bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding the Redox Reaction Mechanism of Li2CoPO4f Cathode Material for Achieving Two Lithium Intercalation
Authors: An Jae Youn , Palanichamy Sennu , Lee Sol Nip , Samuthira Pandian Amaresh , Lee Yun Sung 
Published: February 2020

Lithium ion batteries have attracted considerable attention as important energy storage and conversion systems for applications including electric vehicles (EVs) and hybrid electric vehicles (HEVs), owing to their high energy and power densities, as well as a long cycle life. Recently, lithium transition metal phosphates, such as LiFePO4, LiMnPO4, and Li3V2(PO4)3, have been considered as potential cathode materials for lithium ion batteries. It is well known that the phosphates display much better electrochemical and thermal stability compared to conventional lithium metal oxides [1]. However, recently, fluorophosphates are being developed as advanced cathode materials display higher operating potential, corresponding to the redox reaction of transition metal, when compared to the respective metal oxides and phosphates [2]. In addition, the highly electronegative fluoride ion helps to improve the cycle stability, which fluorophosphates make attractive materials for high energy batteries.
Our current work is focused on maximizing the deliverable discharge capacity of Li2CoPO4F cathode material and to reach theoretical capacity by achieving more than one electron intercalation. The redox couple Co2+/3+ and Co3+/4+ was closely followed during galvanostatic charge-discharge test by x-ray photoemission spectroscopy and x-ray diffraction (XRD) analysis. It was found that the incomplete reduction of cobalt ions during discharge initiated the irreversible capacity loss rather than the electrolyte decomposition being solely responsible. A novel approach was carried out to activate the transition metal ions which resulted in a discharge capacity as high as 230 mAh g-1 at a current rate of 20 mA g-1 for Li/Li2CoPO4F cell. A long plateau at 4.8 V has been observed in the charge cycle with an additional voltage plateau at ~5.0 V, which can be attributed to the two lithium intercalation reaction and has been validated using cyclic voltammetry studies. The detrimental cycle stability observed [3] in Li2CoPO4F has been replaced with a stable cycle performance of > 90 % capacity retention as shown in figure 1. A quasi single phase reaction was confirmed using gravimetric intermittent titration technique in addition to the results from ex-situXRD studies. A discussion based on the obtained results will be presented in detail.

References:

[1] S.K. Martha, J. Grinblat, O. Haik, E. Zinigrad, T. Drezen, J.H. Miners, I. Exnar, A. Kay, B. Markovsky, D. Aurbach, Angew. Chem. Int. Ed.48 (2009) 8559–8563.
[2] A. Kraytsberg, Y. E. Eli, Adv. Energy Mater.2 (2012) 922–939.
[3] X. Wu, Z. Gong, S. Tan, Y. Yang, J. Power Sources 220 (2012) 122–129.
Crystal Structure and Electrochemistry of Na2-XLixFePO4f (0≤x≤1) New Cathode Materials for Li- and Na-Ion Batteries
Authors: Kosova Nina V. , Podugolnikov Vladislav R. , Bobrikov Ivan A. , Balagurov Anatoly M. 
Published: February 2020

