bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating Diffusion of Lithium Intercalated in Graphite By a Combination of Multiscale Modeling and NMR
Authors: Grosu Cristina , Döpking Sandra , Merz Steffen , Panosetti Chiara , Jakes Peter , Annies Simon , Matera Sebastian , Granwehr Josef , Scheurer Christoph
Published: December 2020

Lithium ion batteries play a key role in the implementation of fully sustainable electrical mobility. Long lifetime, fast recharging and safety are required for the acceptance of any battery powered vehicle. Graphite is still the state of art as negative electrode. Despite decades of investigation into the mechanism of lithium intercalation, the ion mobility and the underlying microscopic processes are still not fully understood, limiting progress in performance and lifetime prediction of a battery. In particular, improvements in fast charging of batteries mandates a deeper understanding of the lower states of charge (SoC), bellow or around 20 %. We propose a combination of advanced NMR experiments, i.e spin alignment echo (SAE), with a theoretical multi scale modelling approach to investigate relevant phenomena such as lithium ion diffusion in graphite. Here, we present a novel multi-level accelerated first-principles kinetic Monte Carlo (1p-kMC) model to assess in detail the mobility at a low SoC, i.e LiC108. In particular, an external potential is applied in order to mimic the driving force causing (dis)charge of the battery.
Smoothed Boundary Method Simulations of Complex Electrode Microstructures Using Adaptive Mesh
Authors: Malik Affan , Yu Hui-Chia
Published: December 2020

Rechargeable battery electrodes comprise of highly complex microstructures and convoluted electrolyte courses. These configurations dictate the macrohomogeneous properties and electrochemical performances of the electrodes. In addition to the geometric complexity, multiple concurrent physical mechanisms take place in the electrochemical processes of charge-discharge cycles. Understanding these detailed processes occurring in the complex electrode microstructure is the key to improve the design of electrodes. In this work, we present a framework to implement detailed electrochemical simulations in complex electrode microstructures. The framework employs the Smoothed Boundary Method(SBM)[1] which allows simple and fast mesh generation for complex geometries. In SBM, a continuous domain parameter is utilized to distinguish the phases of electrode particles and electrolyte, wherein the particle-electrolyte interface is defined by the region where the domain parameter transitions from zero to one in a continuous manner. With the electrochemical governing equations reformulated using the domain parameter, conformal mesh to the complex geometries is circumvented in the simulations. The SBM is implemented with Octree-based adaptive mesh refinement (AMR)[2], in which fine cubic meshes are generated near the particle-electrolyte interfaces while coarse cubic meshes are used in the bulk regions of particles and electrolyte. As a result, the diffuse interface in the SBM is effectively decreased and the accuracy of the electrochemical simulations is comparable to those of conventional sharp-interface methods. Intercalation electrode materials, namely NMC for the cathode and graphite for the anode, are used in the simulations to reveal the detailed electrochemical processes in the complex electrode microstructures and as a demonstration of the presented simulation framework. Material parameters in the simulations are directly obtained from experimental data to study the electrochemical phenomena occurring in the microstructures. The results can be used to extract macrohomogeneous electrode properties in the Porous Electrode Modeling for device-level simulations. Thus, it is shown that the presented simulation framework can serve as a useful tool for examining the effects of electrode microstructures and intrinsic material properties on the electrodes’ performance and as well as for electrode design.

References:

[1] Hui-Chia Yu, Hsun-Yi Chen, and K Thornton. Extended smoothed boundary method for solving partial differential equations with general boundary conditions on complex boundaries. 2012.

[2] Chohong Min, Fr ́ed ́eric Gibou, and Hector D Ceniceros. “A supra-convergent finite difference scheme for the variable coefficient Poisson equation on non-graded grids”. In: J. Comput. Phys.218.1 (Oct. 2006), pp. 123–140.
Characterisation of Redox Species in Pure IL and Its Mixtures with a Molecular Solvent By Electrochemical Impedance Spectroscopy
Authors: Chaabene Nesrine , Ngo Kieu , Turmine Mireille , Vivier Vincent
Published: December 2020

Ionic liquid (IL) are molten salt at room temperature. They are of ever increasing interest due to their outstanding properties and appear to be candidates for many electrochemical applications. Thus, there are more and more works concerning their use as electrolyte for storage or conversion energy1. For this application, the addition of redox species is needed. In such case, the electrochemical properties of these compounds in IL must be determined and especially the determination of their diffusion coefficient (D) and heterogeneous electron-transfer rate constant (k°). One of the drawbacks of IL is their important viscosity. To reduce it, a molecular solvent can be added2.

In this work, we studied the electrochemical properties of some redox compounds (Alizarine, Tempo, Quinone, iron chloride) in an aprotic IL, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, C2mimTFSI, and its mixtures with γ-butyrolactone (GBL) as molecular solvent. The addition of this solvent decreases drastically the viscosity of the medium, at 298K, from 30 mPa.s to 10 mPa.s for a molar fraction of IL about xIL = 0.5. The diffusion coefficient and heterogeneous electron-transfer rate constant of the four redox compounds in IL-GBL mixtures of different composition were determined by cyclic voltammetry and electrochemical impedance spectroscopy. For all these species the diffusion coefficients were about 10-7 to 10-8 cm2 s-1 and their value decreases when the IL content increases as expected, due to the viscosity of the medium. The same trend is observed for the heterogeneous electron-transfer rate constant values.

