bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying Reaction Products of Silicon Monoxide Electrodes during Initial Cycle in Lithium-Ion Batteries
Authors: Yu Denis , Tan Tian , Lee Pui-kit 
Published: February 2020

Silicon monoxide (SiO) is a potential high-capacity anode material for lithium-ion batteries. However, its low initial Coulombic efficiency hinders its adoption in commercial batteries. The irreversible capacity of SiO is typically attributed to the formation of lithium silicate (such as Li4SiO4), lithium oxide (Li2O) and solid electrolyte interphase (SEI), but the amount of each product is typically not quantified. Here, we use an electrochemical approach, depth of discharge test, which we developed earlier [1] to estimate the amount of reaction products. Based on the first cycle discharge-charge capacities as well as the proportion of reversible capacity at different state of discharge (see Figure 1a and 1e), the lithiation mechanism of pristine SiO1.12 is estimated to be:
SiO1.12 + 3.10 Li+ + 3.10 e- → 0.63 Li3.75Si + 0.15 Li2O + 0.11 Li4SiO4 + 0.26 SiO2

where inactive SiO2 in the material accounts for the lower-than-theoretical capacity, Li4SiO4 takes in lithium but cannot release them back, while Li3.75Si and Li2O give partial reversibility upon delithiation.
We found that the amount of reaction products depends strongly on how the material is treated. Table I summarizes the corresponding reaction mechanisms [2]. In particular, while carbon-coating (SiO@C) increases the reversible capacity (y) as it increases its electrical conductivity which allows easier access to the lithium from Li2O, larger irreversible capacity is also observed with more Li4SiO4 formation. On the other hand, disproportionation (d-SiO@C-900°C and 1000°C) decreases the irreversible capacity in the initial cycle with the formation of large cluster of SiO2 which is electrochemically inactive. Though, the reversible capacity is reduced. Our results suggest that there are opportunities to further improve the first cycle efficiency of SiO by finding ways to control the reaction products during the initial lithiation process. More results and discussions will be presented at the meeting.
References:

P.-K. Lee, Y. Li, D. Y. W. Yu “Insights from studying the origins of reversible and irreversible capacities on silicon electrodes” J. Electrochem. Soc. (2017) 164, A6206-A6212.

T. Tan, P.-K. Lee, D. Y. W. Yu, “Probing the reversibility of silicon monoxide electrodes for lithium-ion batteries” J. Electrochem. Soc. (2019) 166, A5210-A5214.

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Understanding the Effects of Ultra-Thin Al2O3 Coatings Prepared By Atomic Layer Deposition on Lithium Ion Battery Cathode Materials
Authors: Kang Donghyeon , Mane Anil U. , Elam Jeffrey W. , Barry Edward F. , Warburton Robert , Greeley Jeffrey 
Published: February 2020

Although various cathode materials possessing high capacity have been developed to date, most of them are still suffering from early capacity fading. Several strategies such as doping, surface treatment and coating have been adopted to minimize this problem. Among a variety of coating strategies, atomic layer deposition (ALD) is regarded as the best technique for coating of cathode materials. ALD is a thin-film growth technique that offers the unique capability to coat complex, three-dimensional objects with precise, conformal layers by atomic-level control over thickness and composition. Over the last decade, ALD has emerged as an effective strategy for coating cathode materials to enhance the overall performance Li-ion batteries.
ALD Al2O3 coatings prepared using trimethyl aluminum (TMA) and H2O have been evaluated previously on cathodes including LiCoO2 (LCO), LiMn2O4 (LMO), and Li(NixMnyCoz)O2 (NMC), and the effect of the coating on cycling stability was found to vary between these different materials. Moreover, our recent study of TMA/H2O chemistry on LMO revealed a unique nucleation mechanism leading to unexpected products and altered electrochemical behavior. In an effort to better understand these observations, we are exploring Al2O3 ALD using a range of aluminum precursors (TMA, tris(dimethylamido) aluminum, aluminum trichloride, dimethyl aluminum isopropoxide, and aluminum triisopropoxide) and a variety of cathode materials (LCO, LMO, and several NMCs). We discovered that the ALD aluminum precursor reduces cations on the cathode surface, and the degree of reduction depends on the relative Lewis acidity of the precursor ligands, and on the composition of the cathode surface. In this presentation we will elaborate on these findings and describe the correlations between the chemistry of the ALD-modified cathode surface and the resulting electrochemical behavior and cycling performance.
2D Layered Manganese Oxide Nanosheets as a Bifunctional Electrocatalyst for Zn-Air Batteries
Authors: Kosasang Soracha , Ma Nattapol , Sawangphruk Montree 
Published: February 2020

The sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a crucial issue that limits a practical utilization of metal-air batteries. Manganese oxides with various structures, δ-, β-, α-, or γ-MnO2, have been studied and reported as electrocatalysts for the ORR and/or OER. Here, we have suggested birnessite-typed layered manganese oxides (δ-MnO2) with their sheet-like structure and interlayer spacing of ca. 7 Å containing different alkaline intercalated cations within the layers as bifunctional electrocatalysts. Surprisingly, the experimental results together with a fundamental explanation by density functional theory (DFT) calculations show that the intercalated cations between layers of the birnessite (Bir) play an important role on the ORR and OER catalytic activities which have the activity trend as follow: Li-Bir > Na-Bir > K-Bir > Rb-Bir > Cs-Bir.[1] Apart from the fundamental study, primary Zn-air batteries with these materials are also demonstrated. Zn-air battery with the Li-Bir catalyst shows the highest performance among these catalysts. Moreover, we also integrated the Li-Bir with reduced graphene oxide (rGO) as a composite to improve the electronic conductivity of the MnO2. The mechanical rechargeable Zn-air battery with Li-Bir/rGO composite as an air electrode demonstrates better performances than the Zn-air battery with a pristine Li-Bir catalyst. Interestingly, even the Zn-air battery with the Li-Bir/rGO composite (0.687 V) shows higher potential gap between discharge and charge potentials than state-of-art Pt/C+RuO2 (0.667 V) in the first cycle (2 hours per cycle), however, the Zn-air with our composite catalyst exhibits smaller potential gaps of 0.697 V and 0.719 V (0.720 and 0.761 V for Pt/C+RuO2) at the second and third cycles, respectively. In addition, our mechanical rechargeable Zn-air battery displays an impressive cyclability of discharge-charge processes (10 minutes per cycle) of 500 cycles or over 83 hours at a current density of 2 mA cm-2. Therefore, the Li-bir/rGO composite could be used as a bifunctional electrocatalyst in a practical application for Zn-air batteries.
Reference
[1] S. Kosasang, N. Ma, P. Wuamprakhon, N. Phattharasupakun, T. Maihom, J. Limtrakul, M. Sawangphruk, Chem. Commun.
2018, 54, 8575.
Tailoring Mesoporous Silica Nanoparticles and Thin Films: Synthesis, Characterization and Electrochemical Applications
Authors: Weldekidan Ephrem Terefe , Hornebecq Virginie , Lebouin Chrystelle 
Published: February 2020

Mesoporous silica materials have played great roles in widespread application areas like adsorption, catalysis, and separation due to their high surface area, large pore volume and tunable pore size and structure. One of the approaches for extending the application of mesoporous silica materials is tailoring their wall with various functional groups. However, the conventional post-grafting method results in lightly dense, heterogeneously distributed and less accessible functional groups.
In our work, a new method that leads to dense and uniform functionalization of the wall without clogging of the pores has been employed. The hybrid silica-based materials are fabricated either through diblock copolymer templated sol-gel method or through electro-assisted self-assembly method. In the former case, since the template is self-assembled functional amphiphilic diblock copolymer, the selective removing of the hydrophobic block results in porous and PEO functionalized silica materials. Textural and structural properties of the hybrid porous materials will be presented. Furthermore, their application in the area of Li-ion battery as solid composite polymer electrolytes will be discussed. In the later case, surfactant templated mesoporous silica films have been fabricated on conductive substrates via electro-assisted self-assembly method. Hexagonally well-ordered and vertically oriented mesochannels with a diameter of 3nm are obtained in a large domain across the resulted films. The permeability, morphology and nanostructure of the films will be presented.

