bluuebunny/crossref_metadata_2025_split huggingface dataset:
Insights into Limited Cycling Performance of Li2fe(SO4)2 in the Presence of Polvinylidene Fluoride Binder
Authors: Muthiah Aravind , Baikie Tom , Shukla Shashwat , Ball Sarah , Copley Mark , Hyde Timothy , Sankar Gopinathan , Srinivasan Madhavi 
Published: February 2020

Fe-based high voltage positive electrode material Li2Fe(SO4)2 has shown consistent cycling only in experimental Swagelok cell configurations.[1, 2] In order for it to be practically viable, knowledge of its interaction with commercially used additives in the coating process is lacking. Thus, this report seeks to study the cycling performance of Li2Fe(SO4)2 in a half cell configuration in coin cells as a step towards commercial utilization of the material.
Marked degradation of cycling performance of Li2Fe(SO4)2 was observed in the coin cell configuration in comparison to the consistent cycling in a Swagelok cell. To investigate this performance degradation, the coin cell electrodes were subjected to ex-situ X-ray Fine Absorption Structure (XAFS) analysis. The X-ray Near Edge Absorption Structure (XANES) data showed no change in oxidation state of Fe in contrast to in-situ studies on the Swagelok cell done earlier.[1] However, the Extended X-ray Fine Absorption Structure (EXAFS) analyses yielded permanent changes in Fe-O bond lengths from 2.088 Å for a fresh electrode to 2.076 Å after one full cycle indicating structural changes in the system. The shorter Fe-O bond length is more covalent [3] resulting in the intercalation of the second cycle occurring at a lower redox potential and causing the material to lose its high voltage characteristic.
The structural changes were attributed to the reactivity of the sulphate electrode material with the fluorine in the commercially used polvinylidene fluoride (PVDF) binder used to coat the electrodes. This reactivity has a larger implication of incompatibility of fluoride ions with sulphate based materials and therefore necessitates the use of alternate non-fluorinated binders and electrolytes for their consistent performance.
References:
[1] M. Reynaud, M. Ati, B. C. Melot, M. T. Sougrati, G. Rousse, J.-N. Chotard, et al., "Li2Fe(SO4)2 as a 3.83 V positive electrode material," Electrochemistry Communications, vol. 21, pp. 77-80, 2012.
[2] L. Lander, M. Reynaud, G. Rousse, M. T. Sougrati, C. Laberty-Robert, R. J. Messinger, et al., "Synthesis and electrochemical performance of the orthorhombic Li2Fe(SO4)2 polymorph for Li-ion batteries," Chemistry of Materials, vol. 26, pp. 4178-4189, 2014.
[3] A. Gutierrez, N. A. Benedek, and A. Manthiram, "Crystal-Chemical Guide for Understanding Redox Energy Variations of M2+/3+ Couples in Polyanion Cathodes for Lithium-Ion Batteries," Chemistry of Materials, vol. 25, pp. 4010-4016, 2013.
Probing the Limits of Electron and Ion Transport over Multiple Length Scales
Authors: Takeuchi Esther S , Bock David C , Pelliccione Christopher J , Zhang Wei , Knehr Kevin W , Brady Nicholas W , Cama Christina A , Lininger Christianna Naomi , Kirshenbaum Kevin , Wang Jiajun , Wang Jun , Li Yan , West Alan C , Wang Feng , Marschilok Amy C , Takeuchi Kenneth J 
Published: February 2020

As the demand for large scale batteries has grown, considerations such as earth abundance, cost, and toxicity have assumed a greater significance. Metal oxides such as magnetite (Fe3O4) are worthy of evaluation as active materials for electrochemical energy storage due to its earth abundance, low cost, environmentally benign iron metal centers and high theoretical capacity, 926 mAh/g. Implementation in the future will require understanding of the fundamental electrochemical reduction-oxidation mechanisms of the electroactive materials is required, coupled with characterization at the mesoscale to understand the underlying contributors to localized resistance which must be addressed in order to achieve significant improvements to current capability and reversibility.
An emerging paradigm for the implementation of close-packed materials in higher current applications is the tuning of the materials crystallite dimensions, where the reduction of crystallite size should minimize the path length for ion transport upon discharge, resulting in a reduction of both internal cell resistance and the resultant structural strain associated with lithium insertion. The electrochemical impact of controlled crystallite size of magnetite will be described.
In addition to the crystallite size of the electroactive material, a complete study of an electroactive nanomaterial in the complex mesoscale environment of a composite battery electrode should also consider the level of electroactive particle agglomeration, and agglomerate distribution within the battery electrode. Nanocrystalline magnetite (Fe3O4) powders and composite electrodes with different crystallite sizes were prepared, characterized, and electrochemically evaluated. Transmission electron microscopy (TEM) examination of cross-sectioned electrodes was used to quantify the aggregate size of the Fe3O4 active material. Notably, although the crystallite sizes of two magnetite samples Fe3O4 are different (28 and 9 nm), the observed sizes of the aggregates and aggregate distribution within the electrodes were similar, see TEM images of sectioned electrodes fabricated with the 28 nm (A,B) and 9 nm (C,D) sized Fe3O4 in the Figure. Transmission x-ray microscopy (TXM) combined with x-ray absorption near edge spectroscopy (XANES) at the National Synchrotron Light Source (NSLS) were used to determine the distribution of the iron oxidation states within the electrodes before and after electrochemical testing. The impact of both crystallite size and agglomeration on electrochemical performance were assessed.