Sodium-based cathode materials are interested both for sodium-ion and lithium-ion batteries application. In 2007, Ellis et al
. [1] synthesized a new sodium-based flourophosphate Na2FePO4F. This material operates at 3.3 V and has two-dimensional (2D) pathways for intercalation/deintercalation of alkaline ions and a single-phase (solid solution) mechanism of Li (de)intercalation.
In the present study, Na2-xLixFePO4F with 0≤x≤1 were prepared by mechanochemically assisted solid state synthesis. Na2FePO4F was synthesized via two-step approach including a covalent precursor formation (NaFePO4) and incorporation of ionic NaF into its framework. Both steps consist of preliminary mechanical activation (MA) using AGO-2 planetary mill and subsequent heat treatment in Ar flow. Na2-xLixFePO4F compositions were obtained from NaFePO4, LiFePO4, NaF and LiF with the correspondent ratio. Crystal and local structure was studied by X-ray, neutron diffraction (IBR-2 reactor of JINR, Dubna) using Rietveld refinement (Fig. 1); FTIR and Mössbauer spectroscopy. Phase transformations under heating and cooling of the NaFePO4+NaF activated mixture were investigated by in situ XRD, using a HTK 1200N temperature-controlled X-ray chamber. Particle size and morphology were studied by SEM and TEM. The samples were cycled in Swagelok-type half-cells with Li anode and LiPF6-based electrolyte at 2.0-4.2 V range and 0.1C-10C cycling rates. GITT method was applied for the evaluation of D
Li.
It has been shown that poor-crystalline Na2FePO4F was formed directly at the stage of MA. The completion of the synthesis and crystallization of the final product with Pbcn space group and average particle size of about 100 nm occur upon the subsequent heating of the activated mixture to 600°C. Refined cell parameters, presented in Table 1, well correlate with the literature data [1]. On contrast, the structure of as prepared Na2-xLixFePO4F (0.5≤x≤1.0) is well described in Pnma space group. Mössbauer spectra are fitted by one doublet indicating that all Fe ions are in 2+ state and octahedral coordination.
On galvanostatic charge-discharge curves, a solid solution-like sloping voltage profile was observed for all samples. When cycled with Li anode, Na/Li exchange in Na2FePO4F cathode with the formation of NaLiFePO4F was completed after the 4th cycle. The structure of the product was maintained (S.g. Pbcn), while its lattice parameters decrease. Discharge capacity was 115, 110 and 55 mAh×g-1 for Na2FePO4F, Na1.5Li0.5FePO4F and NaLiFePO4F, respectively (Fig. 2). The determined Li+ diffusion coefficient D
Li in NaLiFePO4F, prepared by electrochemical Na/Li exchange from Na2FePO4F, was 10-15 cm2×s-1 (Fig. 3), while it was only 10-17 cm2×s-1 for NaLiFePO4F and Na1.5Li0.5-xFePO4F (S.g. Pnma) prepared by solid state synthesis.
[1] B. Ellis, W.R.M. Makahnouk, Y. Makimura, K. Toghill, L.F. Nazar // Nat. Mater. 6(2007) 749–753.
Synthesis of Graphene-Supported Nano-Na3MnCO3PO4 for High Rate and High Capacity Sodium Ion Batteries
Authors: Daneshvar-Fatah Farhad , Wang Chualong , Shaw Leon 
Published: February 2020

It has been predicted via ab-initio calculations that Na3MnCO3PO4 possesses a high specific capacity of 191 mAh/g, due to its potential to deliver two-electron transfer redox reactions per formula via Mn2+/Mn3+ and Mn3+/Mn4+ redox reactions (Hautier, et al. 2011). To improve battery performance for high power applications such as hybrid electric vehicles and electric grid systems, it is necessary to enhance the electronic conductivity. Graphene has been reported to be a suitable conductive substrate to grow active materials for energy storage applications owning to its superior electrical conductivity, chemical stability, high mechanical strength, high surface-to-volume ratio, and light weight. In this study, Na3MnCO3PO4, one of the most promising materials for Na-ion batteries, has been synthesized on a graphene sheet surface via hydrothermal method. The cathode material was characterized by FE-SEM, XRD, and electrochemical tests. It is shown that by having the total graphene content as low as 5.1wt%, specific capacity improves 40%. With this improvement in specific capacity, Na3MnCO3PO4 has a great potential to be a viable cathode material for Na-ion batteries.
Magnesium Sulphide As Anode Material for Lithium-Ion Batteries
Authors: Maria Joseph Helen , Fichtner Maximilian 
Published: February 2020

