bluuebunny/crossref_metadata_2025_split huggingface dataset:
Towards a Better Understanding of Batteries: Manufacturing and Modeling Using Comsol
Authors: Moss Pedro L. , Chepyala Seshuteja , Weatherspoon Mark H. 
Published: February 2020

High energy lithium (Li) batteries are fast becoming a promising energy market for applications in the automotive and portable power markets. In the search for better specific energy and lower cost to manufacture the batteries, novel methods are being researched to overcome the design and operational entices before becoming commercially viable. One of these methods to achieve the above said goals is to manufacture the cells and compare the manufactured cell with its model using COMSOL Multiphysics.
This paper proposes battery cell manufacturing and laboratory level testing combined with advance modeling techniques to obtain a correlation for the cell life and stability characteristics data obtained by both simulation and manufactured cell. The batteries are made in the laboratory using the proven and tested methods and the cells are assembled after performing detailed analysis on the surface area and BET analysis of the electrodes. The cells are modeled in COMSOL Multiphysics to estimate the cycle life and stability and to check whether the simulated data is the same as the estimated data. This latter model is then used to check the performance of the cell. The COMSOL simulations are done for different cells and the data is compared with their respective manufactured cell data. The cells are prepared using various available electrode materials and extensive study is carried out regarding the assembly and manufacturing.
Preliminary tests of cathode electrode half cells using lithium iron phosphate (LFP) have achieved good results and the theoretical and practical specific capacities are similar as shown in Figure 1. We are able to achieve the specific capacity of LFP half-cell close to 135mAh (densified) as compared to the theoretical capacity of 155mAh. The cells should show similar charge discharge performance when modeled in COMSOL and achieve the similar results when the cells are tested. The results are discussed and recommendations made on battery dimensioning using the specifications observed.
Figure1:

Figure 1
Hetero-Nanonet Mediated Paper Batteries with Origami Foldability
Authors: Yoo JongTae , Cho Sung-Ju , Choi Keun-Ho , Lee Sang-Young 
Published: February 2020

Advent of new smart energy era including electric vehicles, grid scale energy storage systems, and flexible/wearable electronics indispensably requires full-fledged rechargeable power sources with reliable electrochemical performances and versatile form factors as a key enabling technology. Here, as a naturally abundant and environmentally friendly paper-mediated material/architecture strategy to address the challenges of conventional battery technologies, we demonstrate a new calss of hetero-nanonet (HN) paper batteries based on one-dimensional (1D) building blocks of cellulose nanofibrils (CNFs)/multiwall carbon nanotubes (MWNTs). The HN paper batteries consist of CNF/MWNT-intermingled geteronets embracing electrode active powders and microporous CNF separator membranes. The CNFs and MWNTs are well intermingled, producing the hetero-nanonets embracing LiFePO4 powders. The CNF/MWNT-intermingled heteronets allow the formation of highly-reticulated CNT networks and also interstitial voids, thus creating 3D bicontinuous electron/ion conduction pathways that can boost redox reaction kinetics of the HN electrodes. Also, the HN electrodes can be knotted in the form of a ribbon without mechanical rupture.
Over a wide range of discharge current densities the HN cathode shows significant improvement in the discharge capacities than the conventional one, demonstrating the electrochemical superiority of the HN cathode in the rate capability of cells. The HN cathode can be folded at an interval of 5 mm. Such excellent flexibility of the HN cathode is due to the CNF/MWNT heteronet-mediated structural tolerance/compliance. Finally, we fabricated the paper crane HN full cell. Over a wide range of bending radius the HN paper cells showed the superiority in areal capacity than the previous works.
In summary, we present a new class of hetro-nanonet paper batteries based on one-dimensional building blocks of CNFs/MWNTs. The CNF/MWNT heteronanonet-mediated material/structural uniqueness enables the realization of three-dimensional bicontinuous electron/ion transport pathways and also exceptional mechanical compliance.
Accelerating Rate Calorimetry Tests of 18650 Li-Ion Cells before and after Storage Degradation at High Temperature
Authors: Konakawa Kotaro , Mendoza-Hernandez Omar S. , Sone Yoshitsugu , Ishikawa Hiroaki , Umeda Minoru 
Published: February 2020

