bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase Inversion Strategy to Flexible Freestanding Electrodes: Critical Coupling of Binders and Electrolytes for High Performance Li-S Battery
Authors: Wahyudi Wandi , Chao Zhen , Kumar Pushpendra , Li Mengliu , Wu Yingqiang , Hedhili Mohammed N. , Cavallo Luigi , Li Lain-Jong , Ming Jun , Anthopoulos Thomas D.
Published: February 2020

Development of flexible and freestanding electrode is fascinating for lithium-sulfur (Li-S) batteries to enable higher gravimetric energy density and wider potential applications. However, the lithium polysulfides shuttle effect remains challenging and leads to a severe capacity fading. Here, we study the sulfur cathode prepared via phase inversion method with polyethersulfone (PES) polymeric binder and the coupling strategy of the electrode with polysulfide-modified electrolyte to enhance the cells performance. The flexible/freestanding electrode was successfully prepared by the efficient and straight forward method, even it is possible for massive production of electrodes with various size. The resultant polymeric networks in the electrode can effectively trap the soluble polysulfides owing to the higher hydrophilicity and stronger affinity of PES than that with the routine polyvinylidene fluoride (PVDF) binder. Furthermore, we show a two-fold enhancement of the cell performance by coupling the electrode with polysulfide-modified electrolyte, giving an improved capacity of 1141 mAh g-1, lower polarization of 192 mV and more stable capacity retention with 100% Coulombic efficiency over 100 cycles at 0.25C. The advantages of favored strategy are further demonstrated in lithium-ion sulfur full battery with lithiated graphite anode, which demonstrates much improved performance than those previously reported. This work successfully introduces an efficient strategy for flexible/freestanding electrodes and enlightens the importance of coupling strategy to enhance the performances of Li-S batteries.

Figure 1. (a) Digital photographs of the as-prepared composite via phase inversion method. (b) Cycle performance of half-cells using 2-layer PES-CNT-S and PVDF-CNT-S cathodes with polysulfide(PS)-free electrolyte and polysulfide(PS)-modified electrolyte at 0.25C.

REFERENCES

W. Wahyudi, Z. Cao, P. Kumar, M. Li, Y. Wu, M. N. Hedhili, T. D. Anthopoulos, L. Cavallo, L. J. Li, J. Ming, Adv. Funct. Mater., 2018, 28 (34), 1802244.

J. Ming, Z. Cao, W. Wahyudi, M. Li, P. Kumar, Y. Wu, J.-Y. Hwang, M. N. Hedhili, L. Cavallo, Y.-K. Sun, L. J. Li, ACS Energy Lett., 2018, 3 (2), 335-340.

W. Wang, Z. Cao, G. A. Elia, Y. Wu, W. Wahyudi, E. Abou-Hamad, A. H. Emwas, L. Cavallo, L. J. Li, J. Ming, ACS Energy Lett., 2018, 3 (12), 2899-2907.

Figure 1
In Situ Ambient Pressure X-Ray Photoelectron Spectroscopy Studies of Potassium-Oxygen Redox Reactions
Authors: Wang Wanwan , Wang Yu , Wang Chia-Hsin , Yang Yaw-Wen , Lu Yi-Chun
Published: February 2020

Rechargeable potassium−oxygen (K–O2) batteries have received much attention owing to their higher theoretical energy density (935 Wh/kg, K + O2 = KO2,
E
0 = 2.48 V) compared to conventional lithium−ion batteries and their superior round-trip efficiency.1-3 In order to realize commercialization of K–O2 batteries, identifying fundamental barriers and instability that hinder the development of K–O2 batteries is required. In situ characterization methods provide valuable insight into the discharge/charge mechanisms of metal-oxygen batteries, especially the K-O2 discharge products are highly sensitive to the uncontrolled contaminations. In this work, we employed in-situ ambient pressure X-ray photoelectron spectroscopy (APXPS)4, 5 and examine in situ the chemistry of K-O2 reaction products under ultra high vacuum (UHV) and oxygen condition using APXPS. We will discuss the chemical changes of the K-O2 system during discharge and charge conditions. We show that combining in situ APXPS and electrochemical characterization techniques, the formation and disappearance of K-O2 reaction products can be directly visualized.

Acknowledgement:

This work was supported by a grant from the Research Grants Council (RGC) of the Hong Kong Special Administrative Region, China, T23-601/17-R.

Reference:

X. Ren and Y. Wu, J. Am. Chem. Soc., 135, 2923 (2013).

G. Cong, W. Wang, N.-C. Lai, Z. Liang and Y.-C. Lu, Nat. Mater., 18, 390 (2019).

W. Wang, N. C. Lai, Z. Liang, Y. Wang and Y. C. Lu, Angew. Chem., Int. Ed., 57, 5042 (2018).

Y.-C. Lu, E. J. Crumlin, G. M. Veith, J. R. Harding, E. Mutoro, L. Baggetto, N. J. Dudney, Z. Liu and Y. Shao-Horn, Sci. Rep., 2, 715 (2012).

