bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) MXenes for High-Energy, High-Power Batteries and Electrochemical Capacitors
Authors: Gogotsi Yury 
Published: February 2020

Two-dimensional (2D) nanomaterials have been attractive candidates for a plethora of applications since the successful isolation and demonstration of intriguing electronic properties of graphene in 2004 by the Manchester group. The ‘beyond graphene’ march led to the discovery of new types of conductive 2D materials, expanding the use of low-dimensional nanomaterials in electrochemical energy storage and conversion. MXenes are a relatively new and very large family of 2D transition metal carbides, nitrides, and carbonitrides, which were discovered at Drexel in 2011 and became popular due to their diverse chemistries and unique physicochemical properties. These materials are produced by wet chemical or electrochemical extraction of interleaved ‘A’ atomic layers from the layered ternary carbide or nitride precursors. The resulting MXenes with surface terminations (-O, -F, -OH, -Cl) impart negative surface charges, key for stable MXene dispersions in water and organic solvents, which enable solution processing. More than 30 different MXenes have been experimentally synthesized, with dozens of new MXenes and their properties predicted computationally. The compositional versatility, metallic conductivity, control of surface chemistry, ordered structures versus solid solutions, etc., make MXenes suitable for a wide spectrum of applications in energy storage, ranging from battery and supercapacitor electrodes to current collectors and conductive binders.
The available for ion transport 2D gallery spaces, redox chemistry at the transition metal oxide-like surface and metallic conductivity provided by electrons of the transition metals, make MXenes promising as candidates for high-rate energy storage applications. The ability of MXenes to spontaneously intercalate a variety of cations, from Li+ to Al3+, while promoting fast charge transfer rates, endorses them for hybrid metal-ion capacitors and battery applications. Unlike most of the 2D materials produced in small quantities, pilot scale synthesis of MXenes is a promising aspect for future commercialization. This presentation will describe the potential use of MXenes in metal-ion capacitors, Li-ion and Li-S batteries as materials for anodes and cathodes. The use of MXenes to eliminate polymer binders and metal current collectors will also be addressed.
Double-Net Enclosed Sulfur Composite As a New Cathode in Lithium Sulfur Batteries
Authors: Niu Junjie , Lv Yingying , Shang Mingwei , Chen Xi 
Published: February 2020

The emerging demands in large energy-density storage for portable electronic devices and transportations such as electric vehicles are attracting plenty of interest in developing next-generation batteries. More specifically, scientists are putting tremendous attempts in engineering a series of new electrode materials, e.g., silicon as anode and sulfur as cathode, to replace the conventional graphite/transition-metal based lithium ion batteries (Bruce, Nat Mater 2012), thus to achieve a 3-5 times higher capacity to meet a strategic perspective energy-density of 500 Wh/kg made by China, US, and Europe. Sulfur has been identified as one of most promising cathode materials for its high theoretical capacity (1675 mAh/g, 10x times higher than LiCoO2) and the theoretical specific energy (~2600 Wh/kg, 5x times higher than LiCoO2/graphite) in Li-S battery. Nevertheless, researchers remain stagnant in pushing this high-density battery into industrial applications. Averting chemomechanical degradation poses as one of the primary challenges in exploiting sulfur cathodes. Extensive work has been done on confinements of sulfur/polysulfides using various carbon nanostructures to kinetically ‘slow down’ the ‘shuttling effect’ (Ji, Nat Mater 2009. Seh, Nat Commun 2013). Most of these efforts are focused on the physical confinements by constructing versatile matrix/network configurations which can thermodynamically ‘slow down’ (‘temporally’) the sulfur flowing process. In order to avoid the thermodynamic loss, a stronger chemical bonding is required.
In this presentation, we will introduce a novel double-net matrix, which is composed of industry available activated carbon (AC) covered by a mesoporous silicon oxide cap. The oxide cap not only ‘traps’ (physically) the sulfide molecular, but also chemically bonds the molecular that substantially delays the diffusion of sulfur/sulfides, resulting in high capacity retention and rate performance. The capacity as high as ~780 mAh/g at 0.2 C, ~500 mAh/g at 0.5 C, and ~400 mAh/g at 2.0 C along with a Coulombic efficiency of ~100.0% of the battery using the double-net enclosed sulfur composite as cathode was retained after 1000 cycles, respectively. In parallel, a wide range of sulfur ratio up to ~73% in the composite leads to a high loading of active material (up to 6.5 mg/cm2), thus enabling a high energy density. The improved cycling and rate capability as well as the high energy density of the current Li-S battery using industry available both AC and sulfur make a really practical way in mass production as a high-energy-storage system.
Ionic Liquid Electrolytes – from Novel Separators to Solid Polymer Electrolytes
Authors: Best Adam Samuel , Francis Candice , Huynh Thuy , Lathrop Patrick , Krstina Julia , Chiefari John 
Published: February 2020

