bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Electrochemical Intercalation of Ca2+ and Mg2+ Ions in Layered TiS2: A Fundamental Study in Alkyl Carbonate Based Electrolytes
Authors: Verrelli Roberta , Tchitchekova Deyana S. , Ponrouch Alexandre , Black Ashley , Arroyo-de Dompablo M. Elena , Frontera Carlos , Palacin M. Rosa
Published: February 2020

Batteries based on naturally abundant, light metal anodes (such as Ca and Mg) and multivalent ion host cathodes can potentially achieve very high energy densities at relatively low cost and environmental impact, thus representing a compelling alternative to currently available Li-ion systems.

While reversible Ca metal plating and stripping in conventional alkyl carbonate based electrolytes has been accomplished [1,2], unraveling cathode materials with fast and reversible ion mobility at high operating voltages remains a major open challenge, mainly hampered by the slow diffusion kinetics in the solid state of multivalent ions. Thus, besides the exploration of new materials, revisiting traditional layered intercalation hosts appears as a very useful tool to gain further insight into the fundamentals of divalent ion intercalation.

In this context, a thorough study of the electrochemical intercalation of Ca2+ in layered TiS2, in alkyl carbonate based electrolytes, is herein presented [3]. Fundamental insights on the insertion process are acquired through X-ray diffraction. Ca2+ insertion is unambiguously proved by using both X-ray diffraction and differential absorption X-ray tomography at the Ca L2 edge and the reversibility of the process is demonstrated at moderate temperature.

Different phases can be formed upon reduction of pristine TiS2, whose amount and composition dependon the experimental conditions employed. A comparative study with Mg2+ containing electrolytes and other conventional intercalation hosts, such as V2O5, was also carried out. Careful examination of results highlights the potential relevance of side reactions in these system and the need to use several complementary characterization techniques to unambiguously assess divalent ion intercalation.

[1]A. Ponrouch, C. Frontera, F. Bardé and M. R. Palacín, Nat. Mater. (2016), 15, 169.

[2] A. Ponrouch, M. R. Palacín, Curr. Opin. Electrochem. (2018), 1.

[3] Tchitchekova D.S., Ponrouch A., Verrelli R., Broux T., Frontera C., Sorrentino A., Biskup N., Arroyo-de Dompablo M.E., Bardé F., Palacín M.R., Chem. Mat. (2018), 30, 847.
Adopting Mixed Sulfur and Selenium Chalcogenides As High Energy Density Copolymer Cathodes in Rechargeable Sodium Metal Systems
Authors: Carter Rachel E. , Boyd Darryl A , Nguyen Vinh , McClain Collin , Love Corey T
Published: February 2020

The ever increasing demand for energy storage has encouraged exploration of battery systems with higher energy density and lower cost than Li-ion batteries.1 This work reveals the very first demonstration of a room temperature, sodium/polymeric mixed-chalcogenide battery. The chemistry is enabled by crosslinking of sulfur and selenium, which maintains the elemental mixture in long chains instead of crystalline rings, for a mechanistically different conversion cathode. Room temperature Li-S batteries, which boast ultra-high energy density (~2600 Wh/kg) and low cost/highly abundant sulfur, are expected to succeed the intercalation Li-ion battery (<400 Wh/kg), but to-date deliver impractical cycle life due to active material dissolution. The novel chain assembly provided by crosslinking prevents this behavior, enabling extensive cycle life.2 Herein the crosslinker type and molecular ratio are modulated for optimal chain length and performance. Furthermore, selenium delivers 20 orders of magnitude greater electrical conductivity than sulfur.3 The atomic ratio of sulfur to selenium is modulated for a balance of electrical conductivity and energy density. Notably, these cathodes are simplistically processed at temperatures below 200 ˚C. The crosslinked, mixed chalcogenide cathodes are paired with metallic sodium anodes, that are 3 orders of magnitude more abundant than lithium metal,1 and exhibit favorable plating behavior in the system-prescribed, ether-based electrolytes.4 This full cell touts a theoretical energy density of ~1000 Wh/kg and effective incorporation of highly abundant raw materials.

Hong, X.; Mei, J.; Wen, L.; Tong, Y.; Vasileff, A. J.; Wang, L.; Liang, J.; Sun, Z.; Dou, S. X., Nonlithium Metal–Sulfur Batteries: Steps Toward a Leap. Advanced Materials 0 (0), 1802822.

