bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrated PET-LiClO4 Electrolyte for Structural Energy Storage Applications
Authors: Joyal Nathaniel , Shen Caiwei 
Published: July 2021

In recent years mobile devices have become increasingly dependent on energy storage components such as batteries. Multifunctional structural supercapacitors, which can serve as structural components and store electrical energy at the same time, offer a solution to reducing the total weight of all kinds of mobile devices. Previous work on structural supercapacitors always point to devices with good mechanical strength or good electrical properties but rarely both, as those solid polymer electrolytes with good ionic conductivities use a liquid phase for the transfer of ions which can diminish the mechanical properties of the base polymer.
We present here a strong and conductive all-solid-state electrolyte composed of polyethylene terephthalate (PET) and lithium perchlorate (LiClO4) with a single continuous phase. We find that the electrolyte shows extraordinary ionic conductivity while maintaining its all-solid state when exposed to controlled humidity. The hygroscopic electrolyte will absorb controlled amount of water molecules, all bound to LiClO4 without forming a liquid phase, when the humidity is below 70% at room temperature. Such bound water facilitates ion transport, improves electrode-electrolyte interface, and has minimum impact on the mechanical properties of the electrolyte.
Through both X-Ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis of numerous solid electrolyte compositions that have undergone different treatments it has been shown that the electrolyte has an amorphous phase. The electrochemical tests conducted were electrochemical impedance spectroscopy (EIS) to determine the ionic conductivity, linear sweep voltammetry (LSV) to determine the operating voltage range, and cyclic voltammetry (CV) to determine the interfacial capacitance. These tests were conducted on a range of electrolytes varying in the ratio of PET and LiClO4, as well as varying in the relative humidity that the samples were exposed to. These results demonstrate comparable ionic conductivity to gel electrolytes with operating ranges of at least +2V. The preliminary mechanical testing shows that the solid electrolyte has a high stiffness and good interfacial bonding strength to carbon electrode surface. The use of hydrated lithium salts as opposed to an ionic liquid allows for the electrolyte to perform similarly to the base polymer.
In conclusion, we believe that this solid electrolyte shows great promise for application in composite supercapacitors for structural applications. This solid electrolyte when applied to structural energy storage can be used to deliver a better power to weight ratio than a conventional battery, solving the problem of large and heavy power banks that increase overall weight and take up space.
Assessing Electrochemical Stability Windows of Li1+XAlxM2-X(PO4)3 (M=Ge,Ti) Nasicon Solid Electrolytes for Their Application in All Solid-State Lithium Batteries
Authors: Benabed Yasmine , Rioux Maxime , Rousselot Steeve , Hautier Geoffroy , Dolle Mickael 
Published: July 2021

All-Solid-State Lithium Batteries (ASSLBs) are a new generation of lithium batteries that are developed to meet expectations in terms of safety, stability and high energy density. The liquid electrolyte of conventional Li-ion batteries is replaced in ASSLBs by a safer and more stable solid electrolyte (SE). ASSLBs are promising because they may enable the use of high potential materials as positive electrode and lithium metal as negative electrode. This is only possible through SE stated large electrochemical stability windows (ESW). Nevertheless, values for these electrochemical windows are very divergent in the published literature. Recently, several studies have come to specifically decry the frequent overestimation of SE electrochemical stability windows
1-
4
. Establishing a robust procedure to accurately determine SEs ESW has therefore become crucial.
Our work is focused on using an original experimental set up to assess the ESW of two widely investigated NASICON-type SEs Li1.3Al0.3Ti1.7(PO4)3 (LATP) and Li1.5Al0.5Ge1.5(PO4)3 (LAGP). The experimental set-up provides a large contact surface between the SE and the conductive material, which maximizes the redox current signals. A combination of Potentiostatic Intermittent Titration Technique (PITT) and Electrochemical Impedance Spectroscopy (EIS) measurements allowed us to precisely determine the ESW of LATP and LAGP solid electrolytes. Using EIS and physico-chemical characterizations, we attempted to shed light on the degradation mechanisms occurring upon the solid electrolytes’ oxidation.

1 - Y. Tian et al. Energy Environ. Sci.
2017, 10, 1150.

2 - Z. Zhang et al. Energy Environ. Sci.
2018, 11, 1945-1976.

3 - F. Han et al. Adv. Energy Mater. 2016, 6(8), 1501590.

4 - T. Schwietert et al. Nature Mat. 2020, 19, 428–435.
Rechargeable Lithium Metal Pouch Cell Development
Authors: Crowther Owen 
Published: July 2021

Commercially available Li-ion batteries using graphite or graphite-silicon blended anodes are currently approaching a cell level specific energy of 300 Wh kg−1. The use of lithium metal instead as an anode an intriguing possibility to further increase cell level specific energies to 400 Wh kg−1 and beyond. Lithium is an ideal anode because it is the lightest metal and highly electronegative. However, attempts to commercialize cells using lithium metal anodes have been slowed by poor cycle life and safety issues. This is because nonuniform lithium plating leads to the growth of dendrites that cause loss of active lithium and can eventually lead to internal cell shorts. Safe cell cycle life must be improved to 50-100 cycles for special purpose applications like unmanned aerial vehicles, >300 cycles for portable power applications and >1000 cycles for electric vehicle applications.
The performance of prototype cells developed at EaglePicher Technologies using lithium metal anode will be highlighted. The figure below on the left shows the specific discharge energy of a 2.5 Ah prototype pouch cell using a lithium anode, high nickel cathode and nonaqueous electrolyte. The cell demonstrates an extremely high specific energy of >400 Wh kg−1 at low rates. The effect of electrolyte on capacity retention is shown in the figure below on the right. The optimized electrolyte demonstrates good retention to >50 cycles. This presentation will focus on design considerations for pouch cells with lithium anodes, as well as improving the cycle life and safety characteristics of these cells. Prototype performance data including cycle life, rate capability, temperature effects and safety testing will be presented.
EaglePicher Technologies would like to acknowledge the US Army DEVCOM C5ISR Center in Aberdeen Proving Ground, Maryland for funding this research.