There is a great interest for alternative high capacity, low voltage anode materials in Li ion batteries. In an attempt towards this we report the investigation of magnesium sulphide (MgS) as sustainable anode material for lithium-ion batteries. The theoretical reaction potential of MgS with lithium is 0.5 V. It has a theoretical specific capacity of 951 mAh g-1 assuming the following reaction.
MgS + 2Li ---> Li2S + Mg
In addition, lithium can react with magnesium to form alloys of lithium by further increasing the theoretical capacity. The high capacity combined with low reaction potential makes MgS an interesting anode material for Li-ion batteries in principle. Hence we synthesized MgS-carbon nanocomposites and evaluated them as anode material for lithium-ion batteries. A possible lithiation and delithiation mechanism for MgS is proposed based on electrochemical and ex-situ XRD studies. The electrochemical reaction of MgS with lithium results in the formation of Li2S and Mg, the as-formed Mg simultaneously reacts with lithium and forms LixMg alloy further contributing to the capacity. A stable reversible capacity of 530 mAh g-1 was achieved after 100 cycles within the voltage window of 0.001 - 2.5 V (Figure 1). The compatibility of MgS anode was tested in full cell using lithium nickel manganese cobalt oxide (LNMC) and lithium iron phosphate (LFP) as cathodes.

Figure 1
Liquid-Free Lithium-Oxygen Battery
Authors: Balaish Moran , Peled Emanuel , Golodnitsky Diana , Ein-Eli Yair 
Published: February 2020

Non-aqueous Li-O2 batteries are considered as most advanced power sources, albeit they are facing numerous challenges concerning almost each cell component. Herein, we diverge from the conventional and traditional liquid-based non-aqueous Li-O2 batteries to a solid polymer electrolyte (SPE) Li-O2 system, operated at a temperature higher than the melting point of the polymer electrolyte, where useful and most applicable conductivity values are easily achieved. The proposed SPE-based Li-O2 cell is compared to glyme-based Li-O2 cells through potentiodynamic and galvanostatic studies, showing higher cell discharge voltage by 80mV and most significantly, a charge voltage lower by ∼400mV. The solid state battery demonstrated a comparable discharge specific capacity to glyme-based Li-O2 cells when discharged at the same current density. The discharge products were identified as lithium peroxide by XRD analysis and FT-IR combined with quantitative 1H and qualitative 13C NMR spectroscopies identified lower molecular PEO as the main degradation products, as well as in-chain ester and formates in negligible amounts. The results shown here demonstrate that safer PEO-based Li-O2 battery is highly advantageous and can potentially replace liquid-based cells contingent upon further investigation. While safety is a prime concern in Li-metal based battery, it is of greater challenge once a viable Li-O2 battery development is being considered. A polymer-based system, which is liquid electrolyte-free, seems to be another and important step towards resolving this issue.
* Balaish, M., Peled, E., Golodnitsky, D. and Ein-Eli, Y. (2014), Liquid-Free Lithium–Oxygen Batteries. Angew. Chem. Int. Ed.. doi: 10.1002/anie.201408008
High Performance NiO and NiO/Graphene Composite Thin Film Electrode Via Electrostatic Spray Deposition for Lithium Ion Batteries
Authors: Chen Chunhui , Pedro Perdomo J. , Fernandez Melisa , Barbeito Andres , Wang Chunlei 
Published: February 2020

