bluuebunny/crossref_metadata_2025 huggingface dataset:
Real-Time Characterization of Electrochemical Reaction Products
Authors: Khanipour Peyman , Löffler Mario , Reichert Andreas M. , Kloth Ricarda , Mangoufis-Giasin Iosif , Mayrhofer Karl J. J. , Katsounaros Ioannis
Published: February 2020

The classical way to characterize the selectivity of electrochemical reactions involves potentiostatic or galvanostatic electrolysis and intermittent product determination, for example with chromatography methods, nuclear magnetic resonance etc.1-3 The advantage of this approach is that quantitation is possible in terms of (partial) reaction rates, yields, selectivities or faradaic efficiencies. However, the offered temporal resolution is in the order of several minutes, so transient, dynamic processes that occur

within seconds cannot be captured. Differential electrochemical mass spectrometry was previously developed to address this point and was applied successfully to a wide range of reactions that form highly volatile or gaseous products.4

A newly developed, internationally unique methodology will be presented that allows for the detection of electrochemical reaction products in real time, independent of their vapor pressure and the presence of salts.5 Some examples of applying the electrochemical real-time mass spectrometry (EC-RTMS) in multi-product electrochemical reactions such as the CO2 reduction, the oxidation of alcohols or conversions of furanic compounds will be shown.

Acknowledgments

This work was funded by the German Federal Ministry for Education and Research (BMBF) under the project grants 033RC004C (eEthylen) and 03SFK2Z0 (Power-to-X), and by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy - Excellenzcluster 2186 “The Fuel Science Center”.

References

[1] K.P. Kuhl, E.R. Cave, D.N. Abram, T.F. Jaramillo; Energy Environ. Sci.
2012, 5, 7050-7059.

[2] C.W. Li, J. Ciston, M.W. Kanan; Nature
2014, 508, 504-507.

[3] R.S. Sherbo, R.S. Delima, V.A. Chiykowski, B.P. MacLeod, C.P. Berlinguette, Nat. Catal.
2018, 1, 501-507.

[4] H. Baltruschat, J. Am. Chem. Soc. Mass Spec.
2004, 15, 1693-1706.

[5] P. Khanipour, M. Löffler, A.M. Reichert, F.T. Haase, K.J.J. Mayrhofer, I. Katsounaros; Angew. Chem. Int. Ed. accepted, DOI: 10.1002/anie.201901923
Microelectrode Based Devices for Diagnosis of Electron Transport and Electrochemical Behavior of Redox-Conducting Materials
Authors: Kulesza Pawel J. , Rutkowska Iwona Agnieszka , Miecznikowski Krzysztof
Published: February 2020

We are going to address practical issues related to the principles and analytical aspects of electrochemical studies (typically done at room temperature) of solid, rigid or semi-rigid (nonfluid) systems in the absence of a liquid solution phase. Representative examples include redox and conducting organic polymers, melts and solid solutions of redox centers in solid ionic conductors, mixed-valence polynuclear inorganic materials, transition metal salts, oxides, and zeolites. The emphasis is on the elements of dynamics for the efficient delivery of charge and on reactivity of the ‘redox conducting’ materials. The effective (apparent) diffusional mechanism is critical to the success of most analytical measurements in solid-state.

Historically, electrochemistry in the absence of a bulk liquid phase has focused on the problems of energy storage and production. Recently, it has become possible to apply conventional electrochemical methods to characterize solid-state type redox electrolytes with respect to analytical characterization of materials, measurement of electron transfer rates, and determination of analytes using amperometric sensing. The characterization of materials by solid-state voltammetry primarily has focused on mixed-valence, ionically conducting compounds and on diverse organic ionomers hosting identifiable molecular (redox) sites.

Potential materials for solid-state electrochemical measurements are expected to contain three-dimensionally distributed highly concentrated redox centers between which fast electron self-exchange (hopping) is feasible. Among inorganic systems, single crystals of heteropolyacids of molybdenum and tungsten, as well thin films of Prussian Blue type metal hexacyanoferrates will be considered. These redox centers are fixed and, although they may have short range mobility about an equilibrium position, they classically are macroscopically immobile. The applicable materials also must host mobile counter-ions that are capable of providing charge balance during electron transfers, thereby serving the same purpose as the supporting electrolytes in conventional electrochemistry. The population of these ions must be sufficient to support diffusive mass transport of electrons and to minimize ohmic effects.

We will describe typical electrochemical cells and experimental tactics to overcome the relatively slow dynamics of transport in solid (non-fluid) systems. Application of microdimensional electrodes leads to an improvement in the quality of solid-state electrochemical data and provides new diagnostic and analytical possibilities. Basic concepts of mechanistic studies, which are relevant to the development of novel analytical methods, together with trends towards possible future applications will also be addressed.
Teaching Engineers in Thin Film Deposition: A Project Based Approach with Applications in Photonics and Laser Technologies
Authors: Steglich Patrick
Published: February 2020

A lecture model for a practical lecture is proposed, which is intended for a seminar in the master program photonics of the TH Wildau. As part of the seminar, it is important that students have the opportunity to plan the day-to-day tasks of a researcher. The project can be carried out both at the university or/and in companies.