Martins, V. L.; Torresi, R. M., Ionic liquids in electrochemical energy storage. Curr. Opin. Electrochem.
2018,
9, 26-32.

Papović, S.; Bešter-Rogač, M.; Vraneš, M.; Gadžurić, S., The effect of the alkyl chain length on physicochemical features of (ionic liquids+γ-butyrolactone) binary mixtures. The Journal of Chemical Thermodynamics
2016,
99, 1-10.
Mechanisms of Hydrogen Evolution in Weak Acid Solution Investigated By Using EIS
Authors: Moradighadi Negar , Brown Bruce N , Nesic Srdjan
Published: December 2020

EIS was used in this mechanistic study of the electrochemical reaction mechanisms associated with corrosion of mild steel in the presence of weak acids, such as carbonic acid found in CO2 saturated aqueous solutions. Over the past decade, comprehensive mechanistic studies using DC electrochemical techniques have indicated that direct reduction of carbonic acid is not a significant reaction in CO2 aqueous solutions, contrary to what the conventional wisdom was for a long time. The new results suggest that the only cathodic reaction is hydrogen reduction, and that the main role of carbonic acid is to increase the limiting current by the so-called buffering effect. However, the problem is that the same limiting current is obtained theoretically whether one assumes that the direct reduction of carbonic acid or the buffering effect is true. Therefore, by using DC electrochemical techniques it is impossible to distinguish these two mechanisms in the limiting current region which is always seen in the polarization sweeps. An attempt has been made here to use the EIS technique to identify the role of carbonic acid in accelerating the cathodic reaction. Results indicate that the buffering effect is dominant, as recently proposed.
Electrochemical Impedance Spectroscopy Study with a Blocking Symmetric Cell: Qualitative Analysis for Interface of Electrode-Electrolyte
Authors: Kim Wonhee , Kim Hyeong-Jin
Published: December 2020

Li-ion transport which is the fundamental driving force affects to lithium-ion batteries performance thermodynamically and kinetically. A facile and accurate tool is needed to analyze Li-ion transport affected by the electrode structure and electrolyte. Electrochemical impedance spectroscopy (EIS) is a well-known tool to evaluate a battery system. The actual interface of electrode-electrolyte and Li-ion transport can be confirmed quantitatively by analyzing low frequency region of EIS.

Herein, symmetric cells with SOC 0 state electrodes are analyzed with complex capacitance. In low frequency, Li-ion is accumulated along the electrode surface in the symmetric cell assembled with SOC 0 state electrodes (SC-SOC 0). Therefore, the interface of electrode-electrolyte can be investigated using this cell configuration. The accumulated amount of Li-ion is expressed as a real capacitance (C') (Figure 1a). In addition, the time constant (τ) is the value representing double-layer formation time related with the transport of Li-ion (Figure 1b). This approach can be used as a fundamental tool to understand Li-ion batteries performance by studying the interface of electrode-electrolyte (Figure 1c).

Figure 1
Self-Charging One-FIBER Energy Harvester System
Authors: Kim Keon Jung , Kim Shi Hyeong
Published: December 2020

As the wearable device industry develops, interest in fiber-type energy sources is increasing. In relation to the fiber-type energy source, studies related to the storage of energy in the form of fibers have been actively studied, but studies on the generation of energy in the form of fibers are experiencing difficulties. Although research on mechanical energy harvesters using human movements is being conducted, energy harvesters such as triboelectric and piezoelectric are difficult to produce in fiber form, and in the case of fiber form, the energy generated is very small. In 2017, our group made electrochemical base mechanical energy harvesting using the carbon nanotube yarn. Although this harvester is in the form of a fiber, the longitudinal contraction / relaxation of the harvester is required. In addition, it is studied for solar power generation, but it is difficult to have flexible and tough properties of fibers. Here, we are going to introduce a fiber type energy harvester system that does not require mechanical changes, solar heat, heat, etc. This harvester is composed of electrochemical base two different materials of potential of zero charge (PZC). It is a method of generating energy with the PZC difference of the two materials, so the amount of energy generated is very small, but this system is likely to be the basis for a new energy harvester in the future.
Development of an Accurate Life-Time Prediction Model for Lithium-Ion Batteries
Authors: Atalay Selcuk , Sheikh Muhammad , Widanage Widanalage Dhammika
Published: December 2020

The growing demand of lithium-ion batteries (LIBs) on electric vehicles requires a lifespan of 8-10 years on average for electric vehicles to satisfy the needs of successful market introduction. The life-time of LIBS is, however, typically the bottleneck, hence the fundamental understanding and development of a more accurate life-time predictive model is crucial to estimate the battery life-time without running experimental test for years. In this work, we present a physics-based LIB aging model able to predict aging behaviours associated with a multi-layered SEI, lithium-plating and porosity change. Our model demonstrates that it can predict the life-time of the battery accurately with the 98% goodness-of-fit-error for applied constant-currents and dynamic power duty cycles. It is an important modelling tool for vehicle designers and for the implementation of business models. A key contribution of this work is the parameterization of the aging model by experimental data, while aging simulation in the literature usually lacks the capture of the transition point from linear to nonlinear aging.

*This work has been supported by WMG’s High Value Manufacturing Catapult and APC6 Project H1PERBAT.

