bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Analysis of Proteins in Physiological Samples with Three-Dimensional Paper-Based Isoelectric Focusing
Authors: Niu Jicheng , Li Fei
Published: July 2021

Point-of-care testing (POCT) of proteins is crucial for on-site and rapid diagnosis of diseases in community and family medicine. Microfluidic paper-based analytical devices (µPADs) have attracted growing attention in POCT of proteins, while the practical applications of µPADs in the analysis of proteins in physiological samples is still limited as physiological samples are usually high-salt and complex. Herein, we developed a three-dimensional (3D) paper-based isoelectric focusing (IEF) platform, which is composed of power supply, reservoirs and separation channel make by origami and stacking of cellulose acetate membrane, to simultaneously separate and enrich proteins in both low-salt samples and high-salt samples, especially for directly pretreating and analyzing proteins in physiological samples. Under the optimized experimental conditions, standard proteins (Phy and BHb) were separated in 18 min under a 36.0 V power supply and obtained 10-fold enrichment using the 3D paper-based IEF platform. Then, the capability of the 3D paper-based IEF platform with using a 12.0 V battery as power supply for direct pre-treatment of high-salt samples was proven through separating three standard proteins in saline (0.9 % NaCl) with separation resolution (SR) >1.29. Through further coupling with colorimetric and lateral flow strip measurements, the 3D paper-based IEF platform was applied to directly pre-treat and quantitatively analyze the two disease biomarkers, i.e., microalbuminuria and C-reactive proteins in clinical human serum. The analytical results had the relative deviations of <8.4% and <13.1% to clinical results, respectively. As the first report of the paper-based IEF platform for directly pretreating high-salt samples, this work proposes a new strategy to minimize the difficulty of directly processing high-salt samples with traditional IEF system and provides a versatile, miniaturized and low voltage demand analytical platform for POCT of proteins in physiological samples.

References

[1] J. C. Niu, T. Zhou, L. L. Niu, Z. S. Xie, F. Fang, F. Q. Yang, Z. Y. Wu, Simultaneous Pre-concentration and Separation on Simple Paper-based Analytical Device for Protein Analysis, Analytical and Bioanalytical Chemistry 410.6 (2018): 1689-1695.

[2] J. C. Niu, H. X. Shi, H. G. Wei, B. Gao, J. X. Li, F. Xu, X. G. Li, F. Li, Liquid Plasticine Integrated with Isoelectric Focusing for Miniaturized Protein Analysis, Analytical Chemistry 92.13 (2020): 9048–9056.
Rationally Designed Molecularly Imprinted Polymers for Trace Electroanalysis of Environmental Micropollutants
Authors: Glasscott Matthew William , Moores Lee C , Fernando Ashvin , Shukla Manoj , Jenness Glen , Schutt Timothy , Bresnahan Caitlin
Published: July 2021

The undetected discharge of solubilized micropollutants into natural waterways constitutes a major public health concern. Thus, generalizable strategies to detect various micropollutant species coupled with deployable sensing platforms are paramount for indicating the presence of contamination at its earliest onset. Benchmark chromatographic methods paired with mass spectrometry to quantify micropollutants are expensive and difficult to deploy into waterways as passive environmental probes. In contrast, electrochemical sensors are inexpensive and easily miniaturized. We report the electrochemical detection of two compounds, 2,4,6-trinitrotoluene (TNT), a prevalent munition, and 2,4-dichlorophenoxyacetic acid (2,4-D), a common fertilizer, using molecularly imprinted polymers (MIPs). MIPs were rationally designed using DFT-level molecular simulations to determine an ideal functional monomer with maximal affinity for each micropollutant species. NMR titration methods were used to verify the simulation results and optimize the monomer/micropollutant ratio. Following optimization, MIPs were synthesized by anodic electropolymerization onto gold substrates in the presence of the micropollutant, which was subsequently stripped away via solvent washing to reveal micropollutant-specific binding sites. Upon micropollutant association with the MIP when placed in contaminated water, surface sites were blocked, which was tracked electrochemically. Each sensor exhibited a limit of detection in the sub-parts-per-billion regime, demonstrating the amenability of this sensing method for trace analysis. Combining the sensitivity of electroanalysis with the selectivity provided by the MIP recognition element constitutes a powerful platform for the detection of micropollutants in environmental matrices.

FIGURE CAPTION:

Electroanalytical signal obtained following the adsorption of TNT or 2,4-D molecules to an electropolymerized molecularly imprinted polymer (MIP) recognition element. MIPs may be rationally designed using density functional theory (DFT, inset) to maximize the monomer/toxin binding affinity, enhancing the analytical response and permitting the sub-ppb quantification of these toxins in environmental matrices.

Figure 1
Electrochemical Characterization of a Drawn Thin-Film Glassy Oxide Electrolyte Material for Solid-State Battery Applications
Authors: Wheaton Jacob , Kmiec Steven , Martin Steve
Published: July 2021

Solid-state batteries present many advantages over liquid electrolyte systems, enabling the use of lithium metal anodes due to the non-flammable nature of the inorganic electrolyte. Glassy materials in particular are promising candidates as solid electrolytes due to their highly tunable properties, the absence of grain boundaries, and their ease of processability. The large compositional window of glassy materials allows for optimizing glass-forming ability and conductivity, while the lack of grain boundaries may be beneficial in preventing lithium dendrite formation. While lithium metaphosphate (LiPO3) has a low room temperature ionic conductivity (σ25°C = 1.6 ∙ 10-9 S/cm) that limits its use in solid-state batteries, oxides present similar processability and higher chemical and electrochemical stability than their higher conductivity sulfide analogues. LiPO3 was chosen for a preliminary investigation into the effects and challenges of decreasing electrolyte thickness due to its low processing temperature and ease of fabrication. The electrochemical behavior of drawn thin-film LiPO3 was studied through electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic symmetric cell cycling. These results show that with higher conducting oxy-sulfide glassy electrolyte materials, drawn thin-film electrolytes are a viable and valuable research direction.
Xanthogen Polysulfides As Active Materials for Rechargeable Batteries
Authors: Bhargav Amruth , Manthiram Arumugam
Published: July 2021