The use of Li-ion cells has been growing globally with a large number of cells powering a wide range of applications in variety of environments, and there have been several reported incidents raising safety concerns. Some of the cases have been related to overheating (thermal runaway) of Li-ion cells. Thermal runaway occurs when the exothermic reactions go out of control, thus the self-heating rate of the cell increase to the point that it begins to generate more heat than what can be dissipated. Understanding the behavior of Li-ion cells during thermal runaway is critical to evaluate the safety of these energy storage devices under outstanding conditions. In this work we analyze the thermal runaway behavior of 18650 Li-ion cells before and after storage degradation at high temperatures. The thermal behavior of the cells is analyzed using accelerating rate calorimetry.
Non-degraded and degraded commercial available 18650 Li-ion secondary cells were tested. The nominal capacity of the cells is 2550 mAh anode and cathode materials are graphite and LiCoO2 + additives, respectively. In order to degrade the cells, these were stored at 80°C and at different state of charges. The cells were tested inside an accelerating rate calorimeter (ARC, 2000TM Columbia Scientific Industries) to record exothermic and thermal runaway reactions under adiabatic conditions. The cells were charged/discharged using a battery tester (KIKUSUI, PFX2011).
Figure 1 shows the exothermic degree of non-degraded and degraded Li-ion cells as a function of state of charge. The data were generated from the self-heating rates of the cells obtained during the ARC tests at 180°C, where the self-heating rates of the cells were normalized based on the highest self-heating rate. This plot is useful to compare the exothermic behavior of the Li-ion cells at different state of charges. The non-degraded cell exhibited the largest exothermic degree at 100% SOC and the lowest degree at 0% SOC. The degraded cells presented lower exothermic degrees than that of the non-degraded cell at 100% SOC but higher exothermic degrees at 0% SOC.

Figure 1
LiVxFeyPO4f Nanostructure Cathodes for Lithium Ion Batteries
Authors: Channu V. S. Reddy , Thanedar Shri 
Published: February 2020

Fluorophosphates, like LiVPO4F, are expected to show high operating voltage (4.2V), long term cycle life (~1260 cycles) and low capacity fade behavior compared to the currently favorables LiCoO2 (4.0V), LiFePO4 (3.5V), and LiFePO4F or LiFeSO4F, or NaFeSO4F. The LiVPO4F could replace the current cathode technology to enable the commercial production of low cost, high energy density and safe Li -ion batteries for EV and PHEV applications. However, electrolyte oxidation at higher potential and the formation of poly-vanadate compounds like Li3V2(PO4)3 as an impurity during the two step synthesis process must be controlled. By adopting appropriate surface modification, preferably by various ceramic oxides, carbon and phosphate (FePO4 and AlPO4 etc.) based coatings would be employed to reduce activity towards electrolyte.
Soft-chemical synthesis offers numerous advantages for the formation of novel or advanced material forms including control over morphology (i.e., nanomaterials, coatings), phase, and composition. The controlled synthesis of nanomaterials and coatings, in particular, is imperative for the development of optical and electrical devices with ever-shrinking dimensions.
Substitution of environmental friendly transition metal cations, such as Co or Mn or Fe or Mg, in between vanadium site using soft-chemical or precipitation methods, could lead towards reducing the toxicity and the cost. In brief description, on the synthesis of LiVxFeyPO4F, V2O5, NH4H2PO4, LiOH.H2O, Fe(NO3)2.9H2O,NH4F and oxalic acid were used as-received to prepare the precursor solution. Oxalic acid used as a chelating agent and a reducing agent. First, V2O5 and oxalic acid in a stoichiometric ratio of 1:3 dissolved in deionized water under magnetic stirring at room temperature until forms a clear solution. Second, a mixture of stoichiometricNH4H2PO4, Fe(NO3)2.9H2O, NH4F and LiOH. H2O were added to the solution, followed by vigorously stirred using a magnetic stirrer for 1 h. The mixture solution was heated to 80 °C under active stirring to evaporate the water for several hours until homogenous slurry formed. Finally, the slurry was kept in an oven at 120 °C overnight. The prepared material was pressed into pellets and calcinate at 650 °C for 8 h under a gas flow of 90% Ar and 10 % H2.
MoO2/Mo2c Hybrid Nanowires As High Performance Anode Materials for Lithium Ion Batteries
Authors: Yang Lichun 
Published: February 2020

