bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conditioning-Free MgCl2/AlCl3 Electrolyte for Magnesium Batteries By Chemical Formation of Solvated Chloride
Authors: Kim Seong Shik (Steve) , Bevilacqua Sarah , See Kimberly A 
Published: May 2020

Mg metal is a promising alternative anode material that offers higher theoretical specific capacity than conventional Li-ion batteries (LIBs), and the high natural abundance of Mg makes it more economically appealing than other post-LIB anode materials. The greater energy density hinges on a Mg-metal anode, and reversible Mg electrodeposition and stripping require an effective Mg electrolyte. Various electrolyte systems that support reversible have been introduced, but many of them contain drawbacks, such as narrow electrochemical window, reactivity with electrode materials, or poor Coulombic efficiency. In addition, challenges remain in understanding the relationship between electrochemistry at the Mg anode and the electrolyte composition due to the complicated interface of Mg metal and the electrolyte.
To probe the effect of the interface on Mg electrodeposition, an electrolyte with a known solution phase composition, the magnesium aluminum chloride complex (MACC) electrolyte, is explored. The MACC electrolyte undergoes electrolytic conditioning to support reversible Mg electrodeposition and stripping. During conditioning, free Cl- is released electrolytically while Al3+ is irreversibly deposited, and the concentration of the active species [Mg2(µ−Cl)3·6(THF)]+ increases, activating the MACC electrolyte.
Here, we show that a small concentration of Mg(HMDS)2 to the MACC electrolyte suppresses Al3+ deposition and promotes reversible Mg electrodeposition and stripping on the first cycle. Such a drastic change from a small concentration suggests that changes are localized at the electrode-electrolyte interface. We show spectroscopically that Mg(HMDS)2 scavenges trace water in the solution. Spectroscopic results also suggest that Mg(HMDS)2 reacts with AlCl4
- in the MACC electrolyte to form free Cl-. Based on the spectroscopic and electrochemical results, we suggest that the formation of Cl- is the primary cause for improved behavior on cycle one, highlighting the role of Cl- in Mg deposition and stripping.
(Invited) Kerr Gated Raman Spectroscopy to Investigate Aging Processes on Lithium-Ion Electrode Interfaces
Authors: Hardwick Laurence J. , Cabo-Fernandez Laura , Neale Alex Ryan , Braga Filipe , Kostecki Robert , Sazanovich Igor 
Published: May 2020

Aging mechanisms have a great impact into batteries calendar life and performance. A better understanding of these complex processes is critical to improve the lifetime of the battery. Electrolyte aging plays a key role in the decrease of capacity since insoluble species and gas by-products are formed during the electrochemical cycling of the battery. Fluorescent species are formed during cycling of lithium ion batteries as a result of electrolyte decomposition due to the instability of the non-aqueous electrolytes and side reactions that occur at the electrode surface. The increase in the background fluorescence due to the presence of these components makes it harder to analyze data due to the spectroscopic overlap of Raman scattering and fluorescence. Herein we will demonstrate Kerr gated Raman spectroscopy as an effective technique for the isolation of the scattering effect from the fluorescence enabling the collection of the Raman spectra of LiPF6 salt and LiPF6-based organic carbonate electrolyte, without the interference of the fluorescence component. A comparison will be made with FT-Raman using a Laser excitation at 1064 nm, where we show that it is possible to obtain Raman spectra of Li-ion battery relevant materials above a diminished fluorescence background, but with a much lower sensitivity compared to using Kerr Gated Raman with an excitation at 400 nm. Kerr gated Raman was able to identify POF3 on the LiPF6 particle surface [1], after the addition of trace water and the degradation of graphitic carbon electrodes with respect to number of cycles.
[1] L. Cabo-Fernandez, A.R. Neale, F. Braga, I.V. Sazanovich, R. Kostecki, L.J. Hardwick,
Phys. Chem. Chem. Phys
.
, 2019,21, 23833-23842

Figure 1
Microstructural Analysis of Lithium-Ion Battery Cathodes Using Tomography Methods - Possibilities and Limitations
Authors: Joos Jochen , Kelly Steve T , Volkenandt Tobias , Freitag Stefanie , Weber André , Ivers-Tiffée Ellen 
Published: May 2020