Significant research strides taken in the past decade have shown that lithium-sulfur (Li-S) batteries are a promising technology to compete with current Li-ion batteries owing to their significantly higher specific energy. However, some fundamental and technical challenges, such as the polysulfide shuttle effect and the need for abundant electrolyte for battery operation, have beleaguered Li-S batteries from being the next practical high-energy-density solution.[1] Recent resurgence of Li-organosulfur batteries as alternative sulfur-based cathode chemistry has shown great potential to alleviate some of these challenges.[2] These materials offer control over the order of the lithium polysulfides formed during cycling through the presence of organic terminal groups, thus minimizing the polysulfide shuttle effect. Additionally, they possess the ability to operate under lean-electrolyte conditions, a critical parameter for maximizing cell-level specific energy.

This work introduces a new member into the family of organosulfur cathode materials – xanthogen polysulfides. Diisopropyl xanthogen polysulfide (DIXPS) was used as a model compound to understand the electrochemical characteristics of this new material class. Its chemical transformations within a battery will be discussed. DIXPS shows excellent long-term performance with stability up to 1,000 cycles at a high rate of 4C. DIXPS also demonstrates the ability to deliver a high specific energy of 1,313 W h kg-1 and 1,694 W h L-1 while operating under high-loading and lean-electrolyte conditions. This illustrates the practical applicability of this material. Additionally, the feasibility of using alternate anodes such as sodium-metal will also be explored. The ability to synthesize such battery materials using natural feedstocks, such as sugars and alcohols will also be examined.

References:

[1] A. Bhargav, J. He, A. Gupta, A. Manthiram, Joule
2020, 4, 285.

[2] D. Y. Wang, W. Guo, Y. Fu, Acc. Chem. Res.
2019, 52, 2290.

Figure 1
A Self-Assemble Micelle Electrolyte for Polysulfide Suppression and Li Stabilization in Li-S Battery
Authors: Zhao Yangzhi , Fang Chen , Zhang Guangzhao , Hubble Dion , Nallapaneni Asritha , Zhu Chenhui , Zhao Zhuowen , Liu Zhimeng , Liu Gao
Published: July 2021

Li-S battery, a promising next-generation technology, has received dramatic attention recently due to high theoretical energy density (2600Wh kg-1 ) and low materials cost. However, its application has been impeded by notorious polysulfide dissolution/shuttling which causes poor cycling stability and coulombic efficiency. Herein, I will introduce a novel strategy to suppress the polysulfide dissolution by using hydrofluoroethers (HFEs) electrolyte additive. A bi-functional, surfactant-like molecule structure with a polar lithiophilic “head” attached to a fluorinated lithiophobic “tail”, was designed for these HFE solvents whereby a unique solvation mechanism is proposed: dissociated lithium ions are readily coordinated with lithiophilic “head” to induce self-assembly into micelle-like complex structures. Complex formation is verified experimentally by small angle X-ray scattering (SAXS) and is studied as a function of additive structure and concentration. The modeling work is underway to further investigate coordination between molecules and micelle structure evolution under different conditions. These HFE-based electrolytes are found to prevent polysulfide dissolution and to have excellent chemical compatibility with lithium metal, which is evidenced by superior battery performance: Li-S cells are demonstrated with 1395 mAh g-1 initial capacity and 71.9% retention over 100 cycles at >99.5% efficiency; Li||Cu stripping/plating tests reveal high coulombic efficiency (>99.5%), modest polarization, and smooth surface morphology of the uniformly deposited lithium.
Doping of NaCrO2 Cathode Material to Enhance Electrochemical Performance for Sodium-Ion Batteries
Authors: Wang Ziyong , Shaw Leon
Published: July 2021

The effects of doping on NaCrO2 cathode material are investigated in this study. All doped NaCrO2 powders are denoted as NaMe0.1Cr0.9O2 where Me = Al, Co, Ni, or Mn. To understand the mechanism of doping, field emission scanning microscopy (FESM) and energy disperse spectroscopy (EDS) as well as X-ray diffractometer (XRD) are employed to analyze the morphology and composition of the final products. Further, electrical conductivities of doped NaCrO2 powders are studied using electrochemical impedance spectroscopy (EIS). Compared to pristine NaCrO2, NaNi0.1Cr0.9O2 exhibits a high reversible capacity, while Mn doping contributes to good cycle stability. The charge/discharge behaviors from Ni- and Mn-doped NaCrO2 materials provide us a potential method to co-dope NaCrO2 in the future to achieve high specific capacity and long cycle life simultaneously.
A New Electrode Material for High-Performance Sodium-Ion Batteries: Lithium-Substituted Tunnel/Spinel Heterostructured Cathode
Authors: Liang Xinghui , Kim Hun , Sun Yang-Kook
Published: July 2021