Y.-C. Lu, E. J. Crumlin, T. J. Carney, L. Baggetto, G. M. Veith, N. J. Dudney, Z. Liu and Y. Shao-Horn, J. Phys. Chem. C, 117, 25948 (2013).
Revealing Origins for Sluggish Reaction Kinetics in Li-O2 Battery Via Operando Liquid Electron Microscopy
Authors: Yuan Yifei , He Kun , Bi Xuanxuan , Foroozan Tara , Song Boao , Amine Khalil , Lu Jun , Shahbazian-Yassar Reza
Published: February 2020

Rechargeable lithium-oxygen (Li-O2) battery has the potential to replace conventional lithium ion battery for high-energy applications. However, this system is plagued by its sluggish kinetics during the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) with the mechanisms not fully understood. Here, we explored the discharge/charge (i.e. ORR/OER) fundamentals in a working Li-O2 battery using in situ liquid transmission electron microscopy. During ORR, Li2O2 is observed to nucleate at the carbon electrode/electrolyte interface, and its growth kinetics is controlled by Li+ diffusion in the electrolyte. Li2O2 nucleation and growth are also observed within the electrolyte where there is no direct contact with the carbon electrode, and its growth exhibits O2
- diffusion-limited kinetics, indicating the existence of non-Faradaic disproportionation reaction of intermediate LiO2 into Li2O2. Li2O2 at the carbon electrode surface and within the electrolyte are both actively decomposed during OER. For Li2O2 particles attached to the carbon electrode surface, their decomposition initiates at the electrode/ Li2O2 interface, indicating electron-conduction limited charge kinetics. Interestingly, for Li2O2 isolated within the electrolyte, we observed a side-to-side decomposition mode, which can be associated with the non-Faradaic formation of dissolvable O2
-, whose diffusion in the electrolyte controls the overall charge kinetics. The mechanisms are summarized in Figure 1. This work reveals the ORR/OER fundamentals in Li-O2 battery system in terms of the various limiting factors controlling the discharge and charge process. We expect findings here to guide both the electrode design and the electrolyte screening aiming for enhancement of the ORR and OER kinetics.

Figure 1
Enhanced Cycling Performance of Lithium Metal Batteries By Separator Architecture Design
Authors: Wang Wenxiu , Mukherjee Partha P.
Published: February 2020

Lithium (Li) metal anode has attracted renewed research interests due to its high specific capacity (3860 mAh/g vs 360 mAh/g of a graphite anode) and the lowest negative potential (-3.04V vs the standard hydrogen electrode), which allows Li metal batteries to achieve high energy density when paired with the sulfur or air cathode. However, Li metal anode has safety issues and severe capacity fading. In this report, we will present a facile technique by simply adding a nano-structured interlayer onto the commercial polypropylene separator (PP) to create a composite architecture (AP). By using Li-Li symmetric cells, we will demonstrate the superior performance of AP. This unique architecture design of separator provides new insights for rechargeable lithium metal batteries, which are aimed at high energy density and cycling efficiency.
Evaluation of Trihalide Ion’s Ability As Redox Mediators in Lithium Oxygen Batteries
Authors: Kim Hun , Sun Yang-Kook
Published: February 2020

Redox mediators have been intensively studied for increasing the energy efficiency and cycle life of lithium oxygen(Li-O2) batteries by reducing the high overpotential, which induces degradation of cell components. Lithium halides have been explored as representative redox mediators in Li-O2 batteries because of their low redox potential under 3.6 V. However, there is still controversy about the proper form of halide materials as redox mediators to decompose the discharge product of Li-O2 batteries, lithium peroxide (Li2O2). Therefore, we conducted quantitative analyses such as UV–Vis and GC-MS to confirm the ability of different halide materials to decompose Li2O2 as redox mediators in Li-O2 batteries. By controlling the byproducts during discharge and exempting the misunderstandings when using commercial Li2O2 powder, we clearly demonstrated that triiodide (I3
−) and tribromide (Br3
−) have sufficient ability to decompose Li2O2 in Li-O2 batteries.

[1] W.-J. Kwak, D. Hirshberg, D. Sharon, M. Afri, A.A. Frimer, H.-G. Jung, D. Aurbach and Y.-K.Sun, Energy Environ. Sci.
2016, 9, 2334.

[2] W.-J. Kwak, D. Hirshberg, D. Sharon, H.-J. Shin, M. Afri, J.-B. Park, A. Garsuch, F.F. Chesneau, A.A. Frimer, D. Aurbach and Y.-K. Sun, J. Mater. Chem. A
2015, 3, 8855.

[3] W.-J. Kwak, H. Kim, H.-G. Jung, D. Aurbach and Y.-K. Sun, J. Electrochem. Soc.
2018, 165, A2274.
Self-Organized Titania Nanotubes for Advanced Li-Ion Microbatteries
Authors: Djenizian Thierry
Published: February 2020

Lithium-ion batteries (LIBs) are widely used to power portable devices, microelectronics, vehicles, etc. With many advantages such as high surface area and improved charge transport, self-supported 3-D nanostructured metal oxides such as titania nanotubes (TiO2nts) are promising electrode materials for LIBs and their impact is particularly significant when considering the miniaturization of energy storage systems and the development of 3D microbatteries.

This paper is dedicated to the fabrication of all-solid-state Li-ion microbatteries using modified TiO2nts as negative electrodes [1-9]. Effects of material selection and processing on the performance and reliability are presented as a means to develop conceptual guidelines to understand and improve microbattery designs. Different chemical modifications of nanotubes by doping processes, ALD technique and by the conformal electrodeposition of polymer electrolytes will be presented. The fabrication of full 3D all-solid-state microcells showing high electrochemical performance have been achieved and the development of the next generation of 3D flexible microbatteries will be also introduced.

References

[1] B.L. Ellis, P. Knauth, T. Djenizian, Adv. Mater., 26, 3368 (2014)

[2] N. Plylahan, M. Letiche, M. Barr, and T. Djenizian, Electrochem. Commun., 43, 121 (2014)

[3] N. Plylahan, A. Demoulin, C. Lebouin, P. Knauth, T. Djenizian, RSC Adv., 5, 28474 (2015)

[4] N. Plylahan, M. Letiche, M. Barr, B. Ellis, S. Maria, T. N. T. Phan, E. Bloch, P. Knauth, and T. Djenizian, J. Power Sources, 273, 1182 (2015)

[5] G. Salian, C. Lebouin, A. Demoulin, S. Maria, P. Knauth, M. Lepihin, A. Galeyeva, A. Kurbatov, and T. Djenizian, J.