A deep knowledge of the 3D microstructure is essential for optimizing performance in Lithium ion battery electrodes. Tomography methods like focused ion beam-secondary electron microscopy (FIB-SEM) and X-ray tomography are the most frequently used 3D characterization techniques for battery electrodes. While each method has advantages and disadvantages, understanding the complex morphology of electrodes requires a complementary, multi-scale 3D approach.
In this work, the possibilities and limitations for both 3D techniques, X-ray and FIB-SEM tomography, are studied using the example of a LiNiCoAlO2-LiCoO2 blend cathode from a commercial cell. The same cathode sample was analyzed with both techniques and moreover with different devices to enable a comparison of the obtained data quality. The material fractions, porosity, surface area and tortuosity are calculated from the different data sets and the results are compared with special emphasis on the differentiation of the different active materials and the carbon-binder phase. The reliable determination of these parameters is essential because they are needed, for example, to compare different electrode structures or to study the influence of the microstructure on the electrode performance to optimize the electrode structure.

Figure 1
(Invited) Power Performance of Lithium-Ion Batteries.
Authors: Schougaard Steen Brian 
Published: May 2020

“We need more power Scotty!”. In STAR TREK as in lithium-ion batteries for transportation, power, is a major issue. The battery size in electric vehicles is generally increasing while it is clear that for most consumers, most of the time, the extra capacity will sit idle. This extra capacity, entails higher cost, higher energy consumption and higher environmental impact. Yet, consumers request longer driving autonomy, most likely since charging is still a comparably slow process. Thus, we need faster charging which translate into improved power performance.
A strong tool to analyse and optimize power performance is numerical modeling. However, modeling requires a series of input geometric and materials parameters, some of which until now have been very difficult to obtain reliably. In this talk we will cover our recent advances to measuring these parameters and how these may help improve optimization of power performance. Specifically, in situtechniques based on scanning probes and synchrotron X-rays, as well as new battery chemistries will be discussed.
(Invited) Novel Fluoride Batteries, Fluoride Shuttle Batteries, and Their Positive Electrodes
Authors: Ogumi Zempachi , Abe Takeshi 
Published: May 2020

Progress of battery technology has opened new applications, which requires development of batteries of high performances, especially high energy density. There are two directions to improve the energy densities, i.e., enhancing cell voltage and increasing capacity of active materials. High cell voltage meets, however, the difficulty of stability of electrolyte.
Batteries based on rocking-chair type reactions are limited in their capacity due to requirement of host lattice. On the other hand, conversion type active materials including traditional dissolution-deposition type ones can give higher capacity by using multi electron reactions. Anion mediating system may be able to be operated various metal electrodes using the common charge carrier. Among anion mediating systems, fluoride mediating systems, fluoride shuttle batteries (FSBs), give high capacity because metal fluoride is generally low formal weight.
The authors’ group has focused on developing FSBs based on reactions of metal fluoride and metal, MFm/M. Metal fluoride are usually insulator, while some metal fluorides show ionic conductivity for F-. In this talk BiF3 and CuF2 are focused as positive active material. Electrolyte is a key material for activation of MFm/M electrodes. Solid electrolyte, liquid electrolyte including IL, and polymer electrolyte have been examined.
Addition of anion acceptors to organic electrolyte enhances charge and discharge performances of BiF3/Bi electrode. The selection of adding anion acceptors is critical for each MFm/M electrode. The addition of anion acceptor, fluorobis(2,4,6-trimethylphenyl)borane, in tetragryme-CsF electrolyte increases remarkably the capacity and cyclability of BiF3/Bi electrode1). Copper fluoride is known as a typical insulator and when Cu electrode is oxidized to CuF2 only the skin-layer of Cu metal, ca. 6 nm, is oxidized to CuF2 and is passivated using lanthanum fluoride solid electrolyte operated at 140 oC. The addition of BaF2 to CuF2 powder activates CuF2/Cu electrode2).

Konishi, T. Minato, T. Abe, Z. Ogumi, J. Electrochem. Soc., 2017 161, A3702.