Figure 1
Electrochemical Control and Understanding of the Electronic and Optical Properties of ZnO Formed in Rechargeable Zn-Alkaline Batteries
Authors: Hawkins Brendan , Turney Damon E. , Jadhav Ankur , Yadav Gautam Ganapati , Kiss Andrew M. , Lambert Timothy N. , Banerjee Sanjoy , Messinger Robert J.
Published: December 2020

Rechargeable alkaline batteries using zinc metal (Zn) electrodes are of significant interest for next-generation energy storage because of their high energy density, low cost, environmental friendliness, and inherent safety. Rechargeable Zn-alkaline batteries, however, have not been widely commercialized in part due to the low cyclability of Zn electrodes. At high depths of discharge, zinc oxide (ZnO) discharge product accumulates in the electrode, passivating the zinc-electrolyte interface and ultimately leading to cell failure. While the ZnO discharge product has been studied for decades, there is no general consensus on its local structure, composition, and electrochemical properties, nor on how these properties are affected by the electrode potential or cycling conditions.

In this work, we used in operando analytical techniques including X-Ray diffraction (XRD), confocal Raman spectroscopy, electrochemical impedance spectroscopy (EIS), and ultraviolet-visible (UV-vis) spectroscopy to demonstrate that the discharge product is proton-doped ZnO with oxygen vacancies, and that the electrical conductivity, band gap, and color vary systematically as a function of electrode potential. To investigate local hydrogen and zinc environments within the ZnO discharge product, we performed ex situ solid-state 1H, 2H, and 67Zn magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. Solid-state 1H and 2H NMR measurements establish that hydrogen environments change as a function of potential, while solid-state 67Zn NMR spectra indicate that the local zinc environments are distorted compared to ZnO generated via conventional routes. We also performed 2D 1H-1H exchange (EXSY) NMR measurements to investigate proton mobility between defect environments and acquired 1D 1H-1H dipolar-mediated double quantum-filtered MAS NMR spectra to establish through-space molecular-level proximities between proton sites. This work provides insights into the dynamics of zinc electrodes in alkaline environments, as well as how to electrochemically control the defect structures and electronic and optical properties of ZnO in alkaline media, which are expected to aid the development of next-generation Zn alkaline batteries and electronic devices utilizing ZnO.
Non-Destructive Analysis of Crystal Structure Changes of Component Materials in Cylindrical Lithium-Ion Batteries at Elevated Temperature By Synchrotron Radiation x-Ray Diffraction Measurement
Authors: Saito Yoshiyasu , Okada Ken , Kuratani Kentaro , Shikano Masahiro , Kobayashi Hironori , Hirooka Motoyuki , Unemoto Atsushi , Abe Makoto , Kawaji Jun , Okumura Takefumi
Published: December 2020

Temperature is one of the important factors for lithium-ion battery (LIB) which accelerates degradation of the performance. In many cases, degradation mechanism is studied by post-mortem analysis with destruction of degraded LIBs to obtain their component materials. However, these studies has a risk that any chemical and structural changes may have occurred in the samples during preparation process after destruction. Hence, development of in-situ and non-destructive analytical methods are strongly required. In this study, we report x-ray diffraction (XRD) measurement system using synchrotron radiation facility by which cylindrical LIB itself can be used as the sample without destruction and XRD patterns of cathode and anode layers are obtained separately. In addition, temperature of the sample can be controlled between RT and 250 °C.

18650 type cylindrical LIBs were used as the sample of which capacity were ca. 1.2 Ah. The cathode active material was Li(Ni1/3Mn1/3Co1/3)O2 and the anode active material was graphite.

XRD measurement was performed at BL46XU in SPring-8 with Huber multi-axis diffractometer. The incident beam was high-energy (72 keV) x-ray. A LaBr3 scintillation counter was used as the detector. The temperature of the sample batteries was controlled by specially designed system. Figure 1 shows XRD patterns of the anode layer of a sample LIB located at 1.65 mm inner from surface of the case. While only stage-1 structure (LiC6) was observed at RT, a new peak of stage-2 (LiC12) appeared and increased after the temperature beyond 90 °C which suggested that self-discharge would be accelerated at 90 °C and above.

Figure 1
Operando
Electrochemical Dilatometry of Si-Based Electrodes for Lithium-Ion Cells
Authors: Rodrigues Prado Andressa Yasmim , Rodrigues Marco-Tulio , Trask Stephen E. , Shaw Leon , Abraham Daniel P.
Published: December 2020

Silicon is a promising next-generation anode material for Li-ion batteries, given its high specific capacity, abundance and low working potential. However, its application in commercial cells has been hindered by the large volumetric changes that occur during the Li (de)alloying process. While theoretical calculations predict that the full lithiation of a silicon particle would lead to ~300% expansion,1 experiments suggest that the material can undergo even larger dimensional variations due to morphological changes during repeated cycling.2 Most of the degradation mechanisms associated with Si-based electrodes, which are responsible for the poor cycling stability and rapid capacity decay, derive from the cyclic swelling/contraction effect. Understanding how the particle-level expansion projects into the electrode scale is hence a very relevant topic, specifically considering that composite electrodes are a complex combination of pores and both active and inactive materials.

