bluuebunny/crossref_metadata_2025_split huggingface dataset:
Manganese Dioxide Electrode: Attempts to Increase the Electrochemical Utilization
Authors: Gambou-Bosca Axel , Bélanger Daniel 
Published: February 2020

Manganese dioxide has been the subject of intense research in recent years since it has been demonstrated that they are characterized by pseudocapacitor properties. Furthermore, hybrid electrochemical capacitor using a negative carbon electrode and positive manganese dioxide electrode together with an aqueous electrolyte allows to prepare a device with a higher cell voltage than either carbon/carbon or manganese dioxide/manganese dioxide symetrical electrochemical capacitor. Unfortunately, the high theoretical specific capacity of a manganese electrode cannot be obtained when thick and industrially relevant electrodes are investigated. In fact, no more than 20% of the manganese dioxide-based electrode material is electrochemically addressable. In this talk, attempts to increase the electrochemical utilization of manganese dioxide will be presented. Our recent studies focussing on the effect of carbon additives, shape of manganese dioxide particles, electrode formulation and electrolyte, including water-in-salt electrolyte, on the performance of manganese dioxide electrode tested in the three-electrode configuration (single electrode characterization) and as a full system will be investigated (1-4).
1. A. Gambou Bosca, D. Bélanger, Effect of the formulation of the electrode on the pore texture and electrochemical performance of the manganese dioxide-based electrode for application in a hybrid electrochemical capacitor. Journal of Materials Chemistry A., 2014, 2, 6463-6473.
2. A. Gambou Bosca, D. Bélanger, Chemical mapping and electrochemical performance of manganese dioxide/activated carbon based composite electrode for asymmetric electrochemical capacitor. Journal of the Electrochemical Society. 2015, 162, A5115-A5123.
3. A. Gambou Bosca, D. Bélanger, Electrochemical accessibility of porous submicron MnO2 spheres as active electrode materials for electrochemical capacitors, Electrochimica Acta, accepted.
4. A. Gambou Bosca, D. Bélanger, Electrochemical Characterization of MnO2-Based Composite in the Presence of Salt-in-Water and Water-in-Salt Electrolytes as Electrode for Electrochemical Capacitors, J. Power Sources, submitted.
High Voltage Lithium Ion Capacitor for Elevated Temperature Applications; Built on Activated Carbon and Litfsi Dissolved in Alkylcarbonates Compound
Authors: Salari Maryam , Grinstaff Mark W 
Published: February 2020

The increased number of lithium ion batteries and supercapacitor technologies utilized in everyday products demands more reliable and safer technologies enabling high energy densities with faster response times over extended range of temperatures. This work presents a method to fabricate a thermally resistance lithium ion supercapacitor (LIC); a strategy for realization of a safer supercapacitor for elevated temperature applications. Specifically, we report and discuss the performance of symmetric activated carbon electrodes supercapacitors with LiFTSI in a glycerol carbonate compared to that in EC/DMC electrolytes. The gravimetric analysis based on the total weight of electroactive materials gave a specific capacitance of 162 F/g at 1 mV s-1, energy density of 14.2 Wh kg-1 at 2 A/g and power density of 7.5 KW kg-1 at 10 A/g at a temperature of 100 ºC. Cyclic voltammetry (CV), charge discharge (CD), and electrochemical impedance spectroscopy (EIS) were performed to investigate the electrochemical properties of the fabricated coin cells.
Fig.1 Chronological map cycling behavior of AC electrodes in glycerol carbonate electrolyte at a current density of 2 A/g over a applied potential of a 2.5 V, obtained through various thermal ageing process as well as cycling procedures.