Figure 1
Assessment of Arrays of Permanent Nanomagnets Produced By Bi-Metal Deposits within Porous Silicon
Authors: Rumpf Klemens , Granitzer Petra , Gonzalez-Rodriguez Roberto , Coffer Jeffery L , Poelt Peter , Michor Herwig 
Published: February 2020

This work presents the investigation of the magnetic behavior of bi-metal nanostructures within nanostructured silicon with the aim to exploit the magnetic properties of both metals and gain control of the exchange coupling between the two metals especially with respect to their volume ratio. Furthermore a variation of the structure size and the proximity of the metal deposits modify the exchange coupling and thus the energy product. Finally nanocomposite systems with an energy product as high as possible should be achieved to give rise to on-chip applications using permanent nanomagnets, especially arranged in arrays.
Magnetic nanostructures of two different metals are deposited within nanostructured silicon to control the magnetic switching behavior of the silicon/metal nanocomposite. Two different templates, porous silicon and porous silicon nanotubes are utilized to achieve such nanocomposites. The morphology (pore diameter, tube diameter) of the two systems is comparable. In the case of the utilization of porous silicon templates a mesoporous morphology with average pore diameters of 50 nm is used and these oriented and separated pores are filled with two different metals, namely Ni and Co. The two metals are deposited alternatingly by electrodeposition. A further approach is the chemical growth of Co nanoparticles within porous silicon nanotubes (SiNTs) and the additional deposition of a Ni layer on the outer surface of the tubes. The inner diameter of the silicon tubes is around 50 nm and the wall thickness is about 10 nm. Since the silicon wall of the tubes offers a porous structure the Co particles, which are localized near the pore surface on the wall of a given nanotube, can touch the Ni layer. An alternative structure involves the deposition of an additional Si layer, after the growth of Co particles inside the tubes, as a spacer before the Ni deposition.
The morphology of the deposited bi-metal Ni/Co structures is figured out by SEM and EDX, magnetic measurements are performed by SQUID magnetometry.
In the presented work the dependence of the magnetic properties of a nanostructured silicon/bi-metal nanocomposite on the volume ratio of the metals, on the proximity of the nanostructures and also on the size of the metal deposits is figured out. If the distance between the deposited bi-metal structures is small enough magnetic exchange coupling between them [1] is present which can be explained by the obtained magnetic data. By tuning the bi-metal deposition an optimized energy product [2] is achieved which gives rise to self-assembled nanocomposite systems containing permanent nanomagnets and arrays of them, respectively for on-chip applications.
[1] R. Skomski, J.M.D. Coey, Permanent Magnetism, 1st Edition, CRC Press, Taylor and Francis Group, 1999.
[2] R. Skomski, P. Manchanda, P.Kumar, B. Balamurugan, A. Kashyap, D.J. Sellmyer, IEEE Trans. Mag. 49, 3215, (2013).
Transport Limitations of Sodium-Ions in Type-II Clathrates
Authors: Li Xuemin , Steirer Kenneth , Krishna Lakshmi , Xiao Chuanxiao , Fink Kae , Santhanagopalan Shriram 
Published: February 2020

The development of material for room temperature sodium ion batteries with high cycling stability is of great significance. Clathrates are potential sodium ion conductors with the properties of cage-like frameworks. It is predicted that the open cages can easily accommodate alkali ions with negligible volume changes. In this paper, we evaluated the type II clathrate performance in sodium ion batteries. Slightly elevated testing temperature (45 oC) can improve the cell capacity and rate performance due to the improved ionic conductivity. Side reactions on the solid electrolyte interface and loss of active materials during the first sodiation process contribute to the low Coulombic efficiency of the first cycle. Electrode morphology and elemental mapping analysis for clathrate electrodes at different states corroborate the above analysis.
References:

J. Yang and J. S. Tse, Journal of Materials Chemistry A, 1, 7782 (2013).

N. Wagner, A., R. Raghavan, R. Zhao, Q. Wei, X. Peng and K. Chan Candace, ChemElectroChem, 1, 347 (2013).

A. Marzouk, P. B. Balbuena and F. El-Mellouhi, Electrochimica Acta, 207, 301 (2016).

T. Langer, S. Dupke, H. Trill, S. Passerini, H. Eckert, R. Pöttgen and M. Winter, Journal of The Electrochemical Society, 159, A1318 (2012).

