bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vanadium-Based Nanomaterials As Cathodes for Mg-Ion Batteries
Authors: Christensen Christian Kolle , Mathiesen Jette , Ravnsbaek Dorthe Bomholdt 
Published: February 2020

Exchanging the active specie, Li+ in Li-ion batteries by multivalent, abundant and cheap cations, such as Mg2+, are projected to boost the energy density and lower the cost per kilo-watt-hour significantly, making the Mg-ion battery technology a promising candidate for one of the battery technologies of the future.1,2

The increase in energy density is i.a. a result of the divalent Mg2+ carrying twice as much charge as the monovalent Li+.1,2 However, the higher charge also poses a problem as it significantly increases the charge density of the ion, which results in stronger interactions with the host lattice of the electrodes and hampers facile ion transport. Therefore, development of novel electrode materials for effective Mg-ion storage is a vital step for the realization of this battery technology.3

In this study, we have synthesized series of vanadium oxides with varying chemical composition and varying nanotopologies, e.g. nanosheets, xerogels and nanotubes. The mechanism for Mg-intercalation and deintercalation is studied by electroanalysis, impedance spectroscopy and through operando synchrotron powder X-ray diffraction measured during battery operation. These results show e.g. that Mg-intercalation in multivalled V7O16-nanotubes occurs within the space between the individual vanadium oxide layers building the walls of the nanotubes while the underlying V7O16 frameworks constructing the walls are affected only to a minor degree by the intercalation. Our investigation provides new insights into the size requirements of the channels/layers in the host frameworks that will allow for efficient Mg-ion storage.
Reference:

R. van Noorden, Nature 2014, 507, 26

Pellion Technologies, “Moving Beyond Lithium with Low-Cost, High-Energy, Rechargeable Magnesium Batteries”, Pellion White Paper, September 2011

P. Saha, M. K. Datta, O. I. Velikokhatnyi, A. Manivannan, D. Alman, P. N. Kumta, Progress in Materials Science 2014, 66, 1.
Sb-Based Transition Metal Oxohalides As Negative Electrode Materials for Lithium Ion Batteries
Authors: Renman Viktor , Hu Shichao , Zimmermann Iwan , Maibach Julia , Eriksson Rickard , Pay Gómez Cesar , Johnsson Mats , Edström Kristina 
Published: February 2020

An electrochemical and structural investigation of two transition metal oxohalides has been undertaken. As negative electrodes for Li-ion batteries, these materials exhibit a combination of both conversion and alloying reactions within the same cell, giving rise to interesting electrochemical performances. Alloying-type reactions, typically involving Si, Sn or - as in this case - Sb, generally occur at low potentials vs. Li+/Li and show relatively good reaction kinetics. The main concern regarding alloying reactions, however, is the expansion/contraction exerted by repeated insertion of Li+, which leads to poor cycleability over time. Storage of Li in the family of conversion materials is based on the conversion of metal oxides into metallic nano-clusters and Li2O.1 This generally occurs at higher potentials and with larger voltage polarization between the charge and discharge processes. Here, these two types of reactions are exemplified using Ni3Sb4O6F6
2 and Mn2Sb3O6Cl3 with the intent of finding a compromise between the alloying and conversion mechanisms. The inclusion of a halide allows for a more careful tuning of the crystal structure. In this respect, the relatively open structures are believed to at least partly affect the insertion of Li, and thereby the efficiency of the conversion process in the early stages of lithiation. The choice of the transition metal (i.e. Mn or Ni) and its specific redox potential vs. Li+/Li effectively determines the order in which the (transition metal oxide-conversion) ↔ (antimony conversion-alloying) reaction sequence occurs, with possibly crucial consequences.
Both compounds are shown to react reversibly with Li, with a good cycleability, in complex systems where multiple reactions occur sequentially and/or simultaneously via the in-situ formation of a nano-composite material. Operando XRD complemented with ex-situ XRD, XANES, TEM and an extensive electrochemical analysis have been used to illuminate the mechanisms involved.
1. Poizot, P.; Laruelle, S.; Grugeon, S.; Dupont, L.; Tarascon, J. M., Nano-sized transition-metal oxides as negative-electrode materials for lithium-ion batteries. Nature
2000,
407, 496-499.
2. Hu, S.; Johnsson, M.; Lemmens, P.; Schmid, D.; Menzel, D.; Tapp, J.; Möller, A., Acentric Pseudo-Kagome Structures: The Solid Solution (Co1–xNix)3Sb4O6F6. Chemistry of Materials
2014,
26 (12), 3631-3636.
3. Zimmermann, I.; Johnsson, M., A Synthetic Route toward Layered Materials: Introducing Stereochemically Active Lone-Pairs into Transition Metal Oxohalides. Crystal Growth & Design
2014,
14 (10), 5252-5259.
Modeling the Positive Electrode Side Reaction for a High Voltage Lithium-Ion Battery
Authors: Vadivel Nicole Raley , Gallagher Kevin G. , Dees Dennis W. 
Published: February 2020