In this study, we use operando electrochemical dilatometry to quantify the thickness variation of Si-based electrodes during cycling. An example plot from a 70 wt% Si electrode is shown in Figure 1. The electrode expands to 300% of its initial thickness upon full lithiation. However, the swelling shows a nonlinear behavior being much slower during the initial 1000 mAh/g. At this point, the thickness change is only 17% although ~40% of the electrode capacity is utilized. During this regime, porosity and particle rearrangement within the anode may be able to partially accommodate the particles expansion. Past this stage, however, there is a steep increase in electrode dilation, which often results in coating delamination, as confirmed by post-mortem inspections.

Such quantitative analyses provide important insights into the relationship between electrode capacity and expansion. More importantly, these results can be applied to inform cell design, provide guidelines for selection of cell cutoff voltages, and estimate the effect of anode utilization on cell performance. Obtaining reliable dilatometry information is challenging: hence, strategies for designing experiments that yield reproducible results will also be discussed during the presentation.

REFERENCES

1. Kim et al., Journal of Physical Chemistry C, 115, 2514 (2011).

2. Wetjen et al., Journal of The Electrochemical Society, 165, A1503 (2018).

Acknowledgement: We are grateful for support from B. Cunningham at the U.S. DOE Office of Vehicle Technology. This document has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.

Figure 1
Investigating Na3V2(PO4)3 @C/CNF Hybrid Cathode in Aqueous Zinc-Ion Battery
Authors: Pol Vilas G. , Xu Tong
Published: December 2020

With the rapid development of new energy storage technologies, aqueous zinc-ion batteries (AZIBs) gaining significant attention as one of the most promising candidate due to its lower cost and enhanced safety aspects. The key to the development of full batteries lies in suitable high-performance electrode materials. A NASICON type material, Na3V2(PO4)3 (NVP) has a high ion conductivity and an open three-dimensional structure, which can accommodate zinc-ion intercalation, reversibly. Here, we developed a hybridcarbon coated NVP interconnected with carbon nanofibers (NVP@C/CNF) as cathode in AZIBs. The cyclic voltammogram analysis shows that after adding CNF, electrode material owns higher diffusion coefficient of Zn2+ with lower electrochemical polarization. The as-prepared NVP@C/CNF composite exhibits discharge capacity of 95.1 mAhg-1 at 1 C, larger than that of the NVP@C composite (77.3 mAhg-1 at 1 C). The capacity retention of NVP@C/CNF is 75.6 % after 100 cycles, superior to NVP@C without incorporation of CNF (63.1 %). The uniform carbon layer on the surface of NVP alleviates the vanadium dissolution during cycling, while the CNF network further improves the electrical conductivity and structural stability of the hybrid, which can effectively suppress material expansion caused by insertion and extraction of Zn2+. As verified, NVP@/C/CNF is expected to be a great potential electrode in safer ZIBs.
Investigation of Post-Bond Distortion in Direct Wafer Bonding
Authors: Ip Nathan , Nagata Atsushi , Kohama Norifumi , Wada Norio , Motoda Kimio
Published: December 2020

As device sizes continue to shrink, accurate alignment in semiconductor wafer bonding process becomes more important. In the case of two patterned wafers directly bonded together, proper alignment of the electrical connections between the two bonding surfaces is critical. Misalignment between the wafers during bonding may lead to degraded electrical performance or even device failure. In the case of a patterned wafer directly bonded onto a blank carrier wafer, the relative displacement along the bonded interface is important for subsequent steps. This relative displacement contributes to overlay error in lithography steps. Furthermore, as device density continues to increase, pre-bond wafer shapes become more complex while warp magnitude increases. The distortion contribution from pre-bond wafer shapes becomes more significant as a result. Therefore, it is important to understand the direct wafer bonding distortion mechanics to reduce the yield impact of the process.

This paper develops a mechanics model to study wafer bonder performance. An axisymmetric solid mechanics model simulates the wafer bonding dynamics by using a rate-dependent adhesion model. This simulation model includes calibration parameters to tune against experimental results. Using the optimized calibration parameters, an extended 3D simulation model studies more complex phenomena. This paper will report the simulation results that include local variations in wafer properties, clamping and thermal fluctuation effects. Distortion impact due to pre-bond wafer shapes, such as the relative contributions from the pre-bond wafer pair, is also discussed.

The results of this model can enable improved hardware optimization to address stricter distortion requirements. This model can optimize key hardware features in lieu of large number of wafer tests to minimize the cost of development. Using this model, target performance can be achieved with fewer hardware iterations and reduce development time. Bonder recipes can also be designed and optimized to account for pre-bond wafer characteristics.
(Invited) Low Temperature Wafer-Level Cu-in-Sn Solid-Liquid Interdiffusion Bonding
Authors: Ross Glenn , Vuorinen Vesa , Paulasto-Kröckel Mervi
Published: December 2020

Ubiquitous electronics is the seamless integration of smart systems into our everyday life and a cornerstone of the trillion-sensor vision. Wafer level bonding though 3D-integration could enable multi-sensor fusion with logic in a vertical high-speed package. However, such complex levels of integration require a robust understanding of the manufacturing processes influence on sensitive Micro-Electro Mechanical Systems (MEMS), such as residual stresses and trace impurities.