One of the significant challenges to the application of ionic liquid electrolytes (ILE’s) is the ability to identify separators that can be effectively ‘wetted’ by the electrolyte. There has been significant work in identifying appropriate commercial separators for these electrolytes, with varying degrees of success [1]. To-date, the most effective separator for ILE’s is glass fibre, however, this material has large, open pore structure and this requires it to relatively thick to prevent short circuits between the electrodes. As a consequence, there is a need to identify new materials / structures that can lead to innovative separators that can allow ILE’s to be effectively used in batteries.
To this end, we have examined the use of a “supported” electrospun membrane to be able to “tailor” the interfaces of the electrodes, but also allow effective wetting of the separator with an ILE to enable use in a lithium-ion battery [1]. However, in doing this, we have now made a “simple” separator far more complex in order to address the ILE wetting problem. So the question needs to be asked – can we combine the properties of the complex separator with an ILE into one solution, such as a solid polymer electrolyte? Further, can we improve these materials by exploiting micro-phase structured morphologies to provide us with enhanced mechanical properties as well?
One type of these micro-phase structured polymers [2], known as PILBlox, is made of a high Tg block for mechanical strength and a low Tg ionic block for ionic conductivity [3, 4]. Combining PILBlox with a lithium based ionic salt and an ionic liquid forms a polymer electrolyte which ideally maintains the micro-phase separation present of the pure PILBlox polymer, and confines the ionic salt and ionic liquid to the ionic block of the polymer [4, 5].
In this presentation, we will describe our efforts to make innovative separators using electrospinning techniques and the resulting electrochemistry, before turning our attention to the PILBlox materials and examining their physical properties and their potential use in solid state batteries.

References

Francis. C., et al., manuscript in preparation, 2018.

Bates, F.S., Polymer-Polymer Phase-Behavior. Science, 1991. 251(4996): p. 898-905.

Dean, J.M., et al., Micellar structure and mechanical properties of block copolymer-modified epoxies. Journal of Polymer Science Part B-Polymer Physics, 2001. 39(23): p. 2996-3010.

Nykaza, J.R., et al., Polymerized ionic liquid diblock copolymer as solid-state electrolyte and separator in lithium-ion battery. Polymer, 2016. 101: p. 311-318.

Meek, K.M. and Y.A. Elabd, Polymerized ionic liquid block copolymers for electrochemical energy. Journal of Materials Chemistry A, 2015. 3(48): p. 24187-24194.
New Insights into the Behavior of Polycarbonate-Based Lithium Salt Containing Electrolytes Regarding Thermal Long-Term and Electrochemical Stability
Authors: Buchheit Annika , Grünebaum Mariano , Gerlitz Anna Isabella , Tessmer Britta , Wiemhöfer Hans-Dieter 
Published: February 2020

