bluuebunny/crossref_metadata_2025 huggingface dataset:
Transbattery, a Novel Class of Device to Study Electronic Properties of Nanostructured Materials for Energetics.
Authors: Poli Federico , Lan Tian , Herrera Jose Ramon , Santato Clara , Cicoira Fabio , Soavi Francesca
Published: May 2020

International energy policies aim to promote the efficient use of renewable energy sources and sustainable electric transport. Furthermore, the growing demand for energy autonomy is pushing research towards the development of low consumption/ self-powered electronic devices. This requires high-efficiency energy storage/conversion systems.

In this context, the research is strongly committed to the development of new nanostructured electrode materials, especially for lithium batteries. Nowadays, attention is also paid to the miniaturization of electrochemical energy storage systems and their on-a-chip integration.

Therefore, here we report a systematic study on the electronic conductivity of thin films of nanostructured electrode materials for lithium-ion batteries. In particular, attention has been devoted to high voltage cathodic and stable anodic active materials.

This has been addressed, for the first time, using an "Electrolyte gated transistor" as cell configuration. Indeed, with this cell configuration, it has been possible to evaluate the electronic characteristics of the materials in situ, i.e. during the redox processes that are at the basis of battery operation.

In this study correlation between morphological and electronic properties of the material under charge/discharge cycling has been studied in order to monitor their evolution. The effect of different electrolytes such as commercial ones and, super-concentrated has been studied as well as the cycling performance. Finally, it has been possible to determine the most appropriate strategy to prepare the electrodes and select the right electrolyte in order to guarantee high current output and stability.

Acknowledgments

The research has been carried out under the Executive Bilateral Program Italy-Quebec 2017-2019 “Electronic properties of nanostructured materials for energetics” (M02241, QU17MO01 ).
Synthesis of LiFePO4 Cathode Materials Using Refined Li3PO4 By a Simple Process from Waste Lithium-Ion Batteries
Authors: Heo Kookjin , Im Jehong , Lee Jongkwan , Lim Jinsub
Published: May 2020

Recently, Lithium ion batteries have been widely used in large-scale product such as xEV and ESS system. As the demand of lithium ion batteries increases, the demand of lithium source also increases. Raw lithium material are obtained mainly from two main source; mining of spodumene ores and salt lake brines, there are many disadvantage of the technical complexity and high cost of separating lithium from other mineral salts. As a result, in recent years, lithium ion battery recycling has become an important issue, and it is expected to solve the problem of increased demand for lithium source. In this study, lithium phosphate from LIB recycling wastewater was refined in a simple process using deionized water (DI). The morphologies and compositions associated with purifying Li3PO4 were investigated using X-ray diffraction, field emission-scanning electron microscopy, simultaneous thermogravimetric-differential thermal analysis, differential scanning calorimetry, pH measurement, inductively coupled plasma optical emission spectroscopy, and carbon and sulfur determinators. Simple refining with DI can increase Li3PO4 purity from 94.601% to 98.867%. LiFePO4 (LFP) was then synthesized using the purified Li3PO4; its morphology was studied and its electrochemical performance evaluated by constant current charge/discharge testing and cyclic voltammetry. The LFP cathode fabricated from purified Li3PO4 exhibited improved electrochemical properties, particularly in terms of initial capacity and cycling stability.
Advances in High-Throughput in-Situ X-Ray Diffraction Analysis of Lithium Ion Batteries
Authors: Speakman Scott A , Sommariva Marco , Gateshki Milen , Masiello Fabio , Degen Thomas
Published: May 2020

X-ray diffraction using hard radiation (>17 keV) is able to measure lattice parameter and phase changes of cathode and anode materials simultaneously during battery cycling. Advances in hard radiation optics and detectors, combined with data logging software to correlate diffractometer and potentiostat data, are being used to improve in-situ battery analysis using laboratory diffractometers. Research previously done at synchrotrons can now be conducted with the laboratory diffractometer, improving opportunities for long-term experimental design. In this study, a reversible displacive phase transition in NMC cathodes, marked by significant contraction of the unit cell, is observed during cycling at a modest 4.2V potential. The magnitude of lattice contraction is dependent on the Ni content. This phase transition appears distinct from the H1 to H2 phase transition. Quantitative Rietveld anlaysis is used to precisely track lattice parameter changes in the cathode material. Because transmission diffraction measures cathode and anode simultaneously, anode phase content is quantified between C, LiC12, and LiC6 and these quantities are correlated to behavior of the cathode.
A Novel Quaternary Composite Solid State Electrolyte for Li Batteries
Authors: Al-Salih Hilal , Yim Chae-Ho , Niketic Svetlana , Freytag Annica , Goward Gillian R. , Baranova Elena A. , Abu-Lebdeh Yaser
Published: May 2020