One promising wafer-level bonding method is Solid Liquid Interdiffusion (SLID) bonding, often referred to Transient Liquid-Phase (TLP) bonding. A reliable Cu-Sn SLID bonding at 320ºC has been demonstrated on numerous occasions. However, sub 250ºC bonding temperatures are of significant interest due to low processing temperatures and subsequent low thermally induced Coefficient of Thermal Expansion (CTE) induced global and local residual stresses.

This presentation reviews the recent results on Low Temperature (LT) Cu-In-Sn SLID process from Aalto University that exploits the In-Sn eutectic composition enabling low temperature processing, which results in a wafer-level bond with a high re-melting temperature of >600°C.

The outcomes of this work demonstrate: (i) an optimised LT-SLID process including processing parameters, (ii) resulting microstructural evolution and (iii) mechanical reliability (pre- and post-thermal annealing), such as tensile measurements and fracture surface analysis, to assess the LT-SLID bond stability.

Figure 1
An Advanced Iron-Chromium Redox Flow Battery
Authors: LI Liyu
Published: December 2020

Nowadays, the electricity generation cost using renewable resources has been reduced to such a low level that it is possible to replace most fossil fuel-based energy with renewables in the near future. However, the intermittent property with most renewables, such as solar and wind, requires vast amount, flexible and affordable energy storage products. None of the current widely used energy storage technologies can meet these requirements.

An aqueous-based true redox flow battery has many unique advantages, such as long lifetime, safe, non-capacity decay, minimal disposal requirement, and flexible power and energy design. All these make it a great candidate for the vast renewable energy storage market. The key issue with this technology is the cost and availability of the energy-storage media. Due to the limited vanadium resources, it is very difficult for the vanadium-based redox flow battery to be widely used for fast-growing renewable energy storage market.

Iron-chromium redox flow battery was invented by Dr. Larry Thaller’s group in NASA more than 45 years ago. The unique advantages for this system are the abundance of Fe and Cr resources on earth and its low energy storage cost. Even for a mixed Fe/Cr system, the electrolyte raw material cost can still be less than 10$/kWh. The major issue with this system is the continuous capacity decay due to hydrogen generation, which makes this system impractical for long-term operations.

Here we report our recent results on this system. By using a special system design, the hydrogen generation level was largely reduced, down to less than 0.25% per full cycle. A capacity recovery system was successfully developed, which can compensate the system capacity loss due to hydrogen generation. More than 1000 cycles of operation have been carried out using a system with a kW-scale stack and 100 L electrolyte over a few months. Stable system capacity and stable continuous operation were successfully achieved.

With these results, a containerized product is proposed. For a 20’ ISO container-sized product, the deliverable energy is 250 kWh, and the normal and maximum discharge powers are 25 and 50 kW respectively. The cost for such a product is lower than 80$/kWh, and the energy storage cost using this product is less than $0.02/kWh (assuming the product has 15 yr lifetime, and it operates 300 full cycle per year). With this energy storage cost, it is possible to achieve our ambitious 100% renewable energy goal in the near future.
Cylindrical Lithium-Ion Structural Batteries for Drones
Authors: Jin Jangik , Trott Grace , Rahn Christopher , Hollinger Adam S
Published: December 2020

The increasing use of battery-powered multirotor aircraft for industrial applications has allowed for advancements in a wide range of fields. These aircraft, however, have limited payloads and shorter endurance and range than fuel-powered conventional aircraft. To extend these key performance metrics, we have developed an optimized structural battery that uses commercially available battery cells as load bearing and power source elements for weight critical applications. Multifunctional lithium-based batteries have been previously proposed for the efficient use of space and mass in electric vehicles [1]. Lithium batteries offer an energy density high enough for most small multirotor flight applications [2], however these batteries often constitute a significant portion of the aircraft’s mass. This implementation is proposed to decrease the structural frame mass and thus increase multirotor performance characteristics such as payload capacity and flight time [3].

In this work, structural lithium-ion batteries were integrated into the design of a commercial drone to improve hover time. Hover tests were first performed with the original lithium polymer batteries for comparison purposes. Battery voltage was measured every 2 minutes to monitor voltage decrease versus hover time. With no payload, the original hover time of the drone was 34 minutes. For payloads of 0.5, 1.0, and 1.5 kg, hover times decreased to 28.7, 22.7, and 19.1 minutes, respectively. Standard 18650 cylindrical battery cells (Panasonic NCR18650B) were then integrated into the carbon fiber arms of the drone, to replace the original lithium polymer batteries. This design modification reduced the weight of the drone from 1242 g to 848 g, while also improving the structural integrity of the carbon fiber arms. For both designs, the velocity of the drone was related to the impact force experienced in the case of a crash. The carbon fiber arms would fracture at 4 m/s when hollow, and 7 m/s when reinforced with lithium-ion batteries. Hover tests for this modified design are being performed currently, and times are expected to be on the order of 40% longer [4]. Ongoing efforts to investigate the relationship between the intensity of power usage and the angular inertia of the drone will help to characterize the optimal battery distribution.

[1] Zhang YC, Ma J, Singh AK, et al. (2017) Multifunctional structural lithium-ion battery for electric vehicles. Journal of Intelligent Material Systems and Structures 28: 1603-1613.

[2] Vikstrom, H.; Davidsson, S.; Hook, M., Lithium availability and future production outlooks. Applied Energy 2013, 110, 252-266.