Power Sources, 340, 242 (2017)

[6] I. V. Ferrari, M. Braglia, T. Djenizian, and P. Knauth, J. Power Sources, 353, 95 (2017)

[7] G. Salian, B. M. Koo, C. Lefevre, T. Cottineau, C. Lebouin, A. T. Tesfaye, P. Knauth, V. Keller, T. Djenizian, Adv. Mater. Technol., 3, 1700274 (2018)

[8] Fraoucene, V. A. Sugiawati, D. Hatem, M. S. Belkaid, F. Vacandio, M. Eyraud, M. Pasquinelli, T. Djenizian, Optical and Electrochemical Properties of Self-Organized TiO2 Nanotube Arrays From Anodized Ti−6Al−4V Alloy, Front. Chem., 7, 66 (2019)

[9] G. D. Salian, C. Lebouin, M. Galeyeva, A. P. Kurbatov, T. Djenizian, Electrodeposition of polymer electrolyte into porous LiNi0.5Mn1.5O4 for high performance all-solid-state microbatteries, Front. Chem., 7, 675 (2019)

Figure 1
The Role of Metallic Protection Layers in Extending the Stability of Nasicon Electrolytes for Solid-State Batteries
Authors: Cortes Francisco Javier Quintero , Lewis John A , Tippens Jared , Kondekar Neha , McDowell Matthew T
Published: February 2020

Solid-state batteries with lithium metal anodes are promising candidates for next-generation energy storage devices with improved safety and higher energy density. However, most solid electrolytes with practical ionic conductivities are thermodynamically unstable against lithium metal. Upon interfacial contact with lithium metal, unstable solid electrolytes undergo phase transformations that can be detrimental to battery performance. Lithium aluminum germanium phosphate (LAGP) is a NASICON-type solid electrolyte with relatively high ionic conductivity (10-4 - 10-3 S/cm) and chemical resistance to air and moisture. However, LAGP reacts with lithium to form an electrically-conducting interphase. This interphase continues to propagate from the interface towards the bulk of the solid electrolyte, ultimately leading to failure by causing the solid electrolyte to fracture [1]. In this work, we find that a thin layer of a metal that does not alloy with Li can extend the cycle life of LAGP in symmetric lithium cells from 30 h to more than 800 h at moderate current densities. Interestingly, this significantly improved electrochemical stability is not due to the prevention of interphase formation. Instead, the metal layer alters the morphology evolution of the interphase, creating a uniform and compact interphase. In addition, we find that the inclusion of an electrically insulating thin film, such as Al2O3, between the metal protection layer and the solid electrolyte favors lithium plating and prevents interphase formation over short periods of time. This dual layer approach also extends the electrochemical stability to more than 1000 h during cycling. However, using only the insulator without a metal is not beneficial for electrochemical stability. These results suggest that metallic protection layers may be necessary for attaining stable cycling even if suitable electrically insulating protection layers are developed to completely prevent interphase formation. Our findings are important for enabling the use of a wider range of solid electrolyte materials in solid-state batteries.

[1] J.A. Lewis, et at. Interphase Morphology between a Solid-State Electrolyte and Lithium Controls Cell Failure. ACS Energy Lett. 2019, 4, 2, 591-599
A Composite Solid Polymer Electrolyte Containing Poly(propylene Carbonate) and Li1.5Al0.5Ge1.5(PO4)3 for All-Solid-State Li-Ion Batteries
Authors: Sung Bong-Joon , Didwal Pravin N. , Park Chan-Jin
Published: February 2020

During last ~30 years, lithium-ion batteries (LIBs) have been improved significantly in aspects of energy density and cyclability. In spite of several advantages of LIBs, the conventional LIBs still have suffered from the issues related to organic based electrolytes, such as leakage, volatility, flammability, and lithium dendrite formation through porous separator leading to internal short circuits. A solution is to replace the organic liquid electrolyte with suitable composite solid polymer electrolyte (CSPE). Poly(ethylene oxide) (PEO) based electrolytes are the most studied solid polymer electrolyte (SPE). However, narrow potential window, poor mechanical strength, low lithium transference number, and insufficient ionic conductivity are the major issues to be addressed in case of PEO. In contrast, poly(propylene carbonate) (PPC) has attracted tremendous attention as an alternative owing to its higher ionic conductivity, better lithium transference number, and wide potential window. The weak mechanical strength of PPC membranes is the main bottle neck to be addressed before it sees the limelight of practical application. Incorporation of a ceramic filler into PPC polymer is one of the promising way to improve the ionic conductivity as well as the mechanical strength of SPE. Among the ceramic fillers, NASICON type Li1.5Al0.5Ge1.5(PO4)3 (LAGP) possesses good stability to moisture, thermal stability, and electrochemical stability. In this work, we have studied the effects of LAGP incorporation in PPC matrix on the physical and electrochemical properties of CSPE for all-solid-state LIBs. The formation of LAGP phase was analyzed by XRD, SEM, and TEM. Furthermore, the thermal stability of prepared CSPE was evaluated using DSC and TGA. The CSPE exhibited higher ionic conductivity and mechanical strength compared with pure PPC, leading to improvement in electrochemical properties of all-solid-state lithium ion batteries composed of Li/CSPE/LiNi0.6Co0.2Mn0.2O2 (NCM622).
Direct Observation of Lithium Dendrite Morphology, Propagation, and Reversibility in Garnet Solid Electrolytes Via Operando Video Microscopy
Authors: Kazyak Eric , Garcia-Mendez Regina , LePage William S. , Davis Andrew L. , Sanchez Adrian J. , Sharafi Asma , Chen Kuan-Hung , Sakamoto Jeff , Dasgupta Neil P.
Published: February 2020