All-solid-state batteries continue to grow as an alternative to replace the traditional liquid-based ones not only because they provide increased safety but also higher power and energy density [1]. However, current solid-state electrolytes are either brittle (ceramics) or suffer low ionic conductivity at room temperature (polymers) [1]. Therefore, composite solid electrolytes are considered as a viable option. We have developed flexible and easy film-forming composite solid state electrolytes (CSEs). Our promising CSE is a quaternary composite that consists of the Solid polymer electrolyte (SPE) Poly(ethylene oxide)/ Lithium bis(trifluoromethanesulfonyl)imide (PEO/ LiTFSI), the fast conducting perovskite inorganic ceramic Li0.33La0.557TiO3 (LLTO) and the plasticizer Succinonitrile (SN). Over 40 samples with different (PEO/LiTFSI/LLTO/SN) compositions were prepared and characterized. The optimal mechanical and electrochemical properties was found for the sample 10S which has the following composition: 70%-PEO 12% LiTFSI 9%-LLTO 9%-SN. 10S had the ionic conductivity of ̴ 10-3 S/cm at 55 ̊ C and young’s modulus of around 105 MPa. The all-solid-state battery made by sandwiching 10S between a lithium metal anode and an NMC 532-based cathode achieved specific discharge capacities of 161 mAh/g at C/20. Pulsed-field gradient NMR was performed at different temperatures to measure the diffusion coefficient. The results have shown an Arrhenius-type dependence with a slope switch at around 55 ̊ C which is a similar behavior as the one observed in the Arrhenius plot obtained from conductivity measurements. Further investigation is underway to elucidate the conductivity mechanism in this new type of quaternary composite by advanced NMR and other techniques

Reference

[1] M. Keller, A. Varzi, S. Passerini, J. Power Sources
2018, 392, 206.

Figure 1
Screening the Li-Ni-Mn-Co-O Composition Space in High-Throughput for Li-Ion Batteries
Authors: Hebert Alex , Potts Karlie , McCalla Eric
Published: May 2020

Currently, layered metal oxide materials are the norm in manufactured cathodes for Li-ion batteries, with LiNixMnyCo1-x-yO2 (NMC) being one of the leading class of materials. While NMC has been extensively studied, the composition space for the material has not been entirely explored, especially when one includes Li-rich compositions. Screening entire pseudo-quaternary systems is extremely time-intensive such that high-throughput techniques are necessary in order to enable study of the complex composition spaces. Herein, synthesis and characterization of a large number (several hundreds) of samples is accomplished by performing all work in high-throughput (sets of 64 samples of varying metal concentration were synthesized simultaneously). All samples were characterized structurally using a high-throughput X-ray diffractometer capable of acquiring 64 Rietveld quality patterns on mg-scale samples in 12 h. The XRD patterns were analyzed to generate structural phase diagrams as shown for Li-Mn-Ni-O below. The structural studies are coupled with high-throughput electrochemistry recently developed in the lab. Cyclic voltammetry was performed on all samples to gain insight into their performance as a cathode material. The results for energy density are shown in the figure below. Results for the quaternary system including various concentrations of Co will also be presented. This work marks the beginning of the thorough structural/electrochemical mapping of many layered oxide composition spaces and will enable meaningful structure-property relations that will guide the rational design of new cathode materials for Li-ion cells.

Figure 1
High-Throughput Studies of Li-La-Zr-O Garnet Solid Electrolytes
Authors: Anderson Ethan Christopher , Jonderian Antranik , McCalla Eric
Published: May 2020

Development of next-generation lithium-ion batteries has increasingly focused on all-solid batteries employing either ceramic, polymer, or glass electrolytes in order to address shortcomings in currently commercialized liquid electrolyte lithium-ion batteries including safety, limited lifetime and lower energy densities resulting from the instability with respect to Li metal anodes.[1] Lithium lanthanum zirconium oxide (LLZO) is a leading candidate for solid Li-batteries due to its high lithium-ion conductivity, stability in air and with Li metal, and compatibility with high-voltage cathodes.[2],[3],[4] Despite significant progress being made in its development, our understanding of LLZO is limited by the relatively small number of compositions which have been studied; especially considering the leading contender is a pseudo-quaternary oxide (Ga-doped LLZO).[5]

Herein, we have applied a high-throughput methodology for synthesizing, characterizing, and testing sets of 64 LLZO electrolytes at the mg-scale. This has allowed the study of the entire Li-La-Zr-O pseudo-ternary system by enabling a single researcher to explore hundreds of compositions in a single week. We employ a sol-gel synthesis method whereby a robot dispenses reagent solutions in order to vary the composition across a well-plate. After drying the samples and burning off the citrates, the resulting powders are pressed into pellets using a custom-made 64-pellet die and the pellets are sintered at the desired temperature. The high-throughput characterization techniques utilized include powder X-ray diffraction, electrochemical impedance spectrometry and electrochemical cycling in order to test electrolyte stability; with each method performed on 64 samples simultaneously.

The resulting structural phase diagrams will be presented for various sintering temperatures along with the extracted electrochemical properties. Given that ionic conductivity in ceramic electrolytes depends heavily on the presence/absence of certain structural defects, the complete understanding of the phase diagrams will significantly accelerate the development of this important class of advanced materials.

[1] D. Aurbach et al., Electrochimica Acta
2004, 50, 247-254.

[2] F. Zheng, et al., J. Power Sources
2018, 389, 198-213.

[3] Q. Liu, et al., J. Power Sources
2018, 389, 120-134.

[4] T. Thompson, et al., ACS Energy Letters
2017, 2, 462-468.