We report on our experience with project-based teaching and provide a novel lecture model which allows students to develop an own research project within one semester.

The envisaged research project is investigated by each student itself and the topic is either defined by the lecturer or by the student himself. The work load of such a research and development (R&D) project is similar to one work package of a real research project. However, to motivate students it is reasonable to divide the R&D project into work packages. This task has to be done within the first two weeks and needs to be instructed by the lecturer.

After the topic and work packages are defined, the student starts to work on its own R&D project. According to our experience, it is worth to provide frequently consultations, e.g. every two weeks. Besides that, a handout with instructions about correct scientific writing is strongly recommended.

Finally, the students will present their results as a written report, a scientific poster and an oral presentation. Some outstanding results are may be published in a scientific journal or conference. This should be motivated by the instructor. In this case, the students have a great starting point for their future career.

We present as an example a R&D project in the field of optical sensors and biosensors.
Reusing a Hard Drive Platter To Demonstrate Electrocatalysts for Hydrogen and Oxygen Evolution Reactions
Authors: Gonçalves Ricardo Henrique
Published: February 2020

This demonstration brings the simplest multidisciplinary approach to evaluate the impact of the electrocatalysts in the water electrolysis half-reactions. The experiment is implemented with damaged hard drive (HD) platters as dimensionally stable electrodes for hydrogen and oxygen evolution reactions. The CoPtCr and Ni−P alloys deposited on the top of the platter are electrochemically stable in alkaline electrolyte and have an excellent catalytic activity. Techniques and principles, such as linear sweep voltammetry, chronopotentiometry, activation overpotential, and voltage efficiency, are demonstrated by employing these platters as electrodes.
Electrolytic Zinc Composite Coatings: Ultrasound Assisted Deposition for Morphological and Composition Modification
Authors: Baissac Lucas , Buron Cedric C. , Hihn Jean-Yves , Chantegrel Ludovic
Published: February 2020

Protection of steel by sacrificial coatings is of primary importance in the industry, to extend the lifetime of steel structure parts. This is frequently obtained by zinc coatings, after galvanization or electrodeposition, but pure zinc is sometimes not resistant enough when high protective properties are required. Indeed, zinc corrosion rate is quite important, even if corrosion products play an important role in protection. Therefore, Zn alloys deposition is a privileged process. However, the metallic alloy elements used for codeposition are frequently composed of harmful substances, which use is more and more regulated. In a global strategy of employees and environment protection, and to anticipate more drastic restriction, the European plating shop leader Electropoli proposed a partnership to the research institute UTINAM. The project Zincadher intended to propose an alternative to zinc alloys plating by a zinc matrix, reinforced by silica and PMMA particles which main function is to increase corrosion resistance and adhesion. To overcome the lack of availability of PMMA (poly (methyl methacrylate)) nanoparticles at a reasonable price, an original synthesis of the PMMA particles was first developed [1]. It involves the use of a custom-made ultrasonic system, were MMA (methyl methacrylate) and water mixtures are exposed to different ultrasonic systems and successive sonication steps as follows: 20 kHz → 580 kHz → 858 kHz → 1138 kHz. Then, polymerization of the droplets is conducted, in order to obtain the largest possible concentration of PMMA particles of sub micrometer size range of different electrokinetic properties [2].

In a second part of the study, electrochemical study of acid zinc electrolyte with PMMA and/or silica particle have been carried out. As ultrasound is known to improve greatly mass transfer and coating characteristics as well as particles dispersion [3], a calibration of acoustic streaming at the surface of the working electrode is conducted, to be able to compare with classical mechanical stirring with the concept of equivalent velocity. Then, after particles dispersion in an acid zinc bath, composite coatings are elaborated. The plating parameters (current density, particles nature, hydrodynamic source…) on the morphology and composition of the coatings are evaluated by SEM/EDS and XRD characterization.

Acknowledgement: The authors would like to thank Electropoli Group for funding this project and the ANRT for the CIFRE convention.

[1] K. Nakabayashi, T. Fuchigami, M. Atobe, Electrochimica Acta. 110 593–598 (2013)

[2] L Baissac, CC Buron, L Hallez, P Berçot, JY Hihn, L Chantegrel, G Gosse Ultrasonics sonochemistry 40, 183-192 (2018)

[3] JY Hihn, F Touyeras, ML Doche, C Costa, BG Pollet in Power Ultrasound in Electrochemistry: From Versatile Laboratory Tool to Engineering Solution, John Wiley & Sons, Ltd, 169-214 (2012)

Figure 1
Micro-Bubble Sonic-Electrochemical Preparation of Polyaniline
Authors: Komaba Kyoka , Goto Hiromasa
Published: February 2020

Polyaniline is one of the most promising conductive polymers because the polymer can prepared in water medium, no requirement of inert gas in the preparation process. Further, aniline monomer is low cost for production. Polyaniline is prepared by oxidative chemical polymerization with an aid of oxidizing agent such as ammonium persulfate or H2O2 in the presence of iron catalyst, or electrochemical polymerization in the water. Chemical polymerization affords to synthesize polyaniline in the bulk state or powder. However, deposition onto the metal electrode for applications is somewhat difficult because infusible and insolubility in common organic solvent. On the other hand, electrochemical polymerization allows producing thin film deposited onto the electrode. The thin polyaniline film on the electrode is valid for applications such as battery, anti-corrosion films, and gas-sensors.