Figure 1
One-Dimensional Nanomaterials for Energy Storage
Authors: Mai Liqiang 
Published: February 2020

One-dimensional nanomaterials can offer large surface area, facile strain relaxation upon cycling and efficient electron transport pathway to achieve high electrochemical performance. Hence, nanowires have attracted increasing interest in energy related fields.
To increase the stability of Li-ion battery, V3O7 nanowire templated semi-hollow bicontinous graphene scrolls architecture is designed and constructed through “oriented assembly” and “self-scroll” strategy. The V3O7 nanowire templated semi-hollow bicontinous graphene scrolls with interior cavities provide continuous electron and lithium ion transfer channel and space for free volume expansion of V3O7 nanowires during cycling, thus representing a unique architecture for excellent lithium ion storage capacity and cycling performance. Besides, we have designed and synthesized hierarchical MnMoO4/CoMoO4 heterostructured nanowires by combining "oriented attachment" and "self-assembly". The asymmetric supercapacitors based on the hierarchical heterostructured nanowires show a high specific capacitance and good reversibility with a cycling efficiency of 98% after 1,000 cycles. Recently, we also constructed the hierarchical zigzag Na1.25V3O8 nanowires, K3V2(PO4)3 bundled nanowire, and Li3V2(PO4)3 mesoporous nanotubes with enhanced electrochemical performance. Our work presented here can inspire new thought in constructing novel one-dimensional nanostructures and accelerate the development of energy storage appilications.
Growth Mechanisms in High-Rate Lithium Metal Batteries
Authors: Bai Peng , Wang Miao , Brushett Fikile R. , Bazant Martin Z. 
Published: February 2020

Lithium metal anode is the key for the next-generation high-energy batteries. But lithium dendrites formed during recharge (electrodeposition at the anode) could short-circuit the battery and lead to fires and explosions. Tremendous efforts have been devoted to modify the composition of electrolytes and the surface of lithium electrodes, but mainly improved the stability of lithium under small currents and low capacities. Here, we devise a Li symmetric cell in a fine glass capillary, and the in situ observations reveal that the morphology of lithium deposit changes from a dense porous (mossy) structure to needle-like (dendritic) structure at Sand’s time, when the concentration of electrolyte decreases to zero at the surface of the electrode. Further experiments in sandwich cells of Li|Separator(Electroylte)|Li confirm that mossy lithium can be completely blocked by anodic aluminum oxide (AAO) membrane until Sand’s time, when a sudden voltage jump stimulates dendritic lithium to form, penetrate the nanopores of AAO and then short the cell, just like the behavior of transport-limited dendritic growth of copper. By creating a free compartment on each side of the AAO membrane, our sandwich cells can stably cycle at much higher current densities and capacities, e.g. at 5mA/cm2 for 5mAh/cm2. Our results agree well with a current-dependent critical capacity, C
Sand~ADc0
2/I, which suggests that increasing the concentration of electrolytes c
0 or lithium ion diffusivity D, and tuning the property of SEI to maintain a relatively large active surface area A of the porous lithium are beneficial to engineering rechargeable high-rate and large-capacity lithium metal anode.
Figure: Single dendrite shoots out from the mossy lithium deposits at Sand’s time, indicating a change of growth mechanism.