Among the most promising strategies to enable Li metal anodes for next-generation rechargeable batteries is the use of solid-state electrolytes (SSEs). This new generation of batteries with higher gravimetric and volumetric energy density will be critical to the development of a range of applications, perhaps most importantly for electric vehicles (EVs). To date, however, stabilization of the Li metal/SSE interface at high rates of charge has proven challenging in many material systems. The nucleation and propagation of Li filaments has been observed to cause short-circuit in a range of promising SSE materials.1 As fast-charge capability is a key requirement for many applications, but in particular for EVs, overcoming this challenge is critical to enabling the use of Li metal anodes. Limited understanding of the underlying mechanisms by which these Li structures nucleate and propagate within SSE materials has prevented rational design of solutions to the problem.2

In this work, a new operando visualization platform is developed and used to study the propagation of Li filaments within garnet LLZO SSE materials at current densities relevant to fast charge capability. Time-synchronization of voltage traces with high resolution video microscopy reveal new insights into the nature of the dendritic structures, the mechanism by which they propagate, and their reversibility. Post-mortem electron microscopy analysis of specific sites in the operando experiments provides a high resolution, 3D perspective of the structures, and helps to identify pathways for improved performance.

References

1. L. Porz et al., Adv. Energy Mater., 1701003, 1701003 (2017)

2. M. Wang, J. B. Wolfenstine, and J. Sakamoto, Electrochim. Acta, 296, 842–847 (2019).
Hybrid Ceramic Solid State Electrolyte for High Performance Solid State Batteries
Authors: Thanapisitikul Piyathip , Gattu Bharat , Datta Moni Kanchan , Ramalinga Bandi , Kumta Prashant Nagesh
Published: February 2020

There is a global demand for high energy storage systems for portable consumer devices such as cell phones, laptops, including electric vehicles. Lithium ion batteries (LIBs) are the most promising options due to the high volumetric, gravimetric energy, and power densities. Current LIBs using LiCoO2, LiNiO2, LiMnO4, and LiFePO4 cathodes coupled with a graphite anode exhibit a power density of 100-260 Whkg-1 [1]. With the advent of high capacity Li – S system, efforts are focused on replacing low capacity carbon based anodes with Li metal and composite systems. However, the Li metal plating process on Cu/Li substrates shows undesirable performance due to unstable Li plating leading to formation of high surface area Li, loss of Li due to uneven plating/deplating, increase in internal resistance and formation of the deleterious Li dendrites [2-4]. These characteristic plating phenomena, result in low columbic efficiencies, increase in plating/deplating potentials as well as ensuing hysteresis losses. As a result, there is rapid fade in specific capacity/energy density combined with thermal run away due to either increased internal resistance or internal short-circuiting of the cell due to the formation and growth of unwanted dendrites running the risk of explosive failure of the cells.

Novel hybrid ceramic electrolytes (HCE) were developed utilizing Inorganic Framework Materials Networks (IFM) with enhanced Li+ diffusion utilizing the low activation energy for surface migration. The crystallographic channels in the inorganic framework provide pathways for efficient transport of Li+ ions thus making them attractive ceramic electrolyte materials. The ionic conductivity measurements of these ceramic electrolytes were conducted in Li/Li symmetric CR2025 coin cell. These novel ceramic electrolytes show a Li+ conductivity of ~ 1.26 x 10-4 S/cm. Subsequently the coin cells were cycled at different current densities ranging from 0.5mA/cm2 to 4mA/cm2 and their plating/deplating over-potentials were recorded and analyzed. These hybrid ceramic electrolytes show low plating/deplating potentials ranging from 100mV@1mA/cm2 – 450mV @4mA/cm2 comparable with garnet based solid state electrolytes. Subsequently, the electrolytes were tested for electrochemical performance against Cu and new high interfacial energy alloy based collect collectors identified in a coin cell and their coulombic efficiency recorded. The hybrid ceramic electrolytes show columbic efficiency of ~97-99% for a constant plating and deplating current density of 0.5mA/cm2 for 1h (charge density~0.5mAh/cm2) when tested with Cu electrodes.

The full cell electrochemical performance, SEM analysis of plated and deplated electrodes, combined with Raman and infrared spectroscopy results will be presented and discussed.

Figure 1
Carbon Nano Onions Material Used As Support for Electrocatalysis By Applying the Rotating Disc Electrode Technique for the Improvement of the Oxygen Reduction Reaction
Authors: Ortiz-Santiago Joed E. , Delgado-Seo Harim , Cunci Perez Lisandro
Published: February 2020

