bluuebunny/crossref_metadata_2025_split huggingface dataset:
Porous Li-Rich Cathode Material with Carbonaceous Modified Surface for High Performance Lithium Ion Batterie
Authors: Li Jie , He Xin 
Published: February 2020

Li-rich layered oxides (Li1+zMnx
NiyCo1-x-y
O2) are considered as a most promising family of intercalation cathode materials for rechargeable lithium batteries, due to the advantages of high discharge capacity and high specific energy. Coupled with other benefits like high safety, low toxicity and costs, Li-rich materials are currently significantly attractive for high-power applications. However, weaknesses like intrinsic poor rate capability, dramatically decrease in the discharge potential plateau, irreversible volume expansion and capacity fade during long-term cycling are bringing up concerns about their practical utilization, which need to be surmounted.
Morphology tailoring is considered to be an efficient way to address these issues. It has been proved that the particle size, crystallinity and structural morphology have obvious effects on electrochemical performance of electrode materials. In order to improve the electrochemical performance of Li-rich, the special morphology of the material, with extra space between particles to buffer the volume change and the modified surface to enhance the electronic conductivity, was synthesized in this work.
Specifically, high crystallinity Li1.2Mn0.56Ni0.16Co0.08O2 Li-rich porous materials integrating with an in-situ formed surface containing carbonaceous compounds are obtained through a novel facile approach. The rationally designed procedure involves the formation of a specific morphology of a hydroxide precursor assisted by a self-made template and subsequent high temperature treatment. The porous morphology is investigated using field-emission scanning electron microscopy and its surface area quantitatively examined by gas sorption analysis couple with the Brunauer-Emmett–Teller method. The porous morphology can be viewed from SEM image (Figure 1a), and it owns large surface area which is five time more than the sample in the normal shape. The crystallinity is characterized by X-ray diffraction and high-resolution transmission electron microscopy. X-ray photoelectron spectroscopy, CHN element analysis confirm the presence of the carbonaceous compounds in the surface composition. The prepared material exhibits superior discharge rate capability and excellent cycling stability. It shows minor capacity loss after 100 cycles at 0.5 C and maintains 94.9% of its initial capacity after 500 cycles at 2 C. Even more notably (Figure 1b), the “voltage decay” during cycling is also significantly decreased. It has been found that carbonaceous compounds play a critical role for reducing the layered to spinel structural transformation during cycling. Therefore, the present porous Li-rich material with surface modified a carbonaceous compounds represents an attractive material for advanced Lithium-ion batteries.

Figure 1
Pseudocapacitive Negative Electrodes Based on Mxene Ti2CT
x
for High-Power Li-Ion Batteries
Authors: Kajiyama Satoshi , Iinuma Hiroki , Lucie Szabova , Sodeyama Keitaro , Sugahara Akira , Gotoh Kazuma , Tateyama Yoshitaka , Okubo Masashi , Yamada Atsuo 
Published: February 2020

Development of rapid charging systems in Li-ion batteries is one of the urgent tasks for the widespread use of environmental-friendly electric vehicles towards a sustainable and green society. However, in spite of numerous efforts devoted to realizing the high-power systems, their power density is not satisfactory, partly due to the poor rate capability of the negative electrodes.
A novel family of layered compounds, MXene (M
n

+1X
n
T
x
: M = Ti, V, Nb, etc.; X = C, N; n = 1-3; T = surface termination groups) has attracted increasing attention as negative electrode material with high-rate capability for Li-ion batteries.[1] MXene is the derivative phase of ternary layered compounds, MAX phase (M
n
AX
n
: A = Al, Si, S, etc.), first synthesized with concentrated hydrofluoric acid (HF) solution to extract selectively the A element.[2] Due to the tunable compositions and structures in MXene, there are huge choices for the development of the high-power electrode materials. Gogotsi and colleagues have recently discovered that lithium fluoride (LiF) and hydrochloric acid (HCl) solution also selectively extracts the A element from MAX phase, and Ti3C2T
x
synthesized with the LiF and HCl solution exhibits higher performance as pseudocapactior in aqueous systems than HF-synthesized Ti3C2T
x
.[3]Therefore, the synthetic method for MXene is a key process to determine its electrochemical property.
In this work, we have successfully synthesized Ti2CT
x
with the LiF and HCl solution. The charge-discharge measurement reveals that the Ti2CT
x
delivers large reversible capability of 260 mAh/g in 1M LiPF6/EC-DMC (1:1, v:v) electrolyte, which is larger than that of Ti2CT
x
prepared with concentrated HF solution (180 mAh/g).[4] Reaction mechanism was investigated with combined approach using XANES, XRD, and 7Li-MAS-NMR. We construct the prototype full cell with the Ti2CT
x
and LiNi1/3Co1/3Mn1/3O2 negative/positive electrodes, and demonstrate that the Ti2CT
x
is the promising electrode material for the high-power Li-ion batteries.
[1] M. R. Lukatskaya, et al. and Y. Gogotsi, Science
341, 1502 (2013).
[2] M. Naguib, et al. and M. W. Barsoum, Adv. Mater.
23, 4248 (2011).
[3] M. Ghidiu, et al. and Y. Gogotsi, Nature
516, 78 (2014).
[4] J. Come, et al. and P. Simon, J. Electrochem. Soc.
159, A1368 (2012).
Figure 1. Charge-discharge profile of Ti2CT
x
in 1M LiPF6/EC-DMC (1:1, v:v) electrolyte and comparison in the rate capability synthesized with different solutions.

