bluuebunny/crossref_metadata_2025_split huggingface dataset:
Benchmarking Metal and Metal Oxide Promoters for Oxygen Evolution Reaction in Li-O2 Cells
Authors: Yang Chunzhen , Wong Raymond Albert , Dutta Arghya , O Minho , Hong Misun , Yamanaka Keisuke , Ohta Toshiaki , Byon Hye Ryung 
Published: February 2020

Despite high theoretical capacity, a Li-O2 cell has suffered from huge oxidation potential polarization on carbon-based positive electrode for charge (>4.2 V vs. Li/Li+), due to sluggish decomposition of non-conductive discharge product, lithium peroxide (Li2O2 ↔ 2Li+ + O2 + 2e-) [1]. Such high potential triggers side reactions such as degradation of electrolyte and carbonaceous electrode, which results in poor cycle-ability [1]. To mitigate this problem during oxygen evolution reaction (OER), solid-state metal or metal oxide nanoparticles (indicated as promoters), which have been widely employed as catalysts in aqueous media, were introduced to the electrode [2]. However, the specific role of promoters in the Li-O2 battery is little known due to complication from accompanying parasitic side reactions [3]. In addition, reasonable comparison of promoters’ activities is not feasible under different performance conditions when various reports were referred [2]. Therefore, to gain a reasonable assessment of their activities in the Li-O2 cell and an understanding of the promoters’ role, it is necessary to examine Li-O2 cells with these promoters under the same condition and analyze their reaction processes in detail. Here I present diagnosis of the true role of promoters, representative of platinum (Pt), gold (Au), palladium (Pd) and cobalt oxide (Co3O4), for OER in Li-O2 cells. After preparation of comparable size and mass loading of promoters on carbon nanotube (CNT) electrode, the Li-O2 cells containing these promoter/CNT combinations were examined using galvanostatic mode under the same operating conditions. The promoter/CNT electrodes show reasonably lower charge potentials than the promoter-free electrode for the 1st charge. Through in situ gas analysis of online electrochemical mass spectroscopy (OEMS) and ex situ chemical analysis of X-ray near-edge fine structure (XANES) spectroscopy, the evolved gas amount and remaining product after charge could be correlated, which accounted for the true reaction occurring for each promoter.
References
[1] (a) G. Girishkumar, B. McCloskey, A. C. Luntz, S. Swanson and W. Wilcke, J. Phys. Chem. Lett., 2010, 1, 2193–2203; (b) P. G. Bruce, S. A. Freunberger, L. J. Hardwick and J.-M. Tarascon, Nature Mater., 2012, 11, 19–29.
[2] (a) Y. –C. Lu, H. A. Gasteiger and Y. Shao-Horn, J. Am. Chem. Soc., 2011, 133, 19048-19051; (b) Z. Peng, S. A. Freunberger, Y. Chen and P. G. Bruce, Science, 2012, 337, 563-566; (c) F. Li, D. –M. Tang, Y. Chen, D. Golberg, H. Kitaura, T. Zhang, A. Yamada and H. Zhou, Nano Lett., 2013, 13, 4702-4707; (d) R. Black, J.-H. Lee, B. Adams, C. A. Mims and L. F. Nazar, Angew. Chem. Int. Ed., 2013, 52, 392–396;
[3] B. D. McCloskey, R. Scheffler, A. Speidel, D. S. Bethune, R. M. Shelby and A. C. Luntz, J. Am. Chem. Soc., 2011, 133, 18038-18041.

Figure 1
Li15Si4 As Potential Charged Anode Material:Cycling Stability and Reactivity Towards Carbonate Electrolyte
Authors: Toffoletti Lorenzo , Meini Stefano , Tsiouvaras Nikolaos , Gasteiger Hubert A , Fässler Thomas F. 
Published: February 2020

In the development of high energy density Li-ion batteries, two elements have drawn the interest of the scientific community due to their low cost and high specific capacity: silicon and sulfur. These two elements are considered next generation’s active materials for anode and cathode, respectively. In order to exploit the advantages given by both materials in terms of specific capacity (and thus specific energy), lithium has to be introduced at the time of manufacturing either on the cathode side (as Li2S/Si cell) or on the anode side (as LixSiy/S cell). The Li-Si system has been recently investigated as potential source of lithiated anode materials 1,2, however up to date little is known about their highly exothermal reaction with alkyl carbonate based electrolytes. In this work we address the latter point via in-situ Online Electrochemical Mass Spectrometry (OEMS)3. By monitoring the gas evolution (mainly ethylene) resulting from contacting the metastable phase Li15Si4 and the non-aqueous electrolyte during a simulated electrolyte filling experiment of a Li-ion cell (Fig. 1), it was possible to get fundamental understanding of the challenges that cell manufacturers will have to face when using lithiated anode materials. The cycling stability of Li15Si4 as well as the role played by the total electrode surface area were as well thoroughly investigated.
References: 1) Zeilinger M et al., Chem. Mater. 25 (2013), 4623-4632. 2) Ma R. et al., J. Phys. Chem. Lett. 3 (2012), 3555-3558. 3) Tsiouvaras et al., J. Electrochem. Soc. 160(3) (2013), A471-A477