[3] Dughir, C.; Ieee, Power wire thickness influence on the multicopters flight time. 2016 12th Ieee International Symposium on Electronics and Telecommunications (Isetc'16) 2016, 239-242.

[4] Hollinger AS, McAnallen DR, Brockett MT, DeLaney SC, Ma J, Rahn CD. Cylindrical lithium‐ion structural batteries for drones. International Journal of Energy Research. 2020; 44:560–566.

Figure 1
Investigation of Rare-Earth Chalcogenide Spinel for Mg Solid State Conductors
Authors: Chen Yu , Koettgen Julius , Bartel Christopher , Ceder Gerbrand
Published: December 2020

Magnesium batteries hold potential for overcoming the safety and energy density limitations faced by Li-ion batteries. However, the development of Mg battery technology is plagued by the poor kinetics of Mg transport in solid state materials. Recently, the chalcogenide spinel structure was found to be suitable for rapid Mg2+ diffusion.[1] Based on this result we engaged in a more elaborate study of chalcogenide spinels. Seven stable MgLn2X4 (Ln = lanthanoid, X = S, Se) spinels were evaluated with density functional theory to have low barriers for Mg migration (<380 meV) and reasonable stability. Two of these materials have been synthesized and studied experimentally. We will show how the conductivity can be systematically improved by judicious choice of metal ions. In particular, the effect of large rare-earth cations on expanding the triangular anion bottleneck to reduce the migration barrier and the structure disorder phenomenon will be discussed.

Reference: [1] Canepa, P., Bo, S., Sai Gautam, G. et al. High magnesium mobility in ternary spinel chalcogenides. Nat. Commun. 8, 1759 (2017).
Microstructural Tuning of Silicon-Based Anodes and Their Stress Evolution during Electrochemical Cycling
Authors: Jin Mok Yun , Healy Elizabeth , Xiao Xingcheng , Sheldon Brian W.
Published: December 2020

Composite electrodes that incorporate oxidized silicon are a cost-effective way to accommodate stresses and extend cycle life. To obtain fundamental information about chemo-mechanical phenomena in these composite structures, several different types of materials are being investigated through tuning the microstructures of Si nanoparticles and composite SiOx particles. The evolution of internal stresses in all of these structures was monitored with precise in situ curvature in conjunction with parallel electrochemical measurements. Ex situ characterization with electron microscopy, x-ray diffraction, and XPS provide important complementary information about changes in the materials. The different types of materials used for this work make it possible to systematically investigate key length scales, by independently varying the microstructures such as oxide layer thicknesses and particle/nano-cluster sizes. Analysis of these results requires assessments and models of both the chemical and mechanical effects of oxide surface layers and silicon encapsulation. The implications for optimizing these composite electrode structures will also be presented.
Biphasic Si/SiO
x
-Sio Nanocomposite Anode Material for Lithium-Ion Batteries
Authors: Youn Donghan , Park You Kyung , Park Eunjun , Park Min-Sik , Kim Hansu
Published: December 2020

Silicon oxide materials are promising materials for its use in lithium-ion batteries. Si/SiO
x
takes advantage of enhanced cycling performance compared to other Si-based anode materials due to the existence of oxygen buffer phase. However, they still have some limitation on the electrochemical performance to meet the demands of lithium ion battery market. In this work, we present a core-shell silicon oxide structure that can make a synergic effect by utilizing two different silicon monoxide (SiO) and Si/SiO
x
material. By distinctive nature of two components, a biphasic SiO
x
composite of SiO and Si nanocrystals embedded in SiO
x
(Si/SiO
x
) showed the enhanced electrochemical performance with reduced volume expansion during cycling. The biphasic silicon oxide nanocomposite showed reliable capacity of 966 mA h g-1 with good long-term cycle performance up to 350 cycles as well as excellent dimensional stability due to the core-shell structure. More detailed electrochemical analysis and material characterizations on the biphasic Si/SiO
x
-SiO will be discussed in the presentation.
Electrochemical Performance of Vanadium Nitride/Carbon/N-Doped MWCNT As Anode Materials for Lithium-Ion Batteries
Authors: Pandurangan Muralidharan , Ponraj Rubha , Yun Jong Hyuk , Kim Do-Kyung
Published: December 2020

One of the interesting transition metal nitrides (TMNs) is the vanadium-based compounds that have been reported as a promising candidate as an anode material for lithium-ion batteries. The main issues of the vanadium nitride demonstrations are poor stability but good conductivity. In order to device the application of the vanadium-based electrode materials, a simple preparation method, and the enhancement of conductivity and increased cyclic stability are vital key factors. As a result, this work reports the simple method to prepare vanadium nitride dispersed on carbon matrix and enclosed over the N-doped multi-walled carbon nanotube (MWCNT) as an anode material for lithium-ion batteries. The electrode prepared via a simple synthesis method, cost-effective, and scalable. The conventional preparation method to syntheses TMNs is calcination of precursors in the presence of an ammonia gas atmosphere at high temperature. In the present work, the electrodes are obtained by heat-treating the mixture of ammonium metavanadate (NH4VO3), melamine, and N-doped multi-walled carbon nanotube inflow of nitrogen atmosphere. Galvanostatic discharging-charging (GDC) and Cyclic voltammetry (CV) of the assembled 2032-type stainless coin cells are carried out. The enhanced electrochemical performances can be ascribed to the synergistic effect from the hybrid compositions of vanadium nitrides/carbon and N-doped MWCNT. The detailed results on the above work will be discussed through the presentation and constructively that this work will provide an effective method to fabricate a good electrochemical performance of lithium-ion batteries with the simple anode material.
High-Performance Lithium-Ion Negative Electrodes Based on Silicon Nanowires/Graphite Composites
Authors: Olutogun Mayokun , Kim Guk-Tae , Iordache Adriana , Baggetto Loïc , Burchak Olga , Passerini Stefano , Bresser Dominic
Published: December 2020

