bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visualization of Electrochemical Reactions in Battery Materials with X-ray Microscopy
Authors: Cabana Jordi 
Published: February 2020

In this talk, I will discuss examples of the visualization of phase transformations using a variety of modes within the general family of X-ray microscopy, tailored to suit the scales and phenomena to be probed, but focusing on single particles. Because thermodynamic pathways can be controlled by the presence of electrical potential, the harvesting of a sample from a cycled battery, while providing a useful preliminary insight, can lead to misleading results due to the relaxation of components into a different state that is more stable under open circuit conditions. Therefore, measurements performed during the electrochemical reaction will be leveraged in this discussion. The mechanisms of transformation will be related to their impact on material and architecture properties.
Long-Life Silicon/Graphite Anode with Nano Carbon Coatings for Lithium Ion Battery - Graphene Nanowalls and Nitrogen Incorporated Ultrananocrystalline Diamond
Authors: Tzeng Yonhua , Pan Yen-ting 
Published: February 2020

Although lithium ion batteries (LIBs) have been used in many consumer and industrial products, the energy storage capacity per volume/weight and the battery cycling lifetime have much room for further improvement. This is especially challenging for high demanding applications such as long-range electric vehicles, and smart grid renewable energy storage. Among LIB anode materials, graphite is the most common one in the market today. Many novel anode materials have been studied in pursuit of much higher battery energy storage capacity for a given volume and weight. Among them, silicon is the most attractive one which theoretically is capable of storing more than ten times of energy than that of graphite anode for the same anode weight. However, silicon suffers from extensive volume expansion and shrinkage by about 400% when it cycles through fully charged and discharged states. The volume difference leads to breakage of silicon particles and the loss of their electrical contacts to the current collector and thus its capability of further discharging and charging. On the other hand, graphite has a layered structure, which suffers from breakage between adjacent layers into smaller pieces and thus possibly loses the capability of broken apart small graphite pieces in charging and discharging. Therefore, technologies for preventing aforementioned huddles against achieving long-life and high-capacity LIBs are highly desirable. Novel electrically conductive ultrananocrystalline diamond, graphene nanowalls, and diamond-graphene hybrid nano-carbon coatings have been applied by plasma enhanced chemical vapor deposition technique to graphite and silicon based LIB anodes and achieved much longer cycling lifetime compared to those without such nano carbon coatings. This paper will present the nano-carbon coating processes, materials characterization, LIB fabrication processes, and the characterization of LIB half cells which demonstrates enhance lifetime and charge storage capacity.
Highly Efficient Rechargeable Sodium-Oxygen Battery Using Carbon Paper As Binder and Catalyst Free Air Cathode
Authors: Kretschmer Katja , Sun Bing , Wang Guoxiu 
Published: February 2020

Metal-air batteries, which utilize conversion chemistry rather than intercalation mechanisms, have attracted large research interest due to their high theoretical energy density. Much work has been devoted to investigate and optimize Li-O2 cell, which suffer from large overpotential and poor energy efficiency due to complex cell chemistry and undesired side reactions. Recently, Janek et al. have reported the approach of substituting lithium with sodium in an air battery system and surprised the research community with outstanding performance. Their Na-O2 was reversibly charged/discharged at very low overpotentials using a pure carbon cathode without the addition of a catalyst [1]. They further more claimed that low surface area can provide a more efficient cycling performance as well as high absolute capacity [2]. To further understand the impact of the carbon material used as air cathode inside the Na-O2 system, we investigated a range of carbonized fiber based materials. We found that commercially available and heat-treated filter paper provides outstanding oxygen reduction reaction and oxygen evolution reaction activities without any additional catalyst. An initial absolute capacity of 1.26 mAh cm-2 and low overpotential <400 mV could be achieved when cycled between 1.8 and 3.0 V at 100 µA cm-2 without any capacity restriction.
References:
[1] P. Hartmann, C.L. Bender, J. Janek et al., N
at. mater.
2013, 12, 228-232.
[2] C.L. Bender, P. Hartmann, J. Janek et al. Adv. Energy Mater.
2014, 4, 1301863
Structure and Properties of the Amorphous Lipon Electrolyte By First-Principles Simulations
Authors: Sicolo Sabrina , Albe Karsten 
Published: February 2020