Simmonds, A. G.; Griebel, J. J.; Park, J.; Kim, K. R.; Chung, W. J.; Oleshko, V. P.; Kim, J.; Kim, E. T.; Glass, R. S.; Soles, C. L.; Sung, Y.-E.; Char, K.; Pyun, J., Inverse Vulcanization of Elemental Sulfur to Prepare Polymeric Electrode Materials for Li–S Batteries. ACS Macro Letters
2014,
3 (3), 229-232.

Abouimrane, A.; Dambournet, D.; Chapman, K. W.; Chupas, P. J.; Weng, W.; Amine, K., A New Class of Lithium and Sodium Rechargeable Batteries Based on Selenium and Selenium–Sulfur as a Positive Electrode. Journal of the American Chemical Society
2012,
134 (10), 4505-4508.

Seh, Z. W.; Sun, J.; Sun, Y.; Cui, Y., A Highly Reversible Room-Temperature Sodium Metal Anode. ACS Central Science
2015,
1 (8), 449-455.
Synthesis and Electrochemical Performance of Solution-Processed Cu2-Xo-Fe2O3 Composite As Supercapacitor Electrode Material
Authors: Lin Hwai En , Katayanagi Yuta , Kishi Tetsuo , Yano Tetsuji , Matsushita Nobuhiro
Published: February 2020

Cu2-xO-Fe2O3 composites films were successfully prepared by spin-spray process at 90℃. The materials and electrochemical properties of the composites synthesized with different Fe:Cu molar-ion-ratios were investigated. According to the XRD and XPS analysis, it was confirmed that the as-prepared three specimens were crystallized α-Fe2O3 (Fe:Cu=1:0, FC-0), amorphous CuO-Fe2O3 (Fe:Cu=1:1, FC-1) and crystallized Cu2O-Fe2O3 (Fe:Cu=2:1, FC-2), respectively. A poor wettability with a contact angle of 101.3˚ was observed in FC-0 sample. In contrast, owing to the porous structure and higher specific surface area, better wettability with the average contact angle of 23.4˚ and 9.6˚ were measured for FC-1 and FC-2 samples, respectively. When serving as supercapacitor electrodes, the obtained samples Fe2O3 and Cu2-xO-Fe2O3 composites exhibit wide negative potential window of -0.9 V to 0 V vs Ag/AgCl in 0.5 M Na2SO4. The FC-2 electrode made of molar ratio (Fe:Cu=2:1) exhibited outstanding capacitive properties compared with FC-0 and FC-1 sample. The area normalized capacitance of FC-2 electrode was 182.4 mFcm-2 at 0.5 mAcm-2, which is approximately 150 and 1.3 times higher than that of the FC-0 sample (1.2 mFcm-2 at 0.5 mAcm-2) and FC-1 sample (136.3 mFcm-2 at 0.5 mAcm-2), respectively. Besides, it showed good long-term cycling stability with the capacitance retention of 92.5% after 1000 cycles. The higher area normalized capacitance of FC-2 sample could be mainly ascribed to three reasons which are (1) the higher specific surface area of the porous structure, (2) the better wettability leading to the enhancement of ion transportation, and (3) the pseudocapacitive behavior of both iron oxide and copper oxide. This study indicates that the spin-sprayed Cu2-xO-Fe2O3 composite films show a high potential as an electrode material of energy storage.

Figure 1
Environment-Friendly and Flexible Aqueous Zinc Battery Using an Organic Cathode
Authors: Guo Zhao-Wei , Wang Yong-Gang , Xia Yong-Yao
Published: February 2020

Rechargeable batteries have been used to power various electric devices and store energy from renewables, but their toxic components (i.e., electrode materials, electrolytes and separators) generally lead to serious environment issues when disused. Such toxicity characteristic also makes them difficult to be used for future wearable electronic devices. Herein, we report an environment-friendly and high-safety rechargeable battery, which is based on a pyrene-4,5,9,10-tetraone (PTO) cathode and a zinc anode in a mild aqueous electrolyte. It is demonstrated that the PTO-cathode shows a high specific capacity (336 mAh g-1) for Zn2+ storage with fast kinetics and high reversibility, and thus the PTO//Zn full cell exhibits a high energy density (186.7 Wh kg-1), a supercapacitor-like power behavior and a long-term lifespan (over 1000 cycles). Furthermore, a belt-shaped PTO//Zn battery with robust mechanical durability and remarkable flexibility is first fabricated to clarify its potential application in wearable electronic devices.
MoS2/Carbon Cloth As Free-Standing and Flexible Anode for Sodium-Ion Hybrid Capacitors
Authors: Lin Wei-Hsiang , Chen Han-Yi
Published: February 2020

Sodium-ion hybrid capacitors (NICs) combine the advantages of both battery and supercapacitor, exhibiting high energy and power density. Nevertheless, the sluggish kinetics of battery-type anodes limits its synergy effect with capacitor-type cathodes, which impedes both rate performance and cycling stability. Therefore, it is necessary to develop suitable anode materials for NICs, in order to enlarge the working voltage and long-term stability.