Side reactions in battery electrodes lead to a decrease in battery performance and lifespan. In this work, the side reaction in the positive electrode is examined both computationally and experimentally. Computationally, a transport model was created using the finite element method to track the lithium concentration, potential, and current in each part of the battery. The transport model employs concentrated solution theory and Butler-Volmer kinetics. The side reaction was accounted for with an extra current in the positive electrode. Different functions based on physical conditions were fitted to this current and correlated to our experimental results to determine an expression for the side reaction rate.
Experimentally, a lithium-ion half-cell, coin-cell was charged to 4.6 V at 45°C. The coin cell was held at this potential and temperature for 60 hours. The resulting current at this potentiostatic hold correlates to the relaxation of concentration gradients and the side reaction current. Additionally, the concentration of carbon-conductive additive in the positive electrode, the temperature, and the potential were varied to determine how each factor affects the side reaction rate. By performing both a computational and experimental study, we are able to incorporate an expression for the side reaction into our model with physical significance.
Surface Functionalization of LiNi1/3Mn1/3Co1/3O2 Cathodes for the Enhancement of Rate Properties and the Electrochemical Stabilization at 4.6V
Authors: Yamada Tetsuya , Uchida Shuhei , Zettsu Nobuyuki , Teshima Katsuya 
Published: February 2020

LiNi1/3Co1/3Mn1/3O2 (NCM) and related materials have been focused as alternative cathode materials of Li-ion rechargeable batteries (LIBs) to LiCoO2due to its higher specific capacity and lower Co usage. For the view point of practical use, the increase of working voltage from 3.6 V to 4.6 V will be responsible to further enhancement of the energy density of the LIBs. However, the oxidative reaction at the interface between liquid electrolytes and electrodes at higher voltage of 4.3 V causes drastic capacity fade through the impedance growth and degradation of the NCM electrodes during the charge-discharge operation.
The surface functionalization of cathode with thin oxide layer of electrochemically-inactive materials has been proposed to suppress these unfavorable reactions. Indirect contact between the cathode and electrolytes plays a key role for the electrochemical stabilization, however these oxide layer possibly works as an insulating layer, leading to impedance growth. On the basis of these backgrounds, we propose herein the surface modification of NCM cathode with self-assembled monolayer of NbO
x
nanosheet as well as fluorocarbon-containing organosilane molecule for stabilizing the electrode at high voltage. Through systematic studies, we found the coatings suppress effectively the oxidative decomposition of the electrolyte and disorder in the layered structures on the NCM surface, which result in impedance growth. After 100 cycles at voltage ranges 4.6 V–2.8 V more than 70% of the initial discharge capacity was retained in the coated electrodes. In comparison, the discharge capacity completely faded in the bare NCM cathode. Furthermore, according to Raman spectroscopy, the nanosheets stabilize the delithiated NCM lattice with rock-salt structure and inhibit transformation to the spinel structure.
A Research Tool to Evaluate Safety Response of Lithium Batteries to Internal Short Ciurcuit
Authors: Pesaran Ahmad , Keyser Matthew 
Published: February 2020

Safety of Li batteries is a major concern for many applications. One of major safety concerns is thermal runaway due internal short circuits created because of dormant internal defects. New processes, designs, and materials are being investigated to improve safety of batteries, particularly to prevent thermal runaway due to internal short circuits (ISC). The challenge is how to evaluate these improvements as existing methods using external triggers, such as nail or blunt rod penetration, crush, and heating, are widely known to be deficient.