NiO has been widely studied due to its high theoretical capacity of 718 mAh g-1 when it is used as anode material for LIBs. However, it shows poor cycling performance due to the low electrical conductivity and large volume change during charge/discharge. In the present research, NiO thin film electrode was synthesized by electrostatic spray deposition (ESD) technique and investigated as anodes for lithium ion batteries. 10% weight percent graphene nanoplates were added to form NiO/graphene nano-composite. We expect that additional graphene will provide a high conductive medium for electron transfer during the conversion reaction of NiO with lithium ions. In addition, the porous structure generated through ESD process will be benefical to buffering the volume expansion/constriction during the cycling.
The cycling of NiO electrode results show that it can deliver a reversible capacity of 708 mAh g-1 under the current density of 0.5 A g-1. The number is near the theoretical capacity of NiO which indicates the complete reaction of NiO with lithium ions. As the current density increases, the capacity gradually decreases to 80 at 5 A g-1. For the NiO/graphene composite electrode, capacity decreased from 683 to 125 mAh g-1 as the current density increased from 0.5 to 5 A g-1. Comparing these two electrodes, it shows that additional graphene is not beneficial to the capacity testing under low current densities. Whereas, it has a positive synergistic effect towards the capacity testing under high current densities. It is probably because of two reasons: one is that graphene itself has lower theoretical capacity than NiO; another one is that the porous thin film structure can satisfy the kinetics requirement of the reactions under low current densities. In addition to rate capability tests, material characterization (such as SEM, XRD, FTIR) and additional electrochemical tests (cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), etc.) were performed to evaluate the performance of such electrodes. Detailed discussion will be provided during the meeting.
Electrochemical Properties of a New Class of Europium Sandwich Triple-Decker Complexes with Corrole and Phthalocyanine Macrocycles
Authors: Lu Guifen , Yan Sen , Shi Mengying , Li Jing , Ou Zhongping , Zhu Weihua , Kadish Karl M. 
Published: February 2020

The electrochemical properties of a new class of sandwich (phthalocyaninato)(corrolato) europium triple-decker complexes were synthesized and characterized by cyclic voltammetry in CH2Cl2 containing 0.1 M tetrabutylammonium perchlorate (TBAP) as supporting electrolyte. Two of the compounds described in the current paper are shown in the figure, and represented by HEu2[Pc(R)8]2[Cor(ClPh)3], where R = OC5H11 or OC8H17, Pc represents the dianion of phthalocyanine and Cor represents the trianion of corrole. Both triple-decker complexes exhibit five reversible oxidations and three reversible reductions, all of which are attributed to ligand-based redox processes. The half-wave potentials for the first oxidation and first and second reduction of the two europium triple-deckers are close to E
1/2 values for the double-decker species Eu[Pc(OC8H17)8]2, while half-wave potentials for the second to fifth oxidations are close to E
1/2 values for the triple-decker Eu2[Pc][Pc(OC8H17)8]2. The synthesis and electrochemical properties of the new compounds will be described.
Acknowledgment: This work was supported by the Natural Science Foundation of China (No. 21001054, 21071067) and the Robert A. Welch Foundation (K.M.K., Grant E-680).

Figure 1
Hexabenzocoronene-Porphyrin Conjugates
Authors: Jux Norbert , Lungerich Dominik 
Published: February 2020

Hexabenzocoronene (HBC) is a very interesting building block in terms of structural and electronic properties.[1] We have recently started to look into conjugates with the HBC moiety directly linked to a meso-position of the porphyrin.
Here, we wish to report on the synthesis, characterization, and properties of some of these novel systems.[2,3]

References

[1] S. Ito, P. T. Herwig, T. Böhme, J. P. Rabe, W. Rettig, K. Müllen, J. Am. Chem. Soc. 2000, 122, 7698 – 7706; b) J.Wu, M. D. Watson, N. Tchebotareva, Z. Wang, K. Müllen, J. Org. Chem. 2004, 69, 8194 – 8204.
[2] J. M. Englert, J. Malig, V. A. Zamolo, A. Hirsch, N. Jux, Chem. Commun. 2013, 49, 4827 – 4829.
[3] D. Lungerich, J. F. Hitzenberger, M. Marcia, F. Hampel, T. Drewello, N. Jux, Angew. Chem. Int. Ed..
2014,
53, 12231-12235.