Carbon Nano Onions (CNO) are fullerene-like carbon shells with large external surface area and a high electrical conductivity. These characteristics make this material unique because serve as an electrically conductive support for electrocatalyst that, at the same time, provides plenty active sites for the oxygen reduction reaction (ORR). The CNO is a material obtained by annealing carbon nanodiamond at 1650˚C, modified and oxidized by an acidic procedure and then used as support for metal-free electrocatalysts to polymerize aniline in solution for the final development of the ORR. To execute this procedure the Rotating Disk Electrode was used, where the Chronoamperometry technique was applied using a positive potential for the oxidation of aniline. Cycle voltammetry from the window of -0.2 to 0.8V vs Ag|AgCl was used to characterize the surface of the electrode before and after of every polymerization step. The complex obtained was analyzed and characterized by Scanning Electron Microscope to observe the surface and the Energy Dispersive Spectroscopy to know the elements presents of the hybrid CNO/Polyaniline. Fourier Transform Infrared Spectroscopy was used to confirm the presence of the carbon-nitrogen bonds that come from polyaniline, X-Ray Diffraction was used to confirm the structure, and the Raman Spectroscopy was used to verify the completion of our hybrid. The results shown that the CNO serves as support to convert aniline into polyaniline demonstrating promising uses of this materials for the developing of energy systems without the presence of metals for the carry out of the ORR.
Graphene-Assisted Epitaxy of Group IV Semiconductor Nanostructures and Thin Films
Authors: Shehzad M Arslan , Mohabir Amar T , Filler Michael A
Published: February 2020

The growth of single crystalline group IV materials on amorphous substrates is useful in applications ranging from electronics to renewable energy. Graphene-assisted (or van der Waals) epitaxy is a promising route to achieve such films but has largely been limited to III-V and II-VI materials. In this work, we use graphene as a template for the low temperature epitaxy of group IV nanostructures and thin films. We investigate the effect of growth parameters and type of nucleation site (e.g., metal catalysts vs. graphene defects) on the crystal growth. We observe that metal catalysts enable in-plane group IV nanowire growth via the vapor-solid-solid mechanism at temperatures as low as 150 °C. The observation that neighboring nanowires are oriented 60º with respect to each other implies that the graphene crystal plays a critical role in the growth process. Graphene surface defects, induced by hydrogen radical exposure, can also be used to initiate crystal growth at elevated temperature. We leverage the differences in group IV atom sticking probability on graphene and amorphous surfaces to achieve selective epitaxy on graphene-on-oxide patterns. Transient studies as a function of the graphene pattern dimensions reveal a competition between crystal expansion and ripening. Our studies extend graphene-assisted epitaxy to a new, technologically-relevant materials system and provide fundamental insight into the underlying physicochemistry.
Identifying, Predicting and Preventing Localized Corrosion in Kr-85 Storage Canisters
Authors: Demarest Charles , Scully John R.
Published: February 2020

The influence of rubidium (Rb), both in its metallic and oxidized states, on the corrosion resistance of steels has direct relevance to the storage of radioactive Kr-85 containing nuclear materials. Kr-85undergoes a β-decay to generate stable, metallic Rb. The literature to date is sparse, and divisive as to whether Rb metal, or the Rb oxides, can lead to corrosion of steel materials. There is also evidence that Rubidium oxide may leech alloying elements such as chromium from stainless steels. In both the direct storage of Kr-85 and used nuclear fuel that will contain Kr-85, if Rb is corrosive then continual decay of the Kr-85 will generate an increasingly corrosive environment for the steel canister it is stored in. Current legacy canisters are corroding through, from the inside, in 30 years. These canisters need to last for 100 years in order for the Kr-85 to fully decay to safe levels. The Kr-85 storage system has other risk factors in the corrosion process, such as hydrogen, hydrogen peroxide, radiation, oxygen, and water. In this presentation we look to explain this dynamic system and how these risk factors affect the corrosion of the Kr-85 storage canisters, and what materials can be used as a substitute for the current storage system.
Developing High-Throughput Assays for Screening and Studying Chemical Interactions of Novel Corrosion Inhibitors in Solution and Coatings
Authors: Breedon Michael , White Paul , Collis Gavin , Venkatesan Kishore , Ganther Wayne , Skidmore Melissa
Published: February 2020

In recent years, we have been developing a holistic approach towards the design and screening of novel corrosion inhibitors for solution and coating applications. One of the main challenges in identifying and designing new inhibitors is being able to evaluate different materials under similar conditions to determine their potential efficiency to prevent corrosion. This is further complicated by the need to replicate the environmental conditions where the corrosion inhibitors will be used, understanding the complex chemical interactions in the bulk electrolyte, at the metal interface and in polymer coatings, the large number of different evaluation tests that need to be undertaken and the large amounts of chemicals, metal substrates, instrument techniques, and labour cost that are required to develop commercially viable corrosion inhibitors. To minimise some of these challenges so that we can identify superior corrosion inhibitors worthy of further detailed investigation and development, we are developing computational methods to model inhibitor materials, high-throughput (HTP) corrosion optical solution assay, HTP electrochemistry assay, thin film characterisation methods, neutral salt spray, and novel coating assay protocols. In an effort to accelerate these time consuming processes, we have started to integrate some of these assays into our FASTER™ robotic system. This presentation will highlight some of these challenges and how we have developed some robust HTP assays to expedite our corrosion inhibitor materials development program for solution and coating systems.
(Invited) Plane-Selective Coatings of Layered Oxide Cathode Materials for Li-Ion Batteries
Authors: Kim Hanseul , Lee Kyu Tae
Published: February 2020

Since one of the failure modes of Li-ion batteries is irreversible surface reactions, surface chemistry plays an important role in determining the electrochemical performance of Li-ion batteries.[1,2] For example, transition metal dissolution and electrolyte decomposition on the cathode surface at high voltages and temperatures cause poor electrochemical performance. In this connection, many research groups investigated various coated cathode materials, such as metal oxides, metal fluorides, and carbon-coated cathode materials.[3] These surface modifications reduced the irreversible surface reactions, leading to the improved electrochemical performance.

