bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Study on the Solid Electrolyte Interface Formation by the Reduction of Alkyl Carbonates in Lithium Ion Battery
Authors: Haregewoin Atetegeb Meazah , Leggesse Ermias Girma , Hwang Bing-Joe , Jiang Jyh-Chiang , Wang Fu-Ming , Lin Shawn D.
Published: February 2020

One of the major concerns in lithium ion battery is the composition of the electrolytes as it governs some of the vital physicochemical properties of the electrolytes such as viscosity, ionic conductivity, thermal stability and wettability. Most important properties of lithium ion batteries are related to the properties of the solid electrolyte interface (SEI) layer formed on the electrode surface. The SEI in turn is mainly dependent on the electrolyte composition [1]. Therefore, understanding the nature, mechanism and property of the SEI formation in different electrolyte composition is crucial in selecting electrolytes. In this work, we report a direct comparison of the reduction of propylene carbonate (PC), ethylene carbonate (EC) and diethyl carbonate (DEC) as a single, binary and ternary solvent systems. Battery performance test, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) is employed to study the nature of the surface films formed.

The reduction products are determined by using ex-situ attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), in the glove box, after employing linear sweep voltammetry (LSV) to certain potential regions. EC/PC/DEC based electrolyte shows better capacity retention and less impedance than the EC/PC system. In all systems, the FTIR results indicate the formation of (CH3CH2OCO2Li)2 and Li2CO3 due to the reduction of PC. EC is reduced to (CH2OCO2Li)2 and Li2CO3 in both the binary and ternary solvent system. The FTIR result at the potential where DEC reduction occurs shows the formation of (CH2=CH-OCO2CH2CH3)Li which is less stable and forms a less-passivating layer in the first cycle. However, this product can further react with another species in the subsequent cycles and form a stable SEI.

[1] A.J. Gmitter, J. Gural, G.G. Amatucci, J. Power Sources, 217 (2012) 21-28.

[2] K. Xu, J. Electrochem. Soc., 156 (2009) A751-A755.

[3] G.V. Zhuang, H. Yang, B. Blizanac, P.N. Ross, Electrochem. Solid-State Lett, 8 (2005) A441-A445.
On the Unusually High Fe3+/Fe2+ Redox Potential Exceeding 4V
Authors: Yamada Atsuo , Chung Sai-Cheong , Nishimura Shinichi , Barpanda Prabeer
Published: February 2020

The potential tunability for Fe3+/Fe2+ redox couple at unusually high voltage region of 3.5 – 4.1 V will be reviewed based on the new materials discovered in my group over the past 3 years. Overall energetics will be given by decomposing the thermodynamic definition into electronic and structural factors, leading to the guidelines to develop new high voltage cathode materials. In searching new materials, as often missed by the ground state screening, experimental identification of metastable functional phase by entropy gain (including disorder and/or defects) at finite temperature is important and effective. Very promising new cathode materials led by this concept will be introduced as time permits.
Heat Flow Measurement and Analysis during Lithium-Ion Battery Formation Process
Authors: Xu Jeff Qiang , Sarlashkar Jayant V , Iyengar Vikram , Argo Mickey
Published: February 2020

An important step often overlooked or rarely investigated in lithium-ion battery manufacturing is the formation process. The formation process is the first full charging cycle of a lithium ion battery, which activates the cells before the lithium-ion cells can be used. The study focuses on using novel thermal measurement tool to monitor heat flow during the first charging/discharging cycle and its subsequent cycles of newly manufactured 18650 cylindrical cells. Thermal models and formulations were developed to identify the complexity of heat influence when three cells were tested simultaneously. A heat flow profile versus formation voltage window was discovered to provide important information to the study. Figure 1 shows a clear voltage window from 2.0 V to 3.7 V was identified to use as a reference range for designing alternative formation current rates. The formation process can then be altered to allow the preferential formation current rates to obtain the highest formation efficiency and improved cell performance. The impact of the lithium-ion battery formation process on battery performance such as capacity and cycle life were also examined in this study.

Figure 1: Heater Power Change as a Function of Cell Voltage during C/10 Formation Current Rate
Efficient Computational Strategy for Coupled Multi-Physics Battery Pack Simulations
Authors: Allu Srikanth , Elwasif Wael , Pannala Sreekanth , Kalnaus Sergiy , Simunovic Srdjan , Turner John A
Published: February 2020

Today, most of the battery pack simulations are conducted for design and analysis of the cooling channels to address non-uniform temperature distribution that lead to loss of performance and life. This non-uniformity could lead to different ageing of the cells depending on their location within the pack. This could subsequently trigger undesirable behavior like undercharge or overcharge conditions. In all these simulations, an equivalent circuit model is used to represent electro-chemistry as the detailed model would become computationally expensive. Incorporating degradation and aging mechanisms into these equivalent circuit models are effective for on-board diagnostic devices where time is critical, but a detailed electro-chemical model is necessary to understand balancing of cells in a Li-Ion battery pack. In this paper, we will present an efficient way to simulate battery packs that utilizes high performance computing to demonstrate the importance of detailed electro-chemical model on temperature and potential gradients in a battery pack that lead to cell imbalance. The 3D multi-physics model for the individual Li-Ion pouch cell used to construct the battery pack has been validated earlier with the experimental data at various discharge rates [1]. The battery pack under consideration has modules connected in series. Each module has four cells connected in series and parallel. The Voltage and Temperature profiles of the battery pack with two modules at the end of discharge are shown in Figure 1. Convective cooling boundary condition is imposed on the exterior of the battery pack.
Hybrid Solid Electrolyte Composed of Lithium Aluminum Germanium Phosphate and Poly(ethylene oxide) for All Solid-State Lithium Batteries
Authors: Jung Yun-Chae , Lee Sang-Min , Choi Jeong-Hee , Kim Dong-Won
Published: February 2020

