bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of High Performance LiMn2O4 Thin Films for Nanoscale Batteries
Authors: Put Brecht , Labyedh Nouha , Radu Iuliana P. , Huyghebaert Cedric , Vereecken Philippe M. , Stesmans Andre 
Published: February 2020

Three-dimensional (3D)Li-ion batteries hold the potential to revolutionize the battery landscape. They are expected to provide a high power output and at the same time a large capacity. The potential for high power is related to the fast kinetics associated with thin film materials, while the high capacity may be provided by the large volume of active material1.
One of the best characterized high voltage battery electrodes is LiMn2O4
2.Until now, in order to attain sufficient capacity, powders of relatively thick layers of material with bulk properties were the focus of attention. However, by using 3D substrates the need for thick films to obtain high capacity is relieved, since the capacity is proportional to the area enhancement created by the 3D substrate.
In this work we report on the evaluation of ultra-thin (25-100 nm) LiMn2O4 layers. The material was deposited by RF-sputtering on a Pt substrate. Subsequently, the layers were annealed at 800 °C. Crystallinity and morphology were investigated using x-ray diffraction (XRD) and scanning electron microscopy. Even the thinnest layers (25 nm) were closed and highly crystalline. The stoichiometry of the material has been determined by a combination of elastic recoil detection and X-ray photoelectron spectroscopy (XPS) measurements.
The electrochemical properties of the films were evaluated using a three electrode electrochemical cell. Cyclic voltammetry of all films showed characteristic Li insertion and extraction peaks around 4 V and 3 V vs Li+/Li. Both the cyclability and
rate-performance of the films were investigated by charge/discharge experiments. Cyclability of LiMn2O4/LiPON half cells were also probed.
All films reached 100 % of the theoretical capacity. The 25nm films showed the best rate performance, retaining over 70 % of the theoretical capacity at 50C as seen in figure 1. This highlights the excellent rate properties of ultra thin films. Further information about the film’s kinetic properties was obtained by using potential dependent impedance spectroscopy3.
The work reported here will give more insight into the properties of ultra-thin films that are expected to be used in 3D batteries. It can also serve as model system for nanoparticle based batteries.

Vereecken et al., ECS transactions, 58 (10), 2013

Thackeray et al., Journal of power sources, 21, 1987

Mohamedi et al., Journal of power sources, 93, 2001
High-Capacity Si Microwire Anode with Enhanced Conductivity
Authors: Quiroga-González Enrique , Föll Helmut 
Published: February 2020

As a potential anode for Li ion batteries silicon has a theoretical capacity of 4200 mAh/g, more than ten times that of standard graphite anodes with a capacity of 370 mAh/g. Microstructured Si in wire-shape overcomes problems caused by its four-fold volume expansion during its lithiation, allowing capacity stability over hundreds of cycles [1].
We have developed a new concept of Si microwire anodes that consists of an array of Si microwires embedded at one end in a Cu current collector [2]. The capacity of the anodes is very stable over 100 cycles [3], and breaks all the records when considering the capacity per area (mAh/cm2) [4]. The mechanical stability of the wires is surprising, since their diameter (» 1 µm) is far larger than what was deemed reasonable (< 300 nm) for avoiding cracking. However, it has been observed that the resistance of the wires is large and may increase after tens of cycles, probably due to a porosification process. Due to the large resistance the voltage limits of the anode (at which the galvanostatic charging/discharging is stopped) are reached fast. The anodes are cycled in a standard way, changing to a potentiostatic mode once the voltage limits are reached, stopping until the current decreases to 10 % of the initial value. The potentiostatic mode is slower than the galvanostatic one, thus the longer the galvanostatic mode lasts, the faster is the cycling. For many applications it is desired to have the possibility of charging/discharging fast.
By chemically coating the wires with a thin granular Cu film of about 20 nm (see Fig.1a), their resistance is decreased. The galvanostatic lithiation is low just for the first cycle, and then it is greatly enhanced from the second cycle (see Fig.1b). The low value for the first cycle occurs because during the first cycle the wires are amorphized, and a solid electrolyte interface is formed, which are slow processes. When the wires are uncoated, it takes more cycles to reach a high value. Further details of the enhancement of conductivity and its effect on the performance of the anodes will be shown in the full paper and at the conference.
[1] C.K. Chan, H. Peng, G. Liu, K. McIlwrath, X.F. Zhang, R.A. Huggins, Y. Cui, Nat. Nanotechnol., 3, 31 (2008).
[2] E. Quiroga-González, E. Ossei-Wusu, J. Carstensen, H. Föll, J. Electrochem. Soc., 158, E119 (2011).
[3] E. Quiroga-González, J. Carstensen, H. Föll, Electrochim. Acta, 101, 93 (2013).
[4] E. Quiroga-González, J. Carstensen, H. Föll, Energies, 6, 5145 (2013).
3M HQ-115 (LiTFSI) Electrolyte Additive Dramatically Improves Battery Performance in Electrolytes Containing Trace Amounts of Water
Authors: Xiao Ang , Eberman Kevin W , Lamanna Bill , Jain Gaurav , Ye Hui , Burns John Chris , Sinha Nupur Nikkan , Dahn Jeff 
Published: February 2020