Amorphous materials belonging to the family of Lithium Phosphorus Oxynitrides (LiPON) are increasingly popular solid electrolytes for thin-film Li-ion batteries. RF-sputtering of a lithium orthophosphate target in a nitrogen plasma leads to the deposition of amorphous glasses. Rationalization of the transport properties rests on a valid structural model for these glassy structures, whose simulation represents a main challenge from a computational point of view also because of their non-trivial compositions. In close cooperation with experimental partners, we assessed the structural, electronic and transport properties of an amorphous member of the LiPON family with non-trivial composition and cross-linking.
The issue of structure prediction for a given composition is a longstanding problem even for the simplest crystalline solids. The problem is further complicated in the case of an amorphous material, as the potential energy landscape that describes the glassy region exhibits a large number of minima of varying depths. We circumvented the problem by using an evolutionary algorithm to find a stable structure for a realistic, composition provided by experiments and subjecting it to ab-initio simulated annealing to create disorder.
In this work we present the results of Density Functional Theory calculations. After characterizing the structural and electronic properties of our material, we addressed the issue of ionic conductivity by calculating the defect formation energies of neutral and charged point defects with respect to two different Li reservoirs: a typical anode, metallic lithium, and a typical cathode, lithium cobalt oxide (LCO).
We found that charged defects dominate over neutral ones, as expected of an ionic conductor. Li+ interstitials dominate by far over vacancies, both when the lithium reservoir is metallic lithium and LCO. The formation of charged interstitials when LiPON is brought into contact with LCO has already been observed by our experimental partners. Furthermore, at the interface with metallic lithium the formation of neutral interstitials is a competitive process that results in the chemical reduction of LiPON and the disruption of the network. The occurrence of side reactions at the interface between LiPON and lithium has been observed and quantified by means of X-ray photoemission spectroscopy by our experimental partners. Following up on this result, we proceeded to investigate the structural and electronic properties of the interface between LiPON and metallic lithium with a special focus on the occurrence of side reactions. We conclude by showing preliminary studies of the interface between LiPON and selected LCO terminations suggested by available experimental results.
Dual Carbon-Coated Si Porous-C Composite for Li-Ion Battery Anode
Authors: Chung Eun Hyuk , Lee Sun-Young , Hong Tae Eun , Jong Pil Kim , Jong-Seong Bae , Lee Jung Kyoo , Kim Jeom-Soo , Jeong Euh Duck 
Published: February 2020

Recently Li-ion battery has been used extensively as a portable power source for small electronic devices, a power source for electric vehicles and an attractive option for energy storage.
Artificial graphite, natural graphite, hard carbon, such as carbon-based materials as anode active material have been applied, According to the requirements of high capacity, high theoretical capacity such Si (ca. 4200mAh/g) which is 5 times higher than carbon-based mateirlas has been actively studied in recent years.
There are several problems to overcome despite the advantages of the theoretical capacity values of the Si.
First low electrical conductivity, second due to the significant change in volume of the active material of the Si particle during Li insertion/extraction, it causes pulverization of the active material particels.
In order to overcome these problems, the mixture of high carbon Si/carbon composite was synthesized, but showed a limitation in the number of times the cycle test because of the lack of sufficient change in volume of the internal volume of Si.
Our study was performed to study the synthesis of a nanoparticle dual carbon-coated Si porous-C composite using glucose and PVDF to form an inner space. Also, GO was added to improve the cyclability.
Characterization of Si porous-C was explored by Scaning transmission electron microscopy (STEM), X-ray photoelectron scpectroscopy (XPS) and the electrochemical performace was carried out as shown in figure.
Two different current density (100, 500mA/g) was applied. 100mA/g was applied upto 5th cycles and the rest of cycels was obtained at 500mA/g.