Figure 1
Study the Interface of Cathode Material and Li-La-Zr-O Thin Film Prepared at Low Temperature for All Solid State Li Battery
Authors: Zarabian Mina , Perez-Zurita Maria Josefina , Buyukaksoy Aligul , Pereira-Almao Pedro , Thangadurai Venkataraman 
Published: February 2020

Switching from an organic polymer-based Li ion electrolyte to a ceramic Li ion electrolyte is expected to allow for the higher energy density, improve the safety and cycle lifetime. These, all solid state Li ion batteries can also be miniaturized, which will streamline the packing design. Among studied Li ion conductive solid electrolyte (1, 2) garnet family have recently gained lots of attention due to the high ionic conductivity and electrochemical stability at ambient temperature. Garnet-like structure, Li7La3Zr2O12 (LLZO) has shown comparable Li ion conductivity with the current Li ion electrolytes (3). However, the reported ionic conductivity of a thin film LLZO was three orders of magnitude lower compared to bulk phase (4). The main goal of the current research is to develop thin film solid electrolyte on the LiCoO2 electrode and investigate the interface. For this purpose, LLZO was fabricated using a liquid precursor technique. The Li-La-Zr nitrate solution was coated on the top surface of the LiCoO2 substrate for several times until the appropriate thickness (300 nm – 1 µm) is obtained. After each step of coating, the deposited precursor is dried and decomposed at 450 °C. Figure 1 shows cross section image of crack-free, flat, dense and homogenous solid electrolyte layer deposited on the surface of the LiCoO2. X-ray photoelectron spectroscopy (XPS) coupled with ion etching is used to understand the interface composition and thickness. Electrochemical impedance spectroscopy (EIS) was used to analyze and understand the electrolyte and interfacial resistance.

References

1. S. Teng, J. Tan and A. Tiwari, Current Opinion in Solid State and Materials Science, 18, 29 (2014).
2. V. Thangadurai, D. Pinzaru, S. Narayanan and A. K. Baral, The Journal of Physical Chemistry Letters, 6, 292 (2015).
3. R. Murugan, V. Thangadurai and W. Weppner, Angewandte Chemie International Edition, 46, 7778 (2007).
4. K. Tadanaga, H. Egawa, A. Hayashi, M. Tatsumisago, J. Mosa, M. Aparicio and A. Duran, Journal of Power Sources, 273, 844 (2015).

Figure 1
High Voltage Operation of Surface Coated NMC in Ionic Liquids Based on 1-Ethyl-3-Methylimidazolium Bis(fluorosulfonyl)Imide
Authors: Matsumoto Hajime , Taguchi Noboru , Sakaebe Hikari , Tatsumi Kuniaki , Ogumi Zempachi 
Published: February 2020

Ionic liquids (ILs) have been studied as a unique electrolyte for a lithium battery for a past two decades 1). The thermal stability and less-volatility have been expected to improve safety of a conventional lithium ion battery system using flammable non-aqueous electrolytes. For example, using bis(trifluoromethylsulfonyl)imide (TFSA-) –ILs as a electrolyte, LiFePO4 half cell could be charged and discharge over 100 °C 2).

In this study, we will report that another unique and important features of a zero-solvent electrolyte like ILs was indicated at a high voltage (> 4.7 V) charging and discharging cycle using a transition metal oxide cathode as a LCO and NMC. A modification of NMC by coating with Al2O3 particle successfully improved the high voltage operation over 4.2 V as already reported 3). However, we found that a LCO and also NMC cathode without any coating could be stable over 4.7 V charging and discharging cycle even in 1-ethyl-3-methylimidezolium bis(fluoromethylsulfonyl)amide ([EMI][FSA]) containing a certain amount of Li[FSA]. This finding indicate that a catalytic site for oxidation decomposition of a conventional organic electrolyte on a transition metal oxide, which was deactivate by a surface coating with Al2O3, did not affect the oxidation of the ionic liquids electrolyte, which did not contain any organic solvents. On the other hand, a cycle stability at a high temperature over 45 °C was effectively stabilized by a surface coating on NMC with ZrO2. The result implies that the surface modification of a transition metal cathode effectively protected the structural disorder of a cathode material by a high temperature condition.
These results show that using zero-solvent electrolyte like ILs might be a useful tool to elucidate the effect of surface modification in an organic solvent electrolyte.
Acknowledgment
This work was supported by the “Research & Development Initiative for Scientific Innovation of New Generation Batteries (RISING)” project of the New Energy and Industrial Technology Development Organization (NEDO).
1) H. Matsumoto, in Electrolytes for Lithium-ion Batteries, eds. T. R. Jow, K. Xu, O. Borodin and M. Ue, Springer, 2014, ch.4.
2) H. Matsumoto and K. Kubota, ECS Transactions, 64(4), 425 (2014).
3) K. Araki, N. Taguchi, H. Sakaebe, K. tatsumi, Z. Ogumi, J. Power Sources, 269 (2014) 236.
In Situ Neutron Diffraction Studies of Ion Exchange - Application to Solid State Electrolytes
Authors: Khalifah Peter , Liu Jue , Whitfield Pamela , Saccomanno Michael , Hu Enyuan , Yu Xiqian , Bai Jianming , Yang Xiao-Qing 
Published: February 2020