We recently developed electrochemical polymerization of aniline with bubble air. Nano-bubble has been paid attention for various industrial fields [1]. The polyaniline thus prepared by the micro-bubble electrochemical polymerization has micro-pores on the surface. The size of micro-pores can be tuned by amount and size of micro-bubbles during the polymerization process through tuning of application voltage. The micro-bubble consists of H2 gas as a result of electrolysis of water. Polymerization is occurred during discharge of H2 gas from the anode side with producing micro-pores, resulting polyaniline with micro-pores.

We attempt capture of pollens in the air from the plant with the micro-pores on the polyaniline surface for solution of pollen allergy. The form of micro-pores on the conductive polymer has possibilities for cleaning of air by remove of pollens, removal micro-sands, dusts, oil, and poison gas to improve the environment. Combination of good redox character and the micropores form can lead to construction of electro-active clean up system.

Sonoelectrochemistry has opened a new avenue for electrochemical applications [2,3]. In this paper, we introduce preparation method of polyaniline having micro-pores by micro-bubble electrochemical polymerization with sonic vibration. Surface observation of the polymer with a scanning electron microscopy and discussion of the pore size and effect of the surface state with application of high-power sonic are reported.

References

[1]The latest technology on microbubbles and nanobubbles, Hideki Tsuge ed., CMC, Tokyo, 2007.

[2]J. Mason, J.P. Lorimer, D.J.Walton, Sonoelectrochemistry, Ultrasonics, 28, 333-337 (1990).

[3]J. Klima　Application of ultrasound in electrochemistry. An overview of mechanisms and design of experimental arrangement, Ultrasonics, 51, 202-209 (2011).

Figure 1
Microscopy and Spectroscopy Diagnosis Guided Optimization of Electrode Materials for Lithium Ion Batteries
Authors: Wang Chongmin
Published: February 2020

In-situ diagnosis appears to be one of the essential methods for gaining insights as how an electrode material failure, therefore feeding back for designing and creating new materials with enhanced battery performances. In this presentation, I will focus on recent progress on ex-situ, in-situ and operando S/TEM studies for probing into the structural and chemical evolution of electrode materials for lithium ion battery. I will highlight several recent key observations, which appear to be well documented, while essentially are poorly understood, and therefore act as the bottleneck for the advances of both cathode and anode for better batteries. It would be expected that this presentation can stimulate new ideas as how to attack these bottlenecks to advance the potential cathode and anode materials.
Tuning PAA-Based Binders Towards Optimized Performance for Silicon Anode in Lithium-Ion Batteries
Authors: Shi Zhangxing , Jiang Sisi , Ilavsky Jan , Li Tao , Zhang Lu
Published: February 2020

Poly(acrylic acid) (PAA) based binders have been widely used for silicon anodes in lithium-ion batteries to mitigate the issues caused by reversible volumetric expansion of silicon nanoparticles during lithiation/delithiation process. However, the performance of silicon anodes using PAA-based binders is still far from meeting the requirement of practical applications and the factors affecting the performance of these binders are not fully understood. Neutralization of PAA binders using LiOH is a common strategy for processing silicon anodes in lithium-ion batteries. In our previous studies, lithiated PAA solutions showed significant increased viscosity compared to straight PAA ones, which could benefit the large-scale lamination process and enable the fabrication of mechanically robust electrodes. However, lithiated PAA binders suffer more capacity loss in cycling tests due to the weakened adhesion and more severe side reaction of silicon particles that are mostly related to the increase of pH value of the binder solutions. In this work, non-lithium bases (e.g., NBu4OH, NH4OH, and Et3N) were used to neutralize and tune the viscosity of PAA solution. The resulting modified PAA binder solutions achieved desired viscosity with less increase of pH value. Notably, electrodes made with PAA-NH4 binder showed improved cell performance than electrodes made with PAA-Li binder. Despite the pH difference between PAA and PAA-Li binder solutions, the solvation behavior of the binders could also affect cycling performance. Therefore, a series of PAA solutions were prepared and investigated by small-angle X-ray scattering. The radius of gyration (Rg) of the binders were found to be significantly different depends on lithiation and the choice of solvent. Electrodes made with these binder solutions were evaluated in half cells to explore the relationship between solvation and performance of binders.
Heterogeneity of Ionic Conductivity in Lithium-Ion Battery Electrodes
Authors: Nielsen Kayci , Liu Baichuan , Mazzeo Brian , Wheeler Dean
Published: February 2020

Lithium-ion battery electrodes are known to have irregularities in their microstructure. When electrodes are not uniform in terms of conductivity, such inhomogeneities can lead to localized variability in current flow, potential, and species concentrations, which are associated with cell degradation [1]. Understanding and quantifying heterogeneity of battery electrodes is therefore an important step in engineering better batteries.