The tunnel-type Na0.44MnO2 as promising cathode materials for sodium-ion batteries (SIBs) have attracted interest owing to its abundant resources and potential low cost. Unfortunately, due to the disproportionation of manganese associated with Mn3+, the electrochemical performance of this material is hindered, resulting in rapid capacity decline and poor rate capability. Herein, a Li-substituted, tunnel/spinel heterostructured cathode is successfully synthesized for addressing these limitations. The Li dopant can acts as a pillar inhibiting unfavorable multiphase transformation, improving the structural reversibility and sodium storage performance of the cathode. Meanwhile, the tunnel/spinel heterostructure provides three-dimensional Na+ diffusion channels to effectively enhance the redox reaction kinetics. The optimized [Na0.396Li0.044][Mn0.97Li0.03]O2 composite delivers an excellent rate performance with a reversible capacity of 97.0 mA h g-1 at 15 C, corresponding to 82.5% of the capacity at 0.1 C, and a promising cycling stability over 1200 cycles with remarkable capacity retention of 81.0% at 10 C. Moreover, by combining with hard carbon anodes, the full cell demonstrates a high specific capacity and favorable cyclability. After 200 cycles, the cell provides 105.0 mA h g-1 at 1 C, demonstrating the potential of the cathode for practical applications. This strategy might apply to other sodium-deficient cathode materials and inform their strategic design.

References

J.-Y. Hwang, S.-T. Myung, Y.-K. Sun, Chem. Soc. Rev.
2017, 46, 3529.

J.-Y. Hwang, J. Kim, T.-Y. Yu, Y.-K. Sun, Adv. Energy Mater.
2019, 9, 1803346.

P. Zheng, J. Su, Y. Wang, W. Zhou, J. Song, Q. Su, N. Reeves‐Mclaren, S. Guo, ChemSusChem
2020, 13, 1793.
Enabling High-Voltage Cycling of O3-Type Sodium Layered Oxide Cathode Via Ca-Substitution
Authors: Yu Tae-Yeon , Han Geumjae , Sun Yang-Kook
Published: July 2021

To facilitate the practical realization of sodium-ion batteries(SIBs), the energy density, determined by the output operating voltage and/or capacity, needs to be improved to the level of commercial Li-ion batteries(LIBs). To date, O3-type Na[Ni0.5Mn0.5]O2 cathode has been considered as one of the most promising cathode materials because of its high capacity and good practical applicability. Although an effective approach would be to elevate the operating voltage of the battery to reach higher energy density of SIBs, however, O3-type Na[Ni0.5Mn0.5]O2 generally experiences irreversible phase transition occurs via the redox reaction of Ni2+/Ni4+, which affects the cycling stability within the high-voltage window. In this study, we introduced the Ca substitution into bulk Na sites, which significantly improved the structural and electrochemical properties of the Na[Ni0.5Mn0.5]O2 cathode. The presence of Ca2+ ions in Na sites sufficiently stabilized the crystal structure and effectively mitigated the volume expansion when Na+ ions are almost fully extracted from the structure. Moreover, Ca substitution improves the practically useful aspects such as thermal and air stability.

References

S. Komaba, N. Yabuuchi, T. Nakayama, A. Ogata, T. Ishikawa, I. Nakai, Chem., 2012, 51, 6211.

L. Sun , Y. Xie , X.-Z. Liao , H. Wang , G. Tan , Z. Chen , Y. Ren , J. Gim , W. Tang , Y.-S. He , K. Amine, Z.-F. Ma, Small. 2018, 14, 1704523.
Phosphate Electrolyte Design for Highly Reversible Sodium Ion Batteries
Authors: Jin Yan , Yi Ran , Vo Thanh D , Zhang Ji-Guang
Published: July 2021

Sodium ion battery (NIB) is a very promising technology for the next generation of energy storage systems because of the abundance and low cost of Na in the Earth’s crust. However, the large-scale application of NIBs is still a challenge because of limited cycle life and potential safety concerns. In this regard, electrolyte plays a critical role in both cycle life and safety of NIBs. The battery stability is directly related to the properties of the electrode-electrolyte interphase. Therefore, designing advanced electrolytes with a stable electrode-electrolyte interphase is crucial to develop stable NIBs for their practical applications in large-scale energy storage. In this work, we report a phosphate-based electrolyte for sodium ion batteries with high capacity retention and excellent coulombic efficiency (99.9 %) during long term cycling. The details together with postmortem analysis of the cycled electrode will be discussed at the presentation. The insights obtained in this work can be used to further improve cycling stability and safety of rechargeable batteries.
Extending Non-Hysteretic Electrochemistry Beyond Conventional Transition Metal Capacity in Li and Na-Ion Cathodes Using Pi-Redox
Authors: Kitchaev Daniil , Vinckeviciute Julija , Van der Ven Anton
Published: July 2021

The anomalous electrochemical capacity observed in some Li- and Na-excess materials, extending beyond the conventional limit of transition metal redox, represents one of the most promising sources of untapped energy density in intercalation cathodes. Unfortunately, the majority of materials known to exhibit this behavior suffer from voltage hysteresis and structural degradation. A prominent exception is Na2Mn3O7, which shows no voltage hysteresis despite operating beyond the conventional limit of Mnoxidation. The redox mechanism of this material and the source of the non-hysteretic behavior remain controversial with significant inconsistencies between experimental observations and the commonly invoked "oxygen-redox" theories. We use high-level electronic structure calculations to demonstrate that the origin of the anomalous capacity in Na2Mn3O7 is the oxidation of a delocalized redox center consisting of pi-bonded Mn-d and O-p orbitals, which we term pi-redox. This hybridized redox is unique in that capacity, voltage, and stability are determined by the long-range structure of the metal-oxygen network, rather than any local bonding environment. The pi-redox mechanism competes with oxidation-driven transition metal migration which underlies the hysteresis seen in most excess-capacity compounds, such as those based on Li2MnO3. The new pi-redox mechanism is the first to reconcile all experimental observations of non-hysteretic anomalous capacity, and sets forth rigorous materials design principles for extending this behavior from model systems to high-performance compounds.
Operando Observation of a Highly Reversible Nonporous Sodium Metal Anode with Shiny-Smooth Surface
Authors: Ma Bingyuan , Bai Peng
Published: July 2021