Molybdenum disulfide (MoS­2) is a material with layer structure and can easily store lithium and sodium ions, showing promising energy storage characterization. However, the low electrical conductivity and particles aggregation problems confines its capacity performance. In this work, we grow crescent-like MoS­2 on the carbon cloth to prepare a free-standing and flexible anode without binder. MoS­2 is mainly in charge of ion intercalation and deintercalation; on the other hand, carbon cloth is utilized as a conductive substrate for MoS­2 growth.

The Raman shift peaks of MoS­2 /carbon cloth are at about 375 cm-1 and 402 cm-1, corresponding to MoS­2 in-plane and out-of-plane vibration modes. Energy dispersive spectroscopy mapping shows that MoS­2 is uniformly distribute on the carbon substrate. These results demonstrate that MoS­2 successfully grew on the carbon cloth. Furthermore, electrochemical performances of MoS­2 /carbon cloth electrodes were measured in the potential range from 0.01 V to 3 V vs. Na/Na+. After combining MoS­2 with carbon cloth, the discharging capacity enhanced from 110 mA h g-1 to about 250 mA h g-1 at 50 mA g-1. These results indicate that MoS­2/carbon cloth hybrid material is a potential anode for NICs.

Keywords: Na-ion hybrid capacitors, MoS­2, Free-standing and flexible anode

Figure 1
High Power Energy Storage: New Materials for Large Format Supercapacitors
Authors: Wheeler-Jones Evangeline Chloe , Loveridge Melanie J , Roberts Alexander John
Published: February 2020

Electrochemical double layer capacitors are well known for their high power output. However, pseudocapacitors have recently demonstrated the ability to compete here, with hybrid devices being a compromise between high power and high energy, by way of combined battery and supercapacitor technologies. Metal oxides have shown promising performance within battery and supercapacitor operation. However, cost and low conductivity have limited the performance of many of these materials and has led to the need for doping the material and refining particle shapes and sizes.1 Molybdenum dioxide is a promising material, having many properties required for pseudocapacitance, including its electrical conductivity (atypical for a metal oxide.)2,3 Further to this it has a theoretical specific capacity of 838 mAhg-1 when undergoing a four electron redox reaction. The various niobium oxides have multiple oxidation states, chemical stability and a high potential window making them suitable for energy storage.4 As niobium pentoxide has a theoretical capacity of 200 mAhg-1, which is higher than lithium titanate, (a common anode5), these materials have been tested in batteries and supercapacitors. Yet there remains considerable room for investigation surrounding mixed and doped versions of these materials.

Facile one-pot hydrothermal synthesis was used to make nanostructured pseudocapacitive materials. Molybdenum dioxides and niobium oxides were systematically synthesised with varied reaction conditions to gain shape and size control. Molybdenum dioxide nanoparticles were synthesised with the addition of a shape director to form spherical secondary particles. Upon doping the molybdenum dioxide with niobium, crystalline nanoparticles were formed with an average diameter of ~150 nm. Undoped niobium oxides form ‘flower-like’ particles, with the addition of a molybdenum precursor the reaction yields molybdenum dioxide/niobium oxide composite where molybdenum dioxide nanoparticles decorate the niobium oxide particles.

All materials were manufactured into electrodes using conventional processing methods and activated carbon electrodes were made for asymmetric devices. The materials showed varying electrochemical properties directly influenced by characteristics gained through the synthesis conditions. Electrochemical testing was carried out on these materials vs. Li’Li+ in half-cells and in asymmetric supercapacitor cells to assess their suitability for hybrid devices.

Y. Gogotsi and R. M. Penner, ACS Nano, 12, 2081–2083 (2018).

Y. Liu, H. Zhang, P. Ouyang, and Z. Li, Electrochim. Acta, 102, 429–435 (2013) http://dx.doi.org/10.1016/j.electacta.2013.03.195.