Figure 1
Characterizing Aging Behavior in Li-Ion Batteries Using Micro-XRF
Authors: Boesenberg Ulrike , Michalak Barbara , Ravnsbaek Dorthe Bomholdt , Falk Mareike , Garrevoet Jan , Fittschen Ursula E. A. , Janek Jürgen , Falkenberg Gerald 
Published: February 2020

Aging in Li-ion batteries is accompanied by structural and compositional changes of the active and passive material of the electrodes. Visualization of spatial correlation between morphological properties and chemical phase can help to find origins of aging and failure mechanisms and to understand the ongoing processes. Micro X-ray fluorescence (XRF) analysis allows for chemical imaging of elemental distributions of multiple 3d elements simultaneously, or distribution of the state of charge even at low concentrations or under operando conditions. Utilizing focused synchrotron radiation, representative volumes of the electrodes can be studied with sub-micrometer resolution on acceptable time scales.
Cutting edge instrumentation in this field is the Maia fluorescence detector. It allows for ultra-fast mapping of areas of multiple mm² with high spatial resolution within minutes. This allows e.g. examination of large electrode areas. The backscattering geometry of the detector enables easy mounting of flat samples such as electrodes or pouch-cells. By variation of the energy in the vicinity of an absorption edge, conclusions on local variations of the state of charge can be drawn, probing the oxidation state of the redox-active element. Furthermore, confocal XRF enables spatially resolved measurements of the deposition of transition metals on the graphitic anode without destruction. This will help to understand the impact on capacity fade and degradation.
For the present study, samples of LiNi0.5Mn1.5O4 electrodes cycled vs. Li or graphite were investigated at beamline P06 at DESY, Hamburg Germany.1 The experiment revealed significant inhomogeneities in the local Ni/Mn ratio upon cycling which is correlated to thinning of the electrode. Higher cycling rates showed an increased impact and higher material losses. Inhomogeneities in the phase transformation were also found during the charge and discharge process. The graphitic anodes showed significant amounts of deposited transition metals, few wt%, both Ni and Mn, deeply penetrating into the pores of the electrode. On the other hand, a study on commercial LiFePO4 cathodes with outstanding rate capabilities showed an extremely high degree of homogeneity throughout the investigated areas. These methods are by no means limited to the investigated materials, but are easily transferred to other transition metal containing electrode materials.
1. U. Boesenberg et al., Chem.Mater., 27, 2525–2531 (2015)
Process R&D and Scale-up of Advanced Battery Materials at Argonne's Materials Engineering Research Facility
Authors: Krumdick Gregory , Shin Youngho , Kahvecioglu Feridun Ozgenur , Pupek Krzysztof Z. , Dzwiniel Trevor L 
Published: February 2020

Argonne's Materials Engineering Research Facility (MERF) supports the laboratory's Advanced Battery Materials Synthesis and Manufacturing R&D Program. The MERF is enabling the development of manufacturing processes for producing advanced battery materials in sufficient quantity for industrial testing. The engineering research conducted in this program is known as process scale-up. Scale-up R&D involves taking a laboratory-developed material and developing a safe, reliable and economical commercial-scale process. This represents one of the most significant hurdles in transitioning new battery materials and technologies to the market. By bridging the gap between small-scale laboratory research and high-volume battery manufacturing, research at the MERF will lead to substantial progress in the development, validation and ultimate commercialization of advanced battery materials chemistries. In addition, advanced manufacturing processes are investigated to determine performance and cost benefits to material production. Advanced materials produced are then made available to the battery research community to further their work using high quality, standardized baseline materials. An overview of the program will be given as well as a summary of current scale-up projects.
High Performance Separator Coated with Amino-Functionalized SiO2 Nanoparticles for Safety Enhanced Lithium-Ion Battery
Authors: Cho Jinhyun , Shin Won-Kyung , G Kannan Aravindaraj , Kim Dong-Won 
Published: February 2020