While alkali metal anodes are considered as the promising alternatives to the ion-hosting materials due to the high energy densities, the nonuniform deposition (dendritic growth) that can lead to internal shorts remains a major obstacle of their practical applications (1,2). Here, according to the operando observation in our special capillary cells, we report a shiny-smooth nonporous sodium metal anode that can be cycled reversibly even at high areal capacities, without the formation of any whiskers, mosses, gas bubbles or disconnected metal particles observed in existing studies (3,4). The plating process follows the lateral surface-growing mechanism, which transforms into tip-growing branch-like dendrites at a critical time when applying over-limiting currents (5). The superior interfacial stability is attributed to the non-accumulative solid electrolyte interphases (SEIs) upon cycles, which is supported by the elemental depth profile analysis. As a result, a reversible high capacity sodium metal anode is achieved in coin cells within a critical penetration-related current density (6 mA cm-2). Our study demonstrates the possibility of plating shiny-smooth reactive alkali metal in liquid electrolytes and provides a reliable option applicable for the next-generation alkali metal batteries.

Xu W, Wang J, Ding F, Chen X, Nasybulin E, Zhang Y, et al. Lithium metal anodes for rechargeable batteries. Energy Environ Sci. 2014;7(2):513–37.

Zhao C, Lu Y, Yue J, Pan D, Qi Y, Hu YS, et al. Advanced Na metal anodes. J Energy Chem. 2018;27(6):1584–96.

Rodriguez R, Loeffler KE, Nathan SS, Sheavly JK, Dolocan A, Heller A, et al. In Situ Optical Imaging of Sodium Electrodeposition: Effects of Fluoroethylene Carbonate. ACS Energy Lett. 2017;2(9):2051–7.

Yui Y, Hayashi M, Nakamura J. In situ Microscopic Observation of Sodium Deposition/Dissolution on Sodium Electrode. Sci Rep. 2016;6:1–8.

Bai P, Li J, Brushett FR, Bazant MZ. Transition of lithium growth mechanisms in liquid electrolytes. Energy Environ Sci. 2016;9(10):3221–9.

Figure 1
Stability of Lithium Metal Electrodeposition across Viscoelastic Electrolytes
Authors: Rudnicki Paul E. , Qin Jian
Published: July 2021

The key issue preventing the use of lithium metal anodes in high energy-density batteries is undesirable dendritic deposition at the lithium-electrolyte interface, which raises serious concerns over safety and battery life. Experimental and theoretical studies have been carried out to reveal the mechanism underlying this morphological instability and to suppress it via electrolyte engineering. We study this instability by perturbing a continuum electrodeposition model which couples ionic transport across the cell, mechanical response of the anode and separator, and Marcus reaction kinetics at the anode-electrolyte interface. The analysis is validated against known results for elastic separators, then generalized to include the viscoelastic response of polymer electrolytes and to examine the impact of relaxation time. The work bridges the regimes dominated by ionic transport and reaction kinetics and can guide experimental design of novel electrolytes and separators toward stable, safe lithium metal batteries.
Molecular Chemistry Design of the Silicon SEI Using Oxide-Free PECVD Silicon Nanoparticles
Authors: Neale Nathan R. , Schulze Maxwell C , Carroll Mike Michael , Martin Trevor R.
Published: July 2021

Silicon (Si) is a heavily-studied next-generation battery anode material that has yet to see significant industrial adoption. Significant advancements in stabilizing the Si solid-electrolyte interphase (SEI) against chemical and electrochemical corrosion are needed. In this presentation, we will present recent work on understanding the chemical and electrochemical corrosion processes using model Si nanoparticles (NPs) grown via nonthermal plasma-enhanced chemical vapor deposition (PECVD). The surface chemistry of these hydrogen-terminated, oxide-free Si NPs can be manipulated using molecular chemistry to engineer artificial SEIs composed of hydrophobic, hydrophilic, or conductive coatings. Such coatings allow us to tailor the electrical and ionic conductivity of the SEI and understand the key design principles necessary for a robust and effective artificial Si SEI. Finally, we use these design principles to assemble surface-engineered PECVD Si NP-based electrodes and will present preliminary electrochemical cycling data for these next-generation anodes in both half- and full-cell configuration.
Elucidating the Solubility and Diffusivity of Atmospheric Gases in a Wide Variation of Liquid Electrolytes for Lithium-Air Batteries
Authors: Haas Ronja , Murat Michael , Janek Jürgen , Natan Amir , Schroeder Daniel
Published: July 2021

Due to their high theoretical energy density, Li–O2 and Li–air batteries are considered as a promising alternative to Li-ion batteries, especially for mobile applications. However, dissolved gases in the liquid electrolyte, in particular O2, can be involved in detrimental side reactions at the lithium anode. Moreover, CO2 that can form from side reactions with the electrolyte or the cathode material, and N2 from the ambient air might be dissolved in the electrolyte.

In order to evaluate the impact of these dissolved gases on the stability of the anode and to know their concentrations in possible side reactions, the solubility and the diffusion coefficient for each gas in the electrolyte are crucial parameters to know.