Lithium-ion batteries (LIBs) have enabled significant technological progress in recent years and are considered the state-of-the-art technology for electrochemical energy storage.1 As the market for LIBs grows, so do the requirements for improvements concerning their energy and power density, especially with respect to their application in electric vehicles.2 As a consequence, extensive research efforts have been made towards the development of new and optimized materials that could provide the required leap in performance. Of particular interest are alternative anode materials to (partially) replace graphite and, thus, enable faster recharging of the battery cells.3 Non-toxic and abundant understoichiometric silicon oxide and elemental silicon are presently considered the materials of choice in this regard and have been incorporated already in commercial cells.3

In this work, we present the use of a silicon nanowires/graphite composite as active material for the negative electrode. The approach of using such composite is of great interest because it seeks to combine the advantages of the two components – i.e., the excellent cycling stability of graphite and the much higher specific capacity (3579 mAh g-1) and superior rate capability of silicon. The 1D silicon nanowire morphology compared to bulk silicon materials offers short Li+ transport pathways 4 and provides better contact with the graphite particles within the composite. This improved contact ensures first cycle coulombic efficiencies of well above 80% as well as very good cycling stability and high rate capability – even for high areal capacity electrodes – in half-cells and full-cells; the latter comprising NMC-type cathodes. A specific focus was set moreover on the investigation of the impact of (partially) pre-lithiated anodes, providing superior lithium-ion cycling stability with negligible capacity loss over hundreds of cycles.

References

M. Armand and J. M. Tarascon, "Building better batteries", Nature, 451, 652-657 (2008).

D. Bresser et al., “Perspectives of automotive battery R&D in China, Germany, Japan, and the USA", J. Power Sources, 382, 176-178 (2018).

J. Asenbauer et al., "The success story of graphite as a lithium-ion anode material – fundamentals, remaining challenges, and recent developments including silicon (oxide) composites", Sustain. Energy Fuels, DOI: 10.1039/D0SE00175A (2020).

C. K. Chan et al., “High-performance lithium battery anodes using silicon nanowires", Nat.
Nanotechnol., 3, 31–35 (2008).
Germanium Oxide Negative Electrodes - Tuning Synthesis Conditions Towards High-Energy and High-Power Lithium-Ion Cells
Authors: Eisenmann Tobias , Baek Ha-gyeong , Mullaliu Angelo , Passerini Stefano , Bresser Dominic
Published: December 2020

The transportation sector is continuously transitioning from combustion engines towards fully electric vehicles and lithium-ion batteries (LIBs) are the energy storage device of choice due to their high volumetric and gravimetric energy density.1 However, to meet future targets in terms of driving range and re-/charging times, the state-of-the-art graphite anode graphite needs to be replaced with materials offering even higher energy densities and, especially, better power capabilities.2

Alloying metal-oxides such as ZnO and SnO2 have been widely studied, since they offer high theoretical specific capacities (988 mAh g-1 and 1494 mAh g-1, respectively), while being environmentally friendly and non-toxic. Furthermore, such alloying metal oxides have high densities, which promises higher volumetric capacities compared to graphite. However, these high densities, in combination with the high overall Li+ uptake, result in pronounced volume expansion upon cycling. Furthermore, the eventually irreversible Li2O formation limits the practically achievable specific capacities to the alloying contribution only. It has been shown that this limitation can be overcome by introducing a transition metal (e.g., Fe, Co) into the lattice, leading to a reversible Li2O formation and favorable de-/lithiation kinetics.3,4 This concept of transition metal doping has recently also been transferred to germanium oxide – another example for a Li+ alloying oxide with an even higher theoretical specific capacity (i.e., 2152 mAh g-1) - and was shown to partially enable re-oxidation of germanium to germanium oxide, though (so far) only for the initial cycles.5

Within this study, we tackled the problem from a more comprehensive perspective and elaborate on the effect of different synthesis conditions, the introduction of Fe into GeO2, as well as the impact of different germanium oxide phases on the electrochemical performance. The latter aspect is, indeed, commonly overlooked so far when studying metal oxide anodes. The highly complementary techniques employed include, amongst others, in situ/operando characterization methods such as in situ high temperature XRD, operando XRD and operando dilatometry. Ultimately, we realized lithium-ion cells comprising lithium-rich Li1.2Mn0.6Ni0.2O2 cathodes with a specific energy of about 400 Wh kg-1 and stable cycling for more than 350 cycles.