Molybdenum oxides, mainly including MoO3 and MoO2, are attractive materials with potential applications in catalysis, sensors and energy storage. Owing to the good electronic conductivity, high stability and density, MoO2 was proposed as a host material for lithium ions. However, the application of MoO2 as anode material for lithium ion batteries was limited in the early research, due to the low capacity and poor cycling stability resulting from the bulky dimensions, the consequential slow kinetics and huge volume changes during the charge/discharge process. To improve the performance of MoO2, a most promising way is to design and construct nanostructured composites [1-3].
Here we report on MoO2/Mo2C hybrid nanowires synthesized through simple calcination using MoOx/amine nanowires as a precursor. The small diameters of the nanowires ensure fast lithium ion insertion and extraction, while the long dimensions benefit good electron transport between wires. Besides, Mo2C with a high specific conductance distinctly increases the structural stability and electronic conductivity of the hybrid nanowires. As a result, the cycling and rate performance of the hybrid nanowires is remarkably enhanced. At a current density of 1000 mA/g, a discharge capacity of ~700 mAh/g is still retained after 300 cycles, which indicates the MoO2/Mo2C hybrid nanowires a promising anode material for high performance lithium ion batteries.
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (Nos. 51402110, and 51231003).
[1] Q.S. Gao, L. C. Yang, X. C. Lu, J. J. Mao, Y. H. Zhang, Y. P. Wu, Y. Tang, J. Mater. Chem., 2010, 20, 2807.
[2] L.C. Yang, L. L. Liu, Y. S. Zhu, X. J. Wang, Y. P. Wu, J. Mater. Chem., 2012, 22, 13148.
[3] H. J. Zhang, K. X. Wang, X. Y. Wu, Y. M. Jiang, Y. B. Zhai, C. Wang, X. Wei, J. S. Chen, Adv. Funct. Mater., 2014, 24, 3399.
Facile Preparation of Nanoflake Covered-Hollow NiCo2O4 and the Study of Electrochemical and Structural Properties As an Anode Material in Lithium Ion Batteries
Authors: Yoo Jaeseung , Venugopal Nulu , Son Suhan , Oh Woong , Lew Gil Hwan , Palanisamy Kowsalya , Yoon Won-Sub 
Published: February 2020

Transition metal oxide materials such as NiO, CoO and Co3O4 have been studying as attracting anode materials for lithium ion batteries and currently binary metal oxide systems are considered as promising material because of a great advantage to overcome the drawbacks like poor reversible capacity, conductivity and so on. For example, NiCo2O4 is one of binary metal oxide materials and has advantages such as low cost and toxicity because of low Co content in the material compared with Co3O4. Also electrochemical performance of NiCo2O4 is similar with that of Co3O4. The other strategy to enhance the performance is to make nanostructures such as nanoparticle, nanorod, nanoflake and hollow structure because of their high surface area. In this study, we report a facile preparation to synthesize nanoflake covered hollow NiCo2O4 by precipitation and annealing in air atmosphere. The surface area of the synthesized hollow NiCo2O4 is determined to be about 134 m2g-1 having pore size of 3-4 nm by N2 absorption method. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations reveal that hollow NiCo2O4 ­has unique porous morphology with nanoflakes of about 50 nm appeared on the surface of each hollow particle. The coin cell test with hollow NiCo2O4 electrode shows good electrochemical performance that the NiCo2O4 cell showed 440 mAh g-1 of discharge capacity at a current density of 5000 mA g-1 and was recovered 1519 mAh g-1 at a current density of 100 mA g-1 after fast C-rate. Also, the NiCo2O4 cell has excellent cycle life with above 1500 mAh g-1 at a current density of 100 mA g-1 after 30 cycles. Moreover, we investigated the structural change during the lithiation/delithiation by ex-situ X-ray diffraction (ex-situ XRD) technique based on synchrotron X-ray source. Detailed results will be presented at the meeting.
Improvement of the Electrochemical Performance of Si Anodes By Use of Ultrathin Polydopamine Coating upon Conductive Carbon Particles
Authors: Song Danoh , Jung Dae Soo , Cho Inseong , Lee Yong Min , Ryou Myung-Hyun 
Published: February 2020