[5] J-F. Wu, et al., ACS Applied Mater Interfaces
2017, 9, 1542-1552
Formation Mechanism and Stability of Solid Electrolyte Interphases in Linear Carbonate-Based Electrolytes
Authors: Ebrahiminia Mahsa , Wang Cun , Bedrov Dmitry
Published: May 2020

Broad application of lithium batteries, necessitates improvements in their safety, cycle life, durability and energy density. Clear understanding of the electrode/electrolyte interfaces is one of the important factors in designing batteries with enhanced performance. Linear organic solvents are extensively used in electrolytes of lithium batteries to reduce viscosity and melting temperature of cyclic carbonates. However, these organic compounds are not stable in contact with anode, leading to decomposition of the electrolyte and formation of Solid Electrolyte Interphase (SEI). Although SEI is proven to be one of the most important parts of batteries, its structural complexity, mechanism of formation, and properties are not completely understood yet. In this work, we consider mechanism of formation and stability of SEIs composed of redox products of linear carbonate solvents. So far, the main focus of research was on decomposition products of cyclic carbonates. In case of linear carbonates, the SEI stability consideration is limited to the systems being in DMC solvent and to the best of our knowledge, there are no theoretical investigations on linear carbonate-based SEIs formation mechanism and properties.

In this work, we study Lithium Methyl Carbonate (LMC), Lithium Ethyl Carbonate (LEC) and Lithium Propyl Carbonate (LPC), which are single-electron reduction products of carbonate solvents in contact with the electrode, in their corresponding solvents being Dilithium Methyl Carbonate (DMC), Dilithium Ethyl Carbonate (DEC) and Dilithium Propyl Carbonate (DPC), respectively (Figure 1). Our aim is to chemically, kinetically, and thermodynamically study the aggregation, formation and stability of SEI layer in these systems from experimental, Molecular Dynamics (MD) simulation and Density Functional Theory (DFT) calculation points of view. Our study indicates that in LMC/DMC mixture LMC molecules have strong tendency to self-assemble and have low barriers to undergo second-electron reduction to form stable Li2CO3. Stable SEI was also observed in LPC/DPC as well, which is believed to be a result of slow dynamics of larger molecules and therefore increased possibility of the second-electron reduction near electrode surface. In the LEC/DEC system, however, we did not observe a stable SEI formation due to low tendency of LEC molecules to self-assemble, low electronic affinity coupled with high energy barrier for possible second electron reduction reaction. Therefore, our work illustrates that the selection of the linear carbonate as a blending partner for cyclic carbonates, might have an important impact on the ability of electrolyte to form stable and compact SEI layer.

Figure 1. Carbonate solvents and components studied in this work.

Figure 1
Effect of Electrode Fabrication Process on the Crystallinity of PVDF Binder and Electrochemical Performance of Electrode
Authors: Fu Yanbao , Song Xiangyun , Liu Gao , Battaglia Vincent
Published: May 2020

In lithium ion battery in fabrication of electrode with good mechanical performance, active materials and conductive agent have to be mixed with specific polymer as binder to binding the other components together. As an effective binder, the polymer should meet some requirements for battery performance and production, such as excellent adhesion to current collector, suitable cohesion to active material and conductive agent, good electrochemical stability over a wide voltage window, high lithium ion conductivity, and so on. Because the binder may coat on the surface of active material particles, the binder layer should have high ionic conductivity and lithium ion can pass through the binder. Poly (vinylidene fluoride) (PVDF) is the mostly common used binder in lithium ion battery production. The amorphous phase in PVdF is a good matrix for polar molecules, and lithium ions can pass through a thin layer of swollen PVdF[1]. PVDF is a semi-crystalline polymer with a repeating unit of –CH2-CF2-. The spatial arrangement of the CH2 and CF2 groups along the polymer chains can contribute to the unique properties of PVDF from its crystalline phase. But it is seldom researched that the effect of crystalline structure of PVDF on the electrochemical performance in lithium ion battery. In our recent study, we found that the impedance of electrode is dependent on the drying temperature of coated slurry[2]. In this research we investigated the relationship of process conditions with crystalline phases of PVDF binder in the electrode and the dependence of the electrochemical performance of the electrode on the process conditions.

[1]. K. Tsunemi , H. Ohno , E. Tsuchida , Electrochimica Acta , 28 (6) , 591 (1983) .

[2]. Y. Fu, X. Song, G. Liu, V. Battaglia, 236th ECS Meeting Abstract,353, Oct. 13-17, 2019, Atlanta, GA.

Figure 1
Operando Electrochemical Pressiometry Using Three-Electrode Cells Probing (Electro)Chemo-Mechanics for All-Solid-State Lithium-Ion Batteries
Authors: Jun Seunggoo , Nam Young Jin , Kwak Hiram , Song Yong Bae , Kim Kyu Tae , Park Juhyun , Jun Dayoung , Jung Yoon Seok
Published: May 2020

Due to the nonflammability of inorganic solid electrolytes (SEs) and the wide operation temperature ranges, bulk-type all-solid-state lithium or lithium-ion batteries (ASLBs) have been emerged as a promising power source. In particular ASLBs using sulfide SEs, such as Li10GeP2S12 (LGPS, 1.2 × 10-2 S cm-1) and Li3P7S11 (1.7 × 10-2 S cm-1), are attractive because of the extremely high ionic conductivities of sulfide SE materials, which are comparable to those of conventional organic liquid electrolytes used for lithium-ion batteries.