Our research group has previously succeeded in quantifying the variation of electronic conductivity of electrodes using a four-line microprobe [2]. Methods have also previously been developed for measuring the average ionic conductivity of battery electrodes [3], but there was no method for measuring localized ionic conductivity. Our research group recently developed a way to do such a measurement, allowing us to investigate the heterogeneity of effective ionic conductivity across an electrode.

We report the results of local MacMullin Number measurements (proportional to tortuosity or the inverse of conductivity) for various electrodes. We show the heterogeneity of both conventional Li-ion anodes and cathodes and the effect of cycling. In the future, we hope that this technology can be used as a diagnostic tool for improving design and manufacture of electrodes.

Fig. 1. Map of MacMullin Number for a Li-ion cathode

References:

[1] Vogel et al., Electrochimica Acta 297, 820 (2019).

[2] Lanterman et al., Journal of the Electrochemical Society 162, A2145 (2015).

[3] Pouraghajan et al., Journal of the Electrochemical Society 165, A2644 (2018).

Figure 1
(Invited) Evaluation of Reaction Sites of Graphite Electrode
Authors: Abe Takeshi , Miyazaki Kohei , Miyahara Yuto , Inoo Akane
Published: February 2020

For the fast charge of lithium-ion batteries, internal resistances must be decreased. Among the internal resistances, charge (lithium-ion) transfer resistances and ion transport resistances inside the composite electrode are the major ones. Charge transfer resistance of R
ct can be expressed by 1/R
ct = A/T exp(-E
a/RT). Here, A, T, E
a, and R are pre-exponential factor, absolute temperature, activation energy, and gas constant, respectively. We have extensively studied the activation energies for the charge transfer reactions, and concluded that de-solvation process is responsible for the activation energies. Then, we have tried to understand the pre-exponential factor of A. This factor corresponds to the reaction sites of insertion active materials. Here we evaluated the reaction sites of high oriented pyrolytic graphite by several methods, and the charge transfer resistances of graphite electrode were correlated with the reaction sites.
Lithium Intercalation Edge Effects and Doping Implications for Graphite Anodes
Authors: Peng Chao , Kramer Denis
Published: February 2020

The interface between electrolyte and graphite anodes plays an important role for Li intercalation and has significant impact on the charging/discharging performance of lithium ion batteries (LIBs). However, atomistic understanding of interface effects that would allow to rationally tune the interface is largely missed. In this work, we comprehensively study the energetics of Li near the main non-basal surfaces of graphite, namely the armchair and zigzag edges.

Compared with the bulk, both graphite edges provide stronger absorbing Li sites (i.e., sub-surface sites that lithiate at higher voltages). Furthermore, this effect is significantly more pronounced at the zigzag edge compared to the armchair edge due to its unique electronic structure. The “peculiar” topologically stabilized electronic surface state found at zigzag edges strongly interacts with lithium; thereby changing Li diffusion behavior at the surface as well. Finally, boron/nitrogen doping was identified as a promising strategy to tune the Li intercalation behaviors at both edge systems, which might give some guidance for the modification of graphite anodes with a view enhance intercalation kinetics.
Examination of Reversibility of Lithium Plating
Authors: Fear Conner , Carter Rachel E. , Love Corey T , Mukherjee Partha P.
Published: February 2020

Although Li-ion batteries are the state of the art in energy storage technologies, their lifespan and safety are reduced by a lack of understanding of the lithium plating phenomenon. Despite many years of research, the intricacies of the coupled thermal-electrochemical interactions that govern Li plating behavior remain surprisingly elusive. Some portion of plated Li can be reversibly stripped from the graphite and re-intercalated during either the rest or discharge phase following a charge in which Li plating occurred, but the factors affecting the degree of reversibility have yet to be uncovered. In order to induce Li plating experimentally, two strategies are widely employed: low rate overcharging of graphite beyond its intercalation limit (kinetically limited) and high rate/low temperature charging within the normal graphite intercalation range (transport limited). Although both strategies result in the electrodeposition of Li on the anode, the morphologies of these deposits may be markedly different, which in turn will affect how much of the Li becomes electrically isolated following re-intercalation. In this study, Li plating was induced in graphite half cells under both transport limited and kinetically limited scenarios in order to determine differences in degree of reversibility, plating morphology, and impedance characteristics. Coulombic inefficiency upon de-lithiation allowed for quantification of losses due to a combination of irreversible plating and SEI formation, while optical microscopy was used to characterize the morphology of Li deposits.
Integrated Experiment-Theory Approach to Elucidate Complex Interfacial Chemistry in Solid-State Batteries
Authors: Wan Liwen , Wood Marissa , Wood Brandon C.
Published: February 2020

All-solid-state batteries offer great promise for safer and higher-energy-density storage compared to conventional liquid-based Li-ion batteries. However, their practical use is hindered by high resistance caused by heterogeneity of structure and chemistry at the solid-state interfaces. To overcome these challenges, atomic-scale visualization of the interfaces and a detailed understanding of the correlation between interfacial structure, chemistry and processing conditions is critical. In this work, we use a combination of first-principles simulation and high-resolution scanning transmission electron microscopy with spatially-resolved electron energy loss spectroscopy to probe complex interfacial structures and chemistry in all-solid-state lithium batteries. We will further address how the processing conditions to prepare the interfaces will affects their structures, local chemistries and Li-ion conductivity through these interfaces.