N. Nitta, F. Wu, J. T. Lee, and G. Yushin, Mater. Today, 18, 252–264 (2015).

J. Asenbauer et al., Sustain. Energy Fuels (2020).

D. Bresser et al., Chem. Mater., 25, 4977–4985 (2013).

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

J. Wu, N. Luo, S. Huang, W. Yang, and M. Wei, J. Mater. Chem. A, 7, 4574–4580 (2019).
Evaluating the Deployment of Al Anodes in Primary and Secondary Batteries: Current Status, Future Prospects?
Authors: Faegh Ehsan , Ng Benjamin , Mustain William
Published: December 2020

For decades, aluminum anodes have been looked at as the holy grail for many battery chemistry platforms, promising to increase the gravimetric and volumetric energy density to new heights while keeping battery costs low. However, its deployment has been beset with problems, the most notable of which have been corrosion and surface passivation in investigated electrolytes. Researchers have tried to work around these issues through a combination of electrolyte additives, synthesis of new material morphologies, galvanic protection, and changing the material chemistry by moving away from traditional electrolytes. Each of these approaches have had moments of promise, but they also come with their own limitations and challenges that have practical implications – including practically achievable energy density, rate capability, materials and manufacturing cost, and lifetime. Another complicating factor is that the technical literature (publications and patents) often present only an overwhelmingly sunny outlook for a given approach or technology, even when such an outlook is not reasonably supported by data. This makes it very difficult to understand which of the approaches that have been tried have the potential to be deployed in practical, commercial batteries. This presentation will systematically present and analyze the main deployments of Al anodes in both primary and secondary batteries using aqueous and non-aqueous electrolytes. The focus of this talk with be to be quantitative with regards to the practically-achievable energy density and lifetime of some of the most promising aluminum technologies from the literature and to provide a critical assessment of the state of the field today and the future for Al in primary and secondary energy storage.
Synthesis and Characterization of Von Alpen-Type Nasicon Ceramic and Its Application to Rechargeable Seawater Battery
Authors: Go Wooseok , Wolfenstine Jeff , Kim Youngsik
Published: December 2020

Rechargeable seawater battery (SWB), which utilizes naturally abundant seawater as its cathode, is having attention for a next-generation large-scale energy storage system (ESS) due to its low cost and eco-friendliness. For an effective Na+ transfer solid electrolyte for SWB, Hong-type NASICON (Na3Zr2Si2PO12) ceramic has been used because of its known high Na-ion conductivity (~3x10-4 S/cm). However, the SWB coin cell test showed that the Hong-type NASICON ceramic accounts for 62% (132Ω) of the total cell resistance (214 Ω). This has been considered as one of major drawbacks for developments of SWB technology. Hence, it has been requested to achieve higher ionic conductivity of Na-ion conducting ceramics, increasing power of the current SWB by reducing its cell ohmic resistance.

In this talk, von Alpen-type NASICON (Na3.3Zr1.55Si0.7P1.3O11) ceramic was synthesized by solid-state reaction and was observed to have ~1.0x10-3S/cm of Na-ion conductivity, which three times higher than that of Hong-type one. It was found that the von Alpen-type NASICON has more rhombohedral phases with a bigger grain size (2~6μm) compared to the major phases of Hong-type one, and additionally less secondary phases of ZrO2 were observed in the von Alpen-type NASICON. These differences were believed to be major reasons for higher Na-ion conductivity observed in von Alpen-type NASICON ceramic. These structural characteristics were also found to led to a stronger mechanical strength (50MPa) of the von Alpen-type NASICON rather than that (20MPa) of Hong-type one, which enables us to have thinner thickness (~0.5mm) of the ceramic solid electrolyte at the present work.

With the use of von Alpen-type NASICON having a higher Na-ion conductivity and thinner thickness in SWB coin cell, it shows 96% of the power increased (to 9.8 mW/cm2 from 5.1 mW/cm2 of the cell using Hong-type ceramic). More details will be reported in the talk.
Slurry Design for a Low Cost, High Capacity Magnesium Semi-Solid Flow Battery
Authors: McPhail Matt , Kumar Rajan , Subramanian Vivek
Published: December 2020

Semi solid flow batteries (SSFB) are developed by forming suspensions of electrochemically active and conductive particles for use as an anolyte or catholyte in a redox flow battery. By utilizing micron-scale powders from mature battery chemistries in a flowable suspension, the benefits of energy-dense intercalation chemistries with the scalability of flow battery architectures can be combined for low cost electrochemical storage. Presently, a narrow set of materials has been explored, focusing on chemistries with a lithium anode. In this work, a magnesium SSFB with an optimized MoS2 cathodic slurry is demonstrated as a low cost, high material abundance alternative to lithium-based chemistries.

A mixed ionic-electronic conductive network is designed around a dual-ion (Mg, Li) electrolyte, by combining the all-phenyl complex (APC) + LiCl, MoS2, and ketjen black (KB) to form the cathodic slurry. The rheological, electrical, and electrochemical properties of MoS2-KB-APC slurries with varying compositions have been measured. Full cells, with a Mg foil anode and MoS2 slurry cathode, are shown to cycle reversibly for 20 cycles at C/5 in a non-flowing configuration, reaching 180 mAh/g discharge capacity. LiCl concentration and KB concentration are identified as critical to high capacity slurry cathodes. The relative impacts of Mg and Li ions are quantitatively analyzed, showing that both ions are reversibly intercalated during cycling. Finally, a custom flow cell is used to demonstrate 120 mAh/g discharge capacity at C/8, highlighting the flowable nature of the cathode suspension. This work provides experimental data and insight into how existing low cost material sets can be utilized in a semi solid flow battery architecture.

Figure 1