bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal Stability and Decomposition of Lithium Bis(fluorosulfonyl)Imide (LiFSI) Salts
Authors: Kerner Manfred , Plylahan Nareerat , Scheers Johan , Johansson Patrik 
Published: February 2020

Lithium-ion batteries (LIBs) working at high temperature (HT) (80–150°C) (HT-LIBs) should have a number of intrinsic advantages such as high ionic conductivities, fast electrode kinetics, etc. An HT-LIB could at a vehicle systems level reduce the cooler size, as compared to using conventional LIBs. To comply with HT conditions, however, all parts of the battery have to be thermally stable, to not become a security problem or deteriorated. The most often used LIB electrolyte salt (LiPF6) is unstable at temperatures >60°C [1] and hence it is crucial to explore alternative lithium salts.
The lithium bis(fluorosulfonyl)imide (LiFSI) salt has been suggested as a possible replacement for LiPF6due to an improved thermal stability, high ionic conductivities and electrochemical stabilities in LIB electrolytes [2,3]. However, some contradictory results exist with respect to its promising thermal stability and non-corrosiveness [4,5].
We have investigated three commercial LiFSI salts and compared their properties with focus on thermal stability and phase transitions – including a vibrational spectroscopy based assessment of salt purity and decomposition products [6]. The salts were found to differ significantly in their thermal stabilities as determined by both dynamic and isothermal TGA. The FT-IR spectra of the salts are close to identical, but several additional bands were identified in the Raman spectra of the least stable salt. The latter allows for a discussion of the origin and role of salt impurities for the observed thermal (in-)stability. Furthermore, by adding each salt to the ionic liquid 1-ethyl-3-methylimidazolium FSI (EMIFSI), Li0.1EMI0.9FSI electrolytes were obtained. Galvanostatic cycling and linear sweep voltammetry were both performed to elucidate the influence of the impurities on the electrochemical performance.
[1] S.F. Lux, I.T. Lucas, E. Pollak, S. Passerini, M. Winter, R. Kostecki, Electrochem. Commun. 14 (2012) 47.
[2] H.-B. Han et al.J. Power Sources 196 (2011) 3623.
[3] L. Li, S. Zhou, H. Han, H. Li, J. Nie, M. Armand, Z. Zhou, X. Huang, J. Electrochem. Soc. 158 (2011) A74.
[4] K. Kubota, T. Nohira, T. Goto, R. Hagiwara, Electrochem. Commun. 10 (2008) 1886.
[5] A. Abouimrane, J. Ding, I.J. Davidson, J. Power Sources 189 (2009) 693.
[6] M. Kerner, N. Plylahan, J. Scheers, P. Johansson, submitted

Figure 1: The thermal stabilities of three commercial LiFSI salts.

Figure 1
Enhanced High Rate Performance of a NaTi2(PO4)3/Reduced Graphene Oxide Composite Electrode Via Pyro Synthesis for Sodium Ion Batteries
Authors: Song Jinju , Park Sohyun , Gim Jihyeon , Kim Sungjin , Jo Jeonggeun , Mathew Vinod , Kim Seokhun , Kim Jaekook 
Published: February 2020

The present study reports on a highly rate capable NASICON-structured NaTi2(PO4)3/ reduced graphene oxide (NTP/rGO) composite electrode synthesized by polyol-assisted pyro synthesis for Na-ion batteries (NIBs). X-ray diffraction (XRD) studies confirmed the presence of a rombohedral NaTi2(PO4)3 phase in the composite while Raman spectroscopy studies helped to identify the existence of rGO in the composite. Electron microscopy studies established that NaTi2(PO4)3 nanoparticles of average sizes ranging between 20 and 30 nm were uniformly distributed and embedded on the GO sheets. When tested for sodium storage properties, the obtained NTP/rGO composite electrode registered high rate capacities (95 mAh g-1 at 9.2 C and 78 mAh g-1 at 36.8 C) when compared to that of the NTP/C electrode (~1 mAh g-1 at 9.2 and 36.8 C). The enhanced performance of the composite electrode can be attributed to the nano-sized NaTi2(PO4)3 particles with shorter diffusion path lengths embedded on the rGO sheets with enhanced electrolyte/electrode contact areas that ultimately leads to an improvement in the electrical conductivity at high current densities. Ex-situ XANES studies confirmed reversible Na-ion intercalation/de-intercalation into/from NTP/rGO. The study thus demonstrates that the NaTi2(PO4)3/rGO nanocomposite electrode is a promising candidate for the development of high power/energy density anodes for NIBs.
NaxCo1-YTiyO2 : A New Cathode Material for High Energy Density Sodium Ion Batteries
Authors: Sabi Noha , Doubaji Siham , Solhy Abderrahim , Larzek Mohamed , Hashimoto Kazuki , Komaba Shinichi , Saadoune Ismael 
Published: February 2020

