bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graphene/Na Carboxymethyl Cellulose Composite for Li-Ion Batteries Prepared By Microwave Enhanced Liquid Exfoliation
Authors: Naboka Olga , Yim Chae-Ho , Abu-Lebdeh Yaser 
Published: February 2020

Graphene and its composites have great potential as anode materials for Li-ion batteries (LIB) since their capacity was reported to exceed that of graphite, currently used as anode in most LIB [1].There are many methods to synthesize graphene, but there are still challenges to produce graphene at a large scale with desired properties that suit its perspective applications. Since there is yet no universal method for graphene production, especially that gives high yield, it would be reasonable to develop methods adjusted to specific applications e.g. electrochemical energy storage.
Liquid ultrasonic exfoliation of graphene is very popular technique however satisfactory yield of exfoliation is usually achieved with either toxic organic solvents or in the water solutions of surfactants, the latter results in contaminated final product, which is unacceptable for electrochemical applications.
In our work we used sodium carboxymethyl cellulose (NaCMC) as a water soluble “green” exfoliating agent for the high-yield graphene preparation. Since NaCMC is known to be a good binder for active electrode masses there is no need to remove it from as prepared graphene. Such approach allowed us simultaneous synthesis of graphene and preparation of electrode material for LIB.
Microwave assisted method for the liquid phase graphite exfoliation was developed in the present work. Addition of microwave heating step to sonication of graphite dispersions in solutions of sodium carboxymethyl cellulose (NaCMC) resulted in formation of concentrated graphene dispersions of up to 4.3 mg/ml after 10 hours of sonication; concentration of graphene was increased for 34% compared to using sonication alone. HRTEM and Raman spectroscopy revealed formation of few-layer graphene (3-4 layers). It was found as well that graphene yield depends on the molecular weight of the NaCMC – the higher molecular weight the higher graphene yield (up to 59% increase of graphene yield was observed for NaCMC with 250000 molecular weight compared to NaCMC with 90000 molecular weight). Drying of prepared dispersions resulted in the graphene/NaCMC composites with graphene content up to 38.65%. Yield and concentration of graphene can further be improved by increasing sonication time and recycling of sediment.
Graphene/NaCMC composite was tested as electrochemically active binder for using with Si nanoparticles in LIB electrodes. Si showed up to 51% capacity increase in the presence of graphene/NaCMC binder comparing to conventional NaCMC binder.

N. Lavoie et al. in Y. Abu-Lebdeh and I. Davidson (eds) Nanotechnology for Lithium-ion batteries,117 (Springer, NY, 2013).

A. Cieselski, P. Samori, Chem. Soc. Rev. 43, 381 (2014).
Optimized Solid-State Reaction Process of Synthesizing Li4Ti5O12 with Improved Rate Capability for Li-Ion Batteries
Authors: Kim Jae Hyun , Baek Seong-Ho , Park Jung Soo 
Published: February 2020

Spinel Li4Ti5O12 (LTO) has been actively studied due to its predominant properties in safety issue. LTO can be synthesized by different synthesis techniques including solid-state reaction, sol-gel, high energy ball milling, hydrothermal method, spray pyrolysis, etc. Among these synthesizing methods, the solid-state reaction method is the most commercially available process. It is very important to reduce calcination temperature and time in mass production using solid-state reaction. We prepared several sets of LTOs using commercially available precursors (TiO2) which have various particle sizes. We also varied calcination temperature in each fixed TiO2 particle size. We found the optimum process condition that has the best electrochemical properties. The sizes of the TiO2 precursors are 15 nm, 25 nm, 32 nm, and 40 nm. The calcination temperatures are 700 °C, 750 °C, 800 °C, and 850 °C. The calcination time (36 hr) is too long to prepare single phase LTO at 700 °C. The single phase LTOs are obtained in all the size of the used TiO2 particle at 800 °C and 850 °C, but the LTO particles are 1 ~ 2 um, which is too large. The pure LTOs are synthesized in all the TiO2 particle size except for 15 nm at 750 °C. The calcination time was varied from 36 hr to 1hr.
The rate performance is conducted in all the fabricated samples. When the calcination time is 36hr, the best capacity is obtained in the sample, which 32 nm TiO2 particle is used. At 50 C, the capacity of the sample was 88 mAh/g when the 32 nm TiO2 precursor is used. The synthesized LTO at 750 °C shows best capacity of 122 mAh/g when the calcination time is 1 hr. The best electrochemical performance was due to small particle size, resulting in fast Li-ion diffusion and larger contact area between particles. We also fabricated Li-ion capacitor using the LTO and investigated the electrochemical behaviors.
Improving Lto Performance: Cold Crank, Gassing and Life Studies
Authors: Margez Carine L , Tan Bing , Greszler Thomas A 
Published: February 2020