Figure 1
Electrochemically Controlled Multistability of Ultrathin Films of Double-Decker Lanthanides Phthalocyanines
Authors: Gorbunova Yulia G. , Selektor Sofiya L. , Shokurov Alexander V. , Arslanov Vladimir V. , Tsivadze Aslan Yu. 
Published: February 2020

Molecular-scale systems that exhibit intramolecular electron transfer (IET) induced by various external stimuli occupy a special place among the systems whose behaviour is determined by charge transfer processes. Such redox-isomeric materials are indeed promising for applications in the development of nanoscale information storage devices. Complexes in which both metal and ligand are redox-active are target objects for the study of redox isomerism phenomenon (reversible intramolecular metal−ligand electron transfer). From this standpoint, tetrapyrrole complexes of metals with variable oxidation states are one of the most promising compounds. Lanthanides phthalocyaninates proved to be very promising objects for the development of “molecular switches” and memory devices.
Herein, we report on the electrochemical properties of Langmuir-Blodgett films of series of lanthanides complexes with bis-tetra-15-crown-5-phthalocyanines1,2. A previously unknown phenomenon of orientation-induced redox isomerism in a Langmuir monolayer is revealed in the case of cerium bis-[tetra-(15-crown-5)-phthalocyaninate] – (Ce[(15C5)4Pc]2)3,4 (Fig.1). The mechanism of genuine redox isomerism was confirmed by the results of in-situUV-Vis spectral measurements performed on monolayers and Langmuir-Blodgett films, AFM, and XPS studies of Langmuir-Blodgett films transferred at different surface pressures. The understanding of this reversible IET mechanism is especially important due to possible applications of such redox-isomeric systems in the development of nanoscale multibit information storage devices.
1. Selector, S. L.; Arslanov, V. V.; Gorbunova, Y. G.; Raitman, O. A.; Sheinina, L. S.; Birin, K. P.; Tsivadze, A. Y. Journal of Porphyrins and Phthalocyanines
2008, 12, 1154.
2. Selector, S. L.; Shokurov, A. V; Arslanov, V. V; Gorbunova, Y. G.; Raitman, O. A.; Isakova, A. A.; Birin, K. P.; Tsivadze, A. Y. Rus. J. of Electrochemistry
2012, 48, 218.
3. Selektor, S. L.; Shokurov, A. V.; Raitman, O. A.; Sheinina, L. S.; Arslanov, V. V.; Birin, K. P.; Gorbunova, Y. G.; Tsivadze, A. Y. Colloid J.
2012, 74, 334.
4. Selektor, S.L.; Shokurov, A.V.; Arslanov, V.V.; Gorbunova, Y.G.; Birin, K.P.; Raitman, O.A.; Morote, F.; Cohen-Bouhacina, T.; Grauby-Heywang, Ch.; Tsivadze, A.Yu. J. Phys.
Chem. C
., 2014, 118, 4250.

Figure 1
(Energy Technology Division Graduate Student Award) All-Graphene Energy Storage Device for High Energy and Power Density
Authors: Kim Haegyeom , Lim Hee-Dae , Hong Jihyun , Kang Kisuk 
Published: February 2020