Lithium-ion batteries have rapidly become the dominant power sources for portable electronic devices and electric vehicles, due to their high energy density and long cycle life [1,2].However, safety issues still prevent full utilization of these batteries owing to the use of flammable liquid electrolytes, and safety problems have become a significant concern especially in large capacity applications such as electric vehicles and energy storage systems. In this respect, fabrication of all solid-state lithium batteries by using solid electrolytes may give a fundamental solution for the safety issue of lithium batteries [3,4]. Glass ceramic electrolytes present potential advantages, such as absence of electrolyte leakage, large electrochemical stability window, absence of problems relating to vaporization of organic solvents and high thermal stability. However, sheet manufacturing, especially using thin-film technologies for making large-scale batteries, is considered to be difficult because of hard and brittle ceramic materials. In this work, solvent-free hybrid solid electrolytes composed of lithium aluminum germanium phosphate and poly(ethylene oxide) (PEO) were prepared in the form of flexible film, and their electrochemical characteristics were investigated. Their morphological properties were examined using SEM, EDS and XRD. The ionic conductivities and electrochemical stability of hybrid solid electrolytes were much higher than those of PEO-based polymer electrolyte. The optimized hybrid solid electrolyte was applied to the solid-state Li/LiFePO4 cell, and its electrochemical performance was evaluated.

References

1. J.M.Tarascon, M.Armand, Nature, 414, 359 (2001).

2. P.G.Bruce, B.Scrosati, J.M.Tarascon, Angew. Chem. Int. Ed, 47, 2930 (2008).

3. N.Kamaya, K.Homma, Y.Yamakawa, M.Hirayama, R.Kanno, M.Yonemura, T.Kamiyama, Y.Kato, S.Hama, K.Kawamoto, A.Mitsui, Nat. Mater, 10, 682 (2011).

4. Y.Li, J.B.Goodenough, Electrochem. Commun., 13, 1289 (2011).
Production of Silicon Particles for High-Capacity Anode Material Yielding Outstanding Production Capacity
Authors: Andersen Hanne Flåten , Mæhlen Jan Petter , Klette Hallgeir , Ulvestad Asbjørn , Filtvedt Werner , Kirkengen Martin , Mongstad Trygve Tveiterås , Vie Preben J. S. , Holt Arve
Published: February 2020

Silicon is proven to have a great potential as an anode material in lithium-ion batteries due to its high theoretical electrochemical capacity. The standard, commercial graphite anode has a theoretical capacity of less than 400 mAh/g, whereas the silicon anode can potentially deliver a tenfold capacity as a result of multiple Li-ion incorporation in the structure. However, silicon anodes deteriorate quickly during cyclic charging and discharging, rendering them useless in only a few cycles. This has been attributed to stresses induced by the large volume change of the material during cycling. The methods explored in order to overcome these problems such as using lithography, advanced nanotechnology, incorporation of silicon in carbon nanotubes or similar methods are too slow and too expensive for commercial use.

This work presents results from using a silane-based decomposition reactor in order to produce silicon particles with a suitable nanostructure for use in lithium-ion battery anodes. The silane gas is decomposed in a controlled environment at a temperature of 500-600 °C. The current pilot reactor has demonstrated production of up to 350 g/hour in an easily up-scalable lab version. Particles of diameter ranging from 50 nm and up to 500 nm have been produced with relatively narrow size distribution. This method may produce both amorphous and crystalline particles and the surface of the particles can be terminated by hydrogen or other elements if desired.

The silicon particles were mixed with an organic binder in an aqueous slurry and coated on a Cu-foil, The electrochemical performance was tested with CR-2032 coin cells. In the course of the presented work studies of cyclic voltammetry, cycling stability (Figure 1), voltage profiles and electrochemical impedance were performed. Besides electrochemical methods, SEM (Figure 2), XRD, ICP-MS and particle size distribution measurements were implemented. The silicon particles achieved a high capacity, relatively good stability, as well as a high yield and production capacity. Further developments on the silicon particles, such as doping of Si and in-line surface coating, are feasible.
Imidazolium Salts Modified with 1,4-Dimethoxybenzene Redox Groups and their Use in Electrolytes to Improve the Safety of Lithium-Ion Batteries
Authors: Rochefort Dominic , Forgie John , EL Khakani Soumia , MacNeil Dean
Published: February 2020

Abstract not Available.
Hierarchical Nanostructured Transition-Metal Oxides/Hydroxides for Largely Enhanced Supercapacitors Performances
Authors: Mai Liqiang , Hercule Kalele Mulonda , Wei Qiulong , Xu Lin , Khan Aamir Minhas
Published: February 2020

Abstract not Available.
Perovskite La0.6Ca0.4Co0.8Fe0.2O3 Cathode Catalyst for Li-Oxygen Batteries
Authors: Zhao Xiao , Chen Wei
Published: February 2020

Abstract not Available.
TiC/C/MnO2 Core-Shell Nanowire Arrays on Ti Alloy for Supercapacitor Application
Authors: Biao Gao , Fu Huo Kai , Jiang Fu Ji , Sheng Chen Rong
Published: February 2020

Abstract not Available.
Effect of Phosphorus Functionalities on the Supercapacitive Properties of Nonporous Carbon Nanofibers
Authors: Yan Xiaodong , Lan Jinle , Liu Yuan , Yu Yunhua , Yang Xiaoping
Published: February 2020

Abstract not Available.
CuO-Coated Li[Li0.2Mn0.54Ni0.13Co0.13]O2 Cathode Material with Improved Electrochemical Performance
Authors: Li Bing , Zhao Jin Bao
Published: February 2020

Abstract not Available.
Rice Hull Derived Porous Carbon and Its Cycling Performance of Lithium Sulfur Batteries
Authors: Li Xiang , Gao Mingxia , Liu Yongfeng , Pan Hongge
Published: February 2020

Abstract not Available.
An Imidazolium-Based Polymerized Ionic Liquid As Safe Polymer Electrolytes for Lithium Ion Batteries
Authors: Yin Kun , Zhang Zhengxi , Yang Li
Published: February 2020