This work of was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Defect-Driven Niobium Oxide Electrode for Lithium-Ion Batteries
Authors: Barnes Pete , Dixon Kiev , Zuo Yunxing , Ong Shyue Ping , Du Yingge , Xiong Hui (Claire)
Published: February 2020

The development and innovation of new electrode materials is needed for the next generation of electrochemical energy storage systems (EES). Lithium-ion batteries (LIB) are the leading technology in EES, however, they are plagued with several limitations including safety and stability. Metal oxide electrodes could provide a safer battery while maintaining high reversible capacity. When compared to the commonly used graphite, metal oxides operate at voltages above that of Li plating for safe operation. In addition, nanostructured metal oxides could enhance the performance of the battery by facilitating fast electron and ion transport. Traditionally, intercalation compounds of well-ordered close-packed oxides have been prized because of the general consensus that well-ordered structures having little or no intermixing between Li and transition metal sublattice are required to achieving high capacity with good stability. Consequently, disordered materials have received limited attention and have been less studied. Nevertheless, in recent years evidence has shown that transition metal oxides which have structural defects (e.g., vacancies and interstitials) at cation sites with local disorder have the potential to offer higher capacity and better stability compared to ordered oxides. In this talk, we report our integrated experimental and computational study of a nanostructured amorphous niobium oxide electrode for lithium ion battery. An irreversible phase transformation from amorphous to crystalline phase in niobium oxide electrode is observed during the first discharging process. The newly formed crystalline niobium oxide electrode exhibits high capacity, superb rate capability and good cycle life. The electrochemical charge storage mechanisms of the new electrode will be discussed.
Quenching Cathode Electrolyte Interphase on Ni-Rich Cathode Materials for Preventing Short Circuit Problem in Lithium Ion Battery
Authors: Wang Fu-Ming
Published: February 2020

In January 2017, Samsung announced the reason why the Note 7 explodes and losses of more than 5 billion US dollar. According to their explanations, it was caused by the internal short circuit problem in the lithium ion battery. Currently, there is no effectively solution for eliminating the internal short circuit problem owing to the sudden accident.

In this research, a new technology has been developed, which can be used to terminate the thermal runaway and promise the safety performance of lithium ion battery. High voltage Li-excess and Ni-rich layer-type cathode material is employed and combined with this safety electrode additive for investigation. In terms of the results, the new technology LIVING@additive significantly enhances the cycle performance at 60oC and high voltage. In addition, the following figures illustrated that the battery containing LIVING@technology is stable and passed the nail penetration test. On the other hand, the battery without LIVING@ cannot be used when the short problem is taking place. The LIVING@contains self-polymerized hyper branch structure in order to insulate the directly contact between anode and cathode. This electrode additive not only provides high thermal stability on electrochemical reaction, but the columbic efficiency of charge-discharge is also enhanced.
Electrolyte Additive Effects Observed By Gradient Polarity Solvent Wash
Authors: Fang Chen , Liu Gao
Published: February 2020

The fast evolution of electrical transportation system and smart grid desires advanced energy storage systems. Lithium-ion battery (LIB) is the primary option for energy storage in the global market, but its performance is still subject to improvement. Solid electrolyte interphase (SEI) plays a crucial role in LIB behavior, and electrolyte additives provide a convenient approach for fine-tuning the properties of SEI. It is crucial to obtain detailed structural and chemical information of SEIs and electrolyte soluble byproducts to promote mechanism understanding of the electrolyte additives and formation and function of SEI. Here, we propose to use gradient polarity solvent wash in combination with spectroscopic analysis to characterize both the composition of the electrolyte and layered structure of SEI. A series of model cells with a metal cathode, a lithium anode, and various additives are analyzed to reveal the electrolyte decomposition products in the electrolyte and the SEIs on the electrodes from these test cells.
Interfacial Origins of Degradation in High Energy Li-Rich NMC Cathodes Probed By Online Electrochemical Mass Spectrometry
Authors: Ramakrishnan Srini , Park Byungchun , McCloskey Bryan D.
Published: February 2020

Layered lithium-rich Ni, Mn, Co (NMC) oxide cathodes, with theoretical capacities greater than 250 mAh/g, can provide a game-changing boost to the energy density of current Li-ion batteries. Their high capacities stem from the participation of the oxygen anions of the oxide in charge compensation during Li-extraction at voltages above 4.5 V vs. Li+/0. As a result, however, they suffer from rapid capacity and voltage fade during battery cycling, concomitant with surface O2 release, spinel formation, crack propagation, transition metal migration etc. in the electrode. We study the interfacial origins and effects of this degradation employing Online Electrochemical Mass Spectrometry (OEMS). We demonstrate effective strategies of electrode surface passivation as well as electrolyte modification, that independently cause a significant suppression of the first cycle CO2 and O2 evolution, leading to improved longer-term cycling performance.
High C-Rate Lithium Ion Batteries with Niobium Tungsten Oxide
Authors: Kim Yumi , Jacquet Quentin , Rinkel Bernardine L.D. , Griffith Kent J. , Grey Clare P.
Published: February 2020