In response to this challenge, we have developed a very thin and small “thermal switch” to be implanted in a Li-ion cell for triggering ISC on demand to see if the cell goes to thermal runaway. This “thermal switch” or “ISC emulator device” consists of very thin layers of copper, wax, aluminum, and separator that are all compatible with the Li-Ion chemistries. The ISC device is inactive when is placed anywhere in a cell during its fabrication; the cell could be cycles many times without any performance issues. ISC device is activated by applying heat to raise the temperature of the thermal switch to tunable 45°C-60°C to melt the thin layer of wax and create a current path between positive and negative electrode and or current collectors. The ISC device can create any of 4 types of internal short circuit: +ve current collector to –ve current collector, anode active to +ve current collector, cathode active to –ve current collector, and anode active to cathode active. The ISC device can work in any li-ion cell format (cylindrical can and prismatic pouch/can).

With support from DOE’s Vehicle Technologies Office, we have demonstrated that more than ISC devices are triggered in a cell creating ISC. In laboratory testing, the activated device can handle currents in excess of 300 A to simulate hard shorts (< 2 mohms). Phase change melting has been 100% successful during trigger tests to go from non-conducting to conducting. Experiments have shown that the creating ISC in cells can lead to thermal runaway depending on the type of internal short circuit is created, the safety measures in the cell, and the chemistry. We have provided more than 300 ISC devices to several cylindrical and pouch cell manufacture to implant them into their cell for evaluation of their safety supplying them to their clients for evaluation. The ISC device has been able to initiate thermal runaway in portion of the cells tested. In this paper, we provide details of the ISC device and the results of triggering the device. We believe that the ISC device a useful research tool for evaluating the safety of lithium ion batteries in response to inherent internal defects.

Figure 1
Phosphoranimine Electrolytes for Alkali-Ion Batteries
Authors: Dufek Eric J. , Klaehn John R. , McNally Joshua S. , Rollins Harry W. 
Published: February 2020

Organic carbonates currently compromise the bulk solvent components in electrolytes for Li-ion and Na-ion batteries. With interest in improving the safety and stability of electrolytes under more aggressive use conditions (i.e. higher temperature, higher voltage etc.) there is the need to investigate alternatives for the traditional carbonate mixtures. One key class of electrolyte compounds which has received significant interest is phosphorus-containing electrolytes. As a class of compounds improvements in both electrolyte stability and safety have been observed. Included in the class of phosphorus-containing compounds are phosphazenes. The presentation will describe early work using a sub-class of phosphazenes, phosphoranimines (PAs), as a partial replacement of carbonates in alkali-ion batteries.
Early investigations suggest that the PAs may improve both the stability and safety of alkali-ion batteries due to their wide thermal stability and due to the ability to achieve loading levels which surpass those seen for larger phosphazene compounds. As an example, open-cup flashpoint analysis of high PA content electrolytes shows that the flashpoint can be increased by up to 20˚C and at loading levels of 35% by volume the viscosity of the solution is maintained below 8 cP. As a component in an electrolyte system the use of PAs show the ability to retain capacity on par with traditional carbonate blends. The presentation will discuss cycling performance of a host of electrolyte combinations which contain PAs including the interaction seen with additives such as vinylene carbonate and fluoroethylene carbonate. Also included will be a discussion of synthetic preparation and characterization of this sub-class of phosphazenes.
An Advanced Symmetric Sodium Ion Cell Based on O3-Type NaNi0.33Li0.11Ti0.56O2
Authors: Zhang Shuming , Shang Mengshi , Yang Jianhua , Zhang Na , He Shiyang , Liu Yu 
Published: February 2020