For the success of practical ASLBs, however, a current level of understanding and development on the electrode microstructure and interfacial (electro)chemistry is insufficient. While ASLBs consist of all the solid-state components (i.e., electrode active materials, SEs, conducting additives such as carbon, binders), volumetric strains of electrode active materials upon repeated charge-discharge cycles cause a serious deterioration of the performances. Thus, (electro)chemo-mechanics have been emerging as the critical issue. However, the relevant reports are scarce to date. Moreover, complex interfacial evolutions which could also contribute to the (electro)chemo-mechanical behaviors have been overlooked.

In this work, we first report an operando pressiometry using three-electrode cells to enable deconvolution of voltages and volumetric strains of positive and negative electrodes in-situ. Figure 1 shows the result of Li[Ni,Co,Mn]O2/Li6PS5Cl/graphite all-solid-state full cells cycled at 30 °C. The pressiometry profiles reveal signatures of phase transitions of electrode active materials, providing valuable information in terms of the assessment of the electrochemical performances and/or the management of battery system. More details will be discussed in the presentation.

Figure 1
Full Cell Understanding of Solvents in Battery Systems
Authors: Usrey Monica Lee , Guillot Sarah Lucienne , Johnson Tobias , Peña Hueso Adrián , Zhou Liu , Kerber Brian , Du Peng
Published: May 2020

Lithium ion batteries are complex systems with multiple components that can be optimized to obtain desired performance capability. These components include electrolyte salts, solvents, and additives, as well as electrode active materials and coatings. Rational optimization of battery components requires an understanding of the fundamental science driving the observed performance. Silatronix® has developed a suite of analytical tools and methods using a combination of full format batteries, lab R&D cells, and model systems to construct a complete understanding of the battery from the cell level performance to the fundamental chemistry. This process includes the recovery and analysis of all parts of a full format pouch cell, including liquid electrolyte, generated gas, and electrode surface layers (Fig. 1).

Using this process, Silatronix® has evaluated several battery components, including organosilicon solvents for Li-ion electrolytes, to acquire a comprehensive picture of how these components provide observed performance benefits. For example, OS3®, a novel organosilicon chemistry that merges a silane with a Li+ coordinating nitrile functionality, has provided multiple performance benefits in various advanced Li-ion chemistries. Key experimental results include improved high temperature cycling stability in full format graphite/NMC622 pouch cells with 1%, 2%, or 3% OS3® (Fig. 2a), and using a model system of electrolyte in NMR tubes, we show that enhanced thermal stability of the bulk electrolyte results from HF scavenging and LiPF6 salt stabilization when 2-16% OS3® is present (Fig. 2b). Reduction of gas generation during high temperature testing in pouch cells with a commercial Si-based anode is also shown with 2% OS3® (Fig. 2c), and gas product identification and quantification is determined by GC-TCD for mechanistic analyses. In addition, OS materials change the reactivity of other electrolyte components, particularly at the electrolyte/electrode interfaces that govern critical performance attributes in Li-ion cells such as gas generation and interfacial impedance. These key performance benefits serve to enable several next generation battery chemistries, including a strong synergy with Si-based anodes.

Figure 1
Effect of Pitch-Coating on the Electrochemical Chracteristics of Graphite As Anode Materials for Lithium Ion Battery
Authors: Lee Jongdae , Jo Yoon Ji
Published: May 2020

Lithium ions batteries (LIBs) have become the most promising energy storage device in energy field due to their potential utility as high-energy-density batteries for electric vehicles and hybrid electric vehicles. Graphite, which is the most widely commercialized anode material of LIBs, exhibits structural stability and excellent cycle characteristics. However, graphite has some problems to overcome. Due to the uneven SEI (Solid Electrolyte Interface) layer generated after the initial cycle, considerable irreversible capacity loss occurs. This results in electrode collapse and cycle instability especially in high-rate charging. Therefore, many researchers have been reported to improve the stability of graphite with carbon coating.

In this study, electrochemical characteristics of artificial graphite coated with petroleum pitch were investigated as anode materials of lithium ion batteries. To improve the capacity and stability of graphite, it was coated with petroleum pitch(SP, 150, 200 and 250 ℃). The physical properties of prepared samples were analyzed by MALDI-TOF, TGA, XRD, SEM and TEM. The electrochemical performances of graphite composites as an anode were evaluated by initial charge/discharge, cycle, rate performance, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) tests. The electrolyte used in the half cell was 1.0 M LiPF6 dissolved in organic solvents (EC:DEC=1:1 vol%).