In this work, we utilize gas uptake measurements to systematically determine the diffusion coefficients and Henry’s law solubility constants of O2, N2 and CO2 in different ether- and DMSO-based electrolytes and pure solvents. Additionally, we calculate the diffusion coefficient with molecular dynamics simulations and show good qualitative agreement between simulations and experimental results. We discuss the influence of solvent parameters, such as surface tension and viscosity, on the solubility and the diffusivity as well as the impact of different conducting salts. All investigated conducting salts reduce the diffusivity of the gases; however, we observe the solubility can both decrease or increase, depending on the solvent, the gas and the molecular structure of the salt. Therefore, we emphasize that both components, solvent and conducting salt, have to be considered for optimizing the gas transport properties of the electrolyte for Li–O2 and Li–air batteries.
Scalable 18650 Cylindrical Cells of Lithium Metal Batteries Using Ni-Rich Cathode with Electrolyte Engineering
Authors: Joraleechanchai Nattanon , Duangdangchote Salatan , Sawangphruk Montree
Published: July 2021

Li-ion batteries are approaching their theoretical limits in energy densities, motivating the revival of Li metal chemistry. Nevertheless, uncontrollable side reaction forms a chemically unstable SEI and non-uniform Li diffusion through the surface of Li anode, leading to dendritic growth. These instability and safety issues have been the main challenges of lithium metal batteries. To overcome these drawbacks, tremendous efforts have been devoted to the use of artificial solid electrolyte interphase (ASEI) engineering, lithium hosts & scaffolding, and electrolyte additives. However, the electrolyte engineering in 18650 cylindrical lithium metal cells under the practical condition, for instance, the utilization of high cathode loading (>3.5 mAh/cm2), thin lithium metal (e.g., <50 um), and lean electrolyte (<3 g/Ah)) has not been investigated yet. Herein, the first-scalable 18650 lithium metal battery in high Ni content (>88%) NCA cathode with state-of-the-art electrolytes including fluorinated solvent, and flame-retardant additives were studied. The effect of electrolytes at the positive electrode on the active mass loss and lattice volume changes, charge transfer resistance growth, SEI/CEI composition, and lithium dendrite morphology has also been investigated by the post-mortem analysis. To achieve fundamental understanding, reactive molecular dynamic simulation (Reaxff) has been used to investigate the mechanism and compositions of the passivation layer compounds at the lithium anode. The predicted compounds have a correlation to experimental results and the cell performances in terms of capacity retention and coulombic efficiency.

Figure 1
Metal Organic Framework Derived Magnesium Oxide/Carbon Interlayer for Long-Life Lithium-Sulfur Batteries
Authors: Kang Hyeonmuk , Shin Jaewook , Kim Taehee , Lee Yongju , Lee Daehee , Cho EunAe
Published: July 2021

i-S battery, with abundant S sources and high theoretical capacity, is one of the promising future battery technology. S cathode has a theoretical capacity of 1672 mAhg-1, which is an order of magnitude higher than the transition metal oxides’ of commercial lithium-ion batteries. However, the commercialization of Li-S battery is still struggling due to poor cyclic stability and limited kinetics. These problems come from the low electrical conductivity of S, LiS and Li2S, polysulfide shuttling effect and large volume change during cycling. Polysulfide shuttling effect is a phenomenon that polysulfide intermediate species, generated during charging and discharging of S and Li2S, gets dissolved into electrolyte and cause loss of capacity. Herein, the Mg-MOF-74-derived MgO/carbon interlayer is synthesized. Carbon substrate is known to provide additional electrical conductivity to S cathode, and according to Tao, X., et al, MgO is a good choice to balance between sulfide-adsorption and diffusion on the oxides. Therefore, MOF-derived MgO particles are expected to effectively mitigate polysulfide shuttling and reutilize dissolved polysulfide. Inserting MOF-derived MgO/carbon interlayer, the Li-S cell show excellent cycling stability (87.5% retention within 100 cycles) at 0.2 C with sulfur loading mass 2.6 mg cm-2, whereas the pristine and carbon interlayer sample show 60.0% and 64.3%. The capacity retention still holds at higher loading mass of sulfur electrode. Due to low electrical conductivity and polysulfide dissolution of the sulfur cathode, increasing sulfur content and loading mass of the sulfur electrode, and amount of electrolyte could be detrimental to Li-S cell performance. However, with Mg-MOF-74-derived MgO/carbon interlayer, this limitation could be overcome.

References:

[1] Tao, X., et al., Nat Commun, 2016. 7: p. 11203.
In Situ Stress Evolution on an Au Thin Film Cathode during Charging/Discharging of a Lithium-Oxygen Battery
Authors: Dykes Hannah , Capraz Omer Ozgur
Published: July 2021

The theoretical energy density of lithium-oxygen batteries is by far the closest competitor to gasoline compared to other battery configurations. Unfortunately, the commercial implementation of this technology is hindered by the poor cycling performance, mostly due to the slow oxygen evolution/reduction kinetics. The sluggish oxygen evolution kinetics are typically more severe and cause the slow oxidation of lithium peroxide. This can cause the irreversible formation of a passivating lithium peroxide layer on the cathode surface. The interfacial dynamics due to the growth of lithium peroxide and the formation of cathode-electrolyte interface (CEI) layers remains largely unknown. It is crucial to elucidate how the nucleation of discharge products on the cathode surface affects the electrochemical performance in order to design new electrolytes and cathodes for lithium-oxygen batteries.