The use of lithium-ion batteries has been rapidly expanding in portable electronic devices, electric vehicles and energy storage systems due to their high energy density and long cycle life. In lithium-ion batteries, a separator is a critical component which prevents physical contact of the positive and negative electrodes while permitting free ionic transport within the cell. Most of the separators currently used in lithium-ion batteries are based on microporous polyolefin membranes such as polyethylene (PE) and polypropylene (PP) as well as various combinations of the two [1,2]. Although these separators offer excellent mechanical strength and chemical stability, they shrink and even melt at high temperatures, which causes short circuit between electrodes in the case of unusual heat generation. Furthermore, the large difference in polarity between the non-polar polyolefin separator and the polar organic electrolyte leads to poor wettability. In order to solve these problems, ceramic-coated separators have been developed by combining the characteristics of a polymeric separator and ceramic materials.
In this study, we tried to improve the thermal safety and cycling performance of lithium-ion cells by using separators coated by amino-functionalized SiO2 (A-SiO2) nanoparticles. These separators exhibited enhanced thermal stability and melt integrity. Due to the high affinity of A-SiO2
with liquid electrolyte, the A-SiO2
coated separators exhibited good wettability and high ionic conductivity. Furthermore, A-SiO2 nanoparticles played a role as HF scavenger, which suppressed HF generation and electrolyte decomposition at elevated temperature. As a result, the lithium-ion cells assembled with A-SiO2
coated separator exhibited the improved cycling performance at both ambient temperature and elevated temperature.

References

[1] P. Arora, Z. Zhang, Chem. Rev. 104 (2004) 4419-4462.
[2] S.S.Zhang, J. Power Sources 164 (2007) 351-364.
Influence of Aging on Heat-Release of Lithium Ion Battery Under Adiabatic Conditions
Authors: Luo Ying , Lu Taolin , Yan Liqin , Xie Jingying , Feng Yi 
Published: February 2020

Safety has been the primary issue in the use of the lithium ion technology in high energy and high power applications ranging from power tools to electric vehicles. The safety of lithium ion batteries is mainly derived from the thermal effects of the battery during normal and abnormal operation. Overheating may start exothermal reactions that release even more heat which in turn can lead to an accelerated process called a thermal runaway. In addition to the lithium ion batteries of the body factors (electrode materials [1], membrane [2] and electrolyte [3] and other internal materials) as well as the manufacturing process [4], the battery aging [5] process is also critical to the safety of the lithium ion batteries.
An accelerating rate calorimeter is employed to study the heat release of 5 Ah lithium iron phosphate battery with different aging status under adiabatic condition. We design four aging methods, consisting of cycled at 1 C and 0.5 C, stored at 55 ℃ with SOC 100% and SOC 50%. Thermal behavior of lithium iron phosphate battery charged and discharged at 1C is investigated, and the influence of cycle number, cycle rate, storage time and storage temperature on the overcharge test of lithium iron phosphate battery was studied. The results show that the lithium iron phosphate batteries have no accidents such as leakage, explosion, burning etc, after 600 cycles at 1C or storage for 4 months at high temperature 55 ℃. With the increase of the cycle numbers, the average heat power of the battery charge-discharge and overcharge increases. At the same cycle numbers, the raising range of the temperature and average heat power of the battery cycled at 1 C is decreased, compared with that of battery cycled at 0.5 C. With the increase of the storage time at the high temperature, the average power of the battery charge-discharge and overcharge increase as well. Furthermore, The raising range of the temperature and average heat power of the lithium iron phosphate battery with 100% SOC full power of the battery is smaller than that of battery with 50% SOC. This work was supported by National 863 Program (No. 2013AA050902) and Shanghai Science and Technology Engineering Research Center Program (No. 13DZ2280200).
Reference
[1] Jiang J, Dahn J R. Electrochemistry Communications, 2004, 6: 39~43.
[2] Chen J J, Wang S Q, Dandan Cai, Wang H H. Journal of Membrane Science, 2014, 449, 169-175.
[3] Tyunina, Yu E, Chekunova, Marina D. Journal of Molecular Liquids, 2013.11, 187: 332~336.
[4] Kise M, Yoshioka S,Hamand I.Electrochemistry, 2004,72(9)：641-646.
[5] Sarre G, Blanchard P, Broussely M. Journal of Power Sources, 2004, 127(1): 65-71.
Sulfide Electrolytes: Study of Local Li-Ion Dynamics in Li3PS4 Using Li(7) NMR Relaxometry
Authors: Prutsch Denise , Brandstätter Harald , Pregartner Veronika , Wohlmuth Dominik , Epp Viktor , Wilkening Martin 
Published: February 2020

