V-based POM during charging/discharging. Furthermore, the kinetic studies of V-based POM MCBs were also performed by chronoamperometry experiments in this research.
[1] H. Wang, S. Hamanaka, T. Yokoyama, H. Yoshikawa, K. Awaga, Chemistry-an Asian Journal 2011, 6, 1074.
[2] H. Wang, S. Hamanaka, T. Yokoyama, H. Yoshikawa, K. Awaga, Chemistry-an Asian Journal 2011, 6, 1074.
[3] N. Kawasaki, H. Wang, R. Nakanishi, S. Hamanaka, R. Kitaura, H. Shinohara, T. Yokoyama, H. Yoshikawa, K. Awaga, Angewandte Chemie-International Edition 2011, 50, 3471.
[4] H. Wang, S. Hamanaka, Y. Nishimoto, S. Irle, T. Yokoyama, H. Yoshikawa, K. Awaga, Journal of the American Chemical Society 2012, 134, 4918.
[5] E. Ni, T. Kume, S. Uematsu, Z. Quan, N. Sonoyama, Electrochemistry 2014, 82, 14.
Synthesis and Characterization of Nitrogen-Doped Reduced Graphene Oxides for the Oxygen Reduction Reaction in the Zn-Air Batteries
Authors: Hu Chi-Chang , Wu Sheng-Hui , Li Po-Chieh 
Published: February 2020

The electron transfer number of the oxygen reduction reaction (ORR) on the nitrogen-doped reduced graphene oxide (N-rGO) has been controlled using the experimental design strategy which includes the studies of the fractional factorial design and the paths of the steepest ascent/descent. For the applications in the zinc-air batteries and alkaline fuel cells, the electron transfer number approaching 4 is desirable; i.e., rendering the ORR to undergo the four-electron transfer mechanism. The maximum electron transfer number of the ORR is 3.9 on our N-rGO prepared in this work. The structure and distribution of nitrogen doped onto the rGO have been measured by the x-ray photoelectron spectroscopic analysis. The N-rGO with the electron transfer number of the ORR close to 4 is employed in the aqueous Zn-air batteries. The typical discharge behavior of the zinc-air battery with an air cathode using N-rGO in 6 M KOH at 2, 10, and 20 mA cm-2 was examined in this work. The corresponding discharge curves of the Zn anode and air cathode were measured to investigate their individual performances. The discharge capacity of the above full cell test is above 775 mAh g-1 (based on the zinc mass) which is very close to the theoretical value (820 mAh g-1).
Oxygen Reduction in Si-Air Battery Employing MnO2 Catalyst - a Phenomenological Thermodynamic Analysis
Authors: Harinipriya S , Sangaranarayanan M.V. 
Published: February 2020

The steps involved in Oxygen Reduction Reaction (ORR) mechanism are as follows:
Step (i) : Diffusion of molecular oxygen on MnO2 catalyst
Step (ii): Chemisorption of molecular oxygen at MnO2 surface
Step (iii): Dissociation of molecular oxygen on MnO2 surface
Step (iv): Reduction of molecular oxygen on MnO2 surface and reduction of MnO2 (Mn(IV)) to Mn2O3 (Mn(III))
Step (v): Diffusion of oxygen anion on the MnO2 surface
Step (vi): Incorporation of oxygen in MnO2 lattice at the oxygen vacant site
Assumptions :
(i) maintenance of electroneutrality
(ii) VO (surface) >> VO(bulk) of MnO2 lattice
(iii) electrons for oxygen reduction and reduction of Mn4+ to Mn3+ comes from anodic reaction
(iv) effects due to formation of MnF2 during discharge of Si-air battery is neglected.
(v) wherever partial bonds are formed or dissociated, the bond energy is averaged over the coordination number or total number of vacant sites as the case may be
(vi) the pressure of oxygen gas is written using the van der Waals equation
of state
Derived Equation can now be utilized to estimate the free energy of activation for ORR mechanism in Si – air battery and engineer catalysts suitable for fast ORR in these batteries.
Electrode Calendering Optimization
Authors: Gonzalez Daniel , Rubio Irene , Beattie Shane D 
Published: February 2020