3M has successfully commercialized lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) (trade name: HQ-115) as an electrolyte additives in commercial lithium ion batteries. Based on our investigations and customer’s feedback, when used as an electrolyte additive, HQ-115 improves cycle life in Graphite/LiCoO2 cells at high temperature. Similar results are obtained in Graphite/MNC cells. Cycle life improvements achieved by adding HQ-115 correlates with reduced cell impedance. HQ-115 also reduces gassing at the negative electrode and can prevent shorting under high temperature float test conditions with single layer PE separator. Thus cell life and safety are improved using HQ-115 as additives in standard electrolyte.
Recent studies by 3M, Dalhousie University, and Medtronic indicate that HQ-115 is a useful additive for maintaining acceptable cell performance under conditions where moisture levels in the electrolyte are elevated. It is interesting that the addition of HQ-115 to either VC+100 ppm water or VC+1000 ppm water cells reduced the cell swelling and impedance rise compared to identical cells without HQ-115, consistent with later long term cycling data at 55oC. Thus HQ-115 additive can enable relaxation of specifications on water in electrolyte. The results reported herein suggest that relaxing specifications on water content in electrolyte with added HQ-115 as additives may be one avenue for cost-reduction of Li-ion cells with graphite negative electrodes. In August 2013, 3M, Dalhousie University, and Medtronic jointly filed a global patent application to cover these new benefits of 3M’s HQ-115 electrolyte additives in lithium ion batteries.
References:

Burns, John Christopher; Dahn, Jeffrey Raymond; Eberman, Kevin Wilmot; Jain, Gaurav; Lamanna, William Mario; Sinha, Nupur Nikkan; Xiao, Ang; Ye, Hui, US Patent Application 61/868043, Lithium Ion Battery Electrolytes and Electrochemical Cells, August 2013
Invited Presentation: US DOE Battery R&D Progress related to Electric Drive Vehicles
Authors: Howell David 
Published: February 2020

The Department of Energy’s Vehicle Technology Office (DOE VTO) is focused on funding high-reward/high-risk research by national laboratories, universities, and industry – to develop low-cost and high-performance batteries necessary for the broad consumer acceptance of hybrid and plug-in electric vehicles (PEV) in the marketplace. In fiscal year 2013 (FY 2013), the DOE VTO battery R&D funding totaled about $88 million. The status of current battery technologies for transportation applications, especially lithium-ion technologies, will be highlighted in this talk and the associated issues will be discussed. Current battery technology performance lies very far below its theoretically possible limit. In the near-term, even for existing lithium-ion technology, there is an opportunity to more than double the battery pack specific energy (from 100 Wh/kg to 250 Wh/kg) by using new high-capacity cathode materials, higher voltage electrolytes, and by replacing graphite anodes with high capacity silicon or tin-based intermetallic alloys. Despite recent promising advances, much more R&D is needed to achieve performance and lifetime requirements necessary for their successful deployment in PEVs. In the longer term, certain “beyond Li-ion” battery chemistries (e.g., lithium-sulfur, magnesium-ion, zinc-air, lithium-air, and other advanced chemistries) offer the possibility of specific energy values significantly higher than those of current lithium-ion batteries and they also show the potential for significantly reducing the battery cost. However, certain major shortcomings in the areas of cycle life, power density, energy efficiency, and/or other critical performance parameters; along with cost, currently hinder the commercial introduction of such “beyond Li-ion” battery systems. Therefore, innovative breakthroughs are needed for these new battery technologies to enter the market. This paper summarizes VTO-supported battery R&D projects for FY 2013 and provides a progress update on them. The research directions being pursued by VTO to develop next-generation lithium-ion batteries and beyond are described, along with a discussion of the current focus on materials development.
Figure: Battery manufacturers derived the above cost projections by using the USABC’s battery manufacturing cost model and assuming an annual production volume of 100,000 batteries per year (for validated battery cell and module designs, meeting DOE/USABC requirements for power, energy, and cycle life).
Invited Presentation: High-Energy Cathode Material for Advanced Lithium-Ion Batteries
Authors: Sun Yang-Kook , Noh Hyung-Joo , Nam Kyung-Wan , Yang Xiao-Qing , Amine Khalil 
Published: February 2020