For lithium ion batteries solid-state electrolytes like polymers gained more and more attention in the last years, especially due to safety reasons. Polyethylene oxide (PEO) based systems are still state of the art. One of its major drawbacks is the highly crystalline structure, which inhibits fast migration of lithium ions and results in a low transference number and low conductivity [1]. Recently, polycarbonate based polymer electrolytes gained some interest [2,3]. Polycarbonates were assumed to show weaker ion-dipole interactions in contrast to PEO, given rise to higher transference numbers [2]. With suitable additives and high salt concentrations, higher ionic conductivities were reported at moderate temperatures (>60 °C) [3].
Nevertheless, there is still a lack of knowledge concerning long-term performance of the polycarbonate-salt-mixtures as electrolytes in terms of thermal stability in the temperature range of solid-state batteries. Therefore, we prepared lithium salt containing polycarbonate samples using either solution casting with additional removal of the solvent or the hot press method. We examined the behavior of polycarbonate salt mixtures over a period of time at given temperatures. Investigation methods such as differential scanning calorimetry (DSC), nuclear magnetic resonance spectroscopy (NMR) and electrochemical impedance spectroscopy (EIS) were used. The results of the experiments indicate that e. g. the mixture LiTFSI in polyethylene carbonate (PEC) suffers from a salt catalyzed decomposition for longer times whereas polypropylene carbonate (PPC) is stable.
Furthermore, candidates with good thermal long-term stability (e. g. PPC/LiTFSI) were analyzed concerning their ionic conductivity and their electrochemical stability window. If necessary, improvements were made to increase the electrochemical stability (e. g. down to lithium stripping / plating) or the conductivity by use of different additives, e.g. plasticizers and SEI additives.

Acknowledgements

The authors acknowledge funding by Federal Ministry for Economic Affairs and Energy (BMWi) under the project FesKaBat (03ET6092E).

References

[1] M. M. Hiller et al.; Electrochimica Acta, 114, 21-29 (2013)
[2] Y. Tominaga et al.; J. Electrochem. Soc., 162 (2), A3133-A3136 (2015)
[3] K. Kimura et al.; Electrochimica Acta, 175, 134-140 (2015)
The Search for a Ceramic Lithium-Ion Conductor Using Combinatorial Approach
Authors: Aloni Niv , Tirosh Shay , Meir Simcha , Zaban Arie , Golodnitsky Diana 
Published: February 2020

We present combinatorial method for high-throughput screening and synthesis of libraries of solid lithium-ion conductors. The method has the advantages of speed, simplicity and the capability to produce and control simultaneously a variety of compositions by the co-deposition on a substrate of several different materials to create “materials library”.
In our research we fabricate materials libraries by two methods. The first one is RF-magnetron sputtering, where Ar plasma sputters a target material that is being deposited on a substrate. The effects of RF power applied to Li2O and LiAlSiO2 targets, the deposition time, rotation of the substrate and heat treatment on Li-ion conductivity of 169 samples of one library have been studied. The XPS tests showed that RF coating contains Li2O, Li2CO3, LiAl0.18Si0.13O1.22, LiAl0.67Si0.41O2.49 and LiAl1.17Si0.71O3.93 compounds. The non-stoichiometric lithium aluminum silicates are amorphous as displayed in the XRD patterns. The room-temperature conductivity of sputtered about 350nm-thick LiAlxSiyOz film varies from 10-8 to 10-7S/cm depending on the stoichiometry. The conductivity vs. temperature plots show Arrhenius behavior. The activation energy found for the bulk conductivity is 22kJ/mol and for the grain boundaries- 55kJ/mol. The substrate morphology influences the fabricated film morphology and grain boundaries conductivity.
The second method is spray pyrolysis, based on simultaneous spraying of different precursors solutions from a multi-head nozzle on a substrate. This is followed by pyrolysis and oxidation. The preparation of multi-component solid electrolytes library by spray pyrolysis is a novel approach. Despite relatively low density of the LixLayPO4 ceramics, preliminary ionic conductivities, were found to vary from 2*10-7 to 4*10-5 S cm−1.
The Effects of Vaporized Solid Electrolyte Solution for All-Solid-State Batteries
Authors: Park Jun-Woo , Kim Min-Ju , Kim Byung Gon , Ha Yoon-Cheol , Lee You-Jin , Lee Sang-Min 
Published: February 2020

