bluuebunny/crossref_metadata_2025_split huggingface dataset:
Density Functional Tight Binding Modelling of Lithium Intercalated Graphite with Machine-Learned Repulsive Potential
Authors: Panosetti Chiara , Anniés Simon , Grosu Cristina , Scheurer Christoph 
Published: December 2020

Lithium ion batteries have been a central part of consumer electronics for decades. More recently, they have also become critical components in the quickly arising technological fields of electric mobility and intermittent renewable energy storage. However, many fundamental principles and mechanisms are not yet understood to a sufficient extent to fully realize the potential of the incorporated materials.
The vast majority of concurrent lithium ion batteries make use of graphite anodes. Their working principle is based on intercalation–the embedding and ordering of (lithium-) ions in the two-dimensional spaces between the graphene sheets. This important process–it yields the upper bound to a battery's charging speed and plays a decisive role for its longevity–is characterized by multiple phase transitions, ordered and disordered domains, as well as non-equilibrium phenomena, and therefore quite complex. Such complexity emerges particularly at low states of charge (SOC), and complicates both the interpretation of experiments and the computational modelling.
From a computational standpoint, targeted system sizes compatible with the SOC range of interest are inaccessible to first-principles calculations, yet require first-principles treatment of key effects such as dispersion and long-range electrostatics. Density Functional Tight Binding (DFTB), a semi-empirical approximation to DFT, offers a high-quality trade-off between accuracy and speed. However, this advantage comes at the cost–or rather initial investment–of pairwise parametrization.
As no Li-C DFTB parameters were publicly available yet, we produced a parameter set specifically tailored to this system, employing a parametrization strategy [1] that combines global optimization of electronic parameters via Particle Swarm Optimization (PSO) [2] with our recently developed approach that uses Gaussian Process Regression (GPR) [3] to machine-learn the repulsive potential.
Using the resulting parametrization, we are able to reproduce experimental reference structures at a level of accuracy which is in no way inferior to much more costly ab initio methods. We present structural properties and diffusion barriers for some exemplary system states. Additionally, we are able for the first time to resolve the full Potential Energy Surface (PES) of Li motion in stage-I and stage-II LiC108 (SOC 5%). The PES contains information that enables us to implement, and in perspective discuss, both kinetic Monte Carlo (kMC) models of Li-ion mobility in the graphite host, and free-energy sampling which ultimately yields the computed voltage profile of the anode.
[1] Panosetti et al., https://arxiv.org/abs/1904.13351

[2] Chou et al., J. Chem. Theory Comput. 2016, 12, 1, 53–64
[3] Panosetti et al., J. Chem. Theory Comput. 2020, 16, 4, 2181–2191

Figure 1
(Invited) Strategic Development of Functional Electrode Materials and Electrolytes for Multivalent Ion Storage
Authors: Ha Jung Hoon , Lee Boeun , Oh Si Hyoung 
Published: December 2020

As the global markets for electric vehicles (EVs) and commercial electricity storage systems (ESS) grow rapidly, the demand for more cost-effective and safe alternative to Li-ion technology (LIB) is ever-increasing. The multivalent ion storage based on Mg, Zn and Al metals offers promising candidates for viable energy storage mechanism, since raw materials of these metals are abundant in the earth-crust, environmentally-benign, and safe to handle with. The major technical challenges for rechargeable batteries using multivalent ion storage include lethargic electrode kinetics associated with multivalent cation diffusion through the intercalation hosts, and the development of functional electrolytes equipped with a high reversibility on metal plating-stripping, and a large electrochemical window. In this work, we present a couple of conversion-based electrode materials for facile multivalent ion storage, showing a large reversible capacity and a long-term cycle stability even in the high-current rate [1]. We also demonstrate a series of new electrolytes for Mg-ion batteries based on conventional Grignard reagents containing ionic liquids with allyl-functional group, which shows a fast reaction kinetics on the negative electrode and a high oxidative stability [2].