Figure 1
Effect of AlF3 Surface Coating on High Energy Lmr-NMC Material
Authors: Shin Youngho , Kahvecioglu Feridun Ozgenur , Krumdick Gregory 
Published: February 2020

In this study, we explore the effect of AlF3 surface coating on Li1.2Mn0.54Ni0.13Co0.13O2 to mitigate the voltage fade issue. The precursor of this high energy material was synthesized using carbonate co-precipitation method by a 20L continuous stirred tank reactor (CSTR). Then, the synthesized precursor was mixed with Li-source and calcined at 900°C to generate cathode material. This product was used as the base material for AlF3 surface coatings.
A customized wet coating system was used for surface modification of the pristine material with 0.5, 1.0, 1.5 and 2.0 wt.% AlF3. The morphology, surface area, particle size and its distribution of the pristine and coated materials were characterized by scanning electron microscopy (SEM), BET and particle size analysis. The composition and the structure of the materials were characterized by inductively coupled plasma mass spectroscopy (ICP-MS) and X-ray diffraction (XRD).
The coated and pristine cathode powders were electrochemically tested using Voltage Fade protocol of Argonne National Laboratory. We demonstrate that AlF3 coating shows improved capacity retention compared to its pristine material. As a key factor, uniform surface coating provides improved capacity retention and rate capability of Li1.2Mn0.54Ni0.13Co0.13O2.
Insight into the Lithiation of SiO2 As a New Energy Storage Anode Material for Li-Ion Batteries
Authors: Ostadhossein Alireza , van Duin Adri 
Published: February 2020

Silica (SiO2) has been considered as a promising anode material of lithium ion batteries (LIBs) due to its similar advantages of storing a large quantity of lithium and low discharge potentials of Silicon (Si) electrodes. Besides, Atomic layer deposition of SiO2is a predominant coting material to mitigate the chemo-mechanical degradation of Si nanostructures anode. Si anodes coated with native oxide layer can sustain more than 6000 cycles with little capacity fade. Therefore, it is vital to determine the effect of the oxide layers on the volume expansion, lithium insertion and the morphology changes of Si anodes in LIBs. While the lithiation of Silicon (Si) has been extensively studied from both experimental and theoretical point of view, the underlying mechanism of lithium insertion in the silicon oxide has not yet been recognized well.
To better understand the lithiation behavior in SiO2 at the atomistic level we herein performed a series of reactive molecular dynamics simulation combining with the grand canonical montecarlo (GCMC) to demonstrate the lithiation behavior of SiO2. In addition, the Li transports throughout both crystalline and amorphous silica have been investigated. ReaxFF parameters are improved to account for the interaction of Li with Si and O atoms. We performed density functional theory calculations to examine the structural evolution, bonding mechanism, and voltage profile of lithiated c-SiO2 and a-SiO2. Both ReaxFF and DFT results indicate anisotropic long range Li-diffusion throughout the a-Quartz lattice. More specifically, Li should overcome 0.12 eV barrier heights when it transports along the c-axis of α-Quartz crystal, whereas the barrier of diffusion for Li moving perpendicular to the c-axis is calculated around 0.9 eV. Li transport throughout a-SiO2 bulk is also investigated and the results are compared with barriers obtained from DFT simulations.