SAFT America is developing an LMO/LTO lithium ion cell design for vehicle application in collaboration with U.S. Advanced Battery Consortium (USABC) .
The first two targets set by SAFT are meeting cold crank requirements at -30°C set by USABC and solving gassing issues.
Different electrode formulations, electrolytes and cell designs have been investigated to successfully pass cold crank testing. A specific non carbonate electrolyte satisfies cold crank requirements down to 15% state of charge. Moreover new electrode formulations may potentially help meet cold crank requirements using carbonate electrolytes.
In addition, SAFT will share the outcome of recent electrolyte screening, cycle life improvement and impedance growth reduction experiments. From the results, the gassing mechanism of LTO can be inferred and will be discussed.

Figure 1
Failure Evaluation of Li-Rich Cathode Li-Rich Cathode (Li[NixLi(1-2x)/3Mn(2-x)/3]O2) Materials In Novel in-Situ electrochemical Mass Studies of Lithium Ion Battery
Authors: Wang Fu-Ming , Yeh Nan-Hung 
Published: February 2020

In the presence of literatures [1-4], high-voltage (> 4.8V; 5V class) Li-rich layer compounds (Li[NixLi(1-2x)/3Mn(2-x)/3]O2) have been reported to the next candidate of cathode materials in order to increase the power and energy density instead of LiCoO2 or LiNixMnyCozO2 conventional materials. These high-voltage Li-rich layer materials dedicate their high reversible capacities more than 270 mAh g-1, which is almost twice as higher as LiCoO2. However, this material suffers dramatically challenge due to the irreversible phase change in the first charge. Several studies had discussed the failure mechanism of this high voltage material; however, those comments are different. Mantia et al. [1] have demonstrated direct evidence of oxygen evolution from the Li-excess material at high potentials by in situ differential electrochemical mass spectrometry (DEMS) as well as Hy et al. [2] shown an oxygen activation occurs following electrochemical reaction and forms an irreversible formation of Li2O by surface enhanced Raman spectroscopy (SERS). In Jiang’s result [3], they are unable to detect any oxygen in their ex situ observation. Their XRD pattern and 6Li MAS NMR spectrum comment O2- loss is accompanied with the electrolyte to form CO2.
In our novel in-situ gas evolution experiment, we showed that there are two reaction mechanisms in the first charge process in Figure 1. In the first reaction mechanism, the CO2 (m/z 44) and CO (m/z 28) generate drastically at the potential of 4.25V. In comparison with cyclic voltammogram (CV) (not shown in here), the potential of 4.25V is indicated to the reaction of Ni3+/Ni4+; therefore, the gas evolution at this stage can be concluded the electrolyte is partially decomposed with the catalyst of Ni3+/Ni4+ and the oxygen evolution is not correlated. Second reaction mechanism starts at 4.65V, the CO2forms solely in accompanied with oxygen evolution (m/z 32) from cathode material. Above result indicates that the second reaction mechanism is lead by the oxygen evolution and further reacts with electrolyte.
In this research, we establish a novel in-situ observation for evaluating gas evolution and define the reaction mechanisms of high voltage cathode material.