Morita, T. Abe, Z. Ogumi, et al., in preparation
Electrochemical Behavior and Structural Change of Spinel-LiMn2-XNixO4 (x = 0, 0.5) Cathode in Potassium Cells
Authors: Baddour-Hadjean Rita , Bhatia Ankush , Emery Nicolas , Laïk Barbara , Pereira-Ramos Jean-Pierre 
Published: May 2020

On the recent research front for the next generation secondary batteries beyond Li, potassium insertion into graphite in non-aqueous cells has brought new insights into the electrochemical K+ intercalation behavior and introduced advantageous benefits from potassium. Since potassium resources are much abundant and the standard potential of K+/K is 0.13 V below that of Li+/Li, potassium-ion batteries can be regarded as an appealing alternative to LIBs to realize high voltage systems with low cost. The crucial issue is the development of cathode materials able to accommodate the large K-ion without displaying detrimental structural changes toward cycle life and rate capability performance. The 4.7 V LiMn1.5Ni0.5O4 spinel is already a promising cathode for the next generation of high voltage LIBs, and its host structure, λ-Mn0.75Ni0.25O2, could be of great interest for K-ion batteries.
Here, we investigate for the first time the potassium insertion properties into electrochemically prepared λ-MnO2 (λ-MO) and λ-Mn0.75Ni0.25O2 (λ-MNO) spinels. Lithium ions in LiMn2O4 and LiMn1.5Ni0.5O4 samples are electrochemically extracted in lithium containing electrolyte solution, forming λ-Mn1- xNixO2 (x = 0, 0.25) by first oxidation process. Potassium ions are then inserted into the lithium extracted spinel phases. From structural analysis by X-ray diffraction and Raman spectroscopy, it is found that the original λ-Mn0.75Ni0.25O2 spinel phase converts into a layered phase, K~0.5Mn0.75Ni0.25O2. Then, K~0.5Mn0.75Ni0.25O2 can deliver a high reversible capacity of 90 mAh g-1 at C/20 in the 2 V- 4.6 V vs K+/K voltage range with 78% retention for 60 cycles at C/20 (Fig. 1). Promising rate performance are also evidenced with an initial capacity of 60 mAh g-1 at C/5 (Fig. 1), and 65% retention after 300 cycles at C/5. The origin of the attractive electrochemical performances of λ-MNO is investigated by XRD , Raman and EDS experiments after discharge and charge cycles. These results open the possibility of using inexpensive and high-capacity Mn-based active materials for potassium-ion batteries.

Figure 1. Electrochemical properties of λ-Mn0.75Ni0.25O2 in a potassium cell. 1M KF6 /EC:PC 1:1 electrolyte, 2% vol. FEC. Voltage window 4.5 V- 2 V.

Figure 1
Chemical Bonding Effect on Crystallinity and Electrochemical Properties in Germanium Selenide/Nano-Carbon Composite As an Anode Materials for Potassium Ion Batteries
Authors: Lee Geon-Woo , Park Byung-Hoon , Kim Young-Hwan , Kim Kwang-Bum 
Published: May 2020

Recently, as a promising alternatives to lithium ion batteries (LIBs), sodium-ion batteries (NIBs) and potassium-ion batteries (KIBs) have received considerable attention due to the abundance and low cost of sodium and potassium compared to those of lithium resources.
Recently, similar to graphite, layered metal chalcogenide compounds (LMCs) have been received significant attention as promising anode materials for KIBs, because of their large interlayer space for potassium ion intercalation and also narrow-bandgap semiconductor characteristic.
Germanium selenide (GeSe), one of the LMCs family, shows similar crystal structure to that of graphite lamellar with neighboring layers stacked together via weak van der Waals interlayer interactions along the one axis. The interlayer distance of GeSe (5.41 Å) is large that enables the convenient diffusion of alkali metals with large size without significant structural distortion. The potential multielectron transfer per formula unit is one of the main advantages of GeSe, which is beneficial for exceptionally high energy density in chemical energy storage. However, to the best of our knowledge, the layered GeSe applied as KIBs anode materials and its charge storage mechanism remain unexplored.
Unfortunately, LMCs family materials undergo a large volume expansion after the insertion of large-sized K+ ion which causes active material pulverization, electrical contact loss, and the formation of unstable solid electrolyte interfaces (SEIs), ultimately resulting in drastic capacity fading. Designing composites with carbon is one of the effective strategies to improve the electrochemical performances of LMCs.
However, their packing density is relatively low (0.58~0.83 g cm-3) due to the surplus inner void space, leading to low volumetric energy and power densities of batteries. To satisfy the demand for maximizing the energy density in limited loading spaces, volumetric energy density is becoming a more crucial factor for future KIBs applications than the gravimetric counterpart. In addition, the large surface area of nanomaterials will give rise to severe side reactions and poor thermal stability between electrode and electrolyte interfaces, thus leading to unfavorable cycle reversibility and safety hazard.
Herein, we for the first-time report GeSe/nano-carbon composite with a high tap-density as a novel anode material for KIBs. And the effect of chemical bonding induced by various ball-milling condition and CNT amounts on the crystal structure and carbon structure, so that we can figure out the effect of chemical bonding effect on the electrochemical properties of GeSe/nano-carbon composite. GeSe/nano-carbon composite showed reversible charge/discharge profiles with ~400 mA h g−1 at 0.05 A g−1 from the second cycle on. Further results will be presented in the conference.
Interferometric Optical Isolator with Si Guiding Layer Operated in Unidirectional Magnetic Field
Authors: Yokoi Hideki , Yumoto Atsushi , Hasegawa Hiroyujki , Matsuzaki Shingo 
Published: May 2020