Recently, lithium-ion batteries (LIBs) have been applied to large-scale devices such as electric vehicles and energy storage systems (ESSs), requiring high energy density and long cycle life. The use of organic electrolytes in lithium ion batteries in such large-scale devices has some safety issues. Organic electrolytes have a high ionic conductivity, but there are many risks of leakage, explosion and ignition due to the decomposition reaction of the electrolyte. As a promising solution to this issues, the use of a solid electrolyte have been proposed. In contrast to organic-based liquid electrolytes, all-solid-state lithium batteries (ASLBs) with a solid electrolyte are considered safe because of their non-flammability. These solid electrolytes have the advantages of high stability and high energy density, but they have a disadvantage of very low ionic conductivity at room temperature.
In this work, we prepared sheet-type Li6PS5Cl-infiltrated electrode that has high capacity, even though it has high loading value. We propose two methods to ensure that SE materials are evenly distributed and sufficiently infiltrated into the porous structures of LIB electrode. First, we aimed to reveal the effects of solid electrolyte solution vaporization on the solid electrolyte content in the thick electrode for ASSBs. The performance of the cells at different temperatures were compared. Elevated temperature of SE solution arrive at vaporization point and it result in molecular motion, and it makes more LPSCl infiltrated into electrode. The NCM622 electrode infiltrated LPSCl at 90oC show reversible capacity of 177mAh/g (5.5mg/cm2) and 136mAh/g (17mg/cm2) at 0.05C, 55oC. We also prepared three different active materials having different particle size. The porous electrode which is made by mixing different sized active materials(DS-AM) absorbs SE solution. This absorb effects explain the capillary phenomena. The mixed DS-AM electrode demonstrated higher capacity than non-mixed DS-AM electrodes due to the improved ion transport path.
Reduction of Interfacial Polarization between Inorganic Solid Electrolyte and Li Anode By Using a Metallic Interlayer
Authors: Fung Kuan-Zong , Tsai Shu-Yi , Su Dong-Bow Su , Liu Chi-Yang 
Published: February 2020

In early 1990s, rechargeable batteries using inorganic ionic conductors as solid electrolytes have been proposed. Because of their improved safety features, solid state batteries have received great attention recently. Among several inorganic ionic conductors, Garnet-structured Li7La3Zr2O12 (LLZO) show adequate ionic conduction and excellent structural stability when used as the solid electrolyte for Li battery applications. Using Li metal as anode has been a long-term target Moreover, LLZO exhibits superior reduction stability against metallic Li. However, the poor contact/adhesion between Li and LLZO has caused large interface polarization between LLZO and Li metal. Several metals and oxides have been used as the interlayer between LLZO and Li metal and shown improved interface behaviour with lower polarization. Sputtering has been an excellent thin-film deposition technique for obtaining metallic and oxide thin film. Thus, the main objective of this study is to (i) investigate the feasibility of using metallic thin film as an interlayer for inorganic solid state battery using Li as anode, (ii) to evaluate the interface polarization with and without interlayer; (iii) to determine the effect of interlayer thickness on interface polarization, (iv) to analyse and understand the process and behaviour of Li insertion into metal thin film layer, (v) to demonstrate the effectiveness of metallic interlayer on reduction of interface polarization based on Li stripping/plating and full cell tests.
In this study, LLZO will be densified to >95% dense using nanosized powder. Gold thin film will be first deposited on the polished surface of LLZO using rf magnetron sputtering. Secondly, Li metal will be placed on top of Au film under heating near melting point of Li. Li stripping and plating will be conducted under constant current with monitoring of applied voltage. Impedance resulted from interface variation will be measured using Electrochemical impedance spectroscopy (EIS). XRD analysis and SEM observation will be performed for possible alloy forming processing. Finally, a full cell based on Li/Au (interlayer)/LLZO/LCO will be tested and compared with the one without Au interlayer to show the effectiveness of metallic interlayer.
Electrophoretic Deposition of MnO2/CNT Composite As Host Material for Efficient Li-S Batteries
Authors: Shahzad Hafiz Khurram , Ghashghaie Sasan , Fang Jie , Muhyodin Ghulam , Cheng Samson H. S. , MA Lok Wnag , Chung Chi Yuen 
Published: February 2020