Figure 1
Improvement of Contact Resistance of Graphene Devices Via AuCl3 Doping
Authors: Choi Dong-Chul , Jung Jongwan 
Published: February 2020

Graphene, an atomically thin semi-metal with sp2–bonded carbon atoms arranged in a honeycomb lattice is at center stage of intense research in the field of fundamental physics as well as in low-cost flexible transparent electronics, photovoltaics or microelectronics devices. For electronic devices application, the metal - graphene contact resistance is forefront obstacles hindering further progress of any graphene-based devices. The contact resistance degrades the on-state current of charge-based field-effect-transistor. Gold chloride (AuCl3) doping has been reported for reducing the sheet resistance of graphene films for transparent electrodes. In this work, we used the gold chloride (AuCl3) solution doping only to the metal-graphene contact area to reduce the contact resistance without changing graphene film properties. First, graphene film was grown using chemical vapor deposition (CVD) method. Active pattern was formed by lithography and reactive ion etching (RIE). The metal-graphene pad area was defined by lithography. The exposed graphene surface area for metal pads was dipped in AuCl3 solution. Here we changed the AuCl3 concentration to see the concentration effect. After that, Ti/Au pad metal was evaporated using thermal evaporator. AuCl3 doping was done only to metal-graphene contact interface. KPFM was employed to measure the surface potential of graphene. The Raman spectroscopy and XPS spectra were analyzed before/after the doping of AuCl3 solution on contact area. The contact resistance of un-treated graphene devices, 1773 Ohm.um decreased to 987 Ohm.um after 5mM-treatment, and decreased to 897 Ohm.um after 10mM-AuCl3 doping. At doping above 10mM doping, the contact resistance did not decreased further. We also characterized the contact resistance change with time. The contact resistance of AuCl3-treated graphene increased by ~13% after 2 months. On the contrary, the sheet resistance of AuCl3-treated graphene film(without any photomask) increased by ~50% after 1 month. The contact resistance increase is much less than the sheet resistance change. This could be explained by the fact that the metal pad covers the AuCl3.
This research was supported by the MOTIE (10052928) and KSRC (Korea Semiconductor Research Consortium) support program for the development of future semiconductor devices.
Hydration Structures and Water Chemistry at Zirconia-Water Interface
Authors: Hou Binyang , Park Changyong , Kim Seunghyun , Kim Taeho , Kim Ji Hyun , Kim Jongjin , Hong Seungbum , Bahn Chibum 
Published: February 2020

The life cycle of zirconium cladding is a key safety factor and design parameter for higher fuel burnups in pressurized water reactors. The degradation of the metal alloy is primarily attributed to interactions of native oxide with water. Here we probe the detailed interfacial hydration structures at the 8 mol% yttria-stabilized cubic zirconia (YSZ) surfaces as a model system using synchrotron-based high-resolution X-ray reflectivity technique. Interfacial hydration structures in the major crystallographic orientations, (100), (110), and (111), were determined with sub-angstrom resolution and compared with each other to identify common features as well as different surface chemistry effects on the interfacial processes. All three surfaces terminate with significant number of point defects originating from the metal depletion and the intrinsic oxygen vacancies. Water molecules fill those vacancies, forming an ordered, layered structure on the top surface. Above the termination layer on each surface, two additional adsorbed layers form characteristic interfacial hydration structures. The first adsorbed layers likely include metal species based on the observed local densities, whereas the second layers consist of pure water. The current results provide valuable references for future studies of water chemistry effect on the interfacial hydration structure and the high temperature stability test of the zirconia in pressurized water conditions simulating realistic environment in pressurized water reactors of nuclear power plants.
We also studied the effect of zinc adsorption on the interfacial hydration structure in zinc acetate solutions. Zinc injection into the reactor coolant system has been known to be effective in reducing the radioactive wastes as well as stabilizing crud oxide layers of the cladding materials. Our X-ray reflectivity data qualitatively reveal that there are obvious hydration structure changes at (100) and (111) surfaces while (110) surface show little changes. The interfacial electron density profiles were derived from the structure factor analysis of the measured reflectivity data. The structure factor analysis indicated an inner-sphere adsorption of Zn2+ layer at YSZ (111)-water interface, while there appeared to be an outer-sphere adsorption of Zn2+ layer at YSZ (100)-water interface. We further confirmed the detailed element specific adsorption profile of Zn2+ ions on YSZ (110) and (111)-water interfaces with resonant anomalous X-ray reflectivity measurements.
Highly Concentrated Electrolyte for 5 V Systems
Authors: Inaba Minoru , Masuhara Rin , Shimizu Yusuke , Hashinokuchi Michihiro , Doi Takayuki , Inoue Hidemi , Takahashi Katsuyuki , Nakagawa Hiroe , Inamasu Tokuo 
Published: February 2020