Surface-modified cathode materials are usually obtained via sol-gel synthesis, dry coating, and atomic layer deposition. These coating techniques are pursuing to uniform coating covering the whole surface of cathode powders. However, the full coverage of coating layers interrupts the charge-transfer of Li+ ions, resulting in poor rate capability. Therefore, if we are able to coat specific facets of cathode powders except for the charge-transfer planes, we can improve the rate performance of cathode materials.

In this presentation, we introduce a plane-selective coating of layered oxide cathode materials as a new coating technique. For example, we demonstrate that metal oxide coating layers are grown plane-selectively on the LiCoO2(001) surface. We carried out scanning transmission electron microscopy (STEM) analysis with a high-angle annual dark field (HAADF) mode to observe the plane-selective coatings. We also performed the theoretical calculations to understand the origin of the plane-selective coatings. The plane-selectively coated LiCoO2 showed better electrochemical performance than did the conventionally coated LiCoO2. Moreover, we demonstrate that the plane-selective coating can be extended to various layered oxide cathode materials for Li-ion batteries.

References:

[1] B. Xu, D. Qian, Z. Wang, Y. S. Meng, Materials Science and Engineering: R: Reports 2012, 73, 51

[2] W. Li, A. Dolocan, P. Oh, H. Celio, S. Park, J. Cho, A. Manthiram, Nat Commun 2017, 8, 14589

[3] Y.-K. Sun, C. S. Yoon, S.-T. Myung, I. Belharouak, K. Amine, Journal of The Electrochemical Society 2009, 156, A1005
(Invited) Lithium Sulfur Batteries: From Fundamental Understanding to Pouch Cell Integration
Authors: Xiao Jie
Published: February 2020

With the recent advances of Li-S battery research, new knowledge has been gathered which greatly deepens our understanding of this electrochemical couple. However, a cell-level understanding of Li-S chemistry is rarely reported, although it is expected that the dynamic interactions among sulfur, lithium and electrolyte in the enlarged testing format may lead to quite different findings. Herein, this work discusses the fundamentals underneath a Li-S cell when transiting from a coin cell to a realistic high-energy pouch cell. New challenges and opportunities have been discovered which in turn provide feedback for the rational design of materials/electrode at relevant scales. The potential solutions to further balance the energy density and cycling life of Li-S pouch cells is also proposed.
(Invited) On the Importance of Statistics in Electrode Characterization Techniques for Failure Mechanism Analysis
Authors: Moreau Philippe , Grissa Rabeb , Castaing Rémi , Guyomard Dominique , Bayle-Guillemaud Pascale , Boniface Maxime
Published: February 2020

Characterization techniques, when used on electrodes after cycling and/or post mortem, are crucial to the improvement of battery performance. They can indeed pinpoint which failure mechanism is involved and suggest ways to overcome it. Unfortunately, in order to be more precise or save time, objects of interest are rarely studied in large numbers. One might then wonder how representative of the “real” battery they are. In this presentation, examples based on electrochemistry, XPS and EELS spectroscopies will serve to resolve this problem.

In order to highlight of the importance of statistical treatment, we benefited from the analysis of variance (ANOVA) in order to identify pertinent parameters in the aging of Li-ion batteries. To this end, two battery systems: Li4Ti5O12|LiFePO4 and Li4Ti5O12|LiNi1/3Mn1/3Co1/3O2 cells, were aged. The aging conditions, i.e. the rates of charge and discharge and the usage profile, were chosen within an experimental design. It is noteworthy that, contrary to expectations, the evolutions of capacity and resistance are not generally influenced by the aging conditions…

Additionally, how a rarely-used technique, such as XPS imaging, can improve our understanding of the true repartition of chemical species at the surface of electrodes will also be shown. Electrode mixes (binder, active material, electron conductor) are often so complex that a single spectrum, however precise it may be, can lead to misinterpretation. For example, it might imply an interaction between species even though some of them are too far apart to interact, or lead to a compound composition even though two compounds should be considered. This will be demonstrated by virtue of XPS imaging, and by using lithium metal electrodes [R. Grissa et al., ACS Appl. Energy Mater. 2018, 1, 5694−5702] and solid electrolyte polymers that allow one to discriminate between these possibilities. The importance of PCA treatment of the data will be also indicated.

Finally, since microscopy techniques are notorious for obscuring the big picture when it comes to the electrode as a whole, and all the more so when high-level spectroscopy (Electron Energy Loss spectroscopy) is used, silicon electrodes were analyzed after cycling thanks to a very rapid and optimized phase analysis technique developed by M. Boniface et al. (Nano Lett. 2016, 16, 7381−7388). Although a technique of this kind is able to identify the reaction mechanism and solid electrolyte interphase in an aggregate, the universality of this behaviour in the electrode still needed to be demonstrated. The purpose of this part of the presentation is to prove that such is indeed the case, a conclusion resulting from the analysis of hundreds of particles, as well as a careful and absolute quantification of the species in the sample. Notably, the macroscopic characteristics of the electrode can be obtained from the sum of the microscopic data.
(IBA Technology Award) Energy Storage Batteries using Mn and Ti Based Elelctrode Materials
Authors: Xia Yong-Yao
Published: February 2020

Renewable generation, such as solar and wind, is intermittent, which causes sudden and unanticipated changes to power output and contributes to electricity grid instability. The stability and reliability of electricity grids requires a continuous balance between energy supply and demand. The aqueous lithium-ion battery (LIB) may solve both the safety problem associated with lithium-ion batteries that use highly toxic and flammable organic solvents, and the poor cycling life associated with commercialized aqueous rechargeable batteries including lead-acid and nickel-metal hydride systems. Aqueous LIBs have been demonstrated to be one of the most promising stationary power sources for the sustainable energy such as wind and solar power.