X. Li et al., J. Power Sources, 237, 80–83 (2013) http://dx.doi.org/10.1016/j.jpowsour.2013.03.020.

P. Arunkumar et al., RSC Adv., 5, 59997–60004 (2015) http://xlink.rsc.org/?DOI=C5RA07895D.

E. Lim et al., ACS Nano, 8, 8968–8978 (2014).

Figure 1
Operando NMR to Study the Dynamic Charging Mechanism of Activated Carbon Supercapacitor Electrodes
Authors: Zhou Yuning , Stratford Josh , Märker Katharina , Grey Clare P.
Published: February 2020

Supercapacitors have the potential to play an important role in high-power energy storage solutions, in particular for power quality and stability applications which require fast cycling and long lifetimes. However, their underlying charging mechanisms and the interactions between the electrodes, the ions and the solvent are not fully understood. In situ NMR techniques can measure in-pore ion populations and can thus provide unique insights into the charging mechanisms, but have so far focused on measurements at equilibrium. Since one of the key advantages of supercapacitors is their fast charging/discharging rates, it is crucial to be able to study the dynamic charging behavior that more closely represents the performance of a working device. In this work, we develop an operando NMR technique based on the synchronization between NMR and electrochemical measurements and investigate the dynamic charging mechanism of electric double layer capacitors based on activated carbon electrodes. The novel method uncovers the significance of the so-called “weakly adsorbed” ion environment, which is shown to take part in the charging process and is thought to be associated with mesopores within the carbon electrode. These findings advance our current understanding of supercapacitor charging mechanisms and the role of the 3D electrode structure, and the synchronized operando NMR method can be applied to a wide range of reversible devices.
(Invited) Investigation of Ba0,5Sr0,5CoxFe1-XO3-Δ As Pseudocapacitive Electrode for Aqueous Electrochemical Capacitor
Authors: Lannelongue Pierre , Douard Camille , Crosnier Olivier , Le Vot Steven , Fontaine Olivier , Wu Nae-Lih , Favier Frederic , Brousse Thierry
Published: February 2020

Supercapacitors are attractive electrochemical energy storage devices for high power applications. However, volumetric energy density is the main limitation for their integration in such applications as terrestrial transport systems. The use of high density pseudocapacitive oxides as electrode material could lead to a volumetric energy density improvement. With this aim, materials from Ba0,5Sr0,5CoxFe1-xO3-δ family, so called BSCFs, have been studied. Several compositions have been prepared and evaluated as positive electrode materials in aqueous neutral electrolyte. Volumetric capacitances have shown to be greater than those of activated carbons, already used in commercialized supercapacitors. Their electrochemical properties are strongly related to the cobalt to iron ratio, to the charging rate, to the electrolyte composition, and other key parameters. The study of the charge storage mechanism occuring in these materials has been investigated thanks to in situ X-Ray absorption spectroscopy and operando X-Ray diffraction performed at SOLEIL (France) and SPring-8 (Japan) synchrotron facilities respectively. Devices coupling BSCF based positive electrode with activated carbon or FeWO4 based negative electrode have demonstrated the added value of such materials to improve the volumetric energy density of supercapacitors.
(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.
Metal Sulfide/Mxene Based Nanostructured Electrode Materials for High-Performance Supercapacitors
Authors: Mehran Muhammad Taqi , Baig Mutawara Mahmood M
Published: February 2020

2D transition metal carbides and nitrides, known as MXenes, are an emerging class of 2D materials with a wide spectrum of potential applications, due to their unique layered structure, high surface area, remarkable chemical stability, and electrical conductivity for energy storage. The hydrophilicity of MXenes combined with their metallic conductivity and surface redox reactions is the key for high-rate pseudocapacitive energy storage in MXene electrodes. However, the low capacity of MXene electrodes limits their further application in ECs. In this study we developed the electrode materials comprised of titanium carbide MXene (Ti3C2Tx) decorated with MWCNTs and Metal Sulfide, which are both 2D layered materials that contribute to the fast ion diffusion in the interdigitated electrode architecture. The nanocomposite samples have been characterized by XRD, SEM, TEM, cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements. Due to the synergistic effect between Metal sulfide and Ti3C2 matrix, the nanocomposite exhibits a superior capacitance and shows excellent cycling stability with capacitance up to several hundred cycles. These results show that pseudocapacitive MXene based negative electrodes exhibits excellent properties in asymmetric electrochemical capacitors, leading to an increased energy density.
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.
Computational Study of Cycling Effects on Dendrite Growth in Lithium Metal Batteries
Authors: Tan Jinwang , Ryan Emily
Published: February 2020