Highly concentrated electrolytes have many unique properties,1-4 such as Li+-intercalation into graphite anode without EC,1,3 suppression of S8
2- ion dissolution in Li-S batteries, etc., and is attracting much attention of many researchers. In highly concentrated electrolytes, all solvent molecules are strongly coordinated with Li+ ions, and hence the stability of the electrolytes against oxidation is improved significantly. Yoshida et al. reported that LiCoO2, which is a 4 V-class cathode, can be charged and discharged in a LiTFSI/triglyme (1:1) electrolyte with good cycleability,3 though triglyme is an ether compound and usually cannot be used as solvent.
5 V-calss cathodes, e.g. LiNi0.5Mn1.5O4 and LiCoPO4, are promising for the next-generation LIBs with high energy densities. Unfortunately no electrolyte systems that tolerate the highly oxidative 5 V-class cathode have been reported so far. In the present study, we investigated the effect of concentration on the stability of highly concentrated electrolytes, LiPF6/PC and LiBF4/PC, against a 5 V-class cathode, LiNi0.5Mn1.5O4 to realize 5 V-class LIBs with high energy densities.
Figure 1 compares charge/discharge curves of a 5 V class spinel LiNi0.5Mn1.5O4 in standard (0.83 mol kg-1, Li/PC = 1/11.8) and highly concentrated (4.9 mol kg-1, Li/PC = 1/2) LiBF4/PC at 30°C. The charge/discharge rate of C/10 was employed to emphasize electrolyte decomposition. Thought the LiNi0.5Mn1.5O4 can be charged and discharged in both electrolytes, the irreversible capacity (Qirr) in 1 M LiBF4/PC was high (76 mAh g-1) because of vigorous electrolyte decomposition. In contrast, Qirr was significantly reduced in the concentrated electrolyte, which indicated that stability against oxidation was improved in the highly concentrated electrolyte. Similar tendency was also observed in highly concentrated LiPF6/PC electrolytes, though polarization on charging and discharging were much higher.
A fresh half-cell was fully charged to 5.0 V, and kept at 60°C for 3 days in LiPF6/PC electrolytes. The amount of Mn deposited on lithium counter electrode was evaluated by ICP as a measure of dissolved Mn ions. The amount of dissolved Mn ions decreased with increasing Li/PC ratio, which indicated that the use of highly concentrated electrolytes is also effective for suppressing Mn ion dissolution.
This work was supported by a Kyoto Area Super Cluster Program, Japan Science and Technology Agent (JST), Japan.

References:[1] S.-K. Jeong et al., J. Power Sources, 175, 540 (2008).; [2] K. Dokko, et al., J. Electrochem. Soc., 160, A1304 (2013).; [3] K. Yoshida, et al., J. Am. Chem. Soc., 133,13121 (2011).; [4] Y. Yamada, et al., ACS Appl. Mater. Interfaces, 6, 10892 (2014).

Figure 1
Interfacial Behaviors of Metal Lithium Anode in Solid Lithium Batteries
Authors: Li Wenjun , Li Qun , Liu Xiaosong , Guo Xiangxin , Fu Zhengwen , Chen Jian , Cui Guanglei , Hu Yongsheng , Gu Lin , Li Hong 
Published: February 2020

Energy storage devices with energy density over 350 Wh/kg or 1000Wh/L are highly desirable. Rechargeable solid metal lithium battery is one of the possible solutions. The cathode could be lithium intercalation compounds, sulfides and air. The electrolyte could be polymer and inorganic solid electrolyte with and without liquid additive. Achieving excellent cyclic performance and high safety at reasonable rate and wide temperature range are two main challenges, which are related to the homogeneity of the deposition and depletion of metal lithium, electrochemical or chemical reaction of lithium with contacted gas, liquid and solid, change of the interfacial contact and the morphology change of metal lithium during charging and discharging. In this talk, a joint efforts for investigating metal lithium anodes in various rechargeable solid lithium batteries with and without liquid additive are reported and summarized.
Acknowledgement
Financial supports from "Strategic Priority Research Program" of the Chinese Academy of Sciences (XDA09010200), “973” project of MOST (2012CB932900), NSFC project (51325206, Y5JC011E21), and Beijing S&T Project (Z13111000340000) are appreciated.
Ion Solvation Effects in the Nonaqueous Li-O2 Electrochemistry
Authors: McCloskey Bryan D 
Published: February 2020