Figure 1
Optimization of LiMnPO4 Using Solid State Processes
Authors: Oladimeji Charles F , Moss Pedro L. 
Published: February 2020

The development of lithium ion battery over the years has been in leaps and bound. Research is still ongoing towards the development of better lithium ion batteries and utilization techniques to power devices and machines of the future ranging from hand tools to electric vehicle. Presently LiCoO2is one of the most commercially available secondary batteries in the market right now.
Among the olivine battery materials LiFePO4 is the most researched and understood material. Other olivine materials have higher energy density but some unfavorable characteristics hinder commercialization. LiCoPO4 and LiNiPo4 have really high voltages that is not in the operating range of presently usable electrolytes. LiMnPO4 is a very promising olivine material, its operating voltage is higher than that of LiFePO4 but still within the operating range of conventional electrolytes.
The low energy density of LiMnPO4 at high rate cycling is a major problem that must be solved before it can be commercialized. Studies have shown that this is due to the low electronic conductivity, large volume change between LiMnPO4 and MnPO4 and high activation resistance 1.
Many approaches have been applied to solve this problem. The poor electronic conductivity can be alleviated with the use of carbon coating. Using a one-step carbon coating process results in better coating and increased conductivity compared to two step coating as shown in figure 11. Isovalent co-doping has also been shown to increase the performance of the material. Some other interesting approach to the problem has also been employed. The use of grinding aid to reduce the size of the product has been shown to increase performance 3. Use of oleic acid during fabrication reduces particle growth and agglomeration 4. Improved electrochemical performance was also gotten by the use of off stoichiometric mix of the precursor 2.
The goal of our research is to combine these various methods that has been shown to increase performance of the material then characterize and analysis the material to see if the resulting material would be of higher performance as whole.

REFERENCES

1. Electrochemical Performance of LiMnPO4 Synthesized with Off-Stoichiometry Byoungwoo Kang and Gerbrand Ceder
2. Rate Performance of LiMnPO4 Based Materials from Different Carbon Source Addition Process Haisheng Fang, Enrui Dai, Kun Yang, Bin Yang, Yaochun Yao, Wenhui Ma, Yongnian Dai
3. Grinding aid-assisted preparation of high-performancecarbon-LiMnPO4Lingbing Ran, Xiaoyan Liu, Qiwei Tang, Kunlei Zhu, Jianhua Tian,Jiangyong Du, Zhongqing Shan∗
4. Confined synthesis of hierarchical structured LiMnPO4/C granules by a facile surfactant-assisted solid-state method for high-performance lithiumion batteries Longfei Zhang, Qunting Qu, Li Zhang,* Jing Li and Honghe Zhen

Figure 1
High Energy Density Solid-State Lithium Battery
Authors: Thokchom Joykumar 
Published: February 2020

This presentation seeks to present the science and technology of a safe all-solid-state, high-energy density, rechargeable lithium battery. The main breakthroughs in the solid-state battery technology will be summarized and will share our latest contributions in the advancement of the technology. The unit cell of the battery comprises lithium metal as the anode, a novel high performance lithium nickel manganese cobalt oxide based composite cathode and a lithium stable composite electrolyte as separator. At cell level we are able to achieve a very high energy density at moderate rate and elevated temperature. This achievement is made possible by adopting our proprietary composite cathode composition and processing. Another advantage is its ability to operate at high temperature up to 160oC compared to the commercially available lithium-ion batteries, which normally operate only up to 60oC. The targeted applications for the battery are for automobile and others like consumer electronics, power tools, medical, and oil exploration.
Key Words: solid composite electrolyte, all-solid-state lithium battery, high-energy density, extended temperature range, and electric vehicles
Pulverization Strategy for Graphite-CoOx Composite Cathode of Lithium-Air Batteries
Authors: Kwak Won-Jin , Shin Chang Dae , Ming Jun , Lu Jun , Curtiss Larry , Amine Khalil , Sun Yang-Kook 
Published: February 2020

The lithium-air battery has been attracted around the world owing to very high energy density, which could well satisfy the increased energy requirement from electronic devices, especially the electric vehicle.1-3

However, despite large R&D efforts devoted to its implementation, several issues have so far limited the performance of the lithium oxygen battery because of few discharge-charge cycles, large polarization and low rate capability.4, 5

Some researchers used many materials for cathode in lithium air batteries because inherent activation effect and morphology of each material had an effect to decrease polarization and increase capacity. Although carbon has been talked making by-product like Li2CO3, it is the mostly used material because of the advantage in the way that amount and cost. Some paper told that not only carbon but also electrolyte co-makes this side reaction problem in lithium oxygen battery system.
In this study, a new physical pulverization strategy has been developed to prepare a highly active composite of CoOx and crushed graphite (CG) for the cathode in lithium–air batteries. The effect of CoOx loading on the charge potential in the oxygen evolution reaction was investigated in coin cell tests. The CoOx (38.9 wt%)/CG composite showed a low charge potential of 3.92 V with a delivered capacity of 2 mAh/cm2 under a current density of 0.2 mA/cm2. The charge potential was 4.10 and 4.15 V at a capacity of 5 and 10 mAh/cm2, respectively, with a current density of 0.5 mA/cm2. The stability of the electrolyte and discharge product on the gas-diffusion layer after the cycling were preliminarily characterized by 1H nuclear magnetic resonance spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The high activity of the composite was further analyzed by electrochemical impedance spectroscopy, cyclic voltammetry, and potential-step chronoamperometry. The results indicate that our near-dry milling method is an effective and green approach to preparing a nanocomposite cathode with high surface area and porosity, while using less solvent. Its relative simplicity compared with the traditional solution method could facilitate its widespread application in catalysis, energy storage, and materials science.