A great attention has been made on development of lithium-ion batteries with high energy density and long cycle life for automotive applications such as plug-in hybrid vehicles (PHEVs) and electric vehicles (EV). A successful use in the automotive sectors, where both energy density and safety is of great importance, requires further increase in energy density, cycle life, and safety. Meeting this challenge has centered on finding new cathode materials with high capacity and excellent safety which is the major factor deciding for the real battery applications
One of the promising candidates for such batteries, Li[Ni0.8Co0.1Mn0.1]O2 (Ni-rich NCM) and Li[Ni0.8Co0.15Al0.05]O2 (NCA) have been studied extensively for the last decade [1,2]. Though these materials deliver high capacity of 200 mAh g-1 (4.3 V cutoff voltage), they exhibit very poor thermal characteristics and cycling stability, particularly elevated temperature]. One of the most promising oxides is a core-shell (with gradient) [3] or full concentration gradient lithium nickel-cobalt-manganese oxide [4] composed of a Mn-rich outer surface providing excellent safety and Ni-rich center achieving high capacity. This new approach has made it possible to design and develop materials with different gradient compositions and slopes within a particle.
In this presentation, we report a novel cathode material with two slope full concentration gradients (TSFCG) of Ni, Co, and Mn ions extending throughout each particle to increase average active redox species of Ni concentration and the lower Mn concentration in the particle outer surface. The Ni-rich TSFCG delivers a high capacity of more than 200 mAh g-1 (4.3 V cutoff voltage) with excellent cycle life and good thermal properties. Furthermore, the electrochemical and thermal properties of the TSFCG were compared with those of NCA and conventional cathode (C.C.).
References:

Kostecki, R. & McLarnon, F.: Local-probe studies of degradation of composite LiNi0
.
8Co0
.
15Al0
.
05O2 cathodes in high-power lithium-ion cells. Electrochem. Solid State Lett. , 2004, 7, p. A380_A383.

Kim, M.-H., Shin, H.-S., Shin, D. & Sun, Y.-K.: Synthesis and electrochemical properties of Li[Ni0
.
8Co0
.
1Mn0
.
1]O2 and Li[Ni0
.
8Co0
.
2]O2 via co-precipitation. J. Power Sources, 2006, 159, p. 1328-1333.

Sun, Y.-K. Sun, Myung S.-T., Park B.-C., Prakash J., Belharouak I., Amine K.: High-energy cathode material for long-life and safe lithium batteries, Nature Mat., 2009, 8 (4), p. 320-324.

Sun Y.-K. Sun, Chen Z., Noh H.-J., Lee D.-J., Jung H.-G., Ren Y., Wang S., Yoon C. S., Myung S.-T., Amine K.: Nanostructured high-energy cathode materials for advanced lithium batteries, Nature Mat., 2012, 11(11), p. 942-947.
Electrodes for Sodium-Ion Batteries with Excellent Rate Performance Using Porous Carbon Networks
Authors: Yu Yan , Fu Lijun , Zhu Changbao , Li Weihan , Maier Joachim 
Published: February 2020