Abstract not Available.
Facile Synthesis of Sb-Cu2sb@C Core-Shell Nanocomposite As a Superior Anode Material for Lithium Ion Batteries
Authors: He Yang , Huang Ling , Li Jun-Tao , Sun Shi-Gang
Published: February 2020

Abstract not Available.
Application of Highly Ordered Polymer Resin As Gel Polymer Electrolyte for Lithium Batteries
Authors: Sheng-Min Wang , Yu-Chen Chen , Che-Hsuan Yang , Cheng-Ting Lo , Tzi-Yi Wu , I-Wen Sun
Published: February 2020

Abstract not Available.
Flexible MoS2 Nanosheets/Carbon Nanotube Paper Anode Electrode for Lithium Ion Batteries
Authors: Zhang Xiaogang , Li Hongsen , Wang Xiaoyan , Shen Laifa
Published: February 2020

Abstract not Available.
High Rate Lithium Sulfur Batteries Using a Mesoporous Carbon-Sulfur Composite
Authors: Kim Jun-Young , Manuel James , Zhao Xiaohui , Ahn Jou-Hyeon
Published: February 2020

Abstract not Available.
Hydrogenated ZnO@Amorphous MnO2 for Flexible Supercpacitors
Authors: Yang Peihua , Mai Wenjie
Published: February 2020

Abstract not Available.
Improvement of cycling properties for porous Si powder prepared by acid etching Al-Si alloy powder
Authors: Jiang Zhiyu , Li Chunli , Tian Wensheng
Published: February 2020

Abstract not Available.
Carbon Coated TiO2-SiO2 Nanocomposites with High Grain Boundary Density As Anode Materials for Lithium-Ion Batteries
Authors: Zhang Jingjing , Huang Tao , Yu Aishui
Published: February 2020

Abstract not Available.
Excellent Cycle Performance of SnO2-TiO2/Graphene Composite As Anode Materials for Lithium Ion Batteries
Authors: Qin Xue , Chen Shanshan
Published: February 2020

Abstract not Available.
Tunable Electrolyte/Electrode and Electrolyte/Membrane Interfaces for Li-S Battery with High Capacity and Good Stability
Authors: Huang Jia-Qi , Peng Hong-Jie , Cheng Xin-Bing , Zhu Lin , Yuan Zhe , He Lian-Yuan , Wei Fei , Zhang Qiang
Published: February 2020

Abstract not Available.
Keynote Presentation: Molybdenum Sulfides Based Electro-Catalysts for Hydrogen Evolution Reaction
Authors: Wang Xin
Published: February 2020

Abstract not Available.
Ultra High Performance of Core-Shell Structured Ir@Pt/C Catalyst Prepared By a Facile Pulse Electrochemical Deposition
Authors: LIao Shijun
Published: February 2020

Abstract not Available.
Synthesis and Conductive Property of Alkaline Anion-Exchange Membrane Based on Chitosan/ Emimc-Co-EP Composite
Authors: Qiao Jinli , Liu Yuyu
Published: February 2020

Abstract not Available.
Ceria Diffusion and Electrical Properties on Lanthanum Doped Strontium Titanate
Authors: Yao-Ming Wang
Published: February 2020

Abstract not Available.
Electrochemical and Mechanical Durability of the Cast Membrane and the Reinforced Membrane Based on Sulfonated Poly(arylene ether sulfone) for Polymer Electrolyte Fuel Cells
Authors: Sim Woo-Jong , Choi Young-Woo , Kim Chang Soo
Published: February 2020

Abstract not Available.
Improvement of Crystal Properties for CZTS Thin Film Solar Cell
Authors: Seo Dongwan , Lim Sangwoo
Published: February 2020

Abstract not Available.
Development of New Nanostructured Au/Co/Cu and Au/Cob/Cu Catalysts and Studies of Their Catalytic Activity
Authors: Sukackiene Zita , Balciunaite Aldona , Tamasauskaite-Tamasiunaite Loreta , Pakstas Vidas , Selskis Algirdas , Norkus Eugenijus
Published: February 2020

Abstract not Available.
Cu2s/Cu1.96S /Graphite Oxide Composite As Photocatalyst for CO2 Photoreduction
Authors: Chang Yu-Chung , Wang Chen-Hao , Lin Chong-Hui , Hsu Hsin-Cheng , Shown Indrajit , Chen Li-Chyong , Chen Kuei-Hsien
Published: February 2020

Abstract not Available.
Yttrium Doped Hafnium Oxide Hf0.69Y0.31O2-δ used for Solid Oxide Fuel Cells Electrolyte and Electronic Materials
Authors: Bu Junfu , Jönsson Pär , Zhao Zhe
Published: February 2020

Abstract not Available.
Förster Resonant Energy Transfer at the Interface of Photoanode and Electrolyte in Dye-Sensitized Solar Cells Employing Dcjtb As Energy Relay Dye
Authors: Gao Rui , Cui Yixiu , Liu Xiaojiang , Wang Liduo
Published: February 2020

Abstract not Available.
Light-Gating Titania/Alumina Heterogeneous Nanochannels with Regulatable Ion Rectification Characteristic
Authors: Zhang Qianqian , Liu Zhaoyue , Zhai Jin , Jiang Lei
Published: February 2020

Abstract not Available.
Invited Presentation: Striving Toward an Ultrahigh Energy Density Li-Air Battery
Authors: Abraham K.M.
Published: February 2020

In the pursuit to develop a practical rechargeable Li/air battery, we have studied the mechanisms of O2 reduction and evolution reactions (ORR and OER), and the nature of the products formed, in a series of organic electrolytes and ionic liquids. The distinct ORR products formed in these disparate electrolyte solutions can be explained using a general theory based on the Hard Soft Acid Base (HSAB) concept. We have found that the electron donor property of the solvent modulates Li+ acidity in organic electrolytes , through the formation of complexes (or solvates) of the formula Li(solvent)n
+ where, n = 2-4, and these solvates in turn influence the mechanisms and products of both catalyzed and uncatalyzed ORR in Li-air batteries. A cobalt phthalocyanine-derived catalyst has enabled the full reduction of O2 to Li2O in selected solvents, and provided improved rechargeability for Li-air cells.