Figure 1
Multi-Scale Modeling of Multi-Physics Processes in Lithium Ion Battery Cells
Authors: Salvadori Alberto , Magri Marco 
Published: February 2020

Lithium-ion (Li-ion henceforth) batteries application to high power and high capacity demanding systems still encounters limitations. This technology is based on the classical intercalation reaction, during which Li is inserted into or extracted from electrodes. During this process the hosting material experiences large volume changes, leading to mechanical degradation, loss of integrity and of electric contact with current collectors. Nano-structured and composite material electrodes may reduce such damaging phenomena.
Computational modeling and simulations may be helpful in designing new combinations of materials and geometries. To simulate a whole battery cell at the scale at which Lithium ions intercalate would be computationally unfeasible. A multi-scale approach is desirable and the Computational Homogenization (CH) technique is here adopted. This allows to track micro structural events that initiate damage and lead to macroscopic failure from macroscopic boundary conditions, while limiting the computational cost.
This contribution extends to large strains the framework of the CH developed in [1,2]. Temperature dependence is also included, towards modeling batteries under extreme conditions. The adopted approach originates from the fundamental balance laws (of mass, force, charge) and the weak formulation derived has a clear energy interpretation. Electroneutrality assumption has been taken into account. Maxwell's equations are considered in a quasi-static sense in a rigorous setting.
All the materials forming the multi-component porous electrode are clearly identified. Migration, diffusion, and intercalation of Lithium in the active particles are modeled. Constitutive assumptions, that emanate from a rigorous thermodynamic setting, complete the formulation.
After spatial discretization, a Backward Euler time-advancing algorithm has been implemented in FEM codes. Different finite elements have been designed to deal with the electrolyte, the electrodes and the reaction layer between them. Several case studies have been simulated to validate the implemented formulation.
References
[1] A. Salvadori, E. Bosco, and D. Grazioli. A computational homogenization approach for Li-ion battery
cells. Part 1 - Formulation. Journal of the Mechanics and Physics of Solids, 65:114-137, 2014.
[2] A. Salvadori, D. Grazioli, and M.G.D. Geers. Governing equations for a two-scale analysis of Li-ion
battery cells. International Journal of Solids and Structures, 59:90-109, 2015.
Comparative Study on Experiment and Simulation of Power Prediction of Lithium-Ion Batteries
Authors: Park Joonam , Appiah Williams Agyei , Byun Seoungwoo , Yeon Daeyong , Kim Hee Joong , Kim Tae Shin , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

As the size of lithium-ion batteries (LIBs) becomes larger, it is also time consuming and expensive to get lots of electrochemical properties experimentally. In particular, it needs more resources to optimize all cases for designing and developing the right large format cell for a given application. Hence, we adopt a previously designed pseudo two dimensional (P2D) model to simulate the electrochemical performance of a 20 Ah pouch cell consisting of LiFePO4cathode and a graphite anode. The model was used to analyse the adequacy of two pulse based power measurement methods; hybrid pulse power characteristics (HPPC) and J-pulse (JEVS D 713, Japan Electric Vehicle Association Standards), in predicting the direct resistance (DC-IR) and power as a function of state of charge by comparing the simulation results to those of experiments.
There was a good agreement between the simulation results and those of the experiment. DC-IR as a function of SOC was obtained from P2D model, and converted to power. Both two methods showed that DC-IR of charge and discharge increase from about 10% to about 20% at the SOC below 20%. DC-IR of the cell during charge in HPPC was predicted to be higher than discharge and vice versa for J-Pulse. Hence, a different current density should be used for the two methods for effective power predictions.

References

1. J. Park et al., KEPCO Journal on Electric Power and Energy,
33, 2465-8111 (2015).
2. M. Doyle and J. Newman et al., Journal of the Electrochemical Society, 143, 1890-1903 (1996).
3. H. Lee and Y. M. Lee, Journal of The Korean Electrochemical Society, 10(3), 115-123 (2012).