K. S. Chan, M. A. Miller, C. Ellis-Terrell and C. K. Chan, MRS Advances, 1, 3043 (2016).
(Invited) Modeling at Multiple Scales for Development of Future Energy Storage Technologies
Authors: Stephens Ryan M. , Balachandran Janakiraman , Rudra Indranil , Maheshwari Shantanu , Thakkar Foram , Bonakala Satyanarayana , Verbist Guy , Ratnakar Ram 
Published: February 2020

The energy sector is currently undergoing transition, driven by population growth, demand for more and cleaner energy, and increasing customer choice[1]. To facilitate the growth and uptake of renewable energy in a more electrified energy system, developing efficient and economical means of storing and distributing electricity is vital. Next-generation battery technologies and other electrochemical energy storage and conversion technologies have great promise to enable energy transition. Precise control and understanding of electrochemical and other phenomena over multiple length and time scales will play an important role as the energy transition unfolds.
Within Shell’s Advanced Energy Storage program, we utilize a framework referred to as Experimental-Modeling Powered Optimization Workflow for Energy StoRage Systems (EMPOWERS). The framework seeks to link phenomena observed at different length scales via experimental and computational means.
This talk will share some recent investigation of advanced lithium batteries, with use of DFT, molecular dynamics, and continuum models to investigate advanced battery systems over multiple length and time scales. We will share recent computational investigation into PEO-based polymer systems as electrolytes[2] for lithium metal batteries. We have used molecular dynamics to compute the effect of pressure on key electrolyte parameters, such as density, diffusivity, and transference number. We have also used DFT and ab initio molecular dynamics to study a particular class of cathode material for lithium sulfur batteries. In this case, DFT based on ultrasoft-pseudopotentials was used to calculate the XPS spectra for species present in the cathode in charged and discharged states, which was then validated by experimental XPS data[3]. To complement the electrolyte and electrode-specific component studies, continuum cell models have been used to combine measurements on individual cell components, with an eye towards development of reduced-order models.
[1] http://www.shell.com/investor
Royal Dutch Shell PLC, Shell: Energy transitions and portfolio resilience (2016)
Royal Dutch Shell PLC, 2016 North America Investor Day (2016)
Royal Dutch Shell PLC, Barclays CEO Energy Power Conference (2016)
[2] D. T. Hallinan Jr. and N. P. Balsara, Annual Review of Materials Research, 43, 503-525 (2013).
[3] Experimental work by Guy Verbist (Shell Global Solutions International B.V.), Alexey Deyko and Christina Christova (Polymer Technology Group Eindhoven (PTG/e) BV.)
(Invited) Intermediate Transport on Flexible Cascade Surfaces with Electrostatic Channeling
Authors: Liu Yuanchao , Calabrese Barton Scott 
Published: February 2020

Biocatalytic cascades can potentially utilize the full bond energy stored in complex molecules using sequential active sites. This results in an enhanced electrocatalytic efficiency, enabling biofuel cells of high energy density and biosensors of high sensitivity. Mass transport of cascade intermediates is enhanced by electrostatic channeling, wherein where charged intermediate was transported along an oppositely charged pathway [1]. Natural cascade has be studied for decades and in 2017 we reported the first cascade with artificially introduced electrostatic channeling [2].
That finding highlighted a surface-channeled diffusing mechanism on a 1D bridge. However, intermediate hopping between an artificial bridge and an enzyme binding site is a flexible 2D surface with multiple pathways and increased potential for leakage [3]. This process is of great significance to design and optimization of electrostatic pathways. Here, we further map the channeling pathway between the bridge and intermediate active site for two different enzymes of varying overall electrostatic charge. Enhanced molecular dynamics sampling methods are used to elucidate the intermediate’s ergodicity in this process; the multiple pathways detected by MD are analyzed via a novel Markov State Model approach. Finally, the kinetic Monte Carlo method is used to quantify the overall kinetics, from which the leaking contribution from each channeling area can be evaluated.

I. Wheeldon, S. D. Minteer, S. Banta, S. C. Barton, P. Atanassov, and M. Sigman, Nat. Chem., 8, 299–309 (2016). doi:10.1038/nchem.2459

Y. Liu, D. P. Hickey, J.-Y. Guo, E. Earl, S. Abdellaoui, R. D. Milton, M. S. Sigman, S. D. Minteer, and S. Calabrese Barton, ACS Catal., 7, 2486–2493 (2017). doi:10.1021/acscatal.6b03440

Y. Liu, I. Matanovic, D. P. Hickey, S. D. Minteer, P. Atanassov, and S. C. Barton, ACS Catal., 8, 7719–7726 (2018). doi:10.1021/acscatal.8b01041

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Open-Circuit Voltage Anomalies in Yttria-Stabilized Zirconia and Samaria-Doped Ceria Bilayered Electrolytes
Authors: Miyashita Tomofumi 
Published: February 2020