Over the past few decades, lithium-sulfur (Li-S) batteries have gained growing attention as the next generation energy storage devices owing to their low cost, relative safety as well as higher theoretical capacity (1675 mAh g-1) and energy density (2600 Wh kg-1) [1]. This work employs the multi-step electrophoretic deposition (EPD) method [2] to fabricate a layered structure of conductive agents on the surface of micron-sized 3D carbon fiber paper (as the current collector).
For this purpose, a homogeneous and crack-free film of MnO2/CNT was deposited as the host material (HM) on carbon fiber paper (CFP) by applying uniform DC electric fields of 30-80 V to the stable suspensions of manganese dioxide (MnO2) and carbon nanotubes (MWCNTs) in acetone. The obtained CFP/MnO2/CNT cathode was then impregnated with sulfur using a facile vapor-phase infusion technique at 200 ̊C.
The galvanostatic charge-discharge behavior of the coin cells containing CFP/MnO2/CNT as cathode exhibited an initial discharge capacity of around 1000 mAh g-1 and an improved capacity retention rate after up to 50 cycles at 0.1 C. Also, a coulombic efficiency of above 96% was achieved. It is shown that the EPD-deposited carbon and metal oxide-based host materials, as lithium-sulfur cathode, can achieve high discharge capacity and enhanced cycling behavior. In addition, the rate performance tests conducted at 0.1C, 0.5C, 1C, and 2C revealed relatively high capacities at current rates below 2C, implying excellent conductivity and reaction kinetics of the CFP/MnO2/CNT/S composite. It is concluded that the EPD can be employed as a facile binder-free method to fabricate composite cathode structures for Li-S batteries.

References:

[1] P. G. Bruce, S. A. Freunberger, L. J. Hardwick, and J.-M. Tarascon, “Li–O2 and Li–S batteries with high energy storage,” Nat. Mater., vol. 11, p. 19, Dec. 2011.
[2] K. Kaprans et al., “Electrophoretically deposited α-Fe2O3 and TiO2 composite anchored on rGO with excellent cycle performance as anode for lithium ion batteries,” Solid State Ionics, vol. 319, pp. 1–6, Jun. 2018.

Figure 1
Semi-Interpenetrating Networks for All-Solid-State Lithium Metal Batteries
Authors: Homann Gerrit , Cekic-Laskovic Isidora , Winter Martin 
Published: February 2020

In the past two decades, exponentially growing markets of mobile consumer electronics and electric vehicles caused an increasing demand towards higher energy and power density in energy storage technologies. Aiming to overcome the intrinsic limitations of state of the art liquid organic carbonate-based electrolytes with regard to higher energy densities and cost efficient cells solid state electrolytes are a promising topic of research. Enabling not only the use of electrolyte layers in the range of a few micrometers and a reduction of needed security features of the cell housing, but also the utilization of lithium metal as anode. Besides the prominent classes of oxidic ceramic and sulfidic glassy electrolytes, the class of lithium ion conducting polymer electrolytes comprises a large variety of different subclasses. The subclass of semi-interpenetrating networks (s-IPNs) defines a combination of at least two polymer networks penetrating each other without a covalent bonding between the different polymer species. Thanks to its excellent interface wetting ability, processability and lithium metal compatibility, polyethylene oxide (PEO) was selected as lithium ion conducting polymer.[1] This combination of different polymer types allows the tailoring of vital physicochemical and electrochemical properties of the resulting s-IPN membranes. Possible benefits of a second interwoven polymer matrix refer to the reduction/suppression of PEO crystallization inside of confinements, thus allowing the utilization of polymer membranes at ambient temperature, an enhanced mechanical stability of thin film membranes compared to single polymer materials and the improved homogeneity of lithium precipitation by a more defined interface structure.[2] Depending on the preparation route of the s-IPN, not only the polymer itself but also the polymer interfaces can be tuned selectively by introduction of, for example, highly hydrophobic substances like siloxanes, which tend to accumulate at the membrane surfaces.[3] The prepared s-IPN membranes in this work were investigated by means of selected thermal, electrochemical and spectroscopy techniques including differential scanning calorimetry, galvanostatic and potentiostatic experiments as well as impedance spectroscopy. This work aims for an economic approach to tailor vital physicochemical properties of s-IPN electrolyte membranes by utilization of PEO as lithium ion conductor and lithium metal as anode material using a single-step solution casting synthesis route towards advanced all-solid-state lithium metal batteries.
References
[1] J. Mindemark, M. J. Lacey, T. Bowden, D. Brandell, Prog. Polym. Sci.
2018, 81, 114–143.
[2] J. R. Nair, M. Destro, F. Bella, G. B. Appetecchi, C. Gerbaldi, J. Power Sources
2016, 306, 258–267.
[3] E. Cznotka, S. Jeschke, P. Vettikuzha, H. D. Wiemhöfer, Solid State Ionics
2015, 274, 55–63.