The attractive long-term stability and safety of so-called all-solid-state batteries has given new impetus to developing powerful solid Li+ electrolytes. Post Li-ion batteries equipped with solid electrolytes may also be very attractive for hybrid electric vehicles as these systems are expected to withstand high operation temperatures. Moreover, they may serve as attractive components in Li-oxygen and Li-sulfur batteries. In addition to the various oxides and phosphates studied so far, see, e.g., refs. [1,2], sulfide-based materials have attracted particular attention due to their very high ionic conductivities [3,4].
Li3PS4 represents such a promising candidate, since its achievable Li-ion conductivity is comparable to that of liquid electrolytes. Phase-pure Li3PS4 was prepared by joint high-energy ball-milling of Li2S and P2S5 for 35 hours and subsequent heat treatment at 260 °C for 17 hours. X-ray diffraction analysis corroborated the phase purity of the sample prepared. To study the elementary steps of ion hopping in Li3PS4
7Li solid-state nuclear magnetic resonance (NMR) spectroscopy was employed. In particular, we used temperature-variable relaxometry measurements carried out in both the laboratory and rotating frame of reference to shed light on local as well as long-range ion dynamics. Line shape measurements revealed fast Li-ion exchange able to completely average homonuclear dipole-dipole interactions at temperatures much below ambient. This perfectly agrees with a recent NMR study focusing on field gradient experiments [5]. Moreover, it is in line with our spin-lattice relaxation (SLR) measurements performed at low temperatures: From the low temperature flank of the diffusion-induced SLR rates an activation energy as low as 0.1 eV was determined. Such a low value indicates fast, localized Li jumps present in Li3PS4. The high Li+ diffusivity also manifests itself in the appearance of an SLR spin-lock NMR rate peak that shows up well below room temperature.
[1] H. Buschmann, J. Dölle, S. Berendts, A. Kuhn, P. Bottke, M. Wilkening, P. Heitjans, A. Senyshyn, H. Ehrenberg, A. Lottnyk, V. Duppel, L. Kienle, J. Janek, Phys. Chem. Chem. Phys. 13 (2011) 19378
[2] V. Epp, Q. Ma, E.-M. Hammer, F. Tietz, M. Wilkening, Phys. Chem. Chem. Phys., 17 (2015) 32115
[3] M. Tatsumisago, M. Nagao, A. Hayashi, J. Asian Ceram. Soc., 1 (2013) 17
[4] V. Epp, O. Gün, H.-J. Deiseroth, M. Wilkening, J. Phys. Chem. Lett., 4 (2013) 2118
[5] K. Hayamizu, Y. Aihara, T. Watanabe, T. Yamada, S. Ito, N. Machida, Solid State Ion., DOI: 10.1016/j.ssi.2015.06.016
Mechanistic Illustration of Mononitriles Decomposition in Lithium Ambience Encompassing Development of a Dinitrile-Mononitrile Based Electrolyte System for Lithium Batteries
Authors: Rohan Rupesh , Li Chia-Chen , Lee Jyh-Tsung 
Published: February 2020

In the quest of high voltage electrolytes for lithium batteries, we developed a dinitrile based electrolyte, using mononitrile as a co-solvent with 1 M LiTFSI salt, which possesses electrochemical stability above 5.5 V under ambient conditions. It offers ionic conductivity in the order of 10−
3 Scm−
1 at 30 oC, analogous to the carbonate based electrolytes. However, the mononitriles, propionitrile and butyronitrile, decompose readily with lithium metal and form some dimers, trimer crystals and oligomers/polymers. These by-products are well characterized using NMR and single crystal XRD techniques, and a possible mechanism of the decomposition is demonstrated. To overcome the mononitrile decomposition, 5 wt % of vinylene carbonate is added to the glutronitrile/butyronitrile (6/4 ratio) electrolyte system, and several coin cells are fabricated with this electrolyte system using LiFePO4 cathode and Li metal anode. With capacity retention of more than 95%, the cells performs more than 100 cycles at 0.5 C charge/discharge rate and also found capable to perform upto 3C rate. The developed electrolyte system may pave way to use nitriles as the lithium battery electrolytes.