Reference

[1] J. H. Ha, B. Lee, J. H. Kim, B. W. Cho, S.-O. Kim, S. H. Oh, Energy Storage Mater. 27 (2020) 459-465
[2] B. Lee, j.-H. Cho, H. R. Seo, S. B. Na, J. H. Kim, B. W. Cho, T. Yim, S. H. Oh, J. Mater. Chem. A 7 (2019) 3126-3133.

Acknowledgement

This work was supported by KIST institutional program (2E30211)
3D-Printed Energy Storage Devices
Authors: Ragones Heftsi , Vinegrad Adi , Goor Meital , Ardel Gilat , Dorfman Moty Marcos , Kamir Yosi , Golodnitsky Diana 
Published: December 2020

The increasing demand for multifunctional portable/wearable electronic devices, including wireless sensors and implantable medical devices is continuously growing. Such devices need rechargeable batteries with dimensions on the scale of 1–10 mm3 (few to tens mm2 footprint area of substrate) including all the components and all the associated packing. Thus, in the past decade, along with the developments in battery materials, the focus has been shifting more and more towards innovative fabrication processes, unconventional configurations, and designs with multi-functional components. 3D printing technologies enable a well-controlled creation of functional materials with three-dimensional architectures, representing a promising approach for fabrication of next-generation electrochemical energy storage (EES) devices with high performance due to a higher electrode/electrolyte interfacial area.
In this work, we demonstrate a novel design and a novel approach of 3D printing of batteries of different shapes and size by using filaments composed of active electrode materials bound with polymers. The electrodes were printed by fused-filament fabrication (FFF) method. We demonstrated a reversible electrochemical cycling of 3D printed lithium iron phosphate (LFP) and lithium titanate (LTO) composite polymer electrodes vs. lithium metal anode with high performance and capacity in cells containing both conventional non-aqueous and ionic-liquid electrolytes.
In addition, the development and fabrication of a novel 3D-printed solid-state or quasi-solid electrolyte by FFF has been accomplished. The electrolytes are composed primarily of polyethylene oxide (PEO) and polyethylene glycol (PEG) which are known ionic conductors, and polylactic acid (PLA) for enhanced mechanical properties and high temperature durability.
Our research introduces novel thick-layer 3D batteries, thus reducing cost related to high mass loading per battery footprint of smart 3D structures with the help of low-cost fabrication method.

References

[1] H. Ragones et al. "Towards smart free form-factor 3D printable batteries." Sustainable Energy & Fuels 2.7 (2018): 1542-1549.
[2] H Ragones et al. On the Road to a Multi-Coaxial-Cable Battery: Development of a Novel 3D-Printed Composite Solid Electrolyte Journal of The Electrochemical Society 2019 ,167 (7), 070503.
High Mass-Loading Sulfur-Composite Cathode for Lithium-Sulfur Batteries
Authors: Baikalov Nurzhan , Serik Nurassyl , Kalybekkyzy Sandugash , Mentbayeva Almagul , Bakenov Zhumabay 
Published: December 2020