References

[1] K.M. Abraham Journal of The Electrochemical Society 1996, 143, 1.
[2] G. Girishkumar; B. McCloskey; A.C. Luntz; S. Swanson; W. Wilcke J Phys Chem Lett 2010, 1, 2193-2203.
[3] B. Scrosati; J. Hassoun; Y.K. Sun Energ Environ Sci 2011, 4, 3287-3295.
[4] S.A. Freunberger; Y. Chen; Z. Peng; J.M. Griffin; L. J. Hardwick; F. Bard; P. Novak; P. G. Bruce J. Am. Chem. Soc. 2011, 133, 8040-8047.
[5] G.R. Mettam; L.B. Adams; B.S. Jones; R.Z. Smith Introduction to the Electronic Age, E-Publishing Inc., New York, 2009, 281-304.
Stability of Hard Carbon Coated Low Purity Natural Graphite As a Lithium-Ion Battery Anode Material
Authors: Kim Byung-ryang , Hong Young Kyu , Kang Hye-Joung , Shin Sang-Yong , Lee Jong-hyuk , Kim Sun Ah , Lee Ki-Tae , Shin Jin-Koog 
Published: February 2020

Natural graphite is widely used in commercialized batteries by virtue of low cost, high capacity and stable charge/discharge performance [1]. However, multi-level purification process for battery-grade natural graphite (>99.9%) accompanies high manufacturing cost, although the raw material price is low enough. Accordingly, if we can avoid some purification steps such as acid-based purification process without loss of battery performance, we can reduce the manufacturing costs as well as environmental budget. In order to use low-purity graphite as anode material, one needs a way to prevent potential side reactions.
In this study, we adopted carbon coating method which has been reported to effectively reduce the irreversible capacity and extend the cycle life of Li-ion battery [2]. The hard carbon coating on the low-purity graphite was expected to improve the reliability of Li-ion battery by blocking the impurity diffusion. For hard carbon coating, spherical graphite was blended with thermosetting polymer and then sintered in a nitrogen atmosphere at 1300℃. For electrochemical measurements, we assembled 2032 type coin half-cells. Characteristics of the half-cell were evaluated as a function of cycle number and with different C-rates. Structural and thermal stability of hard carbon coating layer was also evaluated. To examine the structural stability, microstructure of hard carbon layer before and after the repeated charge-discharge cycles was observed using TEM. Thermal stability was evaluated by measuring capacity fading of cells after the elevated temperature storage. Based on the measured results, we discussed the validity of the hard carbon coating for the practical use of low-purity graphite.

♦ Reference

[1] Y.P. Wu, C. Jiang, C. Wan, R. Holze, Solid State Ionics 156 (2003) 283.

[2] J.J. Li, X.M. He, C.Y. Jiang, C.R. Wan, J. New Mater. Electrochem. Syst. 9 (2006) 21.

♦ Acknowlgement

This research was financially supported by the Ministry of Trade, Industry and Energy(MOTIE) and Korea Institute for Advancement of Technology(KIAT) through the Promoting Regional specialized Industry

Figure 1
Surface Modification of Manganese-Rich Cathode Materials in Lithium Ion Batteries
Authors: Lee Jieun , Lee Jeongyeon , Hwang Taejin , Noh Hana , Choi Wonchang 
Published: February 2020

Introduction

High energy density of Li-ion batteries becomes more and more important for electric vehicle and hybrid electric vehicle. The many researches have been focused on cathode materials to substitute the commercial LiCoO2. Among various cathode materials, Over-lithiated Layered Oxide (OLO), recently investigated, is the layered transition metal oxide having more than unit Li concentration. Because OLO exhibits much higher capacity over 250mAh/g as well as lower cost, high safety and thermal stability [1,2]. So the OLO is considered as attractive candidate for cathode material because of the high capacity, reduced toxicity and low cost. However this material generates gas inevitably during charge/discharge process and exhibits not good cycle performance and poor electrical conductivity compared to other cathodes. As one of the approaches to solve these problems, we introduced surface modification with conducting polymer. Field Emission Scanning Electron Microscopy, X-ray diffraction, Fourier Transform Infrared Spectroscopy and Various Charge-discharge measurements were also performed to investigate the effect of surface-coating layer.