Dendrite growth is an ongoing challenge on the anode surface in lithium metal batteries. Over multiple charge and discharge cycles dendritic growth leads to a decrease in battery performance and increased safety issues due to short circuiting. The morphology and growth rate of dendrites depend on a number of factors including the rate and depth of charge/discharge. In this work a computational model of dendrite growth at the interface is used to investigate the effects of cycling on dendrite growth rate and morphology. The model resolves the interfacial chemical-physical processes and simulates multiple charge and discharge cycles. Results show that dendrite growth depends on both the charging and discharging cycles, which can lead to heterogeneous growth patterns based on the levels of deposition and dissolution of lithium during the cycles.
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 Combined Effect of Cycling Strategy and Potential Electrolyte in Fast Charging/Discharging of Li-Metal Based Batteries
Authors: Beyene Tamene Tadesse , Hwang Bing-Joe , Su Wei-Nien
Published: February 2020

Abstract: Li-metal batteries with the configuration like Cu||LiFePO4 is a suitable tool to circumvent the dendritic Li growth, induced by non-uniform Li deposition during plating-stripping in direct using lithium anode, by forming good solid electrolyte interface (SEI) on the surface of in-situ deposited Li. However, the repeated SEI breaking induced by the uninterrupted volume change during Li plating and the formation of new SEI consumes the limited Li obtained only from the cathode and electrolyte and leads to a rapid capacity fading and low Coulombic Efficiency (CE). Here, we report that the combined effect between potential electrolytes and cyclic protocols could suppress the amount of Li and electrolyte consumed in the SEI formation process and prolongs cycle life of such an anode free battery (AFB) [Cu||LFP-type] at a high current density. In comparison to the carbonate based commercial 1MLiPF6, the synergy between the laboratory prepared ether based 3M LiFSI electrolyte and our new cycling protocol significantly enhanced the cyclic performance of AFB having the Cu||LiFePO4 Cu||Li half-cell at high current density. Eventually, Cu||Li half-cell manifested extraordinary cyclic performance and cycled up to 1000 cycles with the average CE of more than 99.9% at a high current density of 1.0 mA/cm2 using bare Cu without any modification. In addition, the Cu||LiFePO4 showed a remarkable cyclic performance at 0.2 mA/m2 attaining an average CE of up to 98.99% retaining more 40% of the initial discharge capacity after 100 cycles. More importantly, the Cu||LiFePO4 also cycled a higher rate up to 1.0 mA/cm2 with high CE and retaining a reasonable discharge capacity after 100 cycles. The fast cycling and stable performance these cells attributed to the formation robust, flexible and inorganic components rich conductive SEI on the surface of the in-situ deposited Li by the synergistic effect between our laboratory prepared electrolyte and the new cycling protocol.

Keyword:

anode free, synergy, cycling protocol, ether based electrolyte, Cu||LiFePO4, SEI
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
Sulfide-Compatible Multifunctional Interphase Engineering for Sheet-Type All Solid State Battery
Authors: Park Jesik , Kim KyungSu , Cho Woosuk , Jeong Goojin , Yu Ji-Sang
Published: February 2020

An all-solid-state battery (ASSB) is now accepted as one of promising next-generation rechargeable batteries, since it has a potential to solve the chronic anxiety of safety issue in the current liquid-electrolyte-based lithium-ion battery (LIB) as well as to achieve higher energy density. Of various solid electrolytes for ASSB, sulfide-based solid electrolytes are regarded as more suitable for bulk-type ASSB because of its high conductivity and appropriate mechanical properties such as ductile modulus; It allows the processes of slurry-based sheet coating and cold-pressing required for fabrication of a large areal cell. The bulk-type ASSB, however, has a difficulty yet in increasing reversible capacity and cycle-life because contact area between solid electrolyte and active electrode material is still limited, which is decisive for the cell kinetics. In this presentation, we introduce an ionically-conductive and mechanically-adhesive multifunctional interphase engineering to apply it as both binder and pore-filling agent in all-solid-state composite electrode. The interphase material is hybrid type of ionic liquid and polymer, which is sticky and slightly soft so that build up stable interface between components in the composite electrode. Such combination enables various polymers to be well-mixed in a xylene-based slurry for sulfide-based sheet-type ASSB. The slurry-coated composite electrode showed highly-conductive and well-adhesive physical properties, and finally delivered excellent electrochemical performance in ASSB system. The proposed electrode design and fabrication method can be an effective way to achieve high performance sheet-type sulfide-based ASSB.
Stabilization of Cathode/Sulfide-Electrolyte Interface By Surface Modification
Authors: Park Yong Joon , Kwak Hwan Wook
Published: February 2020