The development of electric vehicles and portable devices require high power and high energy density batteries. In this regard, among the existing energy storage systems, the lithium-ion batteries (LIBs) play a key role. However, the energy and power densities of conventional LIBs are reaching the limited theoretical values and cannot fulfill requirements for new generation portable devices and electric vehicles. Sulfur is a promising replacement for intercalated cathode materials, since it has high theoretical capacity of 1672 mAh g-1 and high gravimetric energy density of 2600 Wh kg-1.1 Moreover sulfur has several advantages such as low cost, environmental friendliness and abundance.2 However, commercialization of lithium-sulfur batteries faces several difficulties related to low conductivity of sulfur, polysulfide dissolution and lithium dendrite growth.3,4 The aim of this research was to increase mass loading of sulfur in the electrode, which in turn requires improvement in the bulk conductivity. For that reason, high sulfur loading S/DPAN/CNT composite cathode was prepared by a simple and efficient way of designing micro and nano level 3D carbon networks. The covalent bonding between pyrolyzed PAN and sulfur diminishes polysulfide dissolution, while CNT maintains structural integrity, acting as nanoscale interwoven skeleton and ensures electron transfer within and between S/DPAN granules.5 Then S/DPAN/CNT was impregnated into pores of commercial carbon fiber paper (CFP), which in its turn provides bulk electron conductivity in macro level. As a result, mass loading of sulfur was increased up to 5 mg cm-2while maintaining a high initial specific capacity of 1400 mAh g-1 and stable cyclability.
Acknowledgements
This research was supported by the targeted state program BR05236524 “Innovative Materials and Systems for Energy Conversion and Storage” from the Ministry of Education and Science of the Republic of Kazakhstan for 2018-2020.
References:
[1] K.H. Shin, K.-B. Kim, C.S. Jin, W. Ahn, K.N. Jung, J. Power Sources 202 (2011) 394–399.
[2] Y. Zhang, Y. Zhao, T. N. L. Doan, A. Konarov, D. Gosselink, H. G. Soboleski, P. Chen, Solid State Ionics 238 (2013) 30–35.
[3] M. Li, R. Carter, A. Douglas, L. Oakes, C. L. Pint, ACS Nano 11 (2017) 4877–4884.
[4] Z. Nie, J.-G. Zhang, N. D. Browning, Q. Li, L. B. Mehdi, X. Xie, J. Liu, G. L. Graff, J. Zheng, S. Ferrara, Adv. Energy Mater. 5 (2015) 1402290.
The Interplay between Thermodynamics and Kinetics in the Solid-State Synthesis of Layered Oxides
Authors: Bianchini Matteo , Wang Jingyang , Clément Raphaële J. , Ouyang Bin , Xiao Penghao , Kitchaev Daniil , Shi Tan , Zhang Yaqian , Wang Yan Eric , Kim Haegyeom , Zhang Mingjian , Bai Jianming , Wang Feng , Sun Wenhao , Ceder Gerbrand 
Published: December 2020

To design a synthesis route for energy storage materials, the phase diagram is a useful starting point. However, non-equilibrium intermediates often appear during synthesis—which are difficult to anticipate and often persist as impurities in the final reaction product. In addition, intermediate phases may template the morphology of particles. Thus, being able to rationalize and predict which metastable intermediates form during solid-state reactions is crucial towards developing rational frameworks in which to create predictive ceramic synthesis approaches.
Guided by real-time in situ synchrotron observations of materials formation, we develop a new theory to model the reactions between ceramic precursors to form NaxMO2 layered oxides (M = Co, Mn), which are important cathode materials for Na-batteries. These layered oxides form in two polytypes: a two-layer (P2) stacking, and a three-layer (O3 or P3) stacking. Even though phase diagrams determine that P2 is the stable phase at Na0.66CoO2 composition, synthesis using a nominal 0.33 Na2O2 + CoO precursor mixture is observed to first form the O3-NaCoO2. The reaction then proceeds sequentially through non-equilibrium O3’and P3 phases, with the equilibrium P2-Na0.66CoO2 only obtained after long time at high temperature. This raises the fundamental question—how do thermodynamic driving forces and kinetic mechanisms conspire to create phases that are not thermodynamic stable, and why can some phases, which are thermodynamically favored at all temperatures, only be formed after long times at high temperature? We show that the first phase to form from the precursors is actually the compound which consumes the most reaction energy, irrespective of whether this compound is at the target stoichiometry. After this initial compound forms, a combination of fast topotactic reactions and slow nucleation and growth processes slowly bring the system to the equilibrium phase.
Based on this insight we can now predict how different precursors change the reaction pathway, driving the crystallization pathway through different intermediates. As an example, we show how P2-Na0.66MnO2 can be formed through very different reaction pathways by changing the precursors. This rationalization of the first phase to form creates a valuable design handle by which reaction paths can be tailored to go through, or circumvent, specific non-equilibrium intermediates. Our combined computational and experimental approach offers a predictive framework for the synthesis design of new energy materials.
Low-Temperature Deposition of Large-Grained Polycrystalline AlN Using Trisdimethylamido Aluminum (TDMAA) and Anhydrous Hydrazine
Authors: Ueda Scott , McLeod Aaron , Alvarez Daniel , Kummel Andrew C 
Published: December 2020