P2-type layer Na0.66Ni0.33Ti0.67O2
is a promising active host for symmetric sodium ion cell as both anode and cathode material due to the high-voltage redox couple Ni2+/Ni4+ (about 3.6V) and the low-voltage redox couple Ti4+/Ti3+ (about 0.6V) [1]. In this work, a new compound of O3-type NaNi0.33Li0.11Ti0.56O2
was proposed and synthesized by introducing Li atom into Ti sites in P2-type Na0.66Ni0.33Ti0.67O2. A symmetric sodium-ion cell based on the O3-type NaNi0.33Li0.11Ti0.56O2
was further assembled. The cell exhibits a high voltage of 3.0 V and a reversible charge/discharge capacity of 80 mAh g-1. The electrochemical performance of the as proposed cell is superior to that of the symmetric cell based on P2-type Na0.66Ni0.33Ti0.67O2. As shown in Fig. 1, the crystal structure and phase purity of the compounds are confirmed from powder XRD patterns. The particle size of the NaNi0.33Li0.11Ti0.56O2 material varies in the range from 2 to 5 μm. Fig. 2a shows the schematic of the symmetric sodium-ion cell. Fig. 2b and 2c represent the CV and typical charge-discharge profiles of the NaNi0.33Li0.11Ti0.56O2 material as anode, cathode and full cell, respectively. In contrary to P2-type Na0.66Ni0.33Ti0.67O2, Li-substituted NaNi0.33Li0.11Ti0.56O2 shows an improved cycling stability, especially as cathode (Fig. 3b). It is obvious that the NaNi0.33Li0.11Ti0.56O2-based symmetric full cell has a good cycle life and excellent charge/discharge capacity (Fig. 3c).
[1] R. Shanmugam, W. Lai, ECS Electrochemistry Letters, 3(4), A23-A25 (2014).

Figure 1
Carbon Based Electrodes for Sodium Storage in Quasi-Solid-State System
Authors: Fu Lijun , Wang Faxing , Zhu Yusong , Wu Yuping 
Published: February 2020

Rechargeable sodium storage gained increasing research attention because of the abundant reserves and relatively even geological distribution of sodium element [1]. Carbon attract great interest as electrode material due to the existing versatile preparation methods [2]. In this contribution, we present carbon based materials for sodium storage in a quasi-solid-state system.
Nitrogen-doped porous carbon prepared via pyrolysis of polypyrrole and activation with KOH presents excellent rate performance as anode material for Na ion battery [2]. When it combines with macroporous graphene prepared by microwave-assisted electrochemical exfoliation method as positive material, and a gel polymer as electrolyte, a quasi-solid-state sodium storage system can be assembled, it could operate at a cell voltage of 4.2 V with an energy density of 168 Wh/kg, and excellent cycle performance [3].
Acknowledgment:
Financial support from Natural Distinguished Youth Scientists Project of China (No. 51425301), NSFC (No. 51502137) and Basic Research Programs of Science and Technology Commission Foundation of Jiangsu Province (BK20151534) are greatly appreciated.
References:
[1] N. Yabuuchi, K. Kubota, M. Dahbi, S. Komaba, Chem. Rev., 2014, 114: 11636-11682
[2] L. J. Fu, K. Tang, K. Song, Y. Yu, J. Maier et al., Nanoscale, 2014, 6: 1384-1389
[3] F. Wang, X. Wang, L. J. Fu*, Y. P. Wu* et al., Adv. Mater., 2015, 27:6962-6968
A Moisture- and Oxygen-Impermeant Separator for Aprotic Lithium-Oxygen Batteries
Authors: Kim Byung Gon , Choi Jang Wook 
Published: February 2020

Lithium-oxygen batteries (Li-O2) have lately received considerable attention because of their exceptional potential gravimetric energies, i.e., 3~5 times compared to those of conventional lithium ion batteries. In spite of the unparalleled theoretical gravimetric energy, lithium-oxygen batteries are still under research because of their insufficient cycle lives. This shortcoming is associated with several entangled fading mechanisms [1,2]: partly irreversible nature of the air-cathode, electrolyte evaporation, unstable lithium anode interface, etc. While the reversibility in air-cathodes has been recently improved significantly by the deepened understanding on the electrode-electrolyte reaction and the integration of diverse catalysts, the stability of the lithium anode interface has received relatively much less attention. The destabilization of the lithium anode interface by crossover of water and oxygen from the air-cathode side can indeed cause as fatal degradation for the cycle life as the irreversibility of the air-cathodes [3]. Here we report that cheap poreless polyurethane separator can effectively prevent this crossover while allowing the selective diffusion of lithium ions by high electrolyte uptake of the polyurethane separator through the interchain space. The polyurethane separator also protects lithium anodes from redox mediators, lithium iodide, used to enhance the reversibility of the air-cathode reaction. Based on the lithium anode protection, a consistent capacity of 600 mAh/g is preserved for more than 200 cycles. This study reveals that in most operation conditions, the destabilization of the lithium anode is more critical for the cycle life than the poor reversibility of air-cathode reaction. The present study can also be readily applicable to many other rechargeable batteries that suffer from similar interfacial degradation by side products from the other electrode.