Although silicon (Si) have received worldwide attention as a promising anode candidate because they are not only able to provide high theoretical capacity ~3500 mAh g-1 but also cheap and environmentally friendly source, a successful implementation of Si anode based lithium-ion batteries (LIBs) has been hindered thus far. This is because Si anodes suffer from huge volume change (c.a. 300%) during cycling. To improve cycle performance of Si anode based LIBs, the mechanical stress should be efficiently alleviated.
In this study, we developed surface modified conductive additive by use a mussel-inspired polymeric material: polydopamine (PD). Due to hydrophilic moiety of PD coating layer, PD-treated Super-P was well dispersed in the water, thus we could use poly(acrylic acid) (PAA) as a polymeric binder. PD-treated Super-P achieved highly improved cycle performance of Si anodes. Using FT-IR, we verified that the improved cycle performance is attributable to the newly formed covalent bonds between the amine group in PD-treated Super-P and the hydroxyl group in PAA. Furthermore, we evaluated adhesion property of anode composite using a Surface And Interfacial Cutting Analysis System (SAICAS). PD-treated Super-P showed the highest adhesion value compared to bare Super-P.

Acknowledgements

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2014R1A1A1005861).
Rice Husk-Derived Porous Silicon with High Purity As Anode for Lithium Ion Batteries
Authors: Jung Dae Soo 
Published: February 2020

Recently, social concerns and the importance of ‘green growth’ and ‘renewed energy technology’ have increased, which resulted from the increase in the cost of fossil fuels and climate change. One of the critical technologies for accomplishing ‘green growth’ is the recycle of waste products generated through manufacturing processes. One of the largest wastes is rice husks, which are generated from the production of rice. Rice is cultivated in more than 75 countries in the world and the worldwide annual rice production amounts to approx. 422 million metric tons, of which about 20% is rice husk. However, its utilization has been limited to low-value applications in the agriculture area, such as stockbreeding rugs, bed soil, fertilization and lagging materials etc., which is the case because of their tough, woody and abrasive properties.
Thus, many researchers have attempted to increase their added value, including the development of rice husks activated carbon, rice husk gasification and electricity generation. Some research groups have studied the potential of using rice husks as a fiber resource. Ah et al. reported the preparation of packing materials and Lee et al. developed a rice husk board. Rice husks contain approximately 20 wt% silica and because of ‘natural selectivity’ of rice plants, it has a lower level of metallic impurities than other representative silica sources, such as quartz, bentonite and diatomaceous earth etc.. Therefore, a significant effort has been directed at the production of high purity silicon-based materials from rice husks, such as SiC, Si3N4, SiO2 and high grade silicon. However, most of these studies are based on using rice husk ash (RHA), which is generated after the combustion of rice husk and very few studies have examined the potential of using the organic part of rice husks.
Thus, we developed a refinery process to integrate the use of rice husks and increase of the value of rice husks. This process has the combined benefit of producing valuable silicon-based materials and cellulose-based materials. The rice husks are divided into fiber and inorganic components during the refinery process. In this work, we investigated the chemical composition and morphological characteristics of the rice-husk derived silica obtained from the refinery process. The conditions for preparing SiO2 with high purity and high surface area were optimized and highly porous nano-structured silicon (Si) with high purity was prepared from rice husk-derived silica. We also examined the potential of using the rice husk derived silicon as an anode material in Li-ion batteries.
A Novel Adhesion Map Correlating Adhesion Properties to the Electrode Design Parameters in Lithium-Ion Battery Electrode
Authors: Kim Kyuman , Byun Seoungwoo , Cho Inseong , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