Figure 1
Electrochemical Investigation of Thermodynamic and Transport Phenomena in LP30 Electrolyte with Various Concentrations of Conducting Salt
Authors: Fröhlich Katja , Bimashofer Gesara , Fafilek Günter , Pichler Franz , Cifrain Martin , Trifonova Atanaska 
Published: February 2020

The electrification of mobility has a strong potential to reduce fuel consumption and CO2emissions. This alternative to combustion engines, however, is hampered by battery systems still insufficient in terms of energy, power and lifetime. Therefore it is important to investigate and understand the electrochemical processes and mechanisms that can maximize the power-to-energy ratio. The electrolyte plays an important role for the efficient operation of the battery. For example, electrolytes with low lithium-ion transport numbers and salt diffusion coefficients cause large concentration polarizations during operation of Li-ion batteries. This leads to poor high-rate performance, unwanted side reactions and ageing. It is therefore important to characterize and model the transport phenomena in electrolytes under battery operation conditions.
There are numerous experimental methods that can be used to characterize the thermodynamic and transport phenomena in electro-diffusion processes (e.g. NMR, Raman spectroscopy, etc.), but the electrochemical methods are more powerful, as they can mirror the relevant working processes occurring in a battery.
In the presented work, the electrolyte characteristics such as viscosity, conductivity, diffusion coefficients of lithium ions and transfer numbers are determined for various LiFP6concentrations. Conductivity was measured by alternating current technique (PEIS and test cell with Pt-electrodes); the transfer numbers were obtained from the diffusion technique (concentration cell) and the diffusion coefficient was determined by the rotary disk electrode method and also calculated from conductivity measurements. Additionally, the temperature dependence of the studied properties was taken into account. The results were further used for the modelling of the mass transport processes in the real cell. The analysis of mass transport phenomena over a range of salt concentrations will be shown and discussed.
Acknowledgement
The authors would like to thank the Austrian Federal Ministry for Transport, Innovation and Technology (bmvit) and the Austrian Research Promotion Agency (FFG) for their financial support.
Interfacial Chemistry and Mechanics of Fluoroethylene Carbonate (FEC)-Derived Electrode/Electrolyte Interfaces
Authors: Shin Hosop , Park Jonghyun , Lu Wei 
Published: February 2020

Fluoroethylene carbonate (FEC) has been commonly used as an electrolyte additive to improve the stability of the solid electrolyte interphase (SEI) at silicon and graphite-based anodes. Although the impact of FEC is well known, there is still lack of understanding how FEC has influence on interfacial chemistry and mechanics at the anode/electrolyte interface. In addition, relatively little attention has been paid to understanding of the effects of FEC on the cathode side.
In this work, we symmetrically investigated the effects of FEC on the graphite/electrolyte and LiMn2O4/electrolyte interfaces at room and elevated temperatures and revealed associated interfacial chemistry and mechanics at the interfaces, using various electrochemical and material characterizations.
We demonstrated that FEC has different effects on the interfacial behavior of the anode and the cathode. In the anode side, the SEI layer derived from FEC exhibited lower interfacial resistance and excellent thermal stability, showing excellent rate capability and improved cycle retention of cells. While the chemical and mechanical instability of the SEI layer were overcome by using FEC additive in the electrolyte, adverse effects of FEC on the cathode side were observed, especially at elevated temperatures. Poor cycling retention and a rapid increase in the interfacial resistance of the cathode were observed at elevated temperature. The poorer performance of the cathode in the FEC-containing cell at elevated temperature was attributed to the formation of a thicker surface layer and to increased Mn dissolution catalyzed by hydrofluoric acid (HF), which resulted from FEC dehydrofluorination initiated or accelerated by elevated temperature. Accordingly, it is suggested that the amount of FEC in a full cell must be optimized to minimize the adverse effects of FEC on cathode.
Based on this work, the necessity of evaluating the effects of the electrolyte additive used on the cathode side should be emphasized in order to further improve the thermal stability of Li-ion batteries.