Reference

[1] F. La Mantia, F. Rosciano, N. Tran, P. Novak, J. Appl. Electrochem. 38 (2008) 893
[2] Sunny Hy, Felix, John Rick, Wei-Nien Su, Bing Joe Hwang, J. Am. Chem. Soc. 136 (2014) 999
[3] Meng Jiang, Baris Key, Ying S. Meng, and Clare P. Grey, Chem. Mater. 21 (2009) 2733

Figure 1
Locally Structural Evolution of Silicon Anode in Lithium-Ion Battery Investigated By in-Situ Synchrotron X-Ray Diffraction and Absorption Spectroscop
Authors: Chen Shi-Wei , Chen Tsan-Yao , Lee Ching-Yun 
Published: February 2020

With the possible exhaust of fossil oil, effective utility of energy becomes an important issue, clean energy and rechargeable energy are thus highly developed. In which, rechargeable lithium-ion batteries attract much attention because of its extensive use such as portable electronic devices, powering hybrid electric vehicles (HEV) and zero-emission vehicles (ZEV). While, capacity and charging rate are needed to be highly improved for the utility in practice. Advancing battery with silicon anode thus becomes increasingly emphasized in the recent years because of the ultra-high theoretical capacity. But the dramatic volume expansion of silicon anode hinders its real utility. Lots of studies focus on this phenomenon and try to overcome this issue with specific design of nano-structure and so on. But one can’t get constant rule to stabilize silicon anode because the real mechanism of volume expansion has not been explored in detail. We thus intend to explore the structural evolution of silicon anode in detail by in-situ charging/discharging synchrotron x-ray techniques, to dig out the mechanism of volume expansion in silicon anode, in this study.
Initially, hollow silicon spheres are synthesized by the reduction of SiO2 surface and selective corrosion. After the measurements of CV, capacity and life time, in-situ charging/discharging synchrotron x-ray diffraction and absorption spectral analyses are used to probe structural variation in silicon anode. At the first cycle of lithiation, silicon structure gradually transforms from crystalline to amorphous and finally changes to Li15Si4 alloy phase. The created defects in silicon anode contribute to the structural disintegration and reconstruction as indicated by the x-ray line profile analysis. The change in local structure can also be evidenced by x-ray absorption near edge spectroscopy (XANES). Lithium ions cause Si-Si bond-breaking and result in the formation of identical short range ordering of Li15Si4.
With the macro and micro analyses of structures, volume expansion of silicon anode with phase transformation has be expounded in detail. Results in this study could be the fundamental to design silicon anode with stable structure, facilitating the utility of Li-ion battery with ultra-high capacity in practice.
Synthesis LiMn0.7Fe0.2Ni0.1PO4 and Carbon Coating with Cassava Powder and Citric Acid as Carbon Source
Authors: Prihandoko Bambang 
Published: February 2020

Lithium ion battery has high energy density. LMPO4 is a cathode active material with good performance and almost commercial battery in the world. The substitution of Fe and Ni was used in synthesis of LiMnPO4 with composition of LiMn0.7Fe0.2Ni0.1PO4 . In this experiment LiMn0.7 Fe0.2 Ni0.1PO4 was carried out with stoichiometric composition of technical raw materials, MnO2 and Fe2O3 from China, Ni from Merck, H3PO4 and LiOH.H2O from Germany. After calcinations process at 7000C in 2 hours and sintering 8000C in 4 hours by powder metallurgy method, the powder was milled and mixed in shaker mill with tapioca or cassava powder under comparison between tapioca and active material 1:7, 1:8, 1:9 in 1 hour. The mixed powder was heated at 8000C in 2 hours under nitrogen gasses. The heated powders was mixed with citric acid and was heated again at 8000C in 2 hours under nitrogen gasses. The produced powder was analyzed the characteristic of crystal structure, SEM, conductivity, cyclic voltammeter and charge – discharge. The produced powder has black color under coated carbon. The crystal structure of LiMn0.7Fe0.2Ni0.1PO4 \C has a base olivine structure of lithiophilite.