INTRODUCTION
In optical communication systems, an optical isolator is indispensable in protecting active photonic devices from unwanted reflected light. An optical isolator with a Si guiding layer is a significant device for silicon photonic integrated circuits. In this paper, the authors report on an interferometric optical isolator with a Si guiding layer which can be operated in unidirectional magnetic field.
DEVICE STRUCTURE
Figure 1 shows an interferometric optical isolator with a Si guiding layer employing a nonreciprocal phase shift [1]. The nonreciprocal phase shift occurs in transverse-magnetic (TM) modes that travel in magneto-optic waveguides in which magnetization is aligned transverse to the light propagation direction in the film plane. The optical isolator employing the nonreciprocal phase shift is attractive because the device utilizes TM modes only so that there is no need for phase matching. The optical isolator includes an optical interferometer that consists of two coupling devices, a nonreciprocal phase shifter and a reciprocal phase shifter. In Fig. 1, one arm in the optical interferometer has a magnetic garnet cladding layer. When the interferometer has distinct layer structures, the optical isolator can be operated in a unidirectional magnetic field.
The optical isolator employing the nonreciprocal phase shift was designed at 1.55 μm. The nonreciprocal phase shifts in the magneto-optic waveguides with a magnetic-garnet/Si/SiO2 structure were calculated. The multimode interference (MMI) coupler and the reciprocal phase shifter were also designed. As a preliminary experiment, deposition of the magnetic garnet crystals were investigated on various substrates.
ACKNOWLEDGMENT
This work was partially supported by the SIT Research Center for Green Innovation.
REFERENCES
1. H. Yokoi, T. Mizumoto and Y. Shoji, Appl. Opt., 42, 6605 (2003).

Figure 1
(Invited) Binary Stochastic Neurons and Compound Synapses from Nano-Magnets
Authors: Appenzeller Joerg 
Published: May 2020

In this presentation I will introduce the nCORE center CAPSL’s activities towards a probabilistic spin logic for Boolean and Non-Boolean computing. While magnetic materials in storage devices are part of our electronic world since many decades and are explored more recently by the semiconductor industry for memory applications such as Spin-transfer torque magnetic random-access memory (STT-RAM), spin based devices for logic applications are still in their infancies. Mimicking a CMOS type logic with magnets requires a “Write” and a “Read” unit as well as proper input/output isolation. Based on this, a device concept in which charge-to-spin conversion occurs through the Giant Spin Hall Effect (GSHE) [1], dipolar coupling mediates the information transfer from a magnet in the Write unit to another one in the Read unit, and a magnetic tunnel junction (MTJ) is used as the Read unit was proposed in 2012 under the name charge spin logic (CSL) [2]. Next, I will explain in how far the use of low-barrier magnets cannot only help to reduce power consumption of CSL devices but introduces a conceptually new way of computing through the introduction of “tunable randomness”. This idea, that is also known as probabilistic spin logic (PSL), was introduced in 2017 [3] and uses a counterintuitive aspect of magnets, namely their capability of creating a truly random magnetic signal if low-barrier circular nano-magnets are used. In particular, I will connect PSL with activities in the realm of quantum computing as well as neural networks.
[1] L. Liu, C.-F. Pai, Y. Li, H. W. Tseng, D. C. Ralph, and R. a. Buhrman, Science 336, 555 (2012).
[2] S. Datta, S. Salahuddin, and B. Behin-Aein, Applied Physics Letters 101, 252411 (2012).
[3] K. Y. Camsari, R. Faria, B. Sutton and S. Datta. Physical Review X 7, 031014 (2017).
Improved Electrochemical Performance of Al2O3 and ZrO2 Coated LiNi0.6Mn0.2Co0.2O2 Cathodes By Atomic Layer Deposition
Authors: Wang Xin , Liu Yongqiang , Li Jianlin , Meng Xiangbo 
Published: May 2020