High quality, large-grained AlN films are of interest for use as either heat spreading layers or as a buffer/templating layer for further film growth. As the typical deposition temperature for high-quality crystalline AlN is usually in excess of 800 oC, there is a large amount of thermal strain in the films and it is advantageous to develop processes to lower the deposition temperature so that it is compatible with back end of line (BEOL) processing. In this work, the low-temperature (<400 oC) deposition of polycrystalline AlN films is demonstrated by atomic layer annealing (ALA) which is a variant of ALD that utilizes a third pulse of low-energy inert gas ions in addition to the usual metal and co-reactant pulses [1].
Using trimethyl aluminum (TMA) or tris(dimethylamido) aluminum (TDMAA) with the highly reactive nitrogen-containing precursor hydrazine (N2H4), AlN can be deposited at ~200 oC [2]; however, these films are amorphous and would have low thermal conductivity due to a high degree of phonon scattering. Using TDMAA with N2H4 or NH3 at temperatures >350 oC, polycrystalline films can be deposited in a purely thermal process; however, the reported grain sizes are small (<5 nm) or there is a mixture of polycrystalline and amorphous phases [3-4]. ALA has been used to deposit crystalline films such as AlN [1,5] and GaN [6] on a near lattice-matched substrate (sapphire) at low temperatures, but a nitrogen-containing plasma was used.
In the present study of AlN ALA on Si (111) (a non-lattice matched substrate), two metal precursors (TMA and TDMAA) were compared using ultra-high purity anhydrous N2H4 as a co-reactant and argon ions with tuned energy for the third pulse. It was found that deposition using TDMAA as the Al precursor resulted in high-quality AlN films with large grain size (>20 nm) and low C/O contamination (<1.5%) whereas films deposited using TMA had much higher carbon content (>5%), owing to its thermal instability at 400 oC. Transmission electron micrographs for a 40 nm film grown using TDMAA and N2H4 show vertical grain structure with grains spanning the entire thickness of the film. As heat spreading layers often need to be in excess of 1 micron thick in order to be relevant for use in high volume manufacturing, it is also demonstrated that these 40 nm films successfully transfer the large grain size of the ALA film to a thick sputtered AlN film (which can be deposited relatively quickly) by acting as a template layer.
[1] H-Y. Shih et al, Scientific Reports 7:39717.
[2] M. Mizuta et al, Japanese J. Appl. Phys. 25(12), L945-L948 (1986).
[3] R. G. Gordon, U. Riaz, and D. M. Hoffman, J. Mater. Res., 7(7) (1992).
[4] A. I. Abdulagatov et al Russian Microelec. 47(2), 118-130 (2018).
[5] W-C. Kao et al, RSC Adv. 9, 12226-12231 (2019).
[6] W-H. Lee et al ACS Sustainable Chem. Eng. 7,1, 487-495 (2019).
This work was supported in part by the Semiconductor Research Corporation.