In this study, we propose to investigate the surface stress generation associated with the formation of discharge products and CEI layers on the cathode. Thin Au films were deposited via e-beam evaporation onto a borosilicate glass substrate. These substrates were used as a cathode material. The electrolyte used was 1 M LiTFSI in DMSO, and it was saturated with oxygen prior to performing electrochemical measurements. In situ stress measurements were conducted using a multiple beam optical sensor (MOS). A custom cell was designed to monitor the physical response of the cathode during cycling while enabling optical access to the back of the substrate for stress measurements.

The in situ curvature evolution on an Au coated borosilicate glass cantilever is monitored during one discharge/charge cycle at 10 µA/cm2. Tensile stress generation is observed during the formation of the lithium peroxide discharge product on the Au cathode. A large stress relaxation into the compressive regime is observed at the onset of charging. From our results, the nucleation of lithium peroxide onto the cathode surface causes tensile stress, while the oxidation of lithium peroxide causes compressive stress. Revealing the mechanical response of the charge/discharge products on the cathode will shed light into the formation mechanisms of these products, which is crucial to design both new electrolytes and cathode materials for lithium-oxygen batteries.

Acknowledgement: This work was supported by the Binational Science Foundation (#2018327), and we are thankful to both Dr. Malachi Noked and Rosy for fruitful discussions.
Additive Manufacturing for Rapid Prototyping of Mixed Potential Electrochemical Sensors
Authors: Agi Kamil , Halley Sleight , Tsui Lok-kun , Garzon Fernando H
Published: July 2021

Natural gas pipeline leaks are responsible methane emissions that amount to over 1.6 x 108 metric tons of CO2 equivalent and more than 2 billion dollars in losses.[1, 2] A widely deployable sensor capable of remotely monitoring pipelines to promptly detect these leaks is needed to curb their environmental and economic impact. YSZ based mixed-potential electrochemical sensors (MPES) fit this need as they are cheap and durable, allowing for wide deployment in the field. Prototyping of these sensors is enhanced by the utilization of additive manufacturing (AM).

The long lead times and high start-up cost of traditional ceramic manufacturing techniques are poorly suited to prototype development of mixed potential electrochemical sensors. Recent advances in AM techniques have opened the possibility for the rapid prototyping of these sensors.[3] We report for the first time a three element mixed potential electrochemical sensor manufactured using direct write syringe extrusion. La0.87Sr0.12CrO3 (LSCO), In2-xSnxO3 (ITO), Au and Pt electrodes bridged with a porous yttria-stabilized zirconia (YSZ) solid electrolyte have been deposited on YSZ substrates. The Pt electrode and leads, as well as the porous YSZ electrolyte and YSZ substrate are deposited by direct write extrusion. The printing parameters for the printing of the YSZ substrate are optimized to achieve desired surface and bulk material characteristics. A density 60% of theoretical of the YSZ substrate is obtained after sintering at 1450 C. The sensors are evaluated for their sensitivity to methane, ethane, ammonia, nitrous oxide, and hydrogen. The sensitivity of the sensors will be compared to that of an industry standard MidIR sensor for natural gas detection.

[1] A.J. Marchese, T. L. Vaugh, D. J. Zimmerle, D. M. Martinez, L. L. Williams, A. L. Robinson, A. L. Mitchell, R. Subramanian, D. S. Tkacik, J. R. Roscioli, S. C. Herndon. Science. 7204 (2018).

[2] Kort, E. A.; Frankenberg, C. Costigan, K.R.; Lindenmaier, R.; Dubey, M. K; Wunch, D. Geophys. Res. Lett, 2014, 41, 19, 6898

[3] Travitzky, N., Bonet, A., Dermeik, B., Fey, T., Filbert‐Demut, I., Schlier, L., Schlordt, T. and Greil, P., 2014. Additive manufacturing of ceramic‐based materials. Advanced engineering materials, 16(6), pp.729-754.

Figure 1. Additively manufactured three electrode pair mixed potential electrochemical sensor.

Figure 1
Influence of Anions on the Electrolyte/Electrode Interfacial Dynamics Probed By in-Situ/Operando Soft X-Ray Absorption Spectroscopy
Authors: Yang Feipeng , Feng Xuefei , McClary Scott A , Matias Ana Sanz , Hahn Nathan T , Prendergast David , Zavadil Kevin R , Guo Jinghua
Published: July 2021

Since the demonstration of room temperature plating and stripping of calcium with high capacities and low polarization using Ca(BH4)2 as the electrolyte, there is considerable interest in the study of electrochemical processes in calcium batteries in addition to the conventional magnesium batteries. The greater polarizability of Ca2+ over Mg2+represents greater configurational flexibility, facilitating ionic cluster formation and rapid delivery of Ca2+ ions to the electrode interface. With such motivation in calcium batteries, a critical question to address is the probing of the solvation and charge transfer mechanism at the electrode/electrolyte interface. In this work, the solvation and charge transfer mechanisms of two calcium electrolytes, Ca(BH4)2 and calcium hexafluoroisopropoxyborate (Ca(BHFIP)2), with different types of anions, are compared under operando conditions. It has been reported that when BH4
- is substituted by the more weakly coordinated BHFIP-, the electrolyte ionic conductivity will increase by an order of magnitude, which demonstrates the strong coordination of BH4
- to Ca2+ in THF. To probe the Ca2+ coordination chemistry difference at this electrolyte/electrode interface as a function of the type of anions, total electron yield (TEY) mode soft X-ray absorption spectra (XAS) sensitive to the interfacial speciation have been employed under operando electrochemical conditions. It was observed that the Ca(BHFIP)2 in THF shows a small shoulder on the right side of the L2-edge and a pre-edge peak on the left side of the L2-edge peak. A less prominent pre-edge peak is also observed on the left side of the L3-edge peak. These signatures become more prominent when the potential is swept negatively and are not reversible when the potential is swept positively in a cyclic voltammetry cycle. On the other hand, the Ca(BH4)2 in THF is more reversible, and no shoulder peak on the right side of the L2-edge peak was observed. The TEY spectra indicate their differences in the Ca2+coordination chemistry at the electrode/electrolyte interface as a result of the interacted anions and it will guide future development of electrolytes for calcium batteries. The detailed solvation structure of the calcium is to be resolved with the DFT calculations. Such operando soft XAS studies of the interfacial dynamics reveal the transient processes in the solvation at the electrolyte/electrode interface and will pave the way for the development of calcium electrolytes in batteries.
Evaluating Solid Electrolyte Interphase Engineering for Rechargeable Aqueous Aluminum Metal Batteries
Authors: Dong Tony , Ng Kok Long , Wang Yijia , Voznyy Oleksandr , Azimi Gisele
Published: July 2021