Keywords:

cathode, LiMnPO4, lithium battery, powder metallurgy, tapioca
Comparaison of Electrochemical Performances of Al Doped ZnO/Graphene Composites As Anode Materials for Lithium Ion Batteries
Authors: Benabdallah Omar , Edfouf Zineb , Lallaoui Abdelfettah , Abd-lefdil Mohammed , Saadoune Ismael , Cherkaoui El Moursli Fouzia 
Published: February 2020

Recently, many efforts have been deployed to develop new electrode materials for lithium ion batteries (LIBs) in order to meet the growing demand for higher energy density and stronger cyclic stability. Among these materials, zinc oxide (ZnO) as anode has attracted a particular attention due to the natural abundance, low cost, facile preparation and chemical stability. Besides, it has a theoretical capacity of 987 mAh/g, much higher than that of the conventional graphite anode (370 mAh/g). However, ZnO suffers from large volume variations during charge/discharge processes resulting on a severe capacity degradation and reduced cycle life [1]. To overcome these limitations, metal doping and composite synthesis with highly conductive matrix such as graphene have been used to improve the electrochemical performances of ZnO anode [2,3].
In this study, zinc oxide (ZnO), ZnO/Graphene composite (ZnO/G), aluminium doped ZnO (AZO) and AZO/Graphene composites (AZO/G) were prepared by sol gel method and utilized as anode material for lithium-ion batteries. Samples were characterized by several methods such as X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron spectroscopy (SEM), and transmission electron microscopy (TEM). Electrochemical properties were investigated by cyclic voltammetry and galvanostatic cycling tests.
The effect on the ZnO structure by aluminium doping with different concentrations is observed in the figure attached. This results in an advanced performance with reversible lithium storage capacities compared to the pure ZnO. Moreover, to improve its electrochemical performances, AZO was uniformly dispersed on graphene sheets and the electrochemical properties exhibit higher reversible capacities, better cycle performances and rate capabilities than ZnO, ZnO/G and AZO. The higher performances of this composite may be attributed to the graphene encapsulation, which enhances the electrical conductivity, avoids the aggregation and stabilizes the structure of AZO nanoparticles during cycling.
This communication will compare results obtained from the four samples and evidence the effect of aluminium and graphene added to ZnO anode material.

References

[1] J.P. Liu, Y.Y. Li, R.M. Ding, J. Jiang, Y.Y. Hu, X.X. Ji, Q.B. Chi, Z.H. Zhu, X.T. Huang, J. Phys. Chem. C 113 (2009) 5336-5339.
[2] G.L. Xu, Y. Li, T. Ma, Y. Ren, H.H. Wang, L. Wang, J. Wen, D. Miller, K. Amine, Z. Chen, PEDOT-PSS coated ZnOC hierarchical porous nanorods as ultralong-life anode material for lithium ion batteries, Nano Energy, 18 (2015) 253–264.
[3] L. Zhang, J. Zhang, Y. Liu, S. Guo, Effect of aluminium doping amount on the electrochemical properties of ZnO nanoparticles as anode for lithium ion batteries, Micro & Nano Letters, IET, 10 (2015) 217-219.