Recently, sodium ion batteries (NIBs) gained increasing attention, because of its abundant reserves and relatively even geological distribution. However, the development of NIBs is greatly hampered because of the lack of appropriate active materials for both cathodes and anodes. Since the Na ion is ca. 55% larger than the Li ion, finding suitable host materials with sufficiently large interstitial space to accommodate sodium ions and to allow reversible and rapid ion insertion and extraction is very difficult. NASICON-type Na3V2(PO4)3 has recently been considered as a prospective cathode material for NIBs, because of its highly covalent 3D framework crystalline structure, high energy density (~400 Wh/kg) and good thermal stability. For anode materials, disordered carbon is particularly attractive because of their large interlayer distance and disordered structure that could accommodate sodium ions.
Here, we briefly present porous carbon based electrodes for NIBs with excellent rate performance: (1) Carbon-coated nanosized Na3V2(PO4)3 embedded in the porous carbon matrix (abbreviated as CC-NVP@PCM); (2) Nitrogen-doped activated porous carbon fibers (ACFs); (3)Flexible free-standing porous carbon nanofibers (P-CNFs) with three-dimensional (3D) interconnected structure.
The CC-NVP@PCM was prepared by using a facile soft-chemistry based method with post heat-treatment. It shows high rate performance (44 mAhg-1at 200C ). This ultrahigh rate performance is comparable to that of supercapacitor, but with much higher energy density.
The ACFs were synthesized by pyrolysis of Ppy nanofiber precursor. It shows excellent capacity retention and extraordinary rate performance. The reversible capacity at 0.05 Ag-1 is 296 mAhg-1 and could still maintain as 72 mAg-1 at a current of 10 Ag-1.
In case of the P-CNFs electrode prepared by electrospinning, it delivers a reversible capacity of 266 mAh.g-1 after 100 cycles at 0.2C, corresponding to 80.3 % of the initial charge capacity. When cycled at a current density as high as 500 mAg-1 (2C), it still delivers a reversible capacity of ~140 mAh.g-1after 1000 cycles.
The improvement of electrochemical performance of these porous carbon based electrodes for NIBs is attributed to the special design and porous structure, which confined a variety of advantages: hierarchical porous channels enabling short transport length for ions and electrons, carbon coated structure resulting in low resistances, good mechanical properties leading to the excellent morphology stability.
Na-Ion Mobility in Layered Na2FePO4F and Olivine NaFePO4
Authors: Wood Stephen M , Tripathi Rajesh , Nazar Linda F , Islam M. Saiful 
Published: February 2020

Materials for sodium-ion batteries are attracting renewed interest. Olivine NaFePO4 and layered Na2FePO4F are interesting materials that have been reported recently as possible positive electrodes. Here, we report their Na-ion conduction behaviour and intrinsic defect properties using atomistic simulation methods.[1,2] In the NaFePO4 olivine, Na ion migration is essentially restricted to the [010] direction along a curved trajectory, similar to that of LiFePO4, but with a lower migration energy. However, Na/Fe antisite defects are also predicted to have a lower formation energy: the higher probability of tunnel occupation with a relatively immobile Fe2+ cation – along with a greater volume change (17%) on redox cycling – contributes to the poor electrochemical performance of the Na olivine. Na+ ion conduction in Na2FePO4F is predicted to be two-dimensional (2D) in the interlayer plane with a similar low activation energy. The antisite formation energy is slightly higher; furthermore, antisite occupation would not impede transport significantly owing to the 2D pathway. This factor, along with the much lower volume change (3.7%) on redox cycling, is undoubtedly responsible for the better electrochemical performance of the layered structure.
[1] R. Tripathi, S.M. Wood, M.S. Islam and L.F. Nazar, Energy and Envrion. Sci., 2013, 6, 2257-2264
[2] M.S. Islam and C.A.J. Fisher, Chem. Soc. Rev., 2014, 43, 185-204
Improvement of High Voltage Cyclic Performance By Novel Binder for High Energy Lithium Ion Battery Application
Authors: Kaneko Mayumi 
Published: February 2020

Introduction

Lithium-ion batteries (LIB) have been used as high density storage devices for several kinds of applications. Higher energy density and higher durability are required for use of high-performance energy devices. Among various attempts to improve energy density of LIB, technologies which increase battery voltage have emerged as a viable solution.
Binder affects electrochemical performance reaction directly because it exists near the active materials. In a previous report, Co-ion dissolution and Co3O4 formation were observed in the electrode with PVdF (Polyvinylidene fluoride) [1].
In this study, we clarified the degradation mechanism of cathode electrode that contain PVdF binder.