Amongst various electrochemical energy storage technologies for renewable energy power grids, the aluminum metal battery (AMB) is arguably the most attractive given the high abundance and high theoretical volumetric/gravimetric capacity of metallic aluminum. The current generation of AMBs, however, utilizes a chloroaluminate ionic liquid (IL) that is intrinsically capacity limiting, highly corrosive, and hygroscopic. These limitations severely hinder the practicality of AMBs. To overcome these drawbacks, aqueous electrolytes are considered as attractive alternatives to ILs. However, their employment is troubled by the spontaneous formation of an ionically-passivating oxide film and hydrogen evolution on aluminum. Impressively, two solid electrolyte interphase (SEI) engineering methods have recently been proposed that seemingly resolves such problems to enable rechargeable aqueous AMBs. The first involves a 5 m (mol kg-1) Al(OTF)3 (aluminum trifluoromethanesulfonate) water-in-salt electrolyte that appears to delay hydrogen evolution by a SEI formed from the reduction of OTF- anions. The second involves an IL pretreatment process for the aluminum electrode, which is argued to be capable of simultaneously removing the native oxide layer and preventing its subsequent formation in aqueous solutions through an organic artificial SEI. Despite the promising results derived from the above methods, there is a lack of understanding for their underlying mechanisms and whether truly reversible aqueous AMBs were achieved. In this study, we reveal the (electro)chemical processes involved in each SEI-building method through a combination of computational, electrochemical and spectroscopic characterizations. We show that both methods unfortunately lack the ability to form stable and effective SEIs and enhancements to electrochemical performances observed in previous studies were largely misinterpretations of the data. Overall, hydrogen evolution remains as the sole cathodic reaction and no aluminum deposition can be achieved. This is the fundamental reason explaining the lower-than-expected voltages and cyclabilities of currently reported aqueous AMBs. To promote future research into enabling truly reversible aqueous AMBs, we offer suggestions for the design of more reliable electrolytes and interphases utilizing the insights gained in our investigation.
Structure and Stability of the Solid Electrolyte Interphase on Silicon Anodes of Lithium-Ion Batteries
Authors: Lucht Brett L.
Published: July 2021

The solid electrolyte interphase (SEI) acts as a protection layer on the surface the anodes of lithium ion batteries to prevent further electrolyte decomposition. Understanding the fundamental properties of the SEI is essential to the development of high capacity silicon anodes. However, the detailed mechanism of the generation of the evolution of the SEI on the silicon anodes is not fully understood. This manuscript reviews our recent investigations of the SEI on silicon anodes. We have studied the fundamental formation mechanism of the SEI on silicon anodes, along with the evolution which occurs to the SEI upon cycling.
Microscopic Understanding of the Ionic Networks of “Water-in-Salt” Electrolytes with Synchrotron X-Ray Scattering
Authors: Liu Xinyi , Yu Zhou , Sarnello Erik , Qian Kun , Seifert Soenke , Winans Randall E. , Cheng Lei , Li Tao
Published: July 2021

Many recent reports have investigated the structures of highly concentrated LiTFSI aqueous electrolytes. However, the solvation behaviors at different concentrations and temperatures are not entirely understood. To fully understand the solvation structure, we systemically changed the LiTFSI concentrations and measured them with SAXS. According to SAXS results, LiTFSI aqueous solutions can be divided into three concentration regimes: low concentration, medium concentration, and high concentration. At a low concentration solution regime, only TFSI- solvated structures exist at room temperature. However, the TFSI- networks can be formed with increasing temperature. For a medium concentration solution regime, two structures (TFSI- solvated structure and TFSI- network) co-exist. There is only one structure at room temperature at a high concentration solution regime, TFSI- network, where all TFSI- have been involved in forming TFSI- networks. TFSI- network structure at high temperature even improves the electrochemical high-temperature stability.
Enabling High-Rate Plating in Solid-State Li Batteries By Interface Engineering and Pulse Plating
Authors: Flatscher Florian , Reisecker Verena , Chamasemani Fereshteh Falah , Brunner Roland , Ganschow Steffen , Chiang Yet-Ming , Rettenwander Daniel
Published: July 2021

High power solid-state Li batteries (SSLB) are hindered by the formation of dendritic structures at high current rates. One of the main reasons for their formation are current constriction that arise from inhomogeneous electrical field distributions at the Li metal | solid-electrolyte interface that originates from, e.g., (i) poor contact between Li metal and the solid electrolyte or (ii) the Li metal void formation during Li metal stripping.1,2 Herein, we present a solution achieved via thorough sample preparation consisting of a mixture of polishing steps, heat treatments and the usage of a molten lithium alloy to effectively wet the electrolyte. This reduces the interfacial resistance to negligible values, which enables critical current density (CCD) up to 4 mA/cm². Moreover, we applied different current waveforms (i.e., pulse plating) to homogenize the current distribution at the interface, which increases the CCD significantly to a value of up to 6.3 mA/cm². These results, suggest that the combination of interface engineering in combination with alternative current waveforms are promising strategies to reach the power requirement for future electrical vehicles.