It was found that the pitch(SP 250 ℃) coated graphite as anode materials had excellent electrochemical characteristics: initial efficiency (92.9%), discharge capacity (343 mAh/g), cycle stability (97%), and rate performance (84.1% in 10 C/0.1 C) than those of pristine graphite.
In Operando Diffraction Radiography and Tomography on Li-Ion Batteries
Authors: Schökel Alexander , Senyshyn Anatoliy , Baran Volodymyr
Published: May 2020

Diffraction radiography and tomography were used to study different commercial Li-ion batteries. Depending on the data processing either 'direct' parameters, such as phase distributions, or more abstract, derived parameters, like degree of lithiation of the graphite anode or even local state of charge, can be extracted. Especially the lithium distribution is an interesting parameter and is surprisingly inhomogeneous throughout the volume of a commercial battery cell.
Investigating Increasing Molar Conductivity in Low Permittivity Electrolytes for Multivalent Battery Applications
Authors: Self Julian , Hahn Nathan T , Fong Kara D , Zavadil Kevin R , Persson Kristin A
Published: May 2020

Many of the liquid electrolyte candidates for multivalent batteries exhibit increasing molar conductivity with concentration. In other words, the concentration-normalized conductivity increases as a function of salt concentration. This is in contrast to conventional electrolytes, e.g. aqueous or cyclic carbonate-based electrolyte solutions, where the molar conductivity decreases with concentration due to increased viscosity and ion aggregation. Low permittivity electrolytes with increasing molar conductivity include Ca(BH4)2 in tetrahydrofuran, Mg(TFSI)2 in monoglyme and Mg(TFSI)2 in diglyme.

In order to investigate the origin of this anomalous molar conductivity trend, we study the physicochemical properties of the electrolytes using a combined computational/experimental approach. Ab initio calculations and classical molecular dynamics simulations are undertaken to study ion speciation, ion activity and changes to solution permittivity. Furthermore, we undertake conductivity, microwave and raman spectroscopy measurements.
Ultrathin Al-Doped ZnO Films Coated Li4Ti5O12 As an Anode Material with Excellent Cycling Stability and Rate Capability for Lithium-Ion Batteries
Authors: Jin Ye , Yu Han , Gao Yan , Liang Xinhua
Published: May 2020

Lithium titanate oxide (Li4Ti5O12, LTO) is a lithium ion intercalated compound, which was identified as a promising anode material for LIBs with a theoretical capacity of 175 mAh g-1 within a typical potential range of 1.0 V–3.0 V. Extending the end voltage from 1.0 V to 0.01 V is an effective way to improve the electrochemical performance of LTO; the tetrahedral (8a) sites of LTO would be available for lithium ion storage to have an “extra” reversible capacity, when the end potential is lower than 0.6 V. However, this approach also leads to some other problems: (1) a lower end potential will cause a more intensive decomposition of electrolyte to form the solid electrolyte interface (SEI), which means that the initial irreversible capacity loss will increase, and (2) the change in lattice dimension during the lithium ion insertion/extraction will be increased and thus the structure stability of LTO will become worse. In this study, an Al-doped ZnO (AZO) film with various thicknesses and compositions were deposited on LTO particles by atomic layer deposition (ALD) method with different deposition temperatures and different ratios of the number of Al2O3 ALD to that of ZnO ALD. The electrochemical characterization results indicated that the coating of AZO significantly improved the electrochemical performance of LTO between 0.1 V and 3.0 V with a proper coating thickness. After 250 cycles of charge/discharge at a 1 C rate, the capacity of the optimum AZO-coated LTO sample decreased from 203 to 190 mAh g-1 with a capacity retention of ~94% at room temperature and from 224 to 216 mAh g-1 with a capacity retention of ~96% at 55 ℃. The AZO coating layer with an appropriate thickness not only increased the capacity of LTO by enhancing conductivity, but also assisted the LTO electrodes to form a beneficial interface layer to protect the LTO from the continuous attack by harmful components in the electrolyte, especially under extreme conditions, such as high temperature and high current rates.
The Effect of Crystalline Structure and Iron Doping on the Electrochemical Behavior of Germanium Oxide Anodes in Lithium-Ion Batteries
Authors: Eisenmann Tobias , Passerini Stefano , Bresser Dominic
Published: May 2020

The need for alternative anode materials for lithium-ion batteries (LIBs) is one of the decisive steps towards the electrification of our public and private transportation, since the state-of-the-art anode material graphite intrinsically limits the energy and power density of current LIBs.1,2 As a potential alternative, alloying metal-oxides such as ZnO and SnO2 have been widely studied, mostly due to their high theoretical specific capacities of 988 mAh g-1 and 1494 mAh g-1, respectively. Nevertheless, the pure oxides reveal poor electrochemical performance as a result of the eventually irreversible formation of the Li2O matrix and the pronounced volume variation, causing active material exfoliation.3–5 When doped with transition metals, however, the Li2O formation turns very reversible and the theoretically possible capacities can be achieved.6–9 As an example, Co-doped ZnO offers substantially higher specific capacities than pure ZnO (i.e., 966 mAh g-1 vs 330 mAh g-1). Recently, the class of TM-doped alloying metal oxides has been extended to Fe-doped GeO2, offering even higher specific capacities than transition metal doped SnO2 (theoretically 2152 mAh g-1).10

Within this study we enlighten the beneficial effects of iron doping on the structural evolution and electrochemical performance of GeO2. For this purpose, we combined a series of highly complementary in situ/operando techniques, including in situ high temperature XRD, operando dilatometry, and operando XRD. The results shed light on a commonly overlooked impact factor for the electrochemical performance of such materials and, in fact, metal oxides in general.