Multiple directions in battery research are now being pursued in hopes of advancing beyond the specific energy limits imposed by conventional Li-ion electrode materials. For example, ‘beyond Li-ion’ battery chemistries, such as Li-O2, Li-S, and Mg-ion, are currently being explored as potential successors to Li-ion batteries given their very high theoretical specific energies; yet severe technical challenges have prohibited them from becoming a practical reality. The objective of this presentation is to provide an assessment of such challenges, in particular, instabilities of the electrolyte and cathode, and Li2O2 electronic conductivity limitations, facing the nonaqueous Li-O2 battery cathode. Results will be presented on the characterization of the Li2O2 formation mechanism and how the mechanism can be manipulated through electrolyte engineering to potentially alleviate problems associated with Li2O2 deposition on the cathode.
Silicon Foam Anode with Stabilized Interface for Lithium-ion Batteries
Authors: Ma Tianyi , Liu Yuan , Zhu Wentao , Qiu Xinping 
Published: February 2020

Silicon has been regarded as an optimized anode material of LIBs1-4 due to its low discharge potential and high specific capacity. Challenges from the huge volume change during the alloying reaction of silicon with lithium still obstacle the application of silicon anode, since the huge volume change causes particle pulverization, electrode disintegration and the solid electrolyte interphase (SEI) film ceaseless growth. Although some nano-structured silicon anode materials, such as hollow nanospheres, silicon core-hollow carbon shell nanocomposites, 1D hollow silicon nanotubes, showed the improved cycle performance. However, the ceaseless growth of SEI film is still absence of evidence. In this work, we report a facile approach to prepare silicon foam with hollow structure with a chemical vapor deposition (CVD). With the built-in space, this silicon foam presents remarkable capacity retention and fairly high coulombic efficiency. The method combining the electrochemical impedance spectroscopy with differential scanning calorimetry (DSC) to elucidate the SEI stability was developed, which confirm that silicon foam have more stabilized interface.

Reference:

1. Huggins, R. A. J. Power Sources
1999, 81, 13-19.
2. Park, C.-M.; Kim, J.-H.; Kim, H.; Sohn, H.-J. Chem. Soc. Rev.
2010, 39, (8), 3115-3141.
3. McDowell, M. T.; Lee, S. W.; Nix, W. D.; Cui, Y. Adv. Mater.
2013, 25, (36), 4966-4984.
4. Su, X.; Wu, Q.; Li, J.; Xiao, X.; Lott, A.; Lu, W.; Sheldon, B. W.; Wu, J. Adv. Energy Mater.
2014, 4, (1), 882-882.
Combining Reversible Oxygen Charge Transfer and Li-Excess to achieve High Capacity Cathodes
Authors: Ceder Gerbrand 
Published: February 2020

The highest energy density cathode materials are currently found among the layered compounds based on Ni,Co and Mn, but achieving much more than 200mAh/g has become difficult. Two new ideas are promising to obtain substantially higher cathode capacity: 1) By using a substantial amount of Li-excess, cathodes can be made tolerant to metal disorder thereby enabling the use of a much larger group of transition metals, while achieving capacities well above 200 mAh/g. 2) Reversible redox process that take place on the oxygen ions rather than on the transition metal ions are now well established and can reduce the transition metal content of cathode compounds. I will explore the physics of both these new directions and demonstrate with several examples how they have enabled novel high-capacity cathodes.
Suppression of Polysulfide Transfer by Polypyrrole Modification on Cathode in Lithium-Sulfur Battery
Authors: Momma Toshiyuki , Nakamura Natsuki , Yokoshima Tokihiko , Nara Hiroki , Osaka Tetsuya 
Published: February 2020