Experimental

To prepare Samples, modified OLO is made by wet-type coating method. Electrode slurry has been made of 94% of cathode materials, 3% of Denka black, 3% of PVdF. The slurry was casted on the Al foil for current collector and assembled with 2032 coin cell. Field Emission Scanning Electron Microscopy, X-ray diffraction, Fourier Transform Infrared Spectroscopy and Various Charge-discharge measurements were also performed to investigate the effect of surface-coating layer.

Results and discussion

Fig. 1 show the discharge profiles of the rate capability for the pristine, 1wt.% PEDOT:PSS coated OLO and 3 wt.%PEDOT:PSS coated OLO electrode between 2 and 4.6 V. Surface-modification of cathode electrodes with conducting polymer leads to the more good rate properties.

Reference

1. M. M. Thackeray, S.-H. Kang, C. S. Johnson, J. T. Vaughey, R. Benedek, S. A. Hackney, J. Mater. Chem. 17, 3053-3272(2007).
2. X. Lie, H. Li, D. Li, M. Ishida, H. Zhou, J. Power Sources 243, 374-380. (2013).

Figure 1
Monoclinic TiO2 As Active Anode Material for Li-Ion Batteries
Authors: Cech Ondrej , Chladil Ladislav , Kazda Tomá , Kapárek Vít , Cudek Pavel , Vanýsek Petr 
Published: February 2020

Chemical and thermal stability are the key bottlenecks of conventional graphite anodes used in the li-ion batteries today. Graphitic materials are the most common anode active materials mostly due to their high specific capacity and relatively low cost. On the other hand, drawbacks like low stability of solid electrolyte interface layer protecting it from spontaneous reaction with electrolyte and the risk of thermal runaway are more and more evident with rising of interest in the electro mobility and EV.
One of the most promising successors in the field of lithium anode active materials is the group of ceramic materials based on titanium oxide. Their thermal and chemical stability is incomparable with graphitic materials – they are almost inert and due to higher operation voltage they do not suffer from irreversible capacity loss as a result of SEI layer formation.
This work deals with structural and electrochemical characterisation of monoclinic TiO2 as anode active materials for lithium-ion batteries.
Soft chemical synthesis was utilized for preparation of monoclinic TiO2 and precursors based on different layered alkali metal titanates were used. Titanates with formula A2TinO2n+1 form variety of layered structures for n between 3 and 6 with alkali metal cations A in the interlayer space. These structures are composed of corrugated layers of TiO6 octaedra which can share edge or corners to form stepped layered structure. The step length for a given composition is determined by the A+ to Ti+ ratio and is in correlation with the ability to form monoclinic TiO2.
Alkali titanate precursors in the form of K2Ti4O9 and Na2Ti3O7 were prepared by high-temerature solid-state reaction and by hydrothermal synthesis respectively. Subsequent ionic exchange of K+ to protons was made and resulting protonated titanate was dehydrated at slightly rised temperature.
The influence of precursor structure and dehydratation temperature on electrochemical properties as anode material for li-ion batteries was investigated by cyclic voltammetry, galvanostatic cycling, electrochemical impedance spectroscopy and rate capability. Physical characterization by XRD, SEM and BET was provided.

Figure 1
Probing Life Limiting Parasitic Reactions: A Conceptual Model for Long Term Impedance Rise
Authors: Takeuchi Esther S , Marschilok Amy C , Takeuchi Kenneth J 
Published: February 2020

The detailed understanding of non-Faradaic parasitic reactions which diminish battery calendar life is essential to the development of effective batteries for use in long life applications. The dissolution of cathode materials including manganese, cobalt and vanadium oxides in battery systems has been identified as a battery failure mechanism, yet detailed dissolution studies including kinetic analysis are absent from the literature. The results presented provide a framework for the quantitative and kinetic analyses of the dissolution of cathode materials which will aid the broader community in more fully understanding this battery failure mechanism.
In this study, a series of vanadium oxide and phosphate based cathode materials are studied relative to their dissolution in battery electrolyte. Kinetic analysis of the results provides a quantitative framework for rationalizing the impact of structure and composition on dissolution. Further, the result of cathode solubility at the systems level is investigated shedding light on the interaction of the negative electrode with the dissolved transition metal species. The findings are used to provide a conceptual model for the resultant impedance rise.