Credit-Based Reliability Service Model in Wireless Communication Networks

Zonghai Ye 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.5

In wireless communication networks, the reliability is greatly important that it is independent of the radio transmission approach, unfortunately due to the failure-prone nature of wireless communication networks, the ability of providing a stable link and consistent quality of service (QoS) to end-users is a key issue. Currently credit-based reliability system becomes a very important security mechanism in the wireless adaptive communication network. This paper introduces a credit-based reliability service model which uses the credit space expressed by the WATCHDOG mechanism so as to access the wireless self-organized network. In this model, the transformation from credit space to reliability space is proposed and the key characteristics are revealed. Experiments are carried out to examine the proposed model. It is observed that, the proposed model is able to evaluate the service value under the credit-based reliability capacity.

Titanium‐Based Anode Materials for Safe Lithium‐Ion Batteries

Chen, Zonghai,Belharouak, Ilias,Sun, Y.‐,K.,Amine, Khalil WILEY‐VCH Verlag 2013 Advanced functional materials Vol.23 No.8

<P><B>Abstract</B></P><P>Lithium‐ion batteries have been long considered a promising energy storage technology for electrification of the transportation system. However, the poor safety characteristics of lithium‐ion batteries is one of several technological barriers that hinder their deployment for automobile applications. Within the field of battery research and development, titanium‐based anode materials have recently attracted widespread attention due to their significantly better thermal stability than the conventional graphite anode. In this chapter, the fundamental properties and promising electrochemical performance of titanium‐based anode materials will be discussed for applications in hybrid electric vehicles.</P>

Role of surface coating on cathode materials for lithium-ion batteries

Chen, Zonghai,Qin, Yan,Amine, Khalil,Sun, Y.-K. Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.36

<P>Surface coating of cathode materials has been widely investigated to enhance the life and rate capability of lithium-ion batteries. The surface coating discussed here was divided into three different configurations which are rough coating, core shell structure coating and ultra thin film coating. The mechanism of surface coating in achieving improved cathode performance and strategies to carry out this surface modification is discussed. An outlook on atomic layer deposition for lithium ion battery is also presented.</P> <P>Graphic Abstract</P><P>Surface coating for advanced cathode materials for lithium ion batteries was reviewed, and the prospects for ultra thin layer coating were also discussed. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0jm00154f'> </P>

Development of Microstrain in Aged Lithium Transition Metal Oxides

Lee, Eung-Ju,Chen, Zonghai,Noh, Hyung-Ju,Nam, Sang Cheol,Kang, Sung,Kim, Do Hyeong,Amine, Khalil,Sun, Yang-Kook American Chemical Society 2014 NANO LETTERS Vol.14 No.8

<P>Cathode materials with high energy density for lithium-ion batteries are highly desired in emerging applications in automobiles and stationary energy storage for the grid. Lithium transition metal oxide with concentration gradient of metal elements inside single particles was investigated as a promising high-energy-density cathode material. Electrochemical characterization demonstrated that a full cell with this cathode can be continuously operated for 2500 cycles with a capacity retention of 83.3%. Electron microscopy and high-resolution X-ray diffraction were employed to investigate the structural change of the cathode material after this extensive electrochemical testing. It was found that microstrain developed during the continuous charge/discharge cycling, resulting in cracking of nanoplates. This finding suggests that the performance of the cathode material can be further improved by optimizing the concentration gradient to minimize the microstrain and to reduce the lattice mismatch during cycling.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2014/nalefd.2014.14.issue-8/nl5022859/production/images/medium/nl-2014-022859_0012.gif'></P>

Nanoconfinement of low-conductivity products in rechargeable sodium–air batteries

Kwak, Won-Jin,Chen, Zonghai,Yoon, Chong Seung,Lee, Joong-Kee,Amine, Khalil,Sun, Yang-Kook Elsevier 2015 Nano energy Vol.12 No.-

<P><B>Abstract</B></P> <P>To alleviate the high polarization and short cycle lifetime of rechargeable Na–air batteries, ordered mesoporous carbon (OMC) was synthesized and evaluated as a nanostructured conductive matrix to host low-conductivity products generated during the discharge of Na–air batteries. The OMC had high specific surface area (1544m<SUP>2</SUP>/g) and a narrow pore size (2.7nm), with the voltage polarization of 1.5V, lower than that of the commonly used Super P carbon black (~1.8V). Although the carbonate-based electrolyte was decomposed to produce Na<SUB>2</SUB>CO<SUB>3</SUB>, the OMC cathode allowed reversible formation and decomposition of Na<SUB>2</SUB>CO<SUB>3</SUB> and exhibited stable cycling behavior with low polarization for 20 cycles with a delivered capacity of 500mAh/g at the current density of 100mA/g.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Cathode Material with Nanorod StructureAn Application for Advanced High-Energy and Safe Lithium Batteries

Noh, Hyung-Joo,Chen, Zonghai,Yoon, Chong S.,Lu, Jun,Amine, Khalil,Sun, Yang-Kook American Chemical Society 2013 Chemistry of materials Vol.25 No.10