Abstract:

Energy storage has become a key issue concerning our welfare in daily life; the increasing claim for powering systems has conducted energy storage to become a figuring topic.
In this regard, lithium-ion battery technology has attracted a respectful interest thanks to its suitable and attractive properties as a powerful source for high voltage applications such as cellular phones, digital cameras and hybrid electric vehicles.
Unfortunately, the little abundance of this alkali metal in the earth’s crust, its evil extraction impact on the environment, restricted its use in lithium ion batteries. In this context, sodium has drawn a wide attention thanks to its abundant resources and low cost. Sodium has a larger ionic radius (1,02 Å) and higher redox potential (-2,71 V vs SHE) of Na+/Na compared to Li and operates in a similar fashion.
In the last decades, NaxCoO2was studied as an electrode material and exhibits promising performances. Nevertheless, it presents nine potential steps during the intercalation/de-intercalation process which could be considered a drawback of this electrode material.
Indeed, we investigated the NaxCo1-yTiyO2 solid solution with the aim to obtain better performances with reduced cost. P2-Na2/3Co1/2Ti1/2O2 selected phase was synthesized by solid-state method. This material offers a specific capacity of 100 mAh/g in the [2-4.2V] potential window. A good capacity retention of the Na// Na2/3Co1/2Ti1/2O2 cell was recorded with a coulombic efficiency approaching 99%. An ex-situ XRD study on the NaxCo1/2Ti1/2O2 sample evidenced that the P2-type structure is preserved until the end of the charge process where a structural transformation occurs leading to structurally faulted oxidized phase.

Key words: Na-ion batteries, NaxCo1-yTiyO2, Energy storage, Ex-situ study.

Acknowledgments:

The financial assistance of the office Chérifien des Phosphates in the Moroccan Kingdom (OCP group): The authors are hereby acknowledged. Ms N. SABI is grateful to Mohammed VI Polytechnic University for the scholarship.

References:

Yabuuchi, N., Kubota, K., Dahbi, M., Komaba,S. (2014), Research Development on Sodium-Ion Batteries,Chem. Rev., 23, 11636-11682.
Kubota, K., Komaba,S. (2015), Practical Issue and Future Perspective for Na-Ion Batteries, Electrochemical Society., 14, 2538-2550.
Clément, J., Bruce, G., Grey, P.(2015),Manganese-Based P2-Type Transition Metal Oxides as Sodium-Ion Cathode Materials, Electrochemical Society., 14, 162, 2589-2604.

Figure 1
Efficiency and Long-Term Cycling Study of Carbon Anode Materials in Sodium-Ion Batteries
Authors: Bommier Clement , Ji Xiulei , Surta Wesley , Jian Zelang , Li Zhifei , Dolgos Michelle 
Published: February 2020

Recently, there has been much discussion about Na-ion batteries (NIBs) emerging as one ideal technology for grid-level energy storage. Large-scale usage of NIBs can be sustainable as the raw materials involved in making such batteries are cheap, plentiful and non-toxic. Thus far, they have demonstrated very promising electrochemical performances in prototype experiments.
Despite the aforementioned benefits, there still remain technical issues associated with the electrode materials, which is currently hindering their development as a fully-functional commercial battery. One of these pressing problems is the efficiency and cyclability of the anode material: an ideal material must possess both a high 1st cycle coulombic efficiency and a stable long-term cycling life—as both of these are crucial to the performance of the battery. However, most candidate materials currently proposed in the literature do not meet such criteria.
Herein, we study self-standing cellulose-derived carbon as a model carbon, where we attempt to understand factors affecting coulombic efficiency and long-term cycling. This material displays one of the highest reported coulombic efficiencies for carbon-based anodes in the literature, with values averaging near 90% for the first cycle with a deep-sodiation in a half-cell. On the other hand, the carbon material also displays extremely poor rate and long-term cycling performances, which leads us to an in-depth investigation of the fading mechanism of carbon materials used as NIB anodes.
Through the course of our investigation on the fading mechanism, we are able to uncover some structural-property relationships to understand the capacity loss during long-term cycling. This was elucidated through the use of traditional characterization methods such as XRD, Raman spectroscopy and XPS measurements along with more advanced TEM characterization, using sample “lift-outs” to probe the structural effects of long-term cycling on the carbon material. These claims are also further supported through electrochemical data including diffusivity tests, CV and EIS measurements. Using the information learned on the efficiency/long-term decay mechanism, we were able to devise ‘proof-of-concept’ solutions to increase long-term cycling of carbon anode materials utilized in NIBs.
A High-Power Symmetric Na-Ion Pseudocapacitor
Authors: Jian Zelang , Raju Vadivukarasi , Li Zhifei , Xing Zhenyu , Hu Yong-Sheng , Ji Xiulei 
Published: February 2020