Sulfur is one of the candidates for cathode of Li battery to realize improved capacity of the cell. The issues to be solved are selection of electrolyte which is compatible to both of sulfur cathode and anode, and high solubility of polysulfides generated during the charge-discharge operation of cathode. The dissolved polysulfide into the electrolyte phase inside the battery leads chemical shortage between the cathode and the anode, i.e. the dissolved redox active polysulfide works as redox shuttle between the electrodes, and causes difficulty of charging and self-discharge. Some ideas to stop the dissolution of polysulfide are proposed, such as (1) apply sulfide organic compound with high molecular weight or polymer as the cathode active material, (2) use insoluble solvent for electrolyte solution, (3) control the mass transfer of Li+ and polysurfide, and so on. For blocking the transfer of dissolved polysulfide, cell structure with the perm-selective membrane inserted the between the electrodes by placing in the electrolyte phase or by covering one of the electrode can be considered. In those cases, the perm-selective membrane should have the property of well-transporting of Li+ with low impedance beside the non-transfer of polysulfide. Since polysurfide has negative charge, cation exchange membrane would be the one of the candidates for the perm-selective membrane.
Ion exchange membrane is well known to be designed with polymer having anionic groups inside the matrix. Polypyrrole, which is known as a redox active polymer and is able to be formed as a sheet form on conducting substrate by electro-oxidative polymerization as anion doped state. Polypyrrole doped with anion having large size exhibit an interesting properties, such as cation exchange properties. For example, Polypyrrole doped with polyanion, such as polystyrenesulfonate acts as cation exchange membrane.
In this work, we prepared polypyrrole doped with soft/large anion by electropolymerization method forming directly onto the surfur-carbone composite cathode. The prepared polypyrrole film was confirmed to exhibit cation exchange properties, and the film prepared on S-C composite electrode was found to be formed with covering the S and C phase. The electrtode of S-C composite covered by polypyrrole exhibits discharge capacity of over 800 mAh/g(sulfur) at 0.1C-rate with the current efficiency of above 95% during the continuous charge-discharge cycling. The detailed battery performance of the polypyrrole coated S cathode and effect of polypyrrole formation condition to the the battery perrormance will be introduced.
Towards Na-ion and K-ion Batteries
Authors: Komaba Shinichi 
Published: February 2020

We have been studing electrode and electrolyte materials for Li-ion batteries. In the past 10 years, we have also studied the materials for Na-ion batteries. Indeed we succeeded high-capacity or high-energy positive / negative electrode materials including binders and electrolytes. Recently, we expand our research target to K-ion batteries, which is potentially expected to show higher-power and higher-voltage than those of Li- and Na-ion batteries. We will talk about our recent achievement on electrode and electrolyte materials and surface chemistry for Na-ion and K-ion batteries and will discuss similarity and difference compared with Li-ion ones.
NMR Beyond Li: New Approaches in Studying Na, Mg and Li-air Batteries
Authors: Grey Clare P. , Liu Tao , Kim Gunwoo , Clement Raphaele , Allan Phoebe , Stratford Josh , Lee Jeongjae , Seymour Ieuan , Liu Zigeng 
Published: February 2020

This talk will describe the use of NMR spectroscopy to characterize a series of “beyond-Li” electrode materials. The NMR results are combined with complementary techniques such as pair distribution function analysis of (X-ray) scattering data. In the sodium-ion battery case, 23Na NMR spectroscopy can be used to follow changes in local structure in a manner very similar to that performed on lithium-ion battery materials. Our work using the method to study local structure and Na+ and electronic ordering in positive layered materials and intermetallic anodes will be described. 25Mg NMR is more challenging, but the use of DFT calculations to predict shift positions and help interpret the spectra speeds up the analysis considerably. This will be illustrated for paramagnetic positive electrode materials. The use of NMR and MRI (magnetic resonance imaging) to link structural changes with electrolyte concentrations will be demonstrated for lithium metal anodes. Finally, new developments in the field of lithium-oxygen batteries will be described. In particular NMR spectroscopy allows the different discharge products and many side-reactions to be followed. For example, 1H and 7Li NMR spectroscopy can be used to separate Li2O2 from LiOH, allowing the formation and removal of LiOH to be quantified. Our recent studies with LiI redox mediators and r-GO electrodes will be described.