Figure 1
Growth and Electrical Characteristics of PE-ALD Germanium Sulfide for 3D Cross-Point Memory
Authors: Kim Myoungsub , Kim Youngjun , Sohn Inkyu , Kim Hyungjun 
Published: December 2020

The 3D cross-point memory, known to contain chalcogenide material-based ovonic threshold switching (OTS) selector, is bringing new changes to the memory hierarchy of DRAM and NAND flash memory. The cross-point memory of current planar 3D structures, meanwhile, is already expected to limit scaling in terms of number of critical masks and normalized cost, so it is necessary to prepare a vertical 3D structures [1]. Atomic layer deposition (ALD) process, which is essential to realize vertical 3D structures, has been mostly studied for phase change materials (PCM) based on GeSbTe but OTS selector research is still in its early stage. So, we have studied plasma enhanced-ALD (PE-ALD) of germanium sulfide (GeS) films containing sulfur chalcogenide element with higher optical bandgap than Te and Se for low off current OTS selector for larger array implementation [2] [3]. The PE-ALD of GeS amorphous chalcogenide films was synthesized using commercially available GeCl4 precursor with H2S plasma reactant. The Ge1S2 film was identified quantitative composition and impurities through AES depth profile analysis, and excellent thermal stability up to 600 ℃ was studied by In-situ high temperature X-ray diffraction (HT-XRD). And PE-ALD Ge1S2 has confirmed the superior step coverage in the vertical 3D structure through FIB-TEM compared to chemical vapor deposited GeS film. In addition, the devices of the 50 nm bottom electrode contact size using PE-ALD Ge1S2 films demonstrated OTS characteristic with of remarkable high threshold field 3.0 MV/cm, and low normalized off-current of 25 nA at half threshold voltage. The achievement of PE-ALD research on simple binary Ge1S2 amorphous chalcogenide will contribute to development the future 3D cross-point memory scaling.
Acknowledgments
This paper was result of the research project supported by SK Hynix Inc.
Reference
[1] T. Kim and S. Lee, “Evolution of Phase-Change Memory for the Storage-Class Memory and Beyond,” IEEE Trans. Electron Devices, vol. 1, pp. 1–13, 2020.
[2] C. C. Wu, C. H. Ho, J. Y. Wu, S. L. Lin, and Y. S. Huang, “Characterization of Ge(Se1-xSx)2 series layered crystals grown by vertical Bridgman method,” J. Cryst. Growth, vol. 281, no. 2–4, pp. 377–383, Aug. 2005.
[3] J. W. Park et al., “Optical properties of pseudobinary GeTe, Ge2 Sb2 Te5, GeSb2 Te4, GeSb4 Te7, and Sb2 Te3 from ellipsometry and density functional theory,” Phys. Rev. B - Condens. Matter Mater. Phys., vol. 80, no. 11, Sep. 2009.
Investigation of Hydrogen Effect on Ferroelectricity of Atomic Layer Deposited Hf0.5Zr0.5O2 Thin Film
Authors: Jung Yong Chan , Mohan Jaidah , Kim Harrison Sejoon , Hernandez-Arriaga Heber , Onaya Takashi , Kim Kihyun , Kim Namhun , Kim Si Joon , Ogura Atsushi , Choi Rino , Ahn Jinho , Kim Jiyoung 
Published: December 2020