Lithium ion batteries are heavily investigated as storage devices, in order to obtain high energy density and high power density. However, there are still many problems to be solved; high rate and low temperature cycling of graphite-based electrode leading to lithium plating, for example. Recently, our group has introduced niobium tungsten oxide (NWO) as a high-rate electrode material for lithium ion batteries[1]. As an extension of this study, Nb16W5O55 is electrochemically tested with commercial cathode materials and the feasibility for high C-rate lithium ion batteries is confirmed. For this purpose, the Ni-rich NMC622 (Li(Ni0.6Mn0.2Co0.2)O2) compound and LFP (LiFePO4) cathode material are coupled with the crystallographic shear structured Nb16W5O55 anode, and 1.0 M lithium hexafluorophosphate (LiPF6) in ethylene carbonate (EC)/dimethyl carbonate (DMC) (1/1 vol.%) is used as electrolyte. From the full cell test with NMC622, NWO shows 86.8% capacity retention at 5C/5C charge/discharge after 500 cycles with high coulombic efficiency. Moreover, with LFP cathodes, an excellent stable performance of 89% of capacity retention at 10C/10C after 1000 cycles is confirmed. Electrolyte analyses are performed by solution NMR, and the full cell degradation is thoroughly investigated by EIS, SEM and XRD. Electrochemical performance at high temperatures is also discussed in detail.

Keywords: niobium tungsten oxide, lithium ion battery, anode, high c-rate material

Reference

[1] K.J. Griffith, K.M. Wiaderek, G. Cibin, L.E. Marbella and C.P. Grey, Nature, 559, 556 (2018).
A Benign Sol-Gel Route Towards Porous Carbon Coated Sb Nanoparticles: A High-Performance Li-Ion Batteries Anode
Authors: Dashairya Love , Saha Partha , Chaturvedi Vikash , Shelke Manjusha
Published: February 2020

Rechargeable batteries have wide applications ranging from portable electronics to hybrid electric vehicles owing to an incessant demand for improved capacity and longer lifetime. Metal-based anodes (Sb, Sn, Si, Ge, etc.) can offer high specific capacity albeit with rapid fade due to inherent volume expansion associated with the active phase impedes their commercialization and rapid growth. In the present work, a novel polymer-derived porous carbon coated antimony nanoparticles (Sb@C) based core-shell architecture is proposed for Li-ion batteries anode, wherein a thin conductive carbon shell over Sb nanoparticles (SbNPs) is developed using polymeric diol-aldehyde reactions via a sol-gel route. The core-shell architecture of Sb@C affords a carbon coating act as a buffer and prevents the structural disintegration of SbNPs during Li-ion alloying/de-alloying reactions while improving the rate capability and capacity fade. The structure and morphology of the as-synthesized Sb@C core/shell architecture were studied by XRD, FESEM, and TEM analyses confirmed the formation of thin carbon coating (~100 nm) on to the SbNPs. Preliminary electrochemical results demonstrate that Sb@C anode can deliver a discharge and charge capacity of ~730 mAhg-1 and ~490 mAhg-1 respectively, at a constant current density of ~100 mAg-1 at first cycle. Electrochemical impedance spectroscopy (EIS) results indicate that Sb@C shows lower charge transfer rate (Rct) and improved Li-ion storage performance than the bare SbNPs.

Figure 1
Directly Electrodeposited Porous Sicu Composites As Li-Ion Batteries Anode Materials
Authors: Li Guomin , Li Bing
Published: February 2020

We prepared SiCu composites which used CuCl-SiCl4-[BMP]Tf2N ionic liquid solution by one-step electrodeposition. SiCu composites provide porous structure which could buffer volume effect when lithiated/delithiated and high conductivity due to the import of Cu elemental. The method that directly electrodeposited the active material on collector without conductive additives and binders simplifies the electrode preparation, reduce production cost and facilitates large-scale preparation. As Li-ion battery anode materials, SiCu composites manifested high capacity retention that the specific capacity is 1302.2mAh/g at 800 cycles, which has theoretical significance and practical applications.
CO2-Derived, in-Situ Carbon-Coated Macroporous Silicon As a High Performance Anode Material for Lithium-Ion Batteries
Authors: Cha Younghwan , Dong Panpan , Zhang Xiahui , Song Min-Kyu
Published: February 2020

The magnesiothermic reduction of silica (SiO2) has been widely explored as a sustainable synthetic route for Si-based anode materials toward advanced lithium-ion batteries. This method utilizes earth abundant SiO2 as a compelling precursor for Si, which is readily attainable from, for example, sea sand, rice husk and diatom frustules. Also, the formation of 3D porous structure via simple removal of magnesium oxide (MgO) is beneficial to improving battery performance since it can help to accommodate 300% volume change during battery operation.

However, many studies have consistently reported incomplete conversion after the synthesis, which is typically in the form of undesirable remnants or side products: unreacted SiO2 and intermediate magnesium silicide (Mg2Si) that need to be chemically removed along with MgO, resulting in active material (Si) loss and uncontrollable porous structure. In addition, to enhance battery performance, it is widely believed that carbon protecting layer should be deposited on Si surface to obtain stable solid electrolyte interphase. The additional process for carbon coating, however, often requires costly and time/energy consuming steps and, therefore, hinders the practical deployment of Si anodes.