Among commercially available batteries Li-ion has one of the highest volumetric energy densities. A critical step that manufacturers use to maximize volumetric energy density is to calender electrodes after coating to reduce thickness and increase density. Although optimal calendering parameters are well known to industry, useful information in the literature is scarce, and systematic studies are difficult to find. This dissertation will provide a methodical study of electrochemical performance as a function of calendaring properties.
Graphite electrodes were calendered at different temperatures (room temperature to 120 oC) with different nip openings (40 to 100 μm). Electrode density is correlated with electrochemical performance using data from coin cell hardware. Results show that the highest amount of calendaring does not necessarily result in the largest volumetric energy density. This may be due to excessive porosity reduction, which prevents the electrolyte from wetting all of the electrode particles.
Synthesis and Performance of Disordered Positive Electrode Materials for Lithium Ion Batteries
Authors: Glazier Stephen , Dahn Jeff R 
Published: February 2020

Disordered rocksalt materials of the form Li1+xMy(1-x)N(1-y)(1-x)O2have been largely overlooked as a potential candidate for high performance positive electrode materials in lithium ion batteries due to the inability of lithium to percolate through the disordered structure. Recent works [1, 2] have shown these materials are able to form percolation networks if sufficient lithium and cation mixing is present in the structure. As these materials become more lithium rich, the probability of finding a network of favourable Li channels increases. However, for many transition metal choices for M and N the available redox capacity decreases. This must be considered in order to design compositions for optimal performance.
This work explores these recent theories and looks to improve the design and understanding of disordered materials. Many elemental combination series are synthesized between x = 0.00 to 0.33 in Li1+xMy(1-x)N(1-y)(1-x)O2 using solid state synthesis methods with varying temperature and excess Li content to explore the role of synthesis in disordering. Choices for M and N include V, Ti, Mn, Fe, Mo, and Cr in order to investigate capacity relationships due to available redox and Li channels. Materials are characterized by X-Ray Diffraction (XRD), in-situ and ex-situ XRD, scanning electron microscopy, Mossbauer spectroscopy, induced coupled plasma optical emission spectroscopy and electrochemical testing. The structural and electrochemical data is compared with theoretical models based on available redox capacity and percolation theory.
Figure 1 shows that synthesis temperature plays an important role in the disordering process. Figure 2 demonstrates a series of Li1+xTiy(1-x)Fe(1-y)(1-x)O2 (0.00 ≤ x ≤ 0.25) heated at 800 °C. Electrochemical results were found to agree with current and proposed theories of disordered materials.
Discussion will include the importance of synthesis in disordered materials, as well as the performance of select series and how they compare to theoretical models.
References:
1. A. Urban, J. Lee, G. Ceder, Adv. Energy Mater.,
4 1400478 (2014)
2. J. Lee, A. Urban, X. Li, D. Su, G. Hautier, G. Ceder, Science, 343 519-522 (2014)

Figure 1
Characterization and Optimization of the Carbon Nanocoatings Onto LiFePO4 Particles for Lithium-Ion Batteries
Authors: Swider Joanna , Molenda Marcin , Dziembaj Roman 
Published: February 2020