Acknowledgements

This work was supported by the Human Resource Training Program for Regional Innovation and Creativity through the Ministry of Education and National Research Foundation of Korea (NRF-2014H1C1A1066977) and by the Sebang Global Battery.

Figure 1
Aligned Helix Si Nanostructures As High Performance Anode Material in Secondary Lithium Ion Battery
Authors: Wang Hsiao-Chien , Yen Wen-Chun , Huang Jian-Shiou , Medina Henry , Chueh Yu-Lun 
Published: February 2020

The increasing demand for advanced electronic devices and energy storage have stimulated significant interest in the development of batteries of high capacity. Li ion based battery is the most promising system which is light-weight and energy-delivering efficient. Compared to the existing graphite-anode system, Si is known to have highest theoretical specific capacitance which makes Si be the most promising candidate for the next-generation anode material for lithium battery systems. However, the large volume expansion and the serious material pulverization of Si after cycling result in a poor life time, and become a stumbling block for being commercialized. In this research, glancing angle deposition (GLAD) technique is utilized to deposit uniform and aligned intrinsic Si-spiral nanostructure. By varying different rotation angles during GLAD, various spiral Si nanostructure with various porosities are deposited. With increasing rotation number , the porosity also increases giving as a result less Si volume occupation. The silicon content in the porous film can be precisely controlled from 77.5% to 74.69% by tuning the formation of the nanostructure. As a result the porous silicon film offers an enhanced battery cycle life for intrinsic silicon based anode material. TEM and XPS analysis were carried out to analyze the composition and bonding information for de-/lithiation mechanism. After the optimization, our porous Si anode shows an electrochemical performance with volumetric specific capacity of 2019.2 mAh/cm3. After 100 cycle test, the volumetric specific capacity retention still remains at 359.4 mAh/cm3. Furthermore, we believe that the adequate porosity helps to retard the enormous stress among the film by providing enough space for volume expansion to gain longer life time and better electrochemical performance.
Atomic Layer Deposition of Lithium Titanate on 3D-Structured 300 Mm Silicon Substrates
Authors: Bönhardt Sascha , Zybell Sabine , Liske Romy 
Published: February 2020

Thin film battery technology delivers high added value for autonomous microsystems in e.g. wireless sensor networks, Internet of Things (IoT) applications and medical implants. The transition to solid state electrolytes means significant improvement of the battery safety and even opens possibilities for integration into silicon technology.
The 3D micro battery concept, including deposition of functional layers on structured surfaces with high aspect ratio, has been shown to improve both, capacity and rate performance of all-solid-state batteries [1]. Our aim is the development and characterization of functional stacks allowing direct integration into microsystems. For CMOS compatible design and production, we manufacture functional electrode and electrolyte layers on 300 mm wafer using standard industrial thin film deposition equipment.
Atomic layer deposition (ALD) is a vapor-phase technique based on sequential, self-limiting surface reactions enabling conformal deposition of thin films. In this work, alternate atomic layer deposition of titanium oxide and lithium carbonate is demonstrated. The formation of the desired spinel lithium titanate (LTO) is investigated by subsequent high temperature anneals. Although its comparatively low capacity LTO is a promising electrode material for 3D integration. It stands out due to its zero-strain characteristics and the three dimensionality of ion transport [2].
[1] Y. Wang, B. Liu, Q. Li, S. Cartmell. S. Ferrara, Z. Deng, and J. Xiao, Journal of Power Sources 286 (2015) 330-345.
[2] V. Miikkulainen, O. Nilsen, M. Laitinen, and T. Sajavaara, RSC Advances 3 (2013) 7537.
Novel Binary Binder PAA-SBR Towards Silicon Anodes in Li-Ion Batteries
Authors: Huang Qianye , Loveridge Melanie , Wan Chaoying , Bhagat Rohit 
Published: February 2020