Ferroelectrics have retrieved great interest since the discovery of a ferroelectric phase in HfO2.1 Especially, ferroelectric Hf0.5Zr0.5O2 (HZO) thin films have studied for application as a non-volatile memory and field-effect transistor, due to their high scalability and compatibility with CMOS process.2 In our previous work, we have achieved a low thermal budget process (400 °C) by controlling the tensile stress from the TiN electrode during the annealing process.3 Moreover, the TiN electrode can act as a barrier layer against hydrogen diffusion, therefore, the HZO films using the TiN electrodes can prevent degradation of the ferroelectric properties from hydrogen incorporation. However, during the deposition of HZO film using atomic layer deposition (ALD), the choice of oxygen source can affect the residue in the deposited film. When hydrogen-related substances are used as the oxygen source, the ferroelectric properties can be altered by the residues remaining in the HZO film.
In this study, we adopted various oxygen sources such as H2O, deuterium oxide (D2O), and O3, for the investigation of hydrogen effect on the ferroelectric properties of the ALD-HZO films. The HZO films were deposited on the TiN bottom electrode by ALD using Hf[N(CH3)2]4 (TDMA-Hf) and Zr[N(CH3)2]4 (TDMA-Zr) as the precursors of Hf and Zr, while H2O, D2O, or O3 as the oxidant. After the TiN top electrode was deposited, rapid thermal annealing was done, and metal-insulator-metal capacitors were fabricated using a Pd/Au hard mask and wet etch process.
The HZO films exhibited the formation of a non-centrosymmetric orthorhombic phase which is origin of the ferroelectricity, without consideration for the oxygen sources.4 However, it was confirmed that the ferroelectricity of the HZO film deposited with the oxygen source including hydrogen such as H2O and D2O, was degraded due to the more incorporation with hydrogen. As a result, the ferroelectric polarization of H2O-, and D2O-based HZO was lower than that of O3-based HZO. Simultaneously, the H2O- and D2O-based HZO exhibited higher leakage current than that of O3-based HZO. The results strongly suggest that the suppression of hydrogen incorporation is important to apply ALD-HZO films for next-generation memory application.
This work is supported by the National Research Foundation of Korea (NRF) grant (No. NRF-2019R1F1A1059972), Brain Pool Program (No. 2019H1D3A2A01101691), and the Fostering Global Talents for Innovative Growth Program (No. P0008750).

1 T. S. Böscke, et al., Appl. Phys. Lett. 99, 102903 (2011).

2 S.J. Kim, et al., Appl. Phys. Lett. 113, 182903 (2018).

3 S.J. Kim, et al., Appl. Phys. Lett. 111, 242901 (2017).

4 S.J. Kim, et al., JOM 71, 246 (2019).

Figure 1
(Invited) High Throughput Atomic Layer Deposition Manufacturing Processes for Improved Batteries
Authors: Dameron Arrelaine A , Martinez Madison , Dumont Jaime , Herbert-Walters Meghan N. , Valceschini Annette M. , Ragonesi James , Hughes Barbara K. 
Published: December 2020

Commercial adoption of EVs requires that we overcome consumer angst around battery range by enabling fast charge and increasing specific capacity, while also significantly decreasing cost ($/kWh). Achieving these objectives requires higher voltage and higher charge rate operation of high capacity cathodes and anodes and process intensification to minimize processing costs. The major challenge of high-capacity cathode materials paired with low-cost graphite anodes is their propensity for transition metal dissolution and crossover, and gas generation, which stems from electrochemical decomposition of the electrolyte solvent at electrode-electrolyte interfaces. This is exacerbated by increased voltage operation which not only requires voltage tolerant electrode materials and high voltage electrolytes but also requires advanced separators that minimize leakage current and maintain safe utilization under the more reactive conditions of high voltage (>4.5V vs Li+/Li). Equally destructive, fast charge operation adds rapid structural changes and cracking of both the cathode and anode materials due to rapid de-intercalation, transport, and intercalation of lithium ions from the cathode to the anode.
Forge Nano has demonstrated that atomic layer deposition (ALD) is effective at maintaining the structural integrity of high energy cathode materials at charge rates up to 6C and up to 4.6V top of charge with greater than twice the lifetime under accelerated conditions. Advanced nanoengineered surface treatments on anodes, particularly ionically conductive coatings, also prevent lithium plating and mitigate anode degradation during fast charge.
ALD is a platform technology that has been widely demonstrated as a laboratory method to modify interfaces to the benefit of a breadth of applications. While ALD is ubiquitous throughout the semiconductor industry, ALD is not yet widely accepted for modification of high surface area materials and few have demonstrated ALD on powder manufacturability. This talk highlights the impacts of ALD when applied to cathodes anodes and separators on battery performance, the various methods for scaling these ALD coatings to meet battery manufacturing requirements and the net pack-cost savings of ALD integration.