As early as in 2005, we developed a new concept hybrid electrochemical supercapacitor in which a Li-ion intercalated compound was used as a positive electrode in combination with an activated carbon negative electrode in a Li2SO4 aqueous electrolyte (ZL. 200510025269.6). A hybrid cell consisting of a spinel LiMn2O4 positive and an AC negative electrode shows excellent reversibility with a sloping voltage profile from 0.8 to 1.8 V at an average voltage near 1.3 V, and delivers an 8 Wh/kg of 60000 F practical cell. In order to improve the specific energy, we employed LiTi2(PO4)3, but the cell shows poorer cycling stability compared with the pure AC anode. We found that, in the presence of oxygen, the discharged state of lithium-ion intercalated compounds (LIC) of all negative electrode materials will react with water and O2 despite of the pH value of the electrolyte, which is mainly responsible for the capacity fading of aqueous lithium-ion batteries during charge/discharge cycling. By eliminating the O2 (using a sealed cell), adjusting the pH values of the electrolyte, and using carbon-coated electrode materials; the LIB shows much cycling stability. A commercialized hybrid LIB shows a specific energy of ca. 30 Wh/kg, and exhibits a good cycling stability over 3500 cycles. In 2005, we also for the first time employed carbon coating technology to improve the electrode performance of Li4Ti5O4. By optimizing the graphitization and the coated carbon layer thickness, the nano-thickness carbon layer coated LTO shows excellent rate capability and less gas generation during cycling and storage. A LMO/LTO Li-ion battery show excellent cycling stability, high power and safety as stationary power source for smart-grid systems.

References:

Xia et al., TiP2O7 and Expanded Graphite Nanocomposite as Anode Material for Aqueous Lithium-Ion Batteries. ACS Appl. Mater. Interfaces, 9, 8075-8082 (2017).

Xia et al., Raising the Cycling Stability of Aqueous Lithium-Ion Batteries by Eliminating O2 in the Electrolyte ”,
Nat

.

Chem

.

,
2, 760-765 (2010).

Xia et al., Hybrid aqueous energy storage cells using activated carbon and lithium-intercalated compounds I. The C/LiMn2O4 system,
Electrochem. Soc.

, 153(2): A450-A454 (2006).
(Keynote) Low Temperature Processing Innovation and Structure Design of Li-Garnetsfor Solid State Batteries and Environmental Sensing of Chemicals
Authors: Rupp Jennifer L.M.
Published: February 2020

Next generation of energy storage and sensors may largely benefit from fast Li+ ceramic electrolyte conductors to allow for safe and efficient batteries and real-time monitoring anthropogenic CO2. Recently, Li-solid state conductors based on Li-garnet structures received attention due to their fast transfer properties and safe operation over a wide temperature range. Through this presentation basic theory and history of Li-garnets will first be introduced and critically reflected towards new device opportunities demonstrating that these electrolytes may be the start of an era to not only store energy or sense the environment but also to emulate environmental data and information based on simple electrochemistry device architecture twists.

In the first part we focus on the fundamental investigation of the electro-chemo-mechanic characteristics and design of disordered to crystallizing Li-garnet structure types and their description. Understanding the fundamental transport in solid state and asking the provokative question: how do Li-amorphous to crystalline structures conduct?

New insights on degree of glassy to crystalline Li-garnet thin films are presented based on model experiments of the structure types. Here, the thermodynamic stability range of maximum Li-conduction, phase, nucleation and growth of nanostructure is discussed using high resolution TEM studies, near order Raman investigations on the Li-bands and electrochemical transport measurements.

In a second part, we focus on new processing opportunities to Lithiate thin film structures in crystalline state and to assure cubic and fast conducting garnet structures for thin film form. For this we will review the field of thin film processing and structure-property for garnet type films and reflect our recent new processing routes based on vacuum and wet-chemical techniques.

The insights provide novel aspects of glass and ceramic thin film processing and material structure designs for both the Li-garnet structures (bulk to films) and their interfaces to electrodes, which we either functionalize to store energy for next generation solid state batteries or ... make new applications such as Li-operated CO2 sensor tracker chips which we present in a final part.
(Invited) Present Status of Lithium Ion Batteries
Authors: Blomgren George E
Published: February 2020

The specific energy of commercial lithium ion batteries has increased substantially, while the price of both cells and batteries have diminished since their introduction in 1991(Figure 1). The results of these improvements have led to wide acceptance of the batteries in a number of applications. In particular, hybrid, plug-in hybrid and pure electric vehicles have been widely developed with lithium ion batteries. In addition, lithium ion batteries in other vehicle types from scooters to bicycles to motorcycles as well as trucks and buses have also been developed and are becoming popular. Lithium ion cells are frequently used in drones or unmanned aerial systems (UAS). High to medium power applications such as power tools and mechanical devices such as mobile robots have also been strongly marketed. Energy storage devices related to electric grid applications are also on a strong growth trajectory.

The design and material changes which have enabled these advances will be discussed and the prospects for further growth in energy and power will be considered. Also, the need for higher charge rates and possible methods of improvement in charge rate will be considered in the search for improved charge times for vehicles and other higher power applications.