Acknowledgment: The US Army US Army RDECOM CERDEC C2D, Aberdeen Proving Grounds, MD, provided financial support for this work

Dr. K. M. Abraham is Professor at Northeastern University Center for Renewable Energy Technology, Boston, Massachusetts, USA. KM has made many pioneering contributions to advance primary and secondary lithium and Li-ion batteries including the invention of the lithium-air battery.
Invited Presentation: Lithium Metal Anode: Challenges and Opportunities
Authors: Zaghib Karim
Published: February 2020

Research on lithium metal combined with polymer electrolyte in lithium rechargeable batteries was started in 1979. Since that time, battery research has expanded worldwide. Several new polymers, solid electrolytes and ionic liquids with improved conductivity were identified. These advances resulted from a better understanding of the major parameters controlling ion migration, such as favorable polymer structure, phase diagram between solvating polymer and lithium salt, and the development of new lithium counter-anions. In spite of the progress so far, the quest for a highly conductive dry polymer at room temperature is still not available. However, effort is continuing, and all-lithium polymer battery (LPB) developers presently face the challenge of whether to heat the polymer electrolyte to enable high-power performance, as required for electric vehicle and energy storage. LPB developers have explored both the high-temperature and low-temperature options.

This presentation discusses the challenges and opportunities in developing thin lithium metal with stable SEI as negative electrode for three battery technologies using:

1. Batteries made from dry polymer and ionic liquid-polymer electrolytes for

rechargeable lithium batteries

2. All solid-state Li-sulfur batteries

3. Li-air batteries.

In addition, we will discuss the safety of lithium, dendrite mechanism, interface phenomena, side reactions, protection of lithium metal, and lithium alloys.
Electrochemical Characterization of Li1.07V0.83Fe0.1O2 ANODE Material for Li-ION Batteries
Authors: Gędziorowski Bartłomiej , Molenda Janina
Published: February 2020

INTRODUCTION

Recently a novel compounds based on layered LiV1-yMyO2 (M = Li, Fe, Cr) were found to be promising anode materials for Li-ion technology [1-3], as they exhibit long low-voltage plateau vs. metallic lithium, and higher volumetric capacity than commonly used graphite-based anode materials.

This work presents synthesis and evaluation of electrochemical properties of Li1.07V0.83Fe0.1O2, in particular open circuit voltage (OCV) and XRD analysis at different discharge (lithium content) stages.

EXPERIMENTAL

Li1.07V0.83Fe0.1O2 was synthesized using a high-temperature solid-state reaction method with Li2CO3, V2O3 and Fe2O3 taken as substrates. Stoichiometric amounts of reactants were milled in a high efficiency mill. Obtained powder was pressed into pellets and sintered in two steps: 1) at 800 °C for 10 h in Ar and 2) at 1050 °C for 12 h in 5 vol.% of H2 in Ar, followed by quenching.

Structural studies were performed in 10-110° range with CuKα radiation using Panalytical Empyrean diffractometer, followed by Rietveld refinement of identified structures.

Electrical conductivity was measured using 4-probe AC technique in -60°C to 70°C temperature range.

Electrochemical studies were done in Li/Li+/ Li1.07V0.83Fe0.1O2 cells constructed using CR2032-type containers. 1M solution of LiPF6in EC/DEC (in 1:1 ratio) was used as the electrolyte. For the positive electrode powder of active material was used (mass ≈ 50mg). OCV values were assumed as voltages of batteries after discharging to designated compositions followed by at least 24 h of relaxation.

RESULTS AND DISCUSSION

XRD analysis shown that the material is single phase and exhibits layered R-3m α-NaFeO2 type structure.

Electrical conductivity values are almost two order of magnitude higher than for materials with no iron substitution.

Discharge characteristics upon load shown step-like character, distinctly different than in Li1.07V0.93O2with shorter and right-shifted low voltage plateau.

ACKNOWLEDGMENT

This work was supported by NCN grant no. NCN 2011/02/A/ST5/00447.

REFERENCES

[1] A. R. Armstrong, C. Lyness, P. M. Panchmatia, M. S. Islam, P. G. Bruce, Nature Mater. 10

(2011) 223-229

[2] W.-T. Kim, Y. U. Jeong, H. C. Choi, Y. J. Lee, Y. J. Kim, J. H. Song, J. Power Sources 221

(2013) 366-371.

[3] X. Ma, G. Hautier, A. Jain, R. Doe, G. Ceder, J. Electrochem. Soc., 160 (2013) A279-A284.
Anode Properties of Si–FeS Films Prepared By Pulsed Laser Deposition in Solid-State Lithium Batteries
Authors: Cervera Rinlee Butch , Suzuki Naoki , Ohnishi Tsuyoshi , Osada Minoru , Mitsuishi Kazutaka , Kambara Takayoshi , Takada Kazunori
Published: February 2020

Lithium–silicon alloys are one of the most attracting anode materials for next-generation lithium-ion batteries due to the high theoretical capacity, low electrode potential, and the second largest Clark number. However, they have exerted their high performance only in nano-sized form. This study reveals that Si-based anodes fabricated into films exhibit excellent performance even in a bulky state, when they are in a solid electrolyte.

The Si-based films were deposited on stainless steel plates used as current collectors by pulsed laser deposition. Because it is impossible to ablate pure Si by the KrF excimer laser used in this study, 10wt% of FeS, which was reported to be effective in enhancing electrode activity in solid electrolytes [1], was added to Si powder before pressed into a target in order to allow the ablation. Film thickness was varied from 30 nm to 1 µm. Electrode properties of the films were investigated in a solid electrolyte, 70Li2S–30P2S5 glass ceramics, with an In–Li alloy as a counter electrode. The films were galvanostatically lithiated (charged) down to 0.01 V vs. Li+/Li and then delithiated (discharged) up to 2.62 V vs. Li+/Li at various discharge rates.