In situ neutron diffraction is for the first time demonstrated to be a powerful tool for precisely following the structural changes associated with mobile light ions during Li+/Na+ ion exchange. While ion exchange is traditionally accomplished using a liquid electrolyte, the present experiments were facilitated by the use of non-molten salts as the source of ions. A novel isotropic Li-ion conductor was investigated in the present work. High quality structural data could be obtained through the Rietveld refinement of neutron diffraction data collected with ~30 minute time steps. The mechanism of ion exchange could be readily resolved from this data, including the identification of a hidden phase transition not apparent from studies of the lattice parameters along, the identification of site-specific contributions to the overall volume change during ion exchange, and the observation of different equilibrium ratios of phases at different temperatures. This method should have general applicability to the study of ion exchange processes in solids, but provides the most advantages for the study of oxide ceramics due to the high sensitivity of neutrons to oxygen and other light elements.
Charge Transfer Catalysis Across Semiconductor/Electrolyte Interfaces By Metalloporphyrin/Polymer Matrices
Authors: Hilal Hikmat S. , Zyoud Ahed H. 
Published: February 2020

Polycrystalline metal chalcogenide (CdS, CdSe, CdTe, CuS, CuSe and others) thin-film electrodes are being considered as alternative for the more costly and advanced-tech demanding photovoltaic (PV) systems. Despite their ease of preparation and economy in starting materials, the thin film electrodes have major drawbacks. Due to lack of surface uniformity, low carrier mobility and high resistance at the solid/liquid interface, such electrodes exhibit low conversion efficiency in PEC processes. Moreover, the electrode surfaces are unstable and tend to undergo photo-corrosion. These shortcomings are a real challenge for using thin film electrodes in PEC technology, and should be overcome. Porphyirinato manganese (MnTPyP) complexes embodied inside different polymeric materials have been used as charge transfer mediators across solid/liquid junctions in PEC processes. The MnTPyP/Polymer coating (~80 nm thick) can be cast onto surfaces of the polycrystalline metal chalcogenide thin film electrodes in simple methods. The coating showed remarkable enhancement in the PEC conversion efficiency of different electrodes. Both short-circuit current and fill factor values have been remarkably enhanced. Conversion efficiency values of as high as 19% have been observed here. Such results have not been preceded before in metal chalchogenide thin-film electrode processes. Moreover, the coating enhanced the semiconductor electrode stability to photo-corrosion under PEC conditions. The MnTPyP/Polymer matrix behaved as charge transfer mediator across the solid/liquid interface. Upon exciting an n-type semiconductor electrode, electrons are excited from the valence band to the conduction band and move to the back contact wiring. The remaining holes must move to the redox couple to make photo-current. In polycrystalline semiconductor electrodes, such a transfer is not fast enough, which lowers the value of the short circuit current, and consequently the conversion efficiency. Therefore, holes accumulate in the space charge layer and cause electrode corrosion. The MnTPyP/Polymer matrix enhances both efficiency and stability of the electrode by behaving as a charge transfer mediator. The MnTPyP complex involves both MnIII and MnII ions together. The holes in the valence band oxidize the MnII ions into MnIII ions. The MnIII ions in turn oxidize the reduced phase of the redox couple. By this way, the MnTPyP complex catalyzes the hole-transfer and enhances both efficiency and stability of the electrode. The charge transfer mediation formalism is summarized in the attached Scheme. Results and discussions will be presented in detail together with effect of the coating on the electrode band edge positions.