1. D. Bresser et al., J. Power Sources, 382, 176–178 (2018).

2. Y. Yamada, Y. Iriyama, T. Abe, and Z. Ogumi, Langmuir, 25, 12766–12770 (2009).

3. I. A. Courtney and J. R. Dahn, J. Electrochem. Soc., 144, 2045–2052 (1997).

4. I. A. Courtney, W. R. Mckinnon, and J. R. Dahn, J. Electrochem. Soc., 146, 59–68 (1999).

5. F. Mueller, D. Geiger, U. Kaiser, S. Passerini, and D. Bresser, ChemElectroChem, 3, 1311–1319 (2016).

6. D. Bresser, S. Passerini, and B. Scrosati, Energy Environ. Sci., 9, 3348–3367 (2016).

7. G. Giuli et al., Inorg. Chem., 54, 9393–9400 (2015).

8. G. Giuli et al., Materials, 11, 49 (2017).

9. Y. Ma et al., Sustain. Energy Fuels, 2, 2601–2608 (2018).

10. J. Wu, N. Luo, S. Huang, W. Yang, and M. Wei, J. Mater. Chem. A, 7, 4574–4580 (2019).
Silicon-Aluminum-Alloy-Derived Porous Silicon/Carbon As Anode Materials for Lithium Ion Batteries
Authors: Liu Shih-Fu , Fang Feng-Zun , Chen Han-Yi
Published: May 2020

Nowadays, most of countries in the world promote energy saving and carbon emission reduction. The development of electric vehicles (EVs) is one of the main solution to reduce the carbon emission. Lithium ion batteries (LIBs) have higher energy density than other secondary batteries so they serve as the most popular energy storage device for EVs. However, the capacity of commercial graphite anode material is limited to ~372 mA h g-1 which is hard to meet the high-energy demand for long-range EVs. Silicon with highest theoretical capacity of 4200 mA h g-1 has been considered as the next-generation anode material. Despite the high capacity, the severe volume change of silicon during charge and discharge processes leads to the peeling-off of the active materials from the current collector. Therefore, the capacity retention of Si is poor. Porous structure and carbon coating are two major methods applying for improving the capacity retention of Si.

In our work, we utilized Si-Al alloys as precursors to synthesize micro-size porous Si anode materials by acidic treatment. Besides, carbon was coated on the porous Si particles to increase the electronic conductivity. Si-Al alloys are commercial available so this micro-size porous Si/C anode material can be mass-produced. High capacity around 1000 mA h g-1 could be achieved with good capacity retention. It indicates that the micro-sized porous Si/C is a promising LIB anode materials for electric vehicle application.
Nitrogen-Doped Hierarchical Porous Carbon Derived from Bacterial Cellulose-Polyaniline Composite As High Performance Anode for Lithium-Ion Batteries
Authors: Illa Mani Pujitha , Sharma Chandra Shekhar , Khandelwal Mudrika
Published: May 2020

An ever increasing demand for high energy and high power rating Lithium-ion batteries (LIB) for electric hybrid vehicles persuaded the development of novel electrode materials with large storage capability and faster kinetic process. Carbon nanomaterials, owing to their unique and tunable physical and chemical properties, have been widely investigated as anode materials for LIBs. Diversified strategies involving the synthesis of carbon materials with hierarchical structures (morphology and porosity), and heteroatom doping have shown significant improvement in electrochemical performance of these carbon nanomaterials. In consideration to this, we hereby demonstrate the synthesis and utilization of hierarchical nitrogen-doped porous carbon structures derived from bacterial cellulose-polyaniline nano-composites as a promising anode material for LIBs. Microstructural analysis of the derived carbon revealed the inheritance of fibrous backbone as obtained from bacterial cellulose along with nano-granular structure of polyaniline. The structural and electrochemical properties of as-derived porous carbon structures are analysed systematically by performing XRD, Raman spectroscopy, XPS, cyclic voltammetry, galvanostatic charge/discharge studies and impedance spectroscopy. These results unveiled significantly large reversible capacities of 432, 233, and 127 mAh/g at 1, 5, and 10 C-rate respectively with excellent capacity retention. The energy and power densities of these hierarchical porous carbon structures were increased by 54% and 41% respectively when compared to pure bacterial cellulose derived carbon. This enhanced electrochemical performance may be attributed to the combined effect of interconnected micro-meso porous network of hard carbon along with nitrogen doping. The core-shell structure of this derived carbon accommodates the volume changes during lithium-ion insertion and de-insertion, rendering excellent cyclic stability even at high C rates without causing pulverization.
Discharge Behaviors of Disulfide with Core-Shell Structure for Thermal Batteries
Authors: Cao Yong
Published: May 2020

Thermal batteries are adopted as the power sources for devices, due to the high power density and long life for storage. So far, disulfides, such as FeS2, CoS2, Fe1-xCoxS2 (0<x<1) are selected as the best cathodes. But limitations are existed, for example, FeS2 is low conductive, and CoS2 exhibits poor environmental stability. Therefore, structure modifications are used to improve the properties. We have done lots of work on constructing the materials with core-shell structure, such as CoS2@FeS2, C@CoS2, FeS2@CoS2, for conductivity, stability and wetting improvement. The results show that performance enhancements of thermal batteries are achieved, with proper adjustment of the composition and thickness of the shell layer. Fig. 1 illustrates the discharge curves of CoS2, with surface covered by the molten salt adsorbent, which is used to enhance the wettability of molten salt on CoS2. The discharge capacity of CoS2 is increased from ~310 mAh/g to ~380 mAh/g, with a current of 200 mA cm-2 at 525 °C, by surface reconstruction.