The Si–FeS films exhibit excellent performance in the solid electrolyte, as shown in the figure. The rate dependence of the discharge capacity clearly indicates that a film with thickness of 30 nm delivers a high capacity approaching the theoretical value at 0.1 C-rate discharge and maintains a high capacity of 2300 mAh g−1 at 100 C. Although such high rate capability may have been reported only for nano-sized Si materials, the film keeps it against increasing thickness. Even a 1-µm-thick film anode delivers a capacity of 3100 mAh g−1 at a discharge rate of 0.1 C, and 2500 mAh g−1is kept at a high rate discharge of 10 C.

It should be emphasized that such high performance is realized in a solid-state cell, which will be free from safety issues. In addition, the use of solid electrolytes is effective in improving cycling performance, which is a great drawback of Si anodes, by preventing detachment of the active material from current collectors. Capacity retention observed for a 400 nm-thick film over 120 cycles exceeds 80% in the solid electrolyte, while it decreases to 38% in an organic liquid electrolyte.

Acknowledgement

This study was partly supported by the Li-EAD project of the New Energy and Industrial Technology Development Organization (NEDO), Japan

Reference

[1] B. T. Hang, T. Ohnishi, M. Osada, X. X. Xu, K. Takada, and T. Sasaki, J. Power Sources 195 (2010) 3323.

Figure. Rate dependence of discharge capacity from the Si−FeS films.
Understanding Structural Changes in NMC Li-Ion Cells by In Situ Neutron Diffraction
Authors: Dolotko Oleksandr , Senyshyn Anatoliy , Mühlbauer Martin , Nikolowski Kristian , Ehrenberg Helmut
Published: February 2020

A combination of the in-situ high-resolution neutron powder diffraction along with electrochemical analysis was applied to study commercial NMC cells (18650-type) based on a Lix(Ni0.5Mn0.3Co0.2)O2(NMC) cathode and a graphitic anode. The structural changes of the electrode materials during cell charge/discharge have been analyzed using Rietveld refinement and single profile decomposition techniques.

A different behavior of electrochemically-driven lattice distortion was observed for NMC material in comparison to LixCoO2 which influence the overall cell performance. Detailed analysis of the structural changes in the Lix(Ni0.5Mn0.3Co0.2)O2 cathode material revealed reversible Li/Ni cation mixing (5.6(8) %), which is state-of-charge independent below 1600 mAh and disappearing above 1800 mAh (~0.8 Qmax). The cation mixing behavior was traced in detail using the neutron diffraction and it is considered as one of the reasons of the nonlinear change of the cathode material lattice parameters.

A transformation of graphite to LiC12 and LiC6 including the formation of higher ordered lithium intercalated carbons was observed, where the evolution of the anode at higher charge states of the cell is reflected in a change of the phase fractions of LiC6 and LiC12 due to further graphite lithiation.
Can LiMnPO4 Compete with LiFePO4
Authors: Moskon Joze , Pivko Maja , Dominko Robert , Gaberscek Miran
Published: February 2020

In contrast to LiFePO4 (LFP), its chemical and structural analogue, LiMnPO4(LMP), has long been considered a low priority material - not viable for practical applications [1,2]. Despite continuous optimization it has showed relatively low reversible capacities and low rate capability. The interest in this material has grown considerably after demonstration of much improved performance when used in mixtures with LFP [3]. In parallel to that, improvements of the performance of pure LMP have also been occasionally reported.[4]

As indicated in our previous work [5], a precondition for increased performance of LMP is creation of small particle size (on the order of 10-20 nm or smaller) whereby agglomeration of particles needs to be prevented as much as possible. A convenient way to separate particles is their embedment into pyrolytic carbon, as known from many other studies. In addition to the small, well separated particles, the improved performance of our LMP material could partly be due to slightly changed structural features; (in our case the lattice volume was 301.5(6) Å3which is about 0.3-0.5 % smaller than reported for other synthetic procedures)[5].

In the present contribution we analyze carefully the behaviour of LMP and compare it to the performance of LFP. First we show that the capacity of LMP can approach to its theoretical limitation, 170 mAh/g. Secondly, we show that the power performance can also be greatly increased if appropriate charge-discharge conditions are taken into account. At high rates the energy efficiency of LMP may even exceed the efficiency of LFP. We explain in some detail the role of inherent hysteresis of LMP in the light of our recent model [6]. In particular, we show that the rate is decreased due to slow redistribution of charge inside the cathode matrix which leads to relatively high polarization at usual rates. In this context we propose directions for further systematic improvement of the electrochemical behaviour of LMP. Finally, we show for the first time, many hundreds of cycles of LMP without significant loss of capacity (see Fig.). We also perform a post-mortem analysis and analyse the reasons for the failure. We point at the problem of electrolyte degradation (causing problems in the charge step).

References

1. A. Yamada, Y. Kudo, K. Y. Liu, J. Electrochem. Soc.
2001, 148, A747.

2. C. Delacourt, L. Laffont, R. Bouchet, C. Wurm, J.-B. Leriche, M. Morcrette, J.-M. Tarascon, C. Masquelier, J. Electrochem.
Soc.
2005, 152, A913.

3. S. K. Martha, J. Grinblat, O. Haik, E. Zinigrad, T. Drezen, J. H. Miners, I. Exnar, A. Kay, B. Markovsky, D. Aurbach, Angew. Chem. Int. Ed.
2009, 48, 8559.