Lithium iron phosphate (LiFePO4, LFP), among the various materials under development for use as cathodes in lithium-ion batteries, has been so far studied and considered as the most promising candidate for this application. Olivine-structured LiFePO4 has been first reported by Pahdi et. al. in 1997 [1] and has gained significant attention because not only exhibits good electrochemical performance (a high theoretical capacity of 170 mAh×g1 and a high discharge potential) but also it has other good features as: good cycle performance, low price, environmental benignity, high thermal and chemical stability [2]. However, low electronic conductivity and low Li+ diffusion rate limits the application of this material for high-power battery. To overcome these limitations it is necessary to synthesize nanosized LiFePO4 particles coated with carbon layer. A variety methods of preparation carbon coating were studied and existed because it is straightforward technology improving the conductivity of LiFePO4. It is still the challenge to prepare homogenous, highly conductive thin layer of carbon that does not block the lithium ion transfer between LiFePO4 and electrolyte [3].
The results of simple and environmental-friendly method of the carbon coatings on low-conductive cathode material powders have been developed, optimized and shown in this work. The carbon nanocoatings were prepared by wet impregnation process of precursor derived from hydrophilic polymer based on poly(N-vinylformamide) modified by pyromellitic acid [4] onto LiFePO4 particles.
The existence of nano-LiFePO4 was confirmed with X-ray powder diffraction (XRD). Transmission electron microscopy (TEM) was used to determine particle size and morphology of carbon nanocoated LFP material. The optimal calcination temperature of C/LFP composite precursors were investigated from thermal gravimetry analyses (TGA/DTG/STDA). The properties of carbon nanocoatings were determined by Raman spectroscopy and electrical conductivity measurements. The process of formation C/LiFePO4 nanocomposite significantly enhances the electrical conductivity of the material and improves its capacity retention and electrochemical performance.

References

[1] A.K. Padhi, K.S. Nanjundaswamy, J.B. Goodenough, J. Electrochem. Soc. 144 (1997) 1188
[2] Y.-D.Cho, G. Ting-Kuo Fey, H.-M. Kao, J. Power Sources 189 (2009) 256–262
[3] A. Örnekn, E. Bulut, M. Özacar, Ceramics International40(2014)15727–15736
[4] M. Molenda, R. Dziembaj, A. Kochanowski, E. Bortel, M. Drozdek, Z. Piwowarska, PAT.216549, Patent appl.: US 2011/015112
Binder Free Graphene- Based Electrodes with Excellent Pseudocapacitive Performance
Authors: Chabi Sakineh , Xia Yongde , Zhu Yanqiu 
Published: February 2020

Owing to the high impact of the electrode’s architecture on the energy storage and power performance, it is very important to create optimum structures that provide efficient short paths for ion and charge transportation. Given excellent advantages of graphene, e.g. very high surface area, and excellent mechanical properties, this material is an ideal candidate to serve as an electrode matrix to stabilise electroactive materials for the charge-discharge process [1].
In this study, three dimensional (3D) binder free graphene composites have been synthesised by a two-step process, a chemical vapour deposition of the graphene followed by a chemical or electrochemical deposition of the redox counterpart. Pure graphene (GN), Polyaniline-graphene (PANI-GN), Polypyrrole-graphene (PPY-GN) and some other electrodes will be described in this work, and their electrochemical performance will be studied by using combined cyclic voltammetry, impedance spectroscopy and galvanostatic charge discharge techniques. Effects of the electrode dimensionality (3D vs 2D) and the binder on the performance will be investigated and explained.
Figure 1 (a) is a SEM image of 3D graphene foam. The open porosity feature of the foam facilitates effectively the ion intercalation and extraction. Figures 1 (b) and 1 (c) are the cyclic voltammetry and Nyquist curve of the 3D PANI-GN. In contrast to the pure graphene and PANI, the composite electrode showed a much better electron conductivity and higher performance.
The performance data have also revealed that using the porous 3D graphene foam as the electrode matrix and eliminating the insulating binder from the electrode structures result in an improved conductivity of the electrode, with excellent cycle life. The improved electrochemical performance efficiency is due to the dual energy storage mechanism and the synergetic effect of the graphene foam and redox counterpart.

Reference:

1. Chabi, S., et al., Ideal Three‐Dimensional Electrode Structures for Electrochemical Energy Storage. Advanced Materials, 2014. 26(15): p. 2440-2445.
Figure caption
Figure 1: SEM image of graphene foam (a) cyclic voltammetry of 3D PANI-GN (b) and Nyquist curve of 3D PANI-GN in 0.5 M H2SO4.