References:

(1) Krauskopf, T.; Hartmann, H.; Zeier, W. G.; Janek, J. Toward a Fundamental Understanding of the Lithium Metal Anode in Solid-State Batteries—An Electrochemo-Mechanical Study on the Garnet-Type Solid Electrolyte Li 6.25 Al 0.25 La 3 Zr 2 O 12. ACS Appl. Mater. Interfaces
2019, 11 (15), 14463–14477. https://doi.org/10.1021/acsami.9b02537.

(2) Kasemchainan, J.; Zekoll, S.; Spencer Jolly, D.; Ning, Z.; Hartley, G. O.; Marrow, J.; Bruce, P. G. Critical Stripping Current Leads to Dendrite Formation on Plating in Lithium Anode Solid Electrolyte Cells. Nat. Mater.
2019, 1–7. https://doi.org/10.1038/s41563-019-0438-9.

Acknowledgment:

The financial support by the Austrian Federal Ministry for Digital and Economic Affairs, the National Foundation for Research, Technology and Development and the Christian Doppler Research Association (Christian Doppler Laboratory for Solid-State Batteries) and the Austrian Science Fund (FWF) (project no. P25702) is gratefully acknowledged.
Electron Leakage through Extended Defects in Inorganic Solid Electrolyte Interphase -- a Non-Equilibrium Green's Function/Density Functional Theory Study
Authors: Smeu Manuel , Leung Kevin
Published: July 2021

The solid-electrolyte interphase (SEI) that forms on lithium ion battery (LIB) anodes prevents the leakage of electrons to the electrolyte, which causes electrolyte degradation and capacity fade. Grain boundaries (GB) between inorganic SEI components, like LiF/LiF or LiF/Li2CO3 boundaries, have been suggested to accelerate Li+ transport[1]. However, SEI GBs on lithium metal anode surfaces have also been predicted to support the existence of Li atoms and nanoclusters at low voltages[2], potentially leading to nucleus for hazardous lithium plating. In this presentation, we further examine the possibility of electron tunneling from the lithium anode through extended defects in LiF films. Using the non-equilibrium Green's function technique (NEGF-DFT), we find that GBs enhance electron tunneling in thin LiF films by 1-2 orders magnitude, depending on the bias. Extrapolating to 5 nm thick films using the WKB method suggests that GBs may enhance electron leakage by up to 9 orders of magnitude. This emphasizes that GBs in the inorganic SEI film are hotspots with respect to electron leakage. We propose that the further development of NEGF algorithms to enable large scale applications to battery interfaces is crucial for predicting SEI passivating properties.

[1] J. Pan, Q. Zhang, X. Xiao, Y. Cheng, and Y. Qi, Design of Nanostructured Heterogeneous Solid Ionic Coatings through a Multiscale Defect Model, ACS Appl. Mater. Interfaces 8, 5687 (2016).

[2] K. Leung and K. L. Jungjohann, Spatial Heterogeneities and Onset of Passivation Breakdown at Lithium Anode Interfaces, J. Phys. Chem. C 121, 20188 (2017).

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-NA0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the document do not necessarily represent the views of the U.S. Department of Energy or the United States Government.

Figure 1
(Invited) Fast Ion Dynamics in Solids As Probed By NMR: Disorder, Dimensionality and Correlation Effects
Authors: Wilkening H. Martin R.
Published: July 2021

NMR offers plenty of tools to analyze ionic jump processes in crystalline and amorphous solids at atomic scale. Both high-resolution and time-domain 1H(2H), 6,7Li, 19F, 23Na NMR helps shedding light on the origins of rapid self-diffusion in materials being relevant for energy storage.

It is well accepted that in materials with strong site preferences, such as LiAlO2, the Li+ ions are subjected to extremely slow exchange processes. The loss of this site preference, as it is the case in glasses and some nanocrystalline phases, may, however, lead to rapid cation diffusion. Examples that benefit from this effect include cation-mixed, high-entropy fluorides ((Ba,Ca)F2) and LiTi2(PS4)3. In general, in non-equilibrium phases site disorder, polyhedra distortions, strain and the various types of local defects will affect both the migration activation energy and the corresponding Arrhenius pre-factor. Whereas in (Me,Ca)F2 (Me = Ba, Pb) cation mixing influences F anion dynamics, in Li6PS5X (X = Br, Cl, I) the potential landscape can be manipulated by anion site disorder and the introduction of extrinsic defects. In some cases, this leads to rather flat landscapes enabling the ions to have access to concerted displacement processes, as is seen in LLZO-type garnets. On the other hand, in the mixed conductor Li4+x
Ti5O12 cation-cation repulsions immediately lead to a boost in Li+ diffusivity at the early stages of chemical lithiation. For Na-bearing closo-borates, the influence of rotational anion dynamics is usually considered to explain long-range cation transport. Recent examples of our group also include Li- and Na-conducting MOFs, for which, as in the case of the closo-borates and the famous Na-β''-alumina, transitions from correlated to uncorrelated motion are observed at sufficiently high temperature.

Finally, rapid diffusion is also expected for materials that are able to guide the ions along (macroscopic) pathways with confined dimensions, as we have recently observed for layer-structured fluorides such as RbSn2F5 or MeSnF4 with their buried interfaces.