Experimental

The cathode electrodes consisted of LiCoO2, acetylene black, and PVdF. The performance tests were investigated in 40mAh laminate type lithium ion cells. The cycle life test was performed at 4.2V or 4.4V. Solid F-NMR of electrode was used for the analysis of binder degradation after cycle test.
Thin-film electrode of LiCoO2 was fabricated on Au substrate by rf-sputtering method [2]. X-ray diffraction pattern indicated that high crystalline LiCoO2 thin-film electrode was prepared. Binders were spin-coated on the thin-film electrode. Three-electrode cell was used for electrochemical measurements of LiCoO2 thin-film electrode. The electrochemical properties of LiCoO2 thin films were investigated by cyclic voltammetry (CV)

Results

Figure 1 shows cycle performance at each cut-off voltage. Cycle performance was dramatically decreased at high cut-off voltage. Figure 2 shows the cyclic voltammograms of LiCoO2 thin-film electrode coated with PVdF in LiClO4/EC/DEC at 60°C. Around 3.9 V, peaks of lithium-ion de-intercalation /intercalation were observed. With cycling, redox currentsgradually decreased and redox voltage shifted. This result suggested the degradation of LiCoO2.
We evaluated the structure change of LiCoO2 after cycle test by TEM spectroscopy. From the TEM spectroscopy, degradation of surface structure was observed at the electrode after cycle test. From the F-NMR, structure of PVdF was slightly changed after the cycle test. It is suggested that PVdF increased the reactivity of active material. From ICP measurements, the amount of metal precipitation on anode was also increased after cycle test. And adhesion strengths wassignificantly decreased after cycle test.
In our presentation, we will show a new type of water-based binder developed by Zeon which can contribute to improvement of cell performance, such as improved cycling performance.
P2 Structure Sodium Manganese Oxides for Na-Ion Batteries
Authors: Billaud Juliette Marie , Singh Gurpreet , Armstrong Anthony Robert , Gonzalo Elena Candida , Roddatis Vladimir , Armand Michel , Rojo Teofilo , Bruce Peter G. 
Published: February 2020

Lithium ion batteries have dominated the world of portable electronic devices over the past two decades and are making their way into the electric vehicle market due to their high energy density. However, recently sodium ion batteries have regained the interest of the scientific community due to the high and uniform abundance of sodium across the world and consequent low cost compared to lithium, making them attractive for grid storage. Various electrode materials have been studied for sodium ion batteries. Layered oxides, NaMO2, where M is one or more transition metals, represent an attractive class of cathodes for Na batteries. Here we show that Na0.67MnO2 with the P2 structure, Fig 1, exhibits a high capacity (175 mAhg-1), close to the best reported for a Na cathode, and with good capacity retention, in contrast to previous studies of Na0.67MnO2 where the capacity faded rapidly.1 Due to the presence of Jahn–Teller active Mn3+ in Na0.67MnO2, the structure undergoes various structural transitions during sodiation/desodiation leading to many voltage steps in the charge/discharge profile.1-3 We have investigated reducing the phase transitions by substituting Mn3+ ions with electrochemically inactive dopant ions, which have a strong preference for octahedral sites in the layered oxide framework. This leads to the formation of a highly stable framework that shows a smooth charge/discharge profile with very low polarization even for a substitution level as low as 5%, Fig. 2, and a capacity of ~ 175 mAhg-1. Such an observation is significant for the future development of sodium ion battery cathode materials.
Lattice parameters of all the substituted compositions could be refined using hexagonal (P63/mcm) and orthorhombic (Cmcm) space group symmetries, whilst the situation pertaining to Na0.67MnO2 samples proved more complex.
References
[1] A. Caballero, L. Hernan, J. Morales, L. Sanchez, J. Santos Pena and M. A. G. Aranda, J. Mater. Chem., 2002, 12, 1142.
[2] N. Yabuuchi, M. Kajiyama, J. Iwatate, H. Nishikawa, S. Hitomi, R. Okuyama, R. Usui, Y. Yamada and S. Komaba, Nature Mater., 2012, 11 512.
[3] X.F. Wang, M. Tamaru, M. Okubo and A. Yamada, J. Phys.
Chem. C, 2013, 117, 15545.