Fabricating the electrodes satisfying the targeted energy density, power density, and loading level is not a simple task to achieve because there are interrelated electrode design parameters such as loading level, density, thickness, composition, etc., affecting on the electrode property. Thus far, the time-consuming repetitive trials have been an only answer to achieve this goal.
To determine the optimized binder content and the electrode density have been also a difficult question because there has been few systematic research on adhesion properties for LIB electrodes. For instance, the conventional peel test with adhesive tape (3M Scotch tape) has been widely utilized to compare adhesion properties in electrode as a measuring tool.
Our group have introduced the Surface and Interfacial Cutting and Analysis System (SAICAS), which are able to measure the shear stress as well as adhesion strength at the interfaces in the LIB electrodes [1-4]. Here in, we utilized the SAICAS to correlate the adhesion property and the typical electrode design parameters–the loading level and the density–by utilizing a SAICAS technique. First, we measured the adhesion properties of LiCoO2 electrodes, having four different electrode densities (2.0, 2.5, 3.0, and 3.5 g cm-3) and three different loading levels (5, 10, and 15 mg cm-2), at the interface between current collector and electrode coating layer and at the middle of the electrode coating layer. Second, from the obtained data, we draw an empirical equation to predict adhesion strength as a function of electrode density and loading level. Third, we verified our attempt was reasonable by predicting the adhesion strength of the LiCoO2electrode randomly chosen in a random loading level and a random density.

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).

References

[1] Son, B.; Ryou, M.-H.; Choi, J.; Lee, T.; Yu, H. K.; Kim, J. H.; Lee, Y. M., Measurement and Analysis of Adhesion Property of Lithium-Ion Battery Electrodes with SAICAS. ACS Appl. Mater. Interfaces 2013, 6, 526-531.
[2] Choi, J.; Ryou, M.-H.; Son, B.; Song, J.; Park, J.-K.; Cho, K. Y.; Lee, Y. M., Improved High Temperature Performance of Lithium-Ion Batteries through Use of a Thermally Stable Co-Polyimide-Based Cathode Binder. J. Power Soures 2014, 252, 138-143.
[3] Choi, J.; Kim, K.; Jeong, J; Cho, K. Y.; Ryou, M.-H.; Lee, Y. M., Highly Adhesive and Soluble Co-polyimide Binder: Improving the Long-Term Cycle Life of Silicon Anodes in Lithium-Ion Batteries, ACS Appl. Mater. Interfaces, 2015, 7, 14851-14858
[4] Song, D.; Lee, S. H.; Kim, K.; Ryou, M.-H.; Park, W. H.; Lee, Y. M., Soluble Polyimide Binder for Silicon Electrodes in Lithium Secondary Batteries, Appl. Chem. Eng, 2015, 26, 674-680
Heat-Resisting and Flame-Retarding Difunctional Separators for Safe Lithium-Ion Battery
Authors: Hwang Suyeon , Jeon Hyunkyu , Lee Taejoo , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

Considering the ever increasing demands for the large-scale lithium-ion batteries (LIBs) targeting for the electric vehicles (EVs) and energy storage systems (ESSs), safety of LIBs is the primary issue to be solved for the successful implementation in a market. Although various types of heat-resisting separators have been suggested by introducing heat-resisting ceramic fillers, the main purpose of them is to improve dimensional stability of polyolefin-based microporous separator at high temperature [1,2]. If the separators are able to prevent not only short-circuit, but also retard flammability of organic liquid electrolytes at an abnormal condition, they can significantly improve the safety of LIBs.
To achieve this goal, here in, we introduced ammonium phosphate, a typical flame-retardant, in the ceramic-coated separators. We optimized the coating process and evaluated physical properties of the surface-coated separators such as morphology, permeability, wettability, ionic conductivity etc. Furthermore, we investigated the heat-resistance using hot electric iron tips and the combustion behavior of surface-coated separators by measuring self-extinguish time. The effect of surface-coated separators on the electrochemical properties of LIBs is also evaluated using 2032-type coin cells.

Reference

[1] Taejoo Lee et al. Effect of Al2O3coatings prepared by RF sputtering on polyethylene separators for high-power lithium ion batteries, Macromolecular Research, 22, 1190-1195 (2014)
[2] Myung-Hyun Ryou et al, Mussel-Inspired Polydopamine-Treated Polyethylene Separators for High-Power Li-Ion Batteries, Adv. Mater., 23, 3066–3070 (2011)

Acknowledgements

This research was supported by the Ministry of Trade, Industry & Energy(MOTIE), Korea Institute for Advancement of Technology(KIAT) through the Encouragement Program for The Industries of Economic Cooperation Region (G02A01280032701)