Figure 1
Reversible Li Insertion Studies on V4O3(PO4)3 As High Energy Storage Material for Li-Ion Battery Applications
Authors: Satyanarayana Maddukuri , Rao R.S , Varadaraju U.V , Pralongb Valerie 
Published: February 2020

Lithium containing metal phosphate LiFePO4, LiMnPO4, Li3V2(PO4)3 etc. were explored as a thermally stable electrode materials results from bonding of oxygen to phosphorous stabilizes the structure from oxygen evolution contradict to layered transition metal oxides at high charge voltages. Li2FeP2O7 and Li2MnP2O7 were explored for 2-electrons transfer at high voltage region. Lipscombite related family of Fe1.37(PO4)(OH) and Fe1.19(PO4)(OH)0.57(H2O)0.43 have been studied for lithium batteries by yanning song et al., which shows reversible capacity of 150 and 100 mAh/g respectively, at current density of 0.5 mA/cm2. In the Present study, we synthesized crystalline orthorhombic V4O3(PO4)3phase related to libscombite/lazulite structure family by solid state reaction method. Reversible Li- insertion studies were performed on this phase in different voltage windows using galvanostatic and cyclic voltammetry unit.
Electrochemical insertion of lithium into V4O3(PO4)3 versus lithium metal as reference electrode was studied. 5.8 Li ions intercalation/f.u. and 4.2 Li ions de-intercalated/f.u. are obtained for 1st cycle with 3.9 Li ions reversible de-intercalation or intercalation/f.u. (195 mAh/g) up to 20 cycles at C/5 rate in the voltage window of 1 – 4 V. In the voltage range of 0.5 – 4 V at C/3 rate reveals 9.8 Li ions intercalation/f.u. and 6.8 Li ions de-intercalated/f.u. Ex-situ diffraction data conducted on discharged and charged electrode material in the voltage range of 1 – 4 and 0.5 – 4 V vs. Li+/Li indicates that phase change occurred after interaction of 2.5 lithium ions per formula unit which is corresponding to initial discharge voltage slope plateau obtained at 2.4 V vs. Li+/Li. On further interaction and de-interaction of lithium ions solid solution behaviour is observed. The obtained results will be presented in the presentation.
Applications of Calorimetry to Safety and Performance Testing of Lithium Batteries
Authors: Rachford Jeffrey , Montgomery Danny 
Published: February 2020

The poster gives a brief oversight into several key areas of application of calorimetry in relation to safety and performance testing of batteries and modules.
This testing results presented specifically apply to secondary lithium-based cells, which due to their high energy density provide the best solution to electrical energy storage in electric vehicle and other high-demand applications.
Performance testing examines the thermal response of the battery while charging and discharging, as well as finding the fundamental thermal property of average heat capacity which can be used in computer modelling. Performance testing can also help establish the operational limits of the battery, such as minimum and maximum operating temperatures, charging rates or battery life.
Safety testing involves taking the battery beyond these safe operating limits and introducing conditions that will prevent further operation of the battery due to damage. The types of abuse are often based on standard protocols and are those that a battery might rarely be exposed to in the event of damage or system failure.
These abuse tests can be further divided depending on the type of abuse; physical such as crushing, piercing etc, electrical such as overcharging or short circuiting, or thermal, which is the “original” ARC method of increasing the temperature in steps until self-heating of the sample occurs.
NaxVxTi1-XO2 (x = 0.6 - 1.0) Phases for Na-Ion Battery Electrode Materials
Authors: Fielden Ryan I , Cole Laura , Obrovac Mark N 
Published: February 2020

Introduction

Due to the high cost of lithium-ion batteries and potential limited accessibility of lithium reserves, sodium-ion batteries have emerged as an alternate battery chemistry [1]. Sodium-ion batteries trade lithium ions for sodium ions while retaining the rocking chair like mechanism for electrochemical transport. The advantage of using sodium instead of lithium is its low cost, which is largely due to its widespread availability. Titanates have been investigated for use as anode materials in Na and Li cells. Recently and new family of titanates, NaxMyTi1-yO2 (M = Li, Ni, Co, or Cr), have been reported. These materials show remarkable low voltage cycling stability [2-5]. Herein another member of this family, namely the NaxVxTi1-xO2 (0.6 ≤ x ≤ 1) series, was studied for use as an anode material in sodium-ion batteries.