Electrochemical batteries and capacitors are important devices for electrical energy storage with wide applications from portable electronics to transportation, and to grid. However, rechargeable batteries are typically limited in poor power density, while supercapacitors deliver low energy density. One “Holy Grail” of energy storage is to have an energy density up to the level of Li-ion batteries and a power density and cycling life identical to supercapacitors. Here we design a novel symmetric Na-ion pseudocapacitor with a power density exceeding 5.4 kW/kg at 11.7 A/g, a cycling life retention of 64.5% after 10,000 cycles at 1.17 A/g, and an energy density of 26 Wh/kg at 0.585 A/g. Such a device operates on oxidation-reduction reactions occurring on both electrodes with an identical active material, viz., Na3V2(PO4)3 encapsulated inside nanoporous carbon. This device, in a full-cell scale utilizing highly reversible, high-rate, cost-effective Na-ion intercalational pseudocapacitance, can bridge the performance gap between batteries and supercapacitors. The characteristics of the device and the potentially low-cost production make it attractive for hybrid electric vehicles and low maintenance energy storage system.
Advanced Polymer Binder for Silicon Anodes Based High Energy Density Lithium Ion Battery
Authors: Zou Feng , Zhu Yu 
Published: February 2020

The state-of-the-art lithium ion batteries (LIBs) do not have sufficient specific energy for emerging applications such as electrical vehicles. One route to increase the energy density of LIBs is the use of a silicon-based anode. Unlike conventional graphite anodes, which only have capacity of one lithium ion per six carbon atoms (372 mA-h/g), silicon-based anodes have a theoretical capacity of 4.4 lithium ions per silicon atom (4,200 mA-h/g). These results indicate that the Si anode offers great promising for achieving high specific energy LIBs. However, silicon-based anodes have yet to achieve widespread adoption or commercialization due to the large volume change that occurs upon lithiation/delithiation, resulting in severe electrode pulverization and degradation. In this work, novel polymer binder materials mitigating the volume expansion of the Si particles were developed. These binder materials were applied in half-cell and the batteries exhibited excellent cyclability. The battery exhibited area capacity over 1.5 mAh/cm2 and negligible degradation in the first 100 cycles. The first cycle coulombic efficiency is over 80%.
Figure 1 LIBs with commercial binder and UA binder. UA binder provides better cyclability at higher mass loading.

Figure 1
Effects of Electrolyte/Sulfur Ratio on Li2S Electrodeposition Kinetics in Li-S Batteries
Authors: Fan Frank , Chiang Yet-Ming 
Published: February 2020

Li2S electrodeposition poses a number of challenges due to slow redox kinetics, the formation of electronically disconnected material, and the fact that Li2S is an electronic insulator. This process is also responsible for the majority of the capacity in a Li-S battery, so it is therefore important to understand and improve its kinetics. Recently we have demonstrated that Li2S electrodeposition occurs by a surface-limited 2-D island nucleation and growth process.1

Here, the kinetics of Li2S deposition on carbon from polysulfide solutions of various concentrations (in DOL:DME 1:1) were characterized potentiostatically. In general, higher polysulfide concentrations were found to result in significantly slower electrodeposition. High polysulfide concentrations can be expected in Li-S batteries with low electrolyte/sulfur (E/S) ratios, as large amounts of electrolyte tend to dilute the polysulfide. We galvanostatically cycled Li-S cells with different E/S ratios and found that a low E/S ratio does indeed result in significantly higher polarization, especially at the beginning of the Li2S precipitation plateau when nucleation of Li2S occurs.
This has significant implications for the design of sulfur cathodes, as low E/S ratios are essential for high energy density Li-S batteries.2 It is therefore necessary to improve electrodeposition kinetics at high polysulfide concentrations. Some strategies for doing so include redox mediators, as well as the use of alternative conducting substrates such as conducting oxides with higher affinities for Li2S.
Figure: (a) Potentiostatic current vs. time curves for Li2S deposition from various concentrations (in molarity of sulfur) of polysulfide at 2.05V vs. Li/Li+. Wider peaks at higher concentrations indicate slower nucleation and growth. (b) Galvanostatic cycling of sulfur-carbon composite cathodes vs. Li at C/8 at various E/S ratios.
References
1. F. Y. Fan, W. C. Carter, and Y.-M. Chiang, Adv. Mater., 27, 5203–5209 (2015) http://doi.wiley.com/10.1002/adma.201501559.
2. D. Eroglu, K. R. Zavadil, and K. G. Gallagher, J. Electrochem. Soc., 162, A982–A990 (2015).