4. T. Drezen, N.-H. Kwon, P. Bowen, I. Teerlinck, M. Isono, I. Exnar, J. Power Sources
2007,174, 949.

5. M. Pivko, M. Bele, E. Tchernychova, N. Zabukovec Logar, R. Dominko, M. Gaberscek, Chem. Mater.
2012, 24, 1041-1047.

6. W. Dreyer, J. Jamnik, C. Guhlke, R. Huth, J. Moškon, M. Gaberšček, Nat. Mater. 2010, 9, 448.
Bromination of Aromatic Carbonyl Derivate As an Organic Anode Material for Sodium Ion Battery
Authors: Jo Mi Ru , Lee Jun Hee , Kang Yong-Mook
Published: February 2020

The sodium battery has the potential to be the next generation battery system which utilizes cheaper and more abundant sodium material but affords nearly the same power as lithium batteries. The key issue to realize such sustainable batteries is to develop suitable organic electrode materials with sufficient redox capacity and cycling stability. Organic molecules are intriguing candidates for electrode materials for use in rechargeable Na ion batteries, organic electrode with aromatic carbonyl derivate structure has gained much attention because of its low cost, no need for rare metals, low safety risks compared to transition metal oxides, and design flexibility at the molecular level. Among possible organic materials, 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) with aromatic carbonyl derivate structure is a promising candidate anode material for lithium rechargeable batteries due to its demonstrate that each carbon in a C6 ring can accept a Li ion to form a Li6/C6 additive complex through a reversible electrochemical lithium addition reaction. In contrast, in this case of sodium addition reaction, NTCDA can insert ~7.5 Na ion in the initial discharge process but with poor cyclability. Recently, the substituents on a phenyl ring can affect the thermodynamic and kinetic properties of aromatic carbonyl derivate structure. In this work, we tried to selectively substitution the functional groups of NTCDA by a bromination, and thus we dramatically enhanced the electrochemical performance of NTCDA.
Nano-Hierarchical Hollow Manganese Oxide Anode Material with High Performance for Lithium-Ion Battery
Authors: Weng Yu-Ting , Lee Rung-Chuan , Wu Nae-Lih
Published: February 2020

Lithium-ion batteries (LIBs) are expected to continue playing important roles in energy storage for mobile communication and electric vehicle (EV) and renewable energy applications in the foreseeable future. Graphite as a commercial anode material for LIB possesses the advantages of high coulombic efficiency and good cycle stability. However, its theoretical capacity is only 372mAh/g, and this limits the total capacity of the full battery. The demand for higher energy capacity of the energy storage cell has been driving the development of alternative anode materials with higher capacities. Certain nanocrystalline metal oxides have been shown to be able to work as a reversible anode through heterogeneous conversion reaction.

The high theoretical capacity and density give metal oxides the edge over graphite as high energy density anodes for LIB. Nevertheless, due to the high kinetic barrier of the conversion reaction at room temperature, metal oxide anodes typically exhibits large potential hysteresis between lithiation and de-lithiation cycles. The hysteresis reduces the operating voltage window as well as the energy efficiency of the LIB cell. Furthermore, the poor conductivity and large volume expansion arising from lithiation of the metal oxide particles are major shortcomings that may cause poor cycling stability. Compared with other conversion–type metal oxide anodes, manganese oxide (MnOx) shows smaller potential hysteresis and lower operation potential. In addition, MnOxhave the advantages of being environment friendly and abundant.

In this work, we have prepared hierarchical hollow MnO2 by utilizing a SiO2-templating hydrothermal process. The results revealed that the novel hollow nanostructure MnO2 electrode had a specific charge capacity as large as 1364 mAh/g at 0.1 C-rate, and it unprecedentedly demonstrates high rate performance, retaining 878 mAh/g at 2 C-rate and good cycle stability.
High-Energy Li-Ion Battery with Long Cycle Life Comprising Silicon-Based Anode and Layered Composite Cathode
Authors: Kim Jaegyeong , Lee Jung Kyoo , Noh Hyung-Joo , Sun Y.-K.
Published: February 2020

Currently, high-energy lithium ion batteries are in unprecedented demand for use in various energy storage applications including emerging electronic devices and a series of electrified vehicles. In this study, high capacity electrodes based on a Si composite anode and a layered composite oxide cathode, Ni-rich Li[Ni0.75Co0.1Mn0.15]O2, were evaluated and combined to fabricate a high energy lithium ion battery. The Si composite anode, Si/C-IWGS (Si/C composite internally wired with graphene sheets), was prepared by a scalable sol-gel process. The Si/C-IWGS anode delivered a high capacity of >800 mAh g-1 with excellent cycling stability up to 200 cycles mainly due to the small amount of graphene (i.e., ~6 wt%), which was ideally dispersed to maintain an electrical network in the composite against large volume changes. The cathode (Li[Ni0.75Co0.1Mn0.15]O2) was structurally optimized (Ni-rich core and a Ni-depleted shell with a continuous concentration gradient between the core and shell, i.e., full concentration gradient, FCG, cathode) so as to deliver a high capacity (>200 mAh g-1) with excellent stability at high voltage (~4.3 V). A novel lithium ion battery system based on the Si/C-IWGS anode and FCG cathode successfully demonstrated a high energy density (240 Wh kg-1 at least) as well as an unprecedented excellent cycling stability up to 750 cycles between 2.7 and 4.2 V at 1 C. As a result, the novel battery system can be an attractive candidate for energy storage applications demanding a high energy density and long cycle life.
Nanostructured Iron Trifluoride from the Fluorination of Iron Silicide
Authors: Guerin Katia , Louvain Nicolas , Hamwi Andre , Laik Barbara , Pereira-Ramos Jean-Pierre , Sougrati moulay-Tahar , Jumas Jean-Claude , Willmann Patrick
Published: February 2020

Metal fluorides are low cost inorganic compounds that have been studied for their industrial applications such as smelting in metallurgy, uranium enrichment processor optical material production. This applied development of the synthesis of inorganic fluorides allowed intense fundamental researches in the 70’s and 80’s as regards their electronic, and more particularly magnetic, properties. In the last decades, research subjects have been shifted toward the nanostructuration of inorganic fluorides, due to potential applications such as in secondary lithium battery. Indeed, nanostructured metal fluoride materials are potential candidate materials as cathodes for lithium-ion batteries through both insertion and conversion reactions and they could improve the theoretical specific capacity of the positive electrode.