There has been an increasing demand on high-energy and low-cost lithium-ion batteries (LIBs) in order to power future transportation. In this context, LiNi1-x-yMnxCoyO2 (NMC) cathodes are particularly attractive, due to their higher capacity and lower cost compared to the traditional LiCoO2 cathodes [1]. Among the NMC cathodes, LiNi0.6Co0.2Mn0.2O2 (NMC622) is one of the most promising cathode materials undergoing extensive investigations, but it still suffers from a series of technical issues, such as dissolution of transition metal elements, and structural instability [2]. Aimed at addressing these issues, we recently applied Al2O3 and ZrO2 coatings on NMC622 using atomic layer deposition (ALD). We coated the composite electrode directly and it revealed that the ALD Al2O3 and ZrO2 coatings can improve the cyclability and sustainable capacity of the NMC622 cathodes at different cutoff voltages. In the study, we investigated the effects of ALD Al2O3 and ZrO2 coatings using X-ray diffraction, X-ray photoelectron spectroscopy, impedance spectroscopy, scanning electron microscopy, and transmission electron microscopy. Our study demonstrated that ALD remains an important tool to tackle technical issues in LIBs [3].
1. Manthiram, A., B. Song, and W. Li, A perspective on nickel-rich layered oxide cathodes for lithium-ion batteries. Energy Storage Materials, 2017. 6: p. 125-139.
2. Hou, P., et al., Surface/Interfacial Structure and Chemistry of High-Energy Nickel-Rich Layered Oxide Cathodes: Advances and Perspectives. Small, 2017. 13(45): p. 1701802.
3. Meng, X., X.-Q. Yang, and X. Sun, Emerging applications of atomic layer deposition for lithium-ion battery studies. Advanced Materials, 2012. 24(27): p. 3589-3615.
A Novel Multi-Functional Electrolyte Additive for Ni-Rich Cathode Materials
Authors: Pham Hieu Quang , Trabesinger Sigita 
Published: May 2020

Ni-rich layer oxides Li[Ni
x
CoyMn1−x−y
]O2 (x ≥ 0.8, NCMs) are promising advanced cathode materials for high-energy Li-ion batteries because of their high specific capacity (≥ 200 mAh g−1) with an average discharge voltage of 3.8 V vs Li+/Li, as compared to the commercialized cathode materials (e.g. LiCoO2, LiFePO4).1 However, the instability of cathode–electrolyte interface causes the structural degradation of cathode active material and the electrolyte consumption, as well as gas evolution due to oxidative decomposition of electrolyte, resulting in a rapid capacity fading.2

Thus, improvement in the stability of cathode–electrolyte interphase is a key requirement to inhibit their structural degradation and enhance their electrochemical properties. The formation of a protective surface film via electrolyte additives is considered a cost-effective and reliable way to improve the cathode–electrolyte interfacial stability, as the stable surface film, uniformly distributed over the entire cathode surface, would prevent direct contact of oxide with the electrolyte, still allowing Li+ transport between the cathode and electrolyte.3 In this work, we report the high-performance NCM cathode through interfacial stabilization using a novel electrolyte additive. The details of surface film stability and formation mechanism, and their relation to gas evolution as well as cycling performance would be discussed.
References:

1 S.-T. Myung, F. Maglia, K.-J. Park, C. S. Yoon, P. Lamp, S.-J. Kim, Y.-K. Sun, ACS Energy Lett. 2017, 2, 196

2 H. Q. Pham, E.-H. Hwang, Y.-G. Kwon, S.-W. Song, Chem. Commun., 2019, 55, 1256

3 K. Kim, Y. Kim, S. Parka, H. J. Yang, S. J. Park, K. Shin, J.-Je Woo, S. Kim, S. Y. Hong, N.-S. Choi, J. Power Sources 2018, 396, 276.