Fig. 1. Comparative schematic illustration of lithium-oxygen cells with (a) conventional polyolefin porous PE separator and (b) poreless PU separator. (c) The cycling performance of the PE, PU, PE+LiI, and PU+LiI cells at a current density of 200mA/g with a fixed capacity of 600 mAh/g. The inset shows XRD spectra and color changes of the Li metals of PE and PU cells after 70 and 100 cycles, respectively.

References

[1] P. G. Bruce, S. A. Freunberger, L. J. Hardwick, J.-M. Tarascon, Nat. Mater. 11 (2012) 19-29.

[2] L. Grande, E. Paillard, J. Hassoun, J.-B. Park, Y.-J. Lee, Y.-K. Sun, S. Passerini, B. Scrosati, Adv. Mater. 27 (2015) 784-800.
[3] R. S. Assary, J. Lu, P. Du, X. Luo , X. Zhang, Y. Ren, L. A. Curtiss, K. Amine, ChemSusChem 6 (2013) 51-55.

Figure 1
Sustainable Redox Mediation for Lithium-Oxygen Battery By Using Protected Lithium Anode
Authors: Lee Hongkyung , Lee Dong Jin , Kim Yun-Jung , Noh Hyungjun , Lee Jinhong , Park Jung-Ki , Kim Hee-Tak 
Published: February 2020

Because of the growing needs for secondary batteries with greater energy density in various applications including electric vehicle, rechargeable non-aqueous lithium–oxygen (Li-O2) battery is receiving a great attention owing to its high theoretical energy density of 3505 Wh kg-1 which far exceeds that of conventional lithium ion battery (LIB) [1, 2]. However, due to the insulating nature of main discharge product, lithium peroxide (Li2O2) the oxygen-evolving reaction (OER) during charge requires a much higher overpotential, which is the one of the main challenges to practical applications [2, 3]. Incomplete decomposition of Li2O2 at the cathode causes excessive accumulation of solid discharge products on cathode surface during cycling, resulting in cell failure by pore clogging. As a consequence, Li-O2batteries usually present poor round-trip efficiencies and severe capacity decays. To alleviate this problem, redox mediators (RMs) as soluble and mobile catalyst in aprotic media, have been intensively studied to address the overvoltage problem [3, 4]. In spite of such a smart strategy, self-discharge of redox mediator is inevitable in current battery configurations due to its chemical reduction at Li metal anode, as shown in Figure 1.
In this presentation, we suggest a synergic combination of soluble redox mediator and protected Li metal electrode for preventing the self-discharge of redox mediator and realize the concept by exploiting a redox mediator of 2,2,6,6,-tegramethylpiperidinyl-1-oxyl (TEMPO) and a composite protective layer (CPL) of Al2O3/PVdF-HFP composite. First, from the electrochemical characterization in conjunction with SEM and XPS analyses, the effectiveness of the highly reversible TEMPO/TEMPO+ redox couple as a RM was verified. More importantly, this presentation provides a detrimental effect of TEMPO on the interfacial stability of Li metal electrode by monitoring the battery cycling under Ar atmosphere, and thus, the necessity of Li metal anode protection was suggested in terms of the reversibility of RMs in the non-aqueous media. The CPL coated on Li metal electrode could suppress the reaction of TEMPO at Li metal electrode and maintain the redox mediated Li2O2 oxidation over repeated cycles, opening a new possibility for a robust use of RM for Li-O2batteries.

Figure 1. Schematic illustration of (a) the self-discharge of redox mediator in Li-O2 battery and (b) the CPL-coated Li electrode which prevent the reaction between redox mediator and Li metal electrode.

References

[1] P. G. Bruce, S. A. Freunberger, L. J. Hardwick, J.-M. Tarascon Nat. Mater.
2012, 11, 19-29.
[2] G. Girishkumar, B. McCloskey, A. C. Luntz, S. Swanson, W. Wilcke J. Phys. Chem. Lett.
2010, 1, 2193-2203.
[3] Y. Chen, S. A. Freunberger, Z. Peng, O. Fontaine, P. G. Bruce Nature Chem.
2013, 5, 489-494.
[4] B. J. Bergner, A. Schürmann, K. Peppler, A. Garsuch, J. Janek J. Am. Chem. Soc.
2014, 136, 15054-15064.

Figure 1