Among the MF3 fluorides (M = metal), iron trifluoride, FeF3, is one of the most promising candidate. However, its application as a cathode material for lithium ion battery has been largely hindered by both its low conductivity and its high sensibility to air humidity leading to cyclability rather limited. This work will present some new strategies to develop nanostructured iron fluoride of high chemical stability. They have been prepared through the reactivity of some unusual metal precursors with molecular fluorine gas. In order to favor the nanostructuration of the metal fluoride, the kinetic of fluorination has been followed by in-situ Infra-Red measurements. All the metal fluorides obtained have been then characterized by Scanning Electronic Microscopy, XRD, IR, MOSSBAUER, and Raman spectroscopies. Finally, the electrochemical performances will be presented and correlated with both the fluorination conditions and the physicochemical characteristics of the samples prepared.
Single-Phase Layered Compositions in the Li-Mn-Ni-O System Which Do Not Significantly Oxidize Electrolyte at 4.6 V Versus Li/Li+
Authors: Rowe Aaron W. , Camardese John , McCalla Eric , Dahn Jeff
Published: February 2020

Detailed phase diagrams of the Li-Mn-Ni-O system have been determined to provide a broader understanding of how synthesis conditions affect the phase composition of Li-Mn-Ni-O positive electrode materials.1,2 Figure 1 shows the positive electrode region of the Li-Mn-Ni-O pseudoternary phase diagram for samples quenched from 900oC. The phase diagram is labeled with various individual compositions, single-phase regions, tie-lines, and multi-phase co-existence regions all elucidated through extensive crystallographic analysis,3 introducing many opportunities for characterization of new positive electrode materials. In order to develop Li-ion batteries with high energy densities and long cycle lives, ideal novel materials would not react with carbonate-based electrolytes at high potentials (≥ 4.6 V vs. Li/Li+).

In this study, three single-phase layered compositions in the Li-Mn-Ni-O system, labeled as A, B and C in Figure 1, were studied by ICP-OES, XRD, and ultra high precision coulometry (UHPC), a technique which uses precise measurement of coulombic efficiency (CE) and charge endpoint capacity slippage to detect electrolyte oxidation. Sample A was determined to be Li[Li0.157Ni0.122Mn0.650□0.071]O2, a Li-deficient, Mn-rich material containing 3.5% metal site vacancies.4 Sample B was Li[Li0.117Ni0.325Mn0.558]O2, an essentially Ni-rich member of the Li-rich oxide solid solution series (dashed orange line in Figure 1), while sample C was determined to be Li[Li0.148Ni0.480Mn0.471]O2, an approximate Li-rich analogue of Li[Ni0.5Mn0.5]O2.

Figure 2 shows the CE, discharge capacity, and normalized charge endpoint capacity for cycle 10 onwards for samples A, B, and C cycled to 4.6 V and 4.8 V, and for Li[Ni1/3Mn1/3Co1/3]O2 cycled to 4.2 V, 4.4 V, and 4.6 V. In general, cycling to 4.6 V yielded better CE and lower slippage of the Li-Mn-Ni-O materials compared to cycling to 4.8 V, which produced more slippage due to electrolyte oxidation. The performance of the Li-deficient Li[Li0.157Ni0.122Mn0.650□0.071]O2 material cycled to 4.6 V was striking, as it maintained a substantially higher CE and a lower charge endpoint capacity slippage per cycle than Li[Li0.117Ni0.325Mn0.558]O2, Li[Li0.148Ni0.480Mn0.471]O2, and industry standard Li[Ni1/3Mn1/3Co1/3]O2 (cycled to only 4.2 V) while maintaining a reversible capacity of 225 mAh/g after 50 cycles. These results highlight the inherent “inertness” of Li[Li0.157Ni0.122Mn0.650□0.071]O2 and its suitability as a thin protective shell in a core-shell particle configuration.

References

1. E. McCalla, A. W. Rowe, R. Shunmugasundaram, and J. R. Dahn, Chem. Mater., 25, 989–999 (2013).

2. E. McCalla, A. W. Rowe, C. R. Brown, L. R. P. Hacquebard, and J. R. Dahn, J. Electrochem. Soc., 160, A1134–A1138 (2013).

3. E. McCalla and J. R. Dahn, Solid State Ion., 242, 1–9 (2013).

4. E. McCalla, A. W. Rowe, J. Camardese, and J. R. Dahn, Chem. Mater., 25, 2716–2721 (2013).
Binder-Free Metal Fibril–Supported Fe2O3 Anode for High-Performance Lithium-Ion Batteries
Authors: Choi Jaecheol , Jeong Jiseon , Ryou Mhyung-Hyun , Kim Chang-Hyeon , Lee Yong Min
Published: February 2020

Metal oxides have been extensively investigated as anode materials for lithium-ion batteries (LIBs) owing to their higher theoretical capacity compared to graphitic carbon (372 mAh g−1), which has been widely used as a commercial anode material1,2. Among the established metal oxide anode materials, Fe2O3 is considered a promising anode candidate because of its numerous advantages including high theoretical capacity (1007 mAh g−1), abundance, relatively low cost, and environmental friendliness. However, a large volume of expansion (six Li+ per formula unit) and electrode destruction upon electrochemical cycling results in severe capacity fading. Moreover, due to the insulating properties of the discharge product, Li2O (Fe2O3 + 6Li+ ↔ 2Fe + 3Li2O), Fe2O3 suffers from sluggish reaction kinetics, especially at a high current rate3.

To solve these problems, we report a simple fabrication process for a stainless steel metal fibril–supported Fe2O3 (Fe2O3/SF) material as a lithium battery anode. Utilizing the well-developed 3D structure of Fe2O3/SF, the material shows not only a superior rate capability but also extremely long cycle life (2000 cycles), even at a high current density.

References

[1] A. S. Aricò, P. Bruce, B. Scrosati, J. M. Tarascon and W. Van Schalkwijk, Nat. Mater., 4, 2005, 366-377.