Figure 1
Study of the Lithium/Polymer Interface and Conductive Deposits on Lithium Metal Used for Lithium Metal Polymer Batteries.
Authors: Storelli Alexandre , Alzate-Carvajal Natalia , Rousselot Steeve , Pelé Vincent , Dollé Mickael
Published: May 2020

Lithium metal anode has recently regained tremendous attention in the frame of the development of higher power and energy density lithium batteries for automotive industry. Lithium metal is indeed an ideal anode for lithium batteries due to its high capacity (3860 mAh/g). However, upon high discharge currents, the growth of dendrites leads to cell short cuts and limited coulombic efficiency.

This issue had first restrained its practical application in rechargeable batteries for high power applications until the use of solid polymer electrolytes that could mechanically prevent the dendrites from crossing the electrolyte. Among the different families of polymer electrolytes, polyethylene oxide-based (PEO-based) electrolytes have been established as the reference thanks to a reasonable conductivity above 60oC and its ability to form a stable solid electrolyte interphase (SEI) with lithium. Nevertheless, due to the low transference number of POE/LiTFSI electrolytes (t+≈0.15), dendrites or uneven lithium plating are still susceptible to form. Nowadays, many efforts are dedicated to solve these problems by focusing either on the improvement of the electrolyte or on the modification of the lithium-electrolyte interface. Gold layers have been proposed as an alternative to prevent dendrite formation; these gold coatings are used mainly together with ceramic electrolytes in order to improve the interface between Li metal anode and electrolyte. However, their use with polymer electrolytes where dendrite formation is favorable due to low transference number and mechanical strength have not being widely studied. In this presentation, three different coatings will be considered; aluminum (Al), gold (Au) and lithium fluoride (LiF). The choice of Al and Au is based on their ability to form Li-rich alloys while LiF is known to act as an artificial ion conducting SEI. The morphology and physico-chemical properties of the coatings are first characterized by Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) before evaluation of the interface between POE-based electrolyte and coated Lithium. Eventually stability during long-term cycling in Lithium Metal Polymer batteries is performed and compared to that of cells made using bare Lithium.
(Invited) Memory-Centric Artificial Intelligence with Nanodevices
Authors: Querlioz Damien
Published: May 2020

When performing artificial intelligence tasks, central and graphics processing units consume considerably more energy for moving data between logic and memory units than for doing actual arithmetic. Brains, by contrast, achieve vastly superior energy efficiency by fusing logic and memory entirely, performing a form of "in-memory" computing. Currently emerging memory nanodevices such as (mem)resistive, phase change and magnetic memories give us an opportunity to achieve similar tight integration between logic and memory. In this talk, we will look at neuroscience inspiration to extract lessons on the design of in-memory computing systems.

We will first study the reliance of brains on approximate memory strategies, which can be reproduced for artificial intelligence. We will give the example of a hardware binarized neural network relying on resistive memory. Binarized neural networks are a class of deep neural networks discovered in 2016, which can achieve state-of-the-art performance with a highly reduced memory and logic footprint with regards to conventional artificial intelligence approaches. Based on measurements on a hybrid CMOS and resistive hafnium oxide memory chip exploiting a differential approach, we will see that such systems can exploit the properties of emerging memories without the need of error correcting codes, and achieve extremely high energy efficiency.

Second, we will see that brains use the physics of their memory devices in a way that is much richer than only storage. This can inspire radical electronic designs, where memory devices become a core part of computing. We will illustrate this concept by our works using magnetic memories as artificial neurons. We have fabricated neural networks where magnetic memories used as nonlinear oscillators implement neurons, and their electrical couplings implement synapses. We will see that such designs can harness the rich physics and dynamics inherent to magnetic memories, without suffering from their drawbacks. This physics-rich approach nevertheless raises important challenges that we will highlight.

References

M. Bocquet, T. Hirztlin, J.-O. Klein, E. Nowak, E. Vianello, J.-M. Portal and D. Querlioz, "In-Memory and Error-Immune Differential RRAM Implementation of Binarized Deep Neural Networks", IEEE International Electron Devices Meeting (IEDM), p. 20.6.1, 2018.