Figure 1
Rechargeable Nonaqueous Aluminum Sulfur Battery
Authors: Gao Tao , Noked Malachi , Xu Kang , Wang Chunsheng 
Published: February 2020

Rechargeable aluminum batteries attracted growing attentions in recent years as one candidate beyond lithium ion battery system. This is due to the great potential of aluminum metal anode owing to its high capacity (2.98 Ah/g and 8.05 Ah/cc), its negative electrochemical potential (-1.67 V vs. NHE), and its highest abundancy among metals in earth crust. Moreover, aluminum has significantly lower reactivity towards moisture and air compared to Li, Na and Mg. Reversible Al deposition/stripping in room temperature is extremely challenging due to the tendency of Al to form real passivation on its surface with both poor ionic and electronic conductivity. Nevertheless, use of aluminum anode was shown to be possible by in ionic liquid based electrolyte (RTIL-AlCl3) with up to 100% coulombic efficiency for aluminum deposition/stripping.
As a high capacity cathode material (1,675 mAh/g), sulfur has attracted intense interest in Li/S, Mg/S and Na/S systems. A rechargeable Al/S battery is also of great interest because the full cell capacity could achieve 1072 mAh/g-(total electrode mass) and voltage could achieve ~1.25 V, estimated from the Gibbs formation energy of Aluminum sulfide( -724 kJ/mol). The gravimetric energy density is hence 1340 Wh/kg, over three times of a commercial LiCoO2/graphite cell and close to that of a Li2S/silicon cell. The high energy density and low cost of both Al and S makes Al/S system a very promising battery chemistry for large scale applications like electric vehicle and grid storage. Motivated by the potential, Cohn et al. recently demonstrated a proof-of-concept non-aqueous Al/S battery. Though demonstrating close to theoretical capacity with operating voltage of 1.2 V, the reported Al/S cell cannot be recharged, resulting in the loss of all capacity within three cycles. Up to now, there was no demonstration of reversible Al/S battery, probably due to the inability to recharge AlSx.
In this work, we demonstrate a reversible Al/S cell with specific cathode capacity of ~1200 mAh/gs for over 20 cycles. Kinetics analysis point out the system is limited by slow diffusion of Al containing anion due to the high viscosity of the ionic liquid electrolyte. Raising temperature is proved to be an effective approach to mitigate the kinetic limitation thus decrease the hysteresis during charge and discharge. Spectroscopic and microscopic observations explore the mechanism of sulfur redox in the RTIL-AlCl3 electrolyte and enabled us to monitor the interfacial processes on both the cathode and anode. We believe that the new scientific insights obtained in this work will demonstrate inspiring progress on the way to realize a rechargeable Al/S battery.
Lightweight Polyanion Frameworks for Li- and Mg-Ion Batteries
Authors: Glass Hugh F J , Dutton Siân E , Grey Clare P. 
Published: February 2020

Mg-ion batteries are a promising “beyond Li-ion” technology as they offer high theoretical capacities, use cheap and abundant materials, and Mg metal can be used as the anode.1 However, the search for high voltage cathodes has been hindered by electrolyte incompatibility and sluggish kinetics which can impede intercalation and charging rates.2