Nowadays, lithium ion batteries (LIBs) are widely used technology as power source for various application fields such as portable devices, electric vehicles, and energy storage systems. However, they are suffering from safety issues attributed to their flammable liquid electrolytes. Introduction of inorganic solid electrolyte would be an ultimate solution to address this safety issue. In this regards, a lot of superionic conductors have been explored as candidates of inorganic solid electrolyte for all-solid-state batteries. Among them, sulfide superionic conductors have attracted a lot of attention due to their high ionic conductivity and good elasticity. However, commercialization of all-solid-state batteries based on sulfide electrolyte have been limited by the interfacial instability at electrolyte/cathodes, which is attributed to the high reactivity of sulfides. As an approach to overcome this problem, surface coating has been applied on the surface of cathode powders. Up to now, stable oxides has been used as coating material for reducing the side reaction at sulfide electrolyte/cathode interface. In this work, LiInO2 was introduced as a new coating materials on the surface of cathode for all-solid-state-batteries. The effect of coating was observed by various measurement system.
Systematic Electrochemical Characterizations of Low Molecular Weight Gelator-Based Quasi-Solid Electrolytes
Authors: Kang Bo-Sung , Lee Ji-Eun , Moon Ha-Neul , Lee Ji-Hyeon , Kang Moon-Sung
Published: February 2020

An electrolyte is one of the essential components in diverse electrochemical devices including lithium secondary batteries and dye-sensitized solar cells (DSSCs). Traditional liquid electrolytes having a high ion conductivity suffer from a problem of lowering the durability of the electrochemical devices because they have high flowability and volatility. Therefore, to improve the reliability of the electrochemical devices, it is preferable to replace the liquid electrolyte with a quasi-solid electrolyte. However, quasi-solid electrolytes are usually difficult to inject the devices and have a lower ion conductivity due to a higher viscosity than liquid electrolyte. In this study, we have developed a quasi-solid electrolyte which is based on a low molecular weight gelator (LMWG) with high conductivity and stability through proper physical crosslinking. In addition, the combination of various polymer materials including special functional groups with LMWG has been investigated for the optimization of the electrolyte performances. Especially, the prepared quasi-solid electrolytes have been systematically analyzed by various electrochemical methods and applied to both lithium battery and DSSC for evaluating their performances. The detailed results will be presented and discussed at the conference. This work was supported by a grant (No.2017000140002/ RE201702218) from the Environmental Industry Advancement Technology Development Project of Korea Environmental Industry & Technology funded by Korea Ministry of Environment.
Three-Dimensional Graphene-Heteroatom-Doped Carbon Nanotubes Hierarchical Architecture As a Polysulfide Trap for Lithium-Sulfur Batteries
Authors: Suk Jungdon
Published: February 2020

Recently, lithium–sulfur (Li–S) batteries have attracted tremendous attention as a strong candidate of replacing current lithium ion batteries due to the high theoretical capacity of 1675 mAh g−1, natural abundance, and low cost of sulfur cathode. However, the practical use of Li-S batteries is hindered by their low specific capacity, low coulombic efficiency, poor rate capability, and poor cycling stability caused by the low conductivity of sulfur, dissolution of polysulfides in the electrolyte and their redox shuttling/parasitic reactions and high volume expansion during discharge. Therefore, the structural design and synthesis of sulfur-carbon composite materials with high performance and long cycleability are a major challenge for rechargeable lithium-sulfur batteries. Interconnected three-dimensional frameworks comprising heteroatom-doped carbon nanotube and graphene oxide offer a combination of constituent advantages and can thus be used to achieve superior energy conversion and storage properties. Herein, we present an easily scalable, room-temperature/ambient-pressure chemical pathway for the synthesis of highly functioning cathode materials using electrostatically assembled, heteroatom-doped carbon nanotube materials. Moreover, we designed and prepared free-standing three-dimensional interlayer containing interconnected heteroatom-doped carbon nanotube. The interlayer provides a medium for scavenging the lithium polysulfides and suppressing them from diffusing to the anode side during charging/discharging. Lithium-sulfur batteries fabricated with the thus prepared sulfur/heteroatom-doped carbon nanotubes composite paper cathode and heteroatom-doped carbon nanotube interlayer exhibit high reversible capacity, stable cycling performance, and excellent rate capability. Thus, we expect the unique architecture of the above composite papers to provide a possible platform for high-performance Li-S batteries and facilitate their further development.