Experimental

Samples were synthesized via high energy ball milling of Na2CO3, V2O3, and TiO2 then heating pellets to 950 °C for 6 hours in an argon/H2:95/5 atmosphere. A 10 % Na excess was added due to the volatility of Na at these elevated temperatures. Samples for X-ray diffraction measurement were loaded under argon into an air-tight sample holder with an aluminized Mylar window. Electrodes comprising NaxVxTi1-xO2, carbon black and PVDF binder were cast using NMP as a solvent and dried at 120°C. Electrodes were cycled in 2325 coin type cells at a rate of C/10 (assuming a 100 mAh/g capacity) using Na metal counter/reference electrodes and 1M NaPF6 in PC electrolyte.

Results and Discussion

Figure 1 shows the XRD patterns of the as synthesized NaxVxTi1-xO2 (0.6 ≤ x ≤ 1) materials. They all have layered type structures. Electrochemical measurements showed that these materials can intercalate Na in bulk particles at low voltages and with very low hysteresis. Figure 2 shows the voltage profile of the x = 0.66 material for the first cycle and a half. These materials have substantial low voltage capacity and remarkably low hysteresis, as shown in Figure 2. As such they are promising candidates for Na-ion battery negative electrodes. Structural changes and stability during cycling, for different cut-off voltages, will be discussed.

References:
[1] D. Kundu et al., Angew. Chem. Int. Ed. Engl., 54 (2015) 3431-3448.
[2] R. Fielden, M.N. Obrovac, J. Electrochem. Soc., 161 (2014) A1158-A1163.
[3] Y. Wang et al., Nature Comm., 6 (2015) 6954-6962.
[4] H. Yu et al., Angew. Chem. Int. Ed. Engl., 53 (2014) 8963-8969.
[5] Y. Wang et al., Nature Comm., 4 (2013) 1-7.

Figure 1
Mxene: Novel Negative Electrode Materials for Sodium-Ion Batteries
Authors: Okubo Masashi , Wang Xianfen , Kajiyama Satoshi , Iinuma Hiroki , Hosono Eiji , Oro Shinji , Moriguchi Isamu , Yamada Atsuo 
Published: February 2020

Recently, urgent concerns over lithium resources have focused attention on Na-ion batteries owing to the abundance and low cost of sodium. However, the presently-considered negative-electrode materials for Na-ion batteries are Na-ion intercalation (carbon compounds, metal oxides and metal sulfides), alloying (phosphorus and tin) or conversion materials (metal oxides and metal sulfides), the energy and power densities of which are not satisfactory if the Na-ion batteries were to outperform the state-of-the-art Li-ion batteries. Hence, exploration for novel negative electrode materials of sodium system is primarily important.
We have targeted MXenes as potential electrodes for sodium system. MXenes have been developed as a novel family of nanosheet compounds, which are chemically derived from layered Mn

+1
AXn
or MAX phases (M: early transition metal, A: A-group element, and X: C and/or N). As the MXene has both a high electrical conductivity and interlayer porous space, its application to Na-ion battery negative electrodes holds great promise.
In this presentation, we report on Ti
n

+1C
n
T
x
as negative electrode materials for Na-ion batteries. Ti
n

+1C
n
T
x
consists of abundant and low-cost elements, enabling fabrication of sustainable energy sources. We demonstrate that Ti2CT
x
exhibits a reversible capacity of 175 mAh/g at the average potential of 1.3 V vs. Na/Na+. Furthermore, the prototype full cell consisting of alluaudite Na2Fe2(SO4)3-Ti2CT
x
delivers a high specific energy of 260 Wh/kg at a high specific power of 1.4 kW/kg based on the weight of Ti2CT
x
. Using various experimental and theoretical analyses, we clarify that the Ti
n

+1C
n
T
x
electrodes allow Na-ion batteries to be liberated from the trade-off between high energy and high power.
[Reference]
X. Wang, et al., M. Okubo, & A. Yamada, Nat. Commun., 2015, 6, 6544.

Figure 1