MgMB2O5 (M = Mn, Fe, Co) are shown to be high voltage, high capacity cathode materials for both Li- and Mg-ion batteries. The open structure facilitates ion diffusion while the light weight polyanion framework increases capacity and voltage. The materials are produced from metal oxalate and boric acid starting materials via a solid state synthesis process. The Mg:M ratio can be altered to manipulate capacity and ordering of the cations.
Mg can be fully removed from MgMnB2O5 giving a capacity of up to 300 mAhg-1 while maintaining the structure. Removal of Mg is confirmed by refinement of powder neutron diffraction data. In a full Mg-ion cell a reversible discharge capacity of ~100 mAhg-1 has been achieved. However, due to the incompatibility of the cell with available electrolytes this is accompanied by irreversible side reactions on charge. Some promising resolutions to the electrolyte problem are discussed. Mg can also be removed from the structure when M = Co or Fe, with the change in transition metal leading to a change in operating voltage. The results presented show that this class of material is a promising candidate for a high capacity, high voltage Mg-ion cathode material.
In a Li-ion battery 1.5 Li can be intercalated into the manganese based material after Mg has been removed, giving a specific capacity of up to 250 mAhg-1 above 1.5 V. The capacity is retained over hundreds of cycles with little drop off observed even at rates of 5C. Ex-situ XRD shows a doubling of the unit cell when the material is cycled, suggesting charge ordering is occurring. Neutron diffraction refinements show a change in volume of ~2%, associated with insertion or removal of Li ions.
References:
1: H.D. Yoo, I. Shterenberg, Y. Gofer, G. Gershinsky, N. Pour and D. Aurbach, Energy Environ. Sci., 2013,6, 2265-2279 DOI: 10.1039/C3EE40871J
2: C. Bucur, T. Gregory, A. Oliver, J. Muldoon, J. Phys. Chem. Lett., 2015, 6 (18), pp 3578–3591 DOI: 10.1021/acs.jpclett.5b01219
High Performance Sulfur-Composite Cathode for Lithium-Ion Sulfur Batteries
Authors: Umirov Nurzhan , Mentbayeva Almagul , Konarov Aishuak , Kurmanbayeva Indira , Hara Toru , Bakenov Zhumabay 
Published: February 2020

Rapid development of portable electronics, electric transport and renewable energy demands for high performance rechargeable batteries. Conventional lithium-ion batteries with intercalation cathodes have limited energy density and expensive. Lithium sulfur (Li/S) battery is an attractive alternative due to a higher theoretical capacity and energy density of 1672 mAh g-1 and 2600 Wh kg-1, respectively [1]. Sulphur is a promising cathode because of its abundance, low-cost and environmentally friendliness as well compared with commercial transition-metal cathodes. However, practical application of Li/S batteries is hindered by several drawbacks: use of dangerous lithium-metal anode, electrical-insulating nature of sulfur causing its low utilization; solubility of lithium polysulfides formed in the electrode process leading to severe capacity fading and low coulombic efficiency. Numerous attempts have been made to overcome these disadvantages by mixing sulfur with conducting agents such as carbonaceous materials and/or conductive polymers, which allows for enhanced utilization of sulfur and capacity per unit mass of sulfur [2-3].
In this work a Sulfur/Polyacrylonitrile/Ketjen Black ternary composite electrode (S/PAN/KB) was prepared and examined as a cathode for Li-ion/S battery coupled with prelithiated graphite anode (Li-Gr) in Li-Gr | Electrolyte| S/PAN/KB cell. The partially pyrolyzed and cyclized PAN stabilizes sulfur and suppresses its dissolution into electrolyte [4]. Formation of a homogeneous hierarchical mesoporous structure in S/PAN/KB was observed by SEM, EDS mapping and XRD techniques. The cell with this composite cathode delivered a reversible discharge capacity of 600 mAh g-1 of composite (1450 mAh g−1 of S) at 0.2 C, and retained about 85% of this value over 200 cycles. Even at high cycling rates up to 1 C, the cell demonstrated a good rate capability, delivering a highly reversible discharge capacity of 750 mAh g−1, which was superior to the performance of a Li-metal anode half-cell counterpart. Using this cell, the batteries of different size were assembled (Fig. a) and tested; the battery stack exhibited stable cycling performance (Fig. b). Further details of this work will be presented at the Meeting.

References

[1] X. L. Ji, L. F. Nazar, J. Mater. Chem. 20 (2010) 9821−9826.
[2] Y. Zhao, Z. Bakenova, Y. Zhang, Z. Bakenov, Ionics DOI: 10.1007/s11581-015-1376-4.
[3] Y. Zhang, Y. Zhao, Z. Bakenov, Nanoscale Research Letters 9 (2014) 137-143.
[4] J. Wang, Y.-S. He, J. Yang, Advanced Materials 27 (2015) 569–575.

Acknowledgements

This work was supported by the Sub-project #157-2013 funded under the Technology Commercialization Project by the World Bank and the Government of the Republic of Kazakhstan, and grant from the Ministry of Education and Science of the Republic of Kazakhstan entitled "High energy density polymer lithium-sulfur battery for renewable energy, electric transport and electronics".

Figure 1