The open-circuit voltage (OCV) in samaria-doped ceria (SDC) electrolytes has been explained by Wagner’s equation. According to this theory, even if there is no external current, two types of internal currents are created by electrons and oxygen ions. Due to the ohmic loss caused by the ionic internal short-circuit current, the OCV is 0.80 V, which is lower than the theoretical voltage of 1.15 V. Coating a thin electron-blocking layer of YSZ (yttria-stabilized zirconia) onto the SDC electrolyte is effective at stopping the electronic leakage current and improving the OCV. For cells with YSZ on the anode side, the OCV is 1.05 V-1.15 V. For cells with YSZ on the cathode side, the OCV is 0.81-0.87 V. Therefore, the electronic leakage currents have been thought to be not entirely stopped.
YSZ films deposited on the anode side are very effective, but YSZ films deposited on the cathode side are clearly less effective. Thus, we proposed experiments to confirm whether electronic leakage currents can be blocked by the YSZ films deposited on the cathode side. A polished YSZ film (500 mm thickness) on the cathode side and a polished SDC film (970 mm) on the anode side were physically contacted. The OCV was measured to be 819 mV at 1073 K, 825 mV at 973 K and 874 mV at 873 K. Then, we noticed that the large voltage loss was not due to electronic leakage currents.
However, there were objections in these experimental results. The surrounding air could enter the contact space between the YSZ film and the SDC film, which indicated that due to air entering the contact, an electronic leakage current could arise in SDC electrolytes.
By measuring the transient process, we showed that the electronic leakage currents were stopped entirely. After changing the anode gas from N2 gas to H2 gas including 3% H2O, the OCV was changed from 85 mV to 755 mV with a short time constant (12 seconds) and from 755 mV to 819 mV with a long time constant (100 seconds) at 1073 K. The equilibrium time based on the electron diffusion coefficient equation should be longer than 49 minutes. Thus, the voltage loss (0.35 V) in SDC could not be explained by the electronic leakage current. Furthermore, a higher OCV (819 mV) was not due to stop the electronic leakage current.

Figure 1
Ferroelectric Properties of Si Doped HfO2 Thin Films with NiSi2 As Bottom Electrode
Authors: Molina-Reyes Joel , Iwatsuka Haruki , Hoshii Takuya , Ohmi Shun-ichiro , Funakubo Hiroshi , Hori Atsushi , Fujiwara Ichiro , Wakabayashi Hitoshi , Tsutsui Kazuo , Kakushima Kuniyuki 
Published: February 2020

It has been already demonstrated that the orthorhombic phase transformation of Zr or Si doped HfO2 (induced by annealing) is responsible for its ferroelectricity but the use of capping top electrodes is usually required [1-4]. Here, we show that by using NiSi2 as bottom electrode (suggesting an orthorhombic structure after annealing), moderate ferroelectric properties of Si-doped HfO2 thin films (8.7 nm in thickness) deposited on NiSi2 electrodes can be generated during post-deposition annealing (PDA). For this Si:HfO2/NiSi2 structure, the bottom and top metallic films are deposited by sputtering at room temperature while atomic-layer deposition is used for deposition of Si:HfO2 with a cycle ratio of 1:16 (SiO2:HfO2), see figs. 1-2. Annealing in argon, forming gas and oxygen atmospheres for temperatures ranging from 1000°C down to 400°C, was done on structures having NiSi2 or TiN (used as reference) as bottom electrodes in order to correlate the influence of these processing conditions to the electrical and ferroelectric properties of the resulting MIM devices. For this, leakage current, capacitance, remanent polarization and fatigue measurements with applied voltage were obtained. Moderate ferroelectric behavior was obtained for PDA samples having NiSi2 as bottom electrode in the temperature range of 750°C–500°C, see figs. 3-4. This result shows the advantage of the use of NiSi2 bottom electrode, broadening the processing window for CMOS-compatible ferroelectric materials.
Acknowledgement
This research is supported by the Center of Innovation Program from Japan Science and Technology Agency, JST.
References
[1] T. S. Boscke, IEDM, p.547 (2011). [2] T. Shimuzu et al., Jpn. J. Appl. Phys., 53, 09PA04 (2014). [3] S. Migita et al., SSDM2018, pp.195 (2018). [4] C. Richter et al., Adv. Electron. Mater. 3, 1700131 (2017).

Figure 1