Figure 1 Development of lithium batteries during the period of 1970–2015, showing the cost (blue, left axis) and gravimetric energy density (from G. Crabtree, E. Kocs and L. Trahey, MRS Bulletin 40, 1067, 2015)

Figure 1
(Invited) Preserving a High Energy Density of the Lithium-Rich Layered Oxides (LLO) and New Lithium Diffusion Model for LLO
Authors: Kang Kisuk
Published: February 2020

Lithium-rich layered oxides (LLOs) are considered promising cathode materials for lithium-ion batteries because of their high reversible capacity, which is attributed to the exploitation of the novel anionic redox in addition to the conventional cationic redox process. Cobalt-free layered lithium-rich nickel manganese oxides, Li[LixNiyMn1
−
x
−
y]O2, are one of the promising positive electrode materials for lithium rechargeable batteries because of their high energy density and low materials cost. However, substantial voltage decay is inevitable upon electrochemical cycling, which makes this class of materials less practical. It has been proposed that undesirable voltage decay is linked to irreversible structural rearrangement involving irreversible oxygen loss and cation migration. In the first part of my talk, we demonstrate that the voltage decay of the electrode is correlated to Mn4+/Mn3+ redox activation and subsequent cation disordering, which can be remarkably suppressed via simple compositional tuning to induce the formation of Ni3+ in the pristine material. By implementing our new strategy, the Mn4+/Mn3+ reduction is subdued by an alternative redox reaction involving the use of pristine Ni3+ as a redox buffer, which has been designed to be widened from Ni3+/Ni4+ to Ni2+/Ni4+, without compensation for the capacity in principle. Negligible change in the voltage profile of modified LLO is observed upon extended cycling, and manganese migration into the lithium layer is significantly suppressed.

In the second part of the talk, I will discuss about transition metal (TM) migration, which is now understood to be the critical factor triggering the anionic redox as well as the phase transition, although the origin is still under debate. A better understanding of the specific TM migration behavior and its effect during charge/discharge would thus enable further development of this class of materials. I will show that the unique TM migration during charge/discharge significantly alters the lithium diffusion mechanism/kinetics of LLO cathodes. I present clear evidence of the much more sluggish lithium diffusion occurring during discharge (lithiation) than during charge (de-lithiation), which contrasts with the traditional lithium diffusion model based on simple topotactic lithium intercalation/deintercalation in the layered framework. The reversible but asymmetric TM migration in the structure, which originates from the non-equivalent local environments around the TM during the charge and discharge processes, is shown to affect the lithium mobility. This correlation between TM migration and lithium mobility led us to propose a new lithium diffusion model for layered structures and suggests the importance of considering TM migration in designing new LLO cathode materials.
(Keynote) Li Inventory Behavior and Control in Lithium-Ion Batteries with Si-Containing Anodes
Authors: Dose Wesley M , Johnson Christopher S
Published: February 2020

Because of their high-gravimetric capacities, use of Si-containing anodes in Li-ion batteries can lead to a big jump in energy densities. The control of lithium consumption, however is a big obstacle for these cells, and many strategies are emerging to address the problem of Li inventory. We search for solutions on the subject from two fronts. The first is to understand the lithium inventory via utilization of a quasi-RE/CE thick LiFePO4 in a Si-type full cell [1-2]. In this study we show the effectiveness of LiFePO4 as a diagnostic tool in order to assay the quantity of Li consumption in a full cell as marked by the percent loss of lithium per cycle via SEI growth and/or SEI consumption and re-formation. This approach allows the Li content to be followed during cycling without Li metal or layered oxide cathode complications (i.e. non-controlled voltage shifts). The second topic focuses on practical solutions to introduce high contents of Li into the cell in the easiest, most straightforward way. We take the approach of designing cathodes and utilizing cathode blends wherein sacrificial Li is introduced into the cell [3]. In these cases greater energy densities can be realized from higher retained cathode capacity, and cycle life is dramatically improved.

“Capacity fade in high energy silicon-graphite electrodes for lithium-ion batteries”, W. M. Dose, M. J. Piernas-Munoz, V. A. Maroni, S. E. Trask, I. Bloom and C. S. Johnson, Chemical Communications, (2018), 54, 3586-3589

“Assessment of Li-Inventory in cycled Si-Graphite anodes using LiFePO4 as a diagnostic cathode”, W. M. Dose, V. A. Maroni, M. J. Piernas-Munoz, S. E. Trask, I. Bloom, and C. S. Johnson, J. Electrochem. Soc., (2018), 165, A2389-A2396

“Mitigating the initial capacity loss and improving the cycling stability of silicon monoxide using Li5FeO4”, L. Zhang, W. M. Dose, A. D. Vu, C. S. Johnson, W. Lu, J. Power Sources, (2018), 400, 549-555.
(Invited) Microscopic Insights into Interfacial Conductivity and Stability of Solid-State Electrolytes for Li-Metal Batteries
Authors: Chi Miaofang
Published: February 2020

Solid-state electrolytes are intensively being investigated as a critical component in future generation Li-metal battery systems, including their uses as the primary electrolyte in all-solid-state batteries, and as the protection layer for Li-metal in Li-air, Li-S, or aqueous batteries. While several solid electrolyte materials were developed recently that demonstrated sufficient conductivity, unexpectedly high resistance and cycling instability from grain boundaries and interfaces are often observed. The practical applications of solid-state electrolytes cannot be realized without a thorough understanding of these phenomena. This talk will cover our recent efforts in elucidating the fundamental origin of (1) interfacial resistivity between solid electrolytes and Lithium metal, and (2) preferential dendrite growth along grain boundaries, by using in situ and atomic-resolution scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS). Interfacial phenomena among different solid electrolytes, e.g. Li(7−3×)AlxLa3Zr2O12 (LLAZO), Li1+xTi2–xAlx(PO4)3 (LATP) and LIPON, will be compared and potential strategies to mitigate interfacial challenges will be proposed.