M. Romera, P. Talatchian, S. Tsunegi, F. A. Araujo, V. Cros, P. Bortolotti, J. Trastoy, K. Yakushiji, A. Fukushima, H. Kubota, S. Yuasa, M. Ernoult, D. Vodenicarevic, T. Hirtzlin, N. Locatelli, D. Querlioz and J. Grollier, "Vowel recognition with four coupled spin-torque nano-oscillators", Nature, Vol. 563, p. 230, 2018.
Looking for the Lost Lithium: Lithium Trapping and Its Effect on Capacity Losses in Li-Ion Batteries
Authors: Rehnlund David , Lindgren Fredrik , Pan Ruijun , Huang Yu-Kai , Wang Zhaohui , Nyholm Leif
Published: May 2020

Rechargeable lithium batteries are well-known to exhibit progressive capacity decays upon cycling, leading to loss of cell voltage, power and energy. However, the origins of capacity losses are still not fully understood and are largely attributed to the formation of a solid electrolyte interface layer and volume expansion. Another largely overlook capacity decay mechanism is lithium trapping 1–4. Lithium trapping, caused by incomplete delithiation, is here demonstrated to be the main source of capacity losses in high energy density anodes (e.g. Si) while SEI formation and dissolution affect the accumulated capacity loss due to decreased coulombic efficiency. In the following paper we will present our findings on capacity losses in standard and optimized Si-Li half cells and how these systems affect lithium trapping inside the active electrode material. We will discuss how the cycling protocol (e.g. full capacity cycling vs coulombic limited cycling) can mask signs of Li trapping and temporarily delay capacity decay in half-cells. We will highlight the importance of lithium-trapping induced capacity or voltage decays effect in lithium-based batteries, explain the mechanism for lithium-trapping and establish diffusion-controlled lithium-trapping models. Approaches toward identifying and circumventing lithium-trapping problem will also be discussed as well as challenges and proposed future research directions within this exciting and important research field.

Figure 1. Capacity evolution for an optimized nano-Silicon composite electrode in a half-cell configuration during coulombic limited cycling (i.e. 1200 mAh/g). Critical capacity decay is observed when the accumulated trapped lithium has saturated the electrode core and counteracts the deposited Li layer 1.

References

1. Lindgren, F. et al. On the Capacity Losses Seen for Optimized Nano‐Si Composite Electrodes in Li‐Metal Half‐Cells. Adv. Energy Mater.
9, 1901608 (2019).

2. Rehnlund, D. et al. Lithium trapping in alloy forming electrodes and current collectors for lithium based batteries. Energy Environ. Sci.
10, 1350–1357 (2017).

3. Rehnlund, D., Pettersson, J., Edström, K. & Nyholm, L. Lithium Trapping in Microbatteries Based on Lithium- and Cu2O-Coated Copper Nanorods. ChemistrySelect
3, 2311–2314 (2018).

4. Zhu, B. et al. Minimized lithium trapping by isovalent isomorphism for high initial Coulombic efficiency of silicon anodes. Sci. Adv.
5, eaax0651 (2019).

Figure 1
Solid-state Battery Designed For Electric Aviation
Authors: Dornbusch Donald A. , Viggiano Rocco , Dynys Frederick W. , Lin Yi , Connell John W. , Wu James J.
Published: May 2020

The demand for higher energy density batteries increases as the demand for portable electronic devices and electric automotive increases, as well as a variety of other applications requiring substantially higher power and energy than attainable with current lithium-ion capabilities which includes the areas of high performance vehicles, military applications, and electric aviation. However, the improvement of energy density is insufficient alone for enabling electric aviation when considering the high flammability and risk of thermal runaway inherent in current state-of-the-art liquid electrolytes. The development of high energy, high power, and safe batteries are required to enable hybrid and fully electric aircraft.

Next generation chemistries such as lithium-sulfur provide high theoretical specific energy density suitable for electric aviation without as strict of volumetric requirements observed in the automotive industry. However, due to the phase transition during discharge where sulfur generates a series of soluble intermediate polysulfides, which are lost to the liquid electrolyte, cause detrimental side effects, and severely limit cycle life battery performance is severely reduced. Additionally, the low electrical conductivity of sulfur requires a large amount of inactive carbon dramatically increasing parasitic mass.

The dissolution issue make sulfur a desirable candidate to pair with a solid-state electrolyte in order to avoid polysulfide dissolution and shuttling. In addition, inorganic solid-electrolytes have low flammability providing the improved safety required. Combining this chemistry with a solid-state electrolyte provides a path for achieving the energy and safety required for electric aviation.

The development of scalable thin solid-state electrolytes paired with lithium-sulfur chemistry will be discussed and how their development will aid in enabling a unique application.
Modeling Thermal Runaway of NMC(1:1:1) Cathodes in Non-Aqueous Electrolytes
Authors: Shurtz Randy C. , Hewson John
Published: May 2020

This work develops a new modeling framework for decomposition of layered metal oxides in non-aqueous electrolytes. Models based on this framework are appropriate for predictions of thermal runaway in lithium-ion battery systems. It accounts for phase changes with oxygen generation and transport limitations. Effects of particle size, limited electrolyte and state of charge are included. Calorimetry measurements from a variety of literature studies are used to calibrate kinetic rate parameters for nickel manganese cobalt oxide cathodes (LixNi0.33Mn0.33Co0.33O2 or NMC 1:1:1), while other measurements are used to validate performance of the resulting model. This model utilizes a recently published method for predicting the heat of reaction from tabulated thermodynamic data.

Acknowledgements:

This work was supported by the US Department of Energy Office of Electricity, Energy Storage Program. The authors wish to thank Dr. Imre Gyuk for his support of research advancing safety in stationary energy storage. Sandia National Laboratories is a multi-mission 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-NA-0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government. SAND No: SAND2019-14403 C