Figure 1
Impedance Spectroscopy of Industrial Batteries
Authors: Stoynov Zdravko , Vladikova Daria , Schiavetti Massimo , Fastelli Irene 
Published: February 2020

The successful application of the Impedance Spectroscopy for measurement and quality control of batteries should obey a number of specific requirements, correspondent to the nature of the batteries as objects under investigation. Batteries are nonlinear and non-stationary large statistical systems with distributed parameters in macro- and micro-scale. Processes of charge and mass-transfer take place in their electrodes, changing the chemistry and the habitus of the active electrode materials.
Starting with the very first successful measurement of a small Lead-acid battery in 1976 [1], we developed a set of complementary techniques providing for reliable measurements of battery impedances, data handling and analysis. The techniques for inductive errors evaluation and correction, for the 4-Dimentional data treatment [2] of the evolving battery State of Charge will be discussed in details. Special attention will be given to the interpretation of the battery impedance as a property of a fuzzy system with un-known parameters distribution. The Differential Impedance Analysis which solves this problem and the related Spectral Transforms are powerful tools for batteries evaluation and quality control [3].
These techniques will be illustrated with practical examples of impedance measurements of large industrial Lead-acid and Li-ion batteries and stacks fabricated by different technologies and for different purposes.
Some related side phenomena as: (i) presence and destruction of the passive layer; (ii) increased inductance of stacks as well as impedance observation of local in-homogeneities in Li-ion batteries will be also discussed.
References
1. M. Keddam, Z. Stoynov, H. Takenouti, J. Appl. Electrochem. 7 (1977) 539.
2. Z. Stoynov in: C. Julien, Z. Stoynov (Eds.), Materials for Lithium- ion Batteries, Kluver Academic Publishers, 3/85 (2000) 359.
3. Z. Stoynov and D. Vladikova, in Encyclopedia of Electrochemical Power Sources, edited by U. Garche ( Elsevier, 2009) pp. 632-642.
Aqueous Sodium-Ion Battery As Post Lithium-Ion Battery
Authors: Okada Shigeto , Kano Yusuke , Nakamoto Kosuke 
Published: February 2020

Three kinds of secondary batteries, nickel metal hydride, Li-ion and Na/S battery were commercialized in Japan for the first time. Among them, Li-ion battery became the most popular power sources for PDA, because of the highest energy density. However, Li-ion battery is difficult to use for large-scale batteries, because its organic electrolytes are flammable, expensive and less conductive.
Recently, aqueous electrolyte has been recognized as an attractive alternative and much attention has been paid to its development, because it has 3 big advantages about the conductivity, nonflammability and cost. In addition, water is an ideal solvent that dissolves a lot of various salts. Here, the most important thing is the selection of electrode active materials to avoid decomposition of the aqueous electrolyte. An aqueous Li-ion battery with LiMn2O4 cathode and VO2 anode was first reported by J. R. Dahn's group [1]. Since them, several combinations of cathodes and anodes have been reported as aqueous Li-ion battery. Theoretically, higher cell voltage more than 1.2 V cannot be obtained in the aqueous battery. So, it is unnecessary to dare to use Li in the aqueous batteries. Nevertheless, there is few report about aqueous Na-ion battery, in comparison with aqueous Li-ion battery. As one of the few exceptions, aqueous sodium-ion hybrid device with Na0.44MnO2cathode and active carbon anode was first proposed by Carnegie Mellon University, 4 years ago [2].
In this presentation, we introduce the aqueous Na-ion battery with pyrophosphate Na2FeP2O7 cathode and NASICON-type NaTi2(PO4)3 anodes. Because these polyanionic electrodes have flat voltage plateaus at 3.0 V and 2.1 V vs. Na/Na+, respectively. These redox voltages are almost located within the potential window of the aqueous electrolyte. In addition, Fe and Ti are the first and the second cheapest redox couple in transition metals, respectively.

References

[1] W. Li, J. R. Dahn and D. S. Wainwright, Science, 264 (1994) 1115.
[2] A. D. Tevar and J. F. Whitacre, J. Electrochem. Soc., 157 (2010) A870.