[2] Z. Wang, L. Zhou and X. W. Lou, Adv. Mater., 24, 2012, 1903-1911

[3] Q. Su, D. Xie, J. Zhang, G. Du and B. Xu, ACS Nano, 7, 2013, 9115-9121.
Electrochemical Two-Step Delithiation/Re-Lithiation of LiCoPO4 Observed By In Situ XRD, In Situ XAS, and Ex Situ 7-Li/31-P NMR Spectroscopy
Authors: Indris Sylvio , Kaus Maximilian , Issac Ibrahim , Heinzmann Ralf , Ehrenberg Helmut
Published: February 2020

LiCoPO4 was synthesized by solid-state and supercritical-solvothermal routes. Electrochemical tests were performed by galvanostatic cycling against Li metal at different rates and cyclic voltammetry. The electrochemical delithiation/re-lithiation mechanism was investigated by in situ x-ray diffraction (XRD), in situ x-ray absorption spectroscopy (XAS), and ex situ
7Li/31P nuclear magnetic resonance (NMR) spectroscopy. In situ XRD experiments reveal a two-step reaction with two subsequent two-phase steps and an intermediate phase of approximate composition Li0.7CoPO4 [1]. In order to gain insight into the oxidation/reduction process of Co2+/3+ during cycling in situ XAS measurements were performed which indicate a highly reversible process. 7Li and 31P NMR spectra of samples with different Li contents obtained during delithiation and re-lithiation again reveal a highly reversible two-step mechanisms with an intermediate phase. For this intermediate phase, two non-equivalent Li environments (peak ratio of 1:1) and two non-equivalent P environments (2:1) could be evidenced. These results are discussed in terms of arrangement of Li ions, Li vacancies, and Co2+/Co3+ and they hint at an intermediate phase of composition Li2/3CoPO4.

[1] N. N. Bramnik, K. Nikolowski, C. Baehtz, K. G. Bramnik, H. Ehrenberg, Chem. Mater.
19 (2007), 908.
Investigating the Phase Transitions of Graphite By In Situ Neutron Diffraction
Authors: Heß Michael , Villevieille Claire , Nesper Reinhard , Novák Petr
Published: February 2020

Graphite is one of the most common negative electrode materials in today’s lithium-ion batteries [1]. Intensive research has revealed most of its thermodynamic properties [2-5] and modeling of its free energy was able to determine some of these properties like the phase diagram and the staging phenomena to some extent [6, 7]. However, these tools were partially insufficient to describe the open-circuit potential and phase transitions in the low state-of-charge regime of the Li-graphite system.

The phase transitions during the intercalation of lithium in graphite were therefore investigated using in situ neutron diffraction. In situ neutron diffraction data have been collected to determine the transitions of the lithium-graphite intercalation compound in the range of 7-30 % of the state-of-charge (100 % = LiC6). Only this limited SOC range has been investigated in detail since previous findings by Billaud and Dahn already describe the range from 0-7 % and 30-100 % very precisely [3,5]. This new set of data suggests a continuous lithium intercalation in a certain solid-solution regime for each pure phase (stage) at room temperature. This result is found to be consistent with the phase diagram of Woo et al. [4] and is able to extract the in-plane density of lithium in each stage.

References:

1. M. Winter, J. O. Besenhard, M. E. Spahr, P. Novák, Adv Materials 10, (1998), 725-763

2. D. Guerard, A. Herold, Carbon 13, (1975), 337-345

3. D. Billaud, F. X. Henry, M. Lelaurain, P. Willmann, J. Phys. Chem. Solids 57, (1996), 775-781

4. K. C. Woo, W. A. Kamitakahara, D. P. DiVincenzo, D. S. Robinson, H. Mertwoy, D. J. Milliken, J. E. Fischer, Phys. Rev. Lett. 50, (1983), 182-185

5. J. R. Dahn, Phys. Rev. B 44, (1991), 9170-1977

6. S. E. Millman, G. Kirczenow, Phys. Rev. B 26, (1982), 2310-2313

7. P. Hawrylak, K. R. Subbaswamy, Phys. Rev. Lett. 53, (1984), 2098-2101
Redox Active Oligomers Synthesized from Anthraquinone for Use in Rechargeable Lithium Batteries
Authors: Yao Masaru , Ando Hisanori , Kiyobayashi Tetsu
Published: February 2020

Using redox active organic materials, that contain no scarce metal resources, as a positive-electrode active material instead of conventionally used rare-metal oxides can be a solution to the resource problem of the current rechargeable lithium batteries. Several types of organic positive-electrode materials have been proposed. Among them, low-molecular-weight crystalline organic compounds have been drawing attentions recently, since these compounds tend to show high utilization ratios during the charge/discharge processes. 9,10-Anthraquinone (AQ) (Fig. 1a), one of those low-molecular-weight crystalline organic compounds, also shows a capacity close to its theoretical value [1,2]; however, the electrode using AQ tends to seriously degrade upon cycling because of the dissolution of the redox-related molecules into the electrolyte solution during cycling.

To suppress the dissolution and to improve their cycle stability, we focused our attention on the oligomerization technique. In this study, an anthraquinone dimer and a trimer connected by the -C≡C- bonds (Figs. 1b and 1c) were newly synthesized using the Sonogashira cross-coupling reaction; and their performances as positive-electrode active materials were compared with the AQ-monomer. The positive electrodes using the dimer and trimer as active materials showed initial discharge capacities of about 200 mAh/g, with the average voltages of 2.2-2.3 V vs. Li+/Li. These values are close to those of the AQ monomer, suggesting the two-electron redox reaction per AQ unit. Fig. 2 compares the cycle-life performances of the electrode using the AQ-monomer, dimer, and trimer. While the capacity of the AQ-monomer electrode rapidly decreased, the synthesized dimer and trimer showed better cycle stabilities. In particular, the trimer retained almost a constant capacity during 50 cycles without drastic decay. The oligomerization of the AQ units effectively reduces the solubility. The present study revealed that oligomerization of the redox active molecular units was an effective way to extend the cycle-life without losing the discharge capacity.

References

[1] Z. Song, H. Zhan, Y. Zhou, Chem. Commun., 4 (2009) 448.

[2] M. Yao, S. Yamazaki, H. Senoh, T. Sakai, T. Kiyobayashi, Mater. Sci. Eng. B, 177 (2012) 483.