Silicon remains a promising anode material for next generation lithium-ion batteries, despite the well-documented issues associated with it, due to its abundance and high capacity (3579mAh/g: almost 10 times higher than the capacity of graphite). The problems still facing Si-based battery commercialization are volume expansion, which results in rapid capacity fade, and continued Li loss through SEI formation from electrolyte decomposition. To address this problem, effective binders are considered to be one solution, and could help to maintain good contact between the active material and current collector but also to generate effective, stable networks between silicon particles and conductive carbon additives.
This work will introduce a new binder system: Polyacrylic Acid-Styrene Butadiene Rubber (PAA-SBR). PAA is an aqueous-based polymer and possesses a high concentration of carboxyl group, which effectively bonds with the surface of silicon but also can H-bond with other polar species contributing to a good cohesive composite. SBR (Styrene Butadiene Rubber) is well known for its good flexibility, which can improve the tensile property of the electrode towards volume expansion. Therefore, it is hypothesized that the binary binder PAA-SBR can help Si anode achieve an improved, more stable performance because it can preserve good adhesion and flexibility simultaneously under the stress of the Si expansion.
A preliminary study was conducted on Si vs.Li/Li+ half cells with different binder systems: PAA, PAA-SBR (2:1 mass ratio) and PAA-SBR (5:1 mass ratio), where PAA-only is used as the control binder. Cells are tested under the maximum lithiation capacity of 1200mAh/g at a C rate of C/5. Electrochemical cycling data indicates that for first 100 charge-discharge cycles, the PAA-SBR (2:1) showed a similar level of performance compared with PAA in terms of specific capacity (~1194mAh/g) and columbic efficiency (~99.5%), while the PAA-SBR (5:1) displayed capacity fade after 80 cycles, as shown in Fig.1. We anticipate that an optimized PAA-SBR ratio will generate superior composite durability during longer-term electrochemical testing. To further approve the hypothesis, a comprehensive study based on PAA-SBR (2:1) will be followed including polymer stability in electrolyte solvents, tensile properties, adhesion and impedance testing.

Figure 1
Ionic Liquid Based Polymer Gel Electrolyte Membranes for Lithium Ion Rechargeable Batteries
Authors: Kataria Shalu - , Balo Liton , Gupta Himani , Singh Varun Kumar , Singh Shishir Kumar , Tripathi Alok Kumar , Verma Yogendra Lal , Singh Rajendra Kumar 
Published: February 2020

Li-ion conducting polymer gel electrolyte membranes (PGEMs) based on polymer poly(vinylidene fluoride-co-hexafluoropropylene) PVdF-HFP, ionic liquid, 1-butyl-3-methylimidazolium tetrafluroborate BMIMBF4 and Lithium bis(trifluoromethanesulfonyl)imide) LiTFSI salt (having different anion i.e. BF4
- and TFSI-) have been synthesized and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), complex impedance spectroscopy and cyclic voltammetry. After incorporation of IL in polymer electrolyte, (i.e. PVdF-HFP+20wt.% LiTFSI) different physicochemical properties such as melting temperature (Tm), glass transition temperature (Tg), thermal stability, degree of crystallinity (Xc), and ionic transport behaviour of these materials are found to change. The pristine PVdF-HFP possessed a semi-crystalline structure and its amorphicity increased with the addition of LiTFSI salt and BMIMBF4 ionic liquid. An impedance measurement indicated that the room-temperature ionic conductivity of the membranes increased with increasing IL content and attains a maximum value of 3.2 *10-3 S/cm at 30 °C and ~ 8.7*10-3 S/cm at 130 °C. An schematic representation exhibiting increase in ionic conductivity with increasing amount of dopant ionic liquid has been shown in the given figure. In addition, temperature dependent ionic conductivity seems to obey Arrhenius type thermally activated behaviour. A high total ionic transference number > 0.99 and the cationic transference number (tLi
+) ~0.33 with a wider electrochemical window (ECW) ~4.0–5.0 V for the PGEMs containing higher loading of IL have been obtained.

Fig. Schematic representation exhibiting increase in ionic conductivity with increasing amount of dopant Ionic Liquid.

Figure 1