To obtain new insights into the incomplete conversion process, we carried out real-time phase evolution studies via in-situ high temperature X-ray diffraction during the magnesiothermic reduction of SiO2 under various thermal treatment conditions. Based on these results, we proposed a novel processing route that can minimize the active material loss and produce in-situ carbon coating on macroporous Si by utilizing gaseous carbon dioxide (CO2) as mild oxidant and precursor for carbon layer. The near-synchrotron X-ray nano-computed tomography was employed to obtain the processing-structure-property relationship. CO2-derived, in-situ carbon coated macroporous Si showed good initial Coulombic efficiency (86%) and high reversible capacity of 2000 mAh/g at 0.2 C-rate with promising cycling performance.
Electronic Structure Elucidation of Two-Step Electrolyte Decomposition Mechanism on Li(x)Mn(1.5)Ni(0.5)O(4) (001) Surfaces
Authors: Leung Kevin
Published: February 2020

High voltage cathode oxide mateirals like the Li(x)Mn(1.5)Ni(0.5)O(4) spinel can potentially enable high energy density lithium batteries for transportation storage applications. However, they rapidly degrade the organic liquid electrolyte. Customized solvent molecules and passivation coatings/strategies have been devised to alleviate this problem. Drawing from previous theoretical work and new hybrid functional Density Functional Theory (DFT) predictions, we argue in this presentation that the degradation mechanism has more than one step on the spinel (001) surface. First, standard battery liquid solvent molecules already decompose at low potentials, and even on the surfaces of spinel oxides without nickel doping, which operate at modest voltages. The organic fragments cover up catalytically active transition metal sites, yielding a functional form of cathode electrolyte interphase (CEI). Later, at high voltages, the decomposed solvent fragments further break down to release carbon dioxide and other species, leaving the catalytic sites uncovered and leading to continuous reactions with the liquid electrolyte. Mechanistic comparison with organic reactions on platinum surfaces will be made. However, the precise voltage range of breakdown offset cannot yet be predicted. These steps underscore the importance of understanding CEI degradation reaction, not just electrolyte oxidation, and will help inform new passivation strategies to enable high voltage cathode materials.

This work was supported by Nanostructures for Electrical Energy Storage (NEES), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DESC0001160. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.
Lithium-Ion Battery Safety Tests Monitored By Labview and Comsol Software for Electrical and Mechanical Characteristics
Authors: Sharma Snigdha , Panwar Amrish K , Tripathi Madan Mohan
Published: February 2020

This paper presents a unique cheaper battery safety test bench for electrical and mechanical performance evaluation of lithium-ion batteries where mechanical performance is tested using software and electrical characteristic is tested using hardware. In this work, simulation of mechanical performance of lithium-ion battery such as thermal modelling test at various temperature has been carried out using Comsol software, where battery voltage and temperature are monitored as a control input during a drive cycle and state of charge of the battery on the positive (65-80%) and a negative electrode (14-29%) is monitored and triggered as a control output. A hardware test bench has been developed to execute various electrical tests for evaluating battery performance during a discharge cycle. These electrical tests have been carried out on the LabVIEW software to obtain the real-time data and display the battery related information such as voltage and current curves. Further, a battery safety test like external short circuit test has been performed and also for improving the battery efficiency capacitors are connected parallelly with varied load condition. Overall, in this exploration, a newly evolved, accurate, affordable battery testing and monitoring system has been developed.

Keywords: LabVIEW Software, Comsol Software, Battery Safety test, Electrical Test, Mechanical Test.
Degradation of Commercial Lithium-Ion Cells Beyond 80% Capacity
Authors: Preger Yuliya , Fresquez Armando , Chalamala Babu R. , Ferreira Summer
Published: February 2020

To defray the upfront cost of lithium-ion electric vehicle (EV) batteries and to minimize waste, there is substantial interest in repurposing them after their EV end-of-life for grid-related applications (battery second life). The reliability of any economic or technical feasibility analysis for second life batteries strongly depends on the battery degradation behavior, but insight into this degradation in the region of interest remains limited. Most cycling studies in the open literature only age batteries to about 80% capacity (the typical cutoff for marking end-of-life). A few studies that have cycled batteries beyond 80% capacity have suggested the existence of a ‘tipping point’ upon which rapid degradation is initiated, but a limited set of cycling conditions and chemistries were explored.

We have previously reported on our large-scale, multi-year aging study of commercial LiFePO4/LFP, LiNixCoyAl1-x-y­O2/NCA, and LiNixMnyCo1-x-yO2/NMC cells, varying the discharge rate, depth of discharge (DoD), and environment temperature. Now that many of those cells have reached 80% capacity, we have initiated a second life aging study. The advantage of studying these cells compared to those from second-hand EV battery suppliers is that the cycling history is known. Thus, it is more feasible to determine the extent to which prior cycling conditions influence later degradation and the early markers that could foreshadow the possibility of rapid degradation beyond 80% capacity. Diverse cycling conditions were studied to determine what protocols, if any, can mitigate rapid degradation.

Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. SAND2019-4631 A
Recycle of End-of-Life NMC 111 Cathodes By Electrochemical Relithiation
Authors: Coyle Jaclyn , Li Xuemin , Santhanagopalan Shriram , Burrell Anthony
Published: February 2020

Recycling end-of-life (EoL) lithium ion batteries (LIBs) is of great significance to provide additional transition metal resources and alleviate environmental pollution from batteries wastes, but lags far behind compared with that of lead-acid batteries in the recycling industry. Conventional LIBs recycling methods including pyrometallurgy and hydrometallurgy processes have limitations with regard to energy inefficiency, extensive gas treatment, as well as complex chemical reactions and purification steps for leaching and separating metals. This project is part of ReCell which is a collaborative effort to develop efficient and economical recycle and reuse methods for EoL battery cathodes. The objective of this work is to recover the EoL cathode performance and structure by electrochemical relithiation using a Li metal sacrificial anode since Li ion (Li+) inventory loss plays a significant role for the cathode degradation. The morphology, composition and structure of the initial NMC 111 pristine and chemically delithiated powders used for the ReCell project were characterized through Raman spectroscopy, FIB SEM and TGA. Chemically Delithiated NMC 111 anodes have been prepared and relithiated using a range of temperatures and currents in order to optimize the electrochemical relithiation for application in a roll to roll process. Initial results indicate that elevated temperatures will be necessary to facilitate fast relithiation of the NMC 111 cathodes with the addition of more thermally stable electrolytes. Analysis and characterization of aged NMC 111 anodes in pouch cells is applied to verify the effectiveness of electrochemically relithiated anodes and to compare to the chemically delithiated NMC 111 model material. This study provides more understanding towards developing a battery material recovery process that will potentially recover specialized material morphology and help to minimize energy use and emissions.

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Detection of Pathogenic Bacteria and Cancer Cells in Body Fluids Using Magnetostrictive Particle (MSP) Biosensors
Authors: Yi Wei , Liu Jiachen , Chin Bryan A. , Cheng Zhongyang
Published: February 2020

Magnetostrictive particle (MSP) provides sensitive tests for measuring tiny amount of mass and it can serve as a useful device for cell detection and offers potentially effective approaches to clinical diagnosis for detecting bacterial pathogens and early-stage cancer cells. Compared to conventional cells identification methods, MSP biosensor has the advantages of short response time and low cost. It does not require any incubation process thus provides a reagent free direct measurement in practice which does not require any complicated biochemical reactions. Each MSP sensor contains magnetostrictive materials coated with modified antibodies and such structure makes the sensor generate different resonance frequencies in an induced magnetic field after exposure to different concentrations of cells.

Those frequency shifts can be analyzed to determine the presence and concentration of certain bacteria or target human cells in body fluid samples. Here we provide a method to use MSPs to detect two type of cells in body fluids. Staphylococcus aureus is used as an example of common infectious pathogens to human and a breast cancer cell line MDA-MB-231 is used as a example for cancer cells. It is found that the detection limit of MSP sensors for cells can be less than 100 CFU/ml. The results are obtained within a few minutes which makes MSP sensors promising tools in diagnosis of bacterial infections and providing early-stage detection of cancer.

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(Invited) Wrinkled PEDOT:PSS Film Based Stretchable and Transparent Triboelectric Sensor for Human Motion Monitor
Authors: Wen Zhen
Published: February 2020

The usage of functionalized conductive polymer has been a promising choice for flexible triboelectric nanogenerators (TENGs). However, how to integrate the solid and rigid film into a stretchable TENG for inspecting human motion or gesture still pose challenges. In this work, a transparent and stretchable wrinkled PEDOT:PSS electrode based TENG (WP-TENG) has been fabricated. The inner wrinkle distance and thickness are ~5 μm and ~1.81 μm, respectively, with maximum stretched strain of ~100%. As an electrode, the optimum conductivity and transparency can reach 0.14 kΩ/□ and 90%, respectively. Operating in the single-electrode mode at 2.5 Hz, the WP-TENG with an area of 6 × 3 cm2 produces an open-circuit voltage of 180 V and short-circuit current of 22.6 μA. It can be worn on the wrist to harvest hand tapping energy and charge a commercial capacitor to 2 V in ~ 3.5 min, and then drive an electronic watch for more than 30 s. Furthermore, by attaching to human skin, the WP-TENG can be treated as an active human motion monitoring sensor, which could inspect the bending angle of the elbow and joint of human by analyzing the peak value of voltage output and monitor the motion frequency by counting the peak number. The triboelectric mechanism also enables the WP-TENG to realize high-performance active tactile sensing. The active sensor with an external resistor of 100 MΩ illustrates the sensitivity of 0.08 kPa−1 in the pressure range from 2 to 60 kPa, and 0.008 k Pa−1 from 60 to 160 kPa, respectively. The assembled 3 pixel × 3 pixel tactile sensor array was fabricated for mapping the touch location or recording the shape of object contacted with the sensor array. The remarkable active sensing capability of WP-TENG with superior transparency and stretchability exhibits the development prospect in novel applications, such as human-machine interaction, e-skins, soft robots and wearable electronics, etc.

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