<P>We have developed a novel cathode material based on lithium–nickel–manganese–cobalt oxide, where the manganese concentration remains constant throughout the particle, while the nickel concentration decreases linearly and the cobalt concentration increases from the center to the outer surface of the particle. This full concentration gradient material with a fixed manganese composition (FCG–Mn-F) has an average composition of Li[Ni<SUB>0.60</SUB>Co<SUB>0.15</SUB>Mn<SUB>0.25</SUB>]O<SUB>2</SUB> and is composed of rod-shaped primary particles whose length reaches 2.5 μm, growing in the radial direction. In cell tests, the FCG–Mn-F material delivered a high capacity of 206 mAh g<SUP>–1</SUP> with excellent capacity retention of 70.3% after 1000 cycles at 55 °C. This cathode material also exhibited outstanding rate capability, good low-temperature performance, and excellent safety, compared to a conventional cathode having the same composition (Li[Ni<SUB>0.60</SUB>Co<SUB>0.15</SUB>Mn<SUB>0.25</SUB>]O<SUB>2</SUB>), where the concentration of the metals is constant across the particles.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2013/cmatex.2013.25.issue-10/cm4006772/production/images/medium/cm-2013-006772_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm4006772'>ACS Electronic Supporting Info</A></P>

Mechanism of capacity fade of MCMB/Li_1.1[Ni_1/3Mn_1/3Co_1/3]_0.9O₂ cell at elevated temperature and additives to improve its cycle life

Amine, Khalil,Chen, Zonghai,Zhang, Z.,Liu, Jun,Lu, Wenquan,Qin, Yan,Lu, Jun,Curtis, Larry,Sun, Yang-Kook Royal Society of Chemistry 2011 Journal of materials chemistry Vol.21 No.44

<P>The performance degradation of graphite/Li<SUB>1.1</SUB>[Ni<SUB>1/3</SUB>Mn<SUB>1/3</SUB>Co<SUB>1/3</SUB>]<SUB>0.9</SUB>O<SUB>2</SUB> lithium-ion cells at elevated temperature was investigated. The electrochemical data suggest that the migration of dissolved transition metals from the cathode to the anode is the key contributor to the performance degradation. With the help of density function theory calculations, lithium difluoro[oxalato] borate was tested to be an effective electrolyte additive to mitigate the performance degradation of lithium-ion cells. The application of this novel electrolyte additive was found to significantly improve both the life and safety characteristics of graphite/Li<SUB>1.1</SUB>[Ni<SUB>1/3</SUB>Mn<SUB>1/3</SUB>Co<SUB>1/3</SUB>]<SUB>0.9</SUB>O<SUB>2</SUB> lithium-ion cells.</P> <P>Graphic Abstract</P><P>The performance degradation of graphite/Li<SUB>1.1</SUB>[Ni<SUB>1/3</SUB>Mn<SUB>1/3</SUB>Co<SUB>1/3</SUB>]<SUB>0.9</SUB>O<SUB>2</SUB> lithium-ion cells at elevated temperature was investigated. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1jm11584g'> </P>

Nanostructured Anode Material for High-Power Battery System in Electric Vehicles

Amine, Khalil,Belharouak, Ilias,Chen, Zonghai,Tran, Taison,Yumoto, Hiroyuki,Ota, Naoki,Myung, Seung-Taek,Sun, Yang-Kook WILEY-VCH Verlag 2010 Advanced Materials Vol.22 No.28

<B>Graphic Abstract</B> <P>A new MSNP-LTO anode is developed to enable a high-power battery system that provides three times more power than any existing battery system. It shows excellent cycle life and low-temperature performance, and exhibits unmatched safety characteristics. <img src='wiley_img_2010/09359648-2010-22-28-ADMA201000441-content.gif' alt='wiley_img_2010/09359648-2010-22-28-ADMA201000441-content'> </P>

Synthesis and characterization of alkylsilane ethers with oligo(ethylene oxide) substituents for safe electrolytes in lithium-ion batteries

Zhang, Lingzhi,Lyons, Leslie,Newhouse, Jocelyn,Zhang, Zhengcheng,Straughan, Megan,Chen, Zonghai,Amine, Khalil,Hamers, Robert J.,West, Robert Royal Society of Chemistry 2010 Journal of materials chemistry Vol.20 No.38

<P>Alkylsilane ethers, containing one or three carbon spacer groups between the silicon atom and oligo(ethylene oxide) moiety, were designed and synthesized. These compounds are non-hydrolyzable and less flammable than their alkoxysilane counterparts. A full cell test using them as electrolyte solvents showed good cycling performance in lithium-ion batteries.</P> <P>Graphic Abstract</P><P>Alkylsilane ethers with oligo(ethylene oxide) substituents were designed and synthesized as safe electrolyte solvents which showed good cycling performance doped with LiBOB in lithium-ion cells. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0jm01596b'> </P>

A polymeric composite protective layer for stable Li metal anodes

Guo Suogang,Wang Li,Jin Yuhong,Piao Nan,Chen Zonghai,Tian Guangyu,Li Jiangang,Zhao Chenchen,He Xiangming 나노기술연구협의회 2020 Nano Convergence Vol.7 No.21

Lithium (Li) metal is a promising anode for high-performance secondary lithium batteries with high energy density due to its highest theoretical specific capacity and lowest electrochemical potential among anode materials. However, the dendritic growth and detrimental reactions with electrolyte during Li plating raise safety concerns and lead to premature failure. Herein, we report that a homogeneous nanocomposite protective layer, prepared by uniformly dispersing ­AlPO 4 nanoparticles into the vinylidene fluoride-co-hexafluoropropylene matrix, can effectively prevent dendrite growth and lead to superior cycling performance due to synergistic influence of homogeneous Li plating and electronic insulation of polymeric layer. The results reveal that the protected Li anode is able to sustain repeated Li plating/stripping for > 750 cycles under a high current density of 3 mA cm −2 and a renders a practical specific capacity of 2 mAh cm −2 . Moreover, full-cell Li-ion battery is constructed by using ­LiFePO 4 and protected Li as a cathode and anode, respectively, rendering a stable capacity after 400 charge/discharge cycles. The current work presents a promising approach to stabilize Li metal anodes for next-generation Li secondary batteries.