The prime importance in the energy storage field is to develop a new system that can combine high energy and power density. While lithium-ion batteries (LIBs) have become scientifically and commercially important because of their high energy densities, their power densities are not sufficient for emerging large-scale applications. Supercapacitors, on the other hand, are capable of delivering very high power due to their intrinsically fast surface-reaction mechanism, but they fail to meet high energy density requirements.
This presentation proposes a new type of battery that adopts the fast surface reaction mechanism mimicking the supercapacitor without sacrificing energy density: an all-graphene energy storage device. The key advantages of an all-graphene energy storage device are that (i) both electrodes (a functionalized graphene cathode and a reduced graphene anode) exhibit fast surface reactions instead of intercalation while maintaining high energy density, and (ii) simple chemical modification of graphene yields either the anode or the cathode in a one-pot synthesis. Combined with controlled porous morphology and high electrical conductivity of graphene, the all-graphene energy storage device was capable of delivering a high energy of 195 Wh/kgtotal electrode, which is comparable to the energy density of conventional LIBs. The newly developed all-graphene energy storage device also retains 8.5 Wh/kgtotal electrode (energy) and 3,300 W/kgtotal electrode (power) at charge/discharge rates of just a few seconds. This energy and power performance perfectly spans the region that conventional LIBs and supercapacitors cannot reach. The performance and operating mechanism of an all-graphene energy storage device resemble those of both supercapacitors and batteries, blurring the conventional distinction between the two. This work sheds new light on the development of advanced energy-storage devices that bridge the performance gap between LIBs and supercapacitors.
Presenting author: H. Kim
E-mail: kimhaegyeom1@gmail.com
Corresponding author: K. Kang
E-mail: matlgen1@snu.ac.kr
3D Zinc Sponge Anodes: Towards Next-Generation Ni-Zn Batteries
Authors: Parker Joseph F. , Pala Irina R. , Chervin Christopher N. , Nelson Eric S. , Long Jeffrey W. , Rolison Debra R. 
Published: February 2020

Zinc-based batteries (e.g., Zn–air, Ag–Zn, Ni–Zn) are endowed with high specific energy (up to 400 Wh kg–1), high specific power, nonflammable alkaline electrolytes, and an earth-abundance of active materials. The advantages of zinc-based batteries make them the ideal energy storage solution to address the pitfalls of its battery-chemistry competitors—from the toxicity and low specific energy of Pb-acid to the flammability of Li-ion. The historical failure of zinc to be recognized as a worthy competitor to other technologies lies in its bedeviled non-rechargeability and modest zinc utilization (typically <60% of theoretical discharge capacity), especially when constructed as an ad-hoc powder composited electrode. Traditionally, when Zn is oxidized to Zn2+ during discharge, it forms zincate complexes (e.g. Zn(OH)4
2–

(aq)
) that are soluble in the alkaline electrolyte. These mobile Zn-carriers can diffuse beyond the site of generation but eventually supersaturate and precipitate as poorly conductive ZnO. The reverse step (charging) is initiated by re-dissolution of the ZnO to zincate prior to reduction back to Zn0. Multiple iterations of the above processes eventually lead to electronic isolation of portions of the electrode, hotspots of high-current density, and growth of short-inducing dendrites. To circumvent these problems, we design and fabricate 3D zinc "sponge" anodes that are monolithic and comprise an interpenetrating, co-continuous network of solid and void [1]. The electrode—now wired in 3D—enables low cell resistances throughout discharge that allow access to >90% of the zinc [2]. The morphology of the discharged sponges reveals a uniform deposition of ZnO on the inner walls of the sponge electrode, providing a core–shell 3D structure with an 3D-wired inner Zn metallic core that is ideal for electrochemical recharge with 100% capacity retention. We have identified the Ni–Zn battery system, with its established and rechargeable NiOOH cathode, as a prime candidate to begin implementing 3D-Zn sponge electrodes towards next-generation alternatives to Pb-acid, Ni–Cd, Ni–MH, and Li-ion batteries. We present the design and fabrication of 3D-Zn sponge anodes and their cycling performance in Ni–Zn full cells, with specific emphasis on cell fabrication, electrolyte composition, and post-mortem analysis.
The information, data, or work presented herein was funded in part by the Office of Naval Research and by the Advanced Research Projects Agency–Energy (ARPA–E), U.S. Department of Energy, under Award Number DE-AR-0000391; the work has been Approved for Public Release, Distribution Unlimited.
[1] J.F. Parker, C.N. Chervin, E.S. Nelson, J.W. Long, D.R. Rolison, Energy Environ. Sci.
7 (2014) 1117–1124.
[2] J.F. Parker, E.S. Nelson, M.D. Wattendorf, C.N. Chervin, J.W. Long, D.R. Rolison, ACS Appl. Mater. Interfaces, in the press.