Figure 1
Composite Solid Polymer Electrolyte Membrane
Authors: Wang Ting , Xie Jingying , Wang Jiulin , Wang Ke 
Published: February 2020

Due to safety issues in the lithium batteries with organic liquid electrolytes, it is expected that the next-generation safe lithium batteries would be the all-solid-state batteries. New solid electrolytes with high Li+ ion conduction such as Li10GeP2S12, Li1.3Al0.3Ti1.7(PO4)3 and Li7La3Zr2O12 have attracted extensive attentions in the development of solid-state batteries. Especially, the garnet-type material Li7La3Zr2O12 has several advantageous properties such as good thermal and chemical stability with lithium metal anode, environmental compatibility, relatively high Li+ion conductivity. However, the poor contact between electrodes and electrolyte is a most important factor limiting the development of LLZO all-solid-state battery.
So we combining P(VDF-HFP) polymer electrolyte and LLZO powder and painting it on the fiberglass to construct composite solid polymer electrolyte. The SEM micrographs of the with 30wt% LLZO added are shown in Fig.1. There are obvious powder have attaching to the fiberglass surface and the polymer on it. Fig.2. compared rate capability of the composite solid polymer electrolyte film and the fiberglass. Founding that the composite system can obviously increasing it.

Fig.1 SEM micrographs of the
composite
solid polymer electrolyte.

Fig.2 Rate capability of the composite solid
polymer electrolyte film and the fiberglass.

Acknowledgements

The project was supported by the National Natural Science Foundation of China (21373137), Shanghai Science and Technology Development Fund (15DZ2282000) and the Foundation of China (NSFC21373137).

Figure 1
Reduction Products of Vinylene Carbonate and Fluoroethylene Carbonate
Authors: Subramanian Parimalam Bharathy , Nie Mengyun , Lucht Brett L 
Published: February 2020

Lithium ion batteries play an important role as energy storage devices in consumer electronics and electric vehicles, thanks to their high energy density, high efficiency and long life. Mixtures of organic carbonates are usually employed as electrolyte solvents in these batteries. Electrolyte reacts reductively with the anode and forms a passivation layer (SEI) during initial charging cycles. SEI layer plays a crucial role in the performance of a lithium-ion battery1 and small amount of additives are generally employed to improve the characteristics of the SEI. Understanding the reduction products of effective electrolyte additives would facilitate us to design better additives to improve the performance of lithium ion battery. Vinylene carbonate and fluoroethylene carbonate are excellent additives. They improve the initial irreversible capacity and high temperature performance of the lithium-ion battery, when added to the electrolyte.2
,
3 Theoretical study on reduction of these additives indicates, they may yield very similar SEI.4 Lithium naphthalenide, a popular one-electron reducing agent, is shown to reduce the electrolyte similar to lithiated graphite anode.5 The same compound is utilized to reduce Vinylene carbonate & fluoroethylene carbonate. The products were analyzed with GCMS, NMR & FTIR and the results will be discussed. Acknowledgement
The authors gratefully acknowledge funding from Department of Energy Office of Basic Energy Sciences
EPSCoR Implementation award (DE-SC0007074). References
(1) R Fong, U von Sacken, J. D. 2009, 137 (7), 3–7.
(2) Aurbach, D.; Gamolsky, K.; Markovsky, B.; Gofer, Y.; Schmidt, M.; Heider, U. Electrochim. Acta
2002, 47 (9), 1423–1439.
(3) McMillan, R.; Slegr, H.; Shu, Z. .; Wang, W. J. Power Sources
1999, 81-82, 20–26.
(4) Hoz, J. D. La; Balbuena, P. Phys. Chem. Chem. Phys.
2014, 1–18.
(5) Nie, M.; Chalasani, D.; Abraham, D. P.; Chen, Y.; Bose, A.; Lucht, B. L. J. Phys. Chem. C
2013, 117 (3), 1257–1267.
Phase Transformations in Layered O and P Type Metal Oxide Na-Ion Battery Cathodes
Authors: Toumar Alexandra J. , Ong Shyue Ping , Richards William Davidson , Huang Wenxuan , Dacek Stephen , Ceder Gerbrand 
Published: February 2020

Current state of the art Na-ion battery cathodes are selected from the broad chemical space of layered first row transition metal (TM) oxides. Unlike their lithium ion counterparts, seven first row layered TM oxides can intercalate Na ions reversibly. Their voltage curves also indicate significant and numerous reversible phase transformations during electrochemical cycling. These transformations are not yet fully understood, but arise from Na-ion vacancy ordering and metal oxide slab glide.
In this study, we investigate the nature of vacancy ordering transformations within the O3, P3 and P2 lattice frameworks. We generate predicted electrochemical voltage curves for each of the Na-ion intercalating layered single TM oxides using a high-throughput framework of density functional theory (DFT) calculations. We determine a set of vacancy ordered phases appearing as ground states in all Na\textsubscript{x}MO\textsubscript{2} systems, and investigate the effect of ordering interactions between adjacent layers. We further investigate the role of TM choice and TM mixing in mitigating phase transformations and synthesis of O3 and P2 type materials.