Figure 1
Improvement of Preparation Scheme for Microelectrode and Single Particle Electrochemical Measurements of LiCoO2 Interfaces Under Absence / Presence Chemical Additives
Authors: Takai Kasane , Takahashi Keitaro , Miyauchi Hibiki , Nishikawa Kei , Nakamura Tatsuya , Seki Shiro 
Published: July 2021

Introduction

Li-ion batteries (LIBs) are expected to stabilize the electrical power supply and utilize the electrical vehicle. Electrode of LIBs is consisted of mixture of active material, conductive additive, and binder. The conventional electrochemical measurement method is influenced not only by active materials but also by conductive additive and binder. Therefore, electrochemical measurement method with improved microelectrode in contact with single particle of active material was proposed［
1
］. This measurement method is generally known as single particle electrochemical measurement, and expected to evaluate the essential characteristics of active materials［
2
］. In this case, shapes and smooth of microelectrode are important factor in order to obtain the high-reliability results.
In this study, we investigated the effects of microelectrode morphology and suitable contact with the surface of active materials.

Experiments

A Pt wire (φ30 µm) was inserted to glass capillary and was heated and cut to obtain supported fine line coating. Coated tip was polished by grinding machine and obtained well-prepared microelectrode (Fig.2(b)).
An open cell was constructed in the argon-filled glovebox (-90℃ dew point). Li foil (φ10 mm) was put on the center of the stainless steel cup as a negative electrode, and a glass separator 110 µL electrolyte (1M-LiClO4/kg-PC) were added as electrolyte layer. LiCoO2 particles (20-30 µm diameter) were put onto electrolyte. The tip of microelectrode was directly attached to certain LiCoO2 single particle and charge / discharge measurements were carried out.

Results & Discussion

Fig.1 shows the charge / discharge profiles of the cell prepared by conventional process. Charge voltage did not reach the upper limited of 4.4V, and sufficient discharge profile was not observed.
Fig.2 also shows the charge / discharge profiles of the cell prepared by new process. Reversible charge-discharge operation of single LiCoO2 particle was observed with appropriate capacity. Sufficient preparation prosses of the microelectrode was important for concise measurement of single particle electrochemical measurements. In the presentation, we will report detailed preparation method of microelectrode, and in-situ directly adding effect of chemical additives into the measurement cells.

References

[1] K. Dokko, et. al., J. Electrochem. Soc.,
148, A422 (2001).
[2] T. Saito, et. al., J. Phys. Chem. C,
124, 31, 16758 (2020).

Figure 1
Synthesis and Electrochemical Properties of Lepidocrocite Titanate- Graphene Heterostructures
Authors: Barim Gozde , Lin Jason , Doeff Marca M. 
Published: July 2021

Layered titanates with lepidocrocite structure can be used as anodes for lithium, sodium or potassium batteries in conventional or flow cell configurations. Although they are attractive owing to their low cost, low toxicity, and high abundancy, their low conductivity and poor cycling performance are major hurdles for these materials. Here, we used a self-assembly approach to overcome electronic transport limitations and to build in the conductivity by incorporating a conductive component such as reduced graphene oxide (rGO) or into nitrogen doped graphene (NDG) in the van der Waals gaps to make 2D heterostructures.
In this presentation, solution-phase synthesis of K0.8[Ti1.73Li0.27]O4 (lepidocrocite titanate, LT) heterostructures with graphene is demonstrated. After synthesis by conventional solid-state routes, K0.8[Ti1.73Li0.27]O4 is proton exchanged and ion-exchanged with bulky cations, causing expansion of the structure, and exfoliated by mechanical shaking. Exfoliated layered titania sheets are self-assembled with either reduced graphene oxide (rGO) or dopamine into heterostructures through flocculation via counter cations (e.g. Mg2+, Na+) or in situ conversion of dopamine into nitrogen doped graphene (NDG), respectively. Both coagulated LT-rGO and LT-NDG heterostructures exhibit capacities which are more than two times higher than the capacities of pristine lepidocrocite titanate (K0.8[Ti1.73Li0.27]O4), and display good capacity retention after 50 cycles in sodium half-cells configurations.
(Invited) Environmental Impact of Carbon Nanotubes & Graphene and Related Materials (GRMs)
Authors: Flahaut Emmanuel , Evariste Lauris , Liné Clarisse , Mottier Antoine , Mouchet Florence , Barret Maialen , Pinelli Eric , Galibert Anne Marie , Soula Brigitte , Larue Camille , Gauthier Laury 
Published: July 2021

Carbon nanomaterials (and especially carbon nanotubes) are often cited first when people are asked about "nanoparticles" in general. For some people, they represent a huge potential of applications due to their extraordinary properties (or more realistically because of their unique combination of different properties), while some others will mention first the (potential) related toxicity issues.
We will quickly review different aspects related to the potential environmental toxicity of carbon nanomaterials and will summarize our main results in this field. In particular, we have identified that the impact of carbon nanomaterials with very different morphologies ranging from zero-D (nanodiamonds) to 2D (few-layer graphene, graphene oxide) can be generalized when the metric used for the comparison of the data is the surface (m²/L) instead of the weight (g/L) [1]. We will illustrate in the specific case of graphene oxide how the modification of surface chemistry (reduction) can be used to significantly decrease the risk during handling and use, in the framework of a "safer(r) by design" strategy [2].
Finally, we will give a brief overview of our recent work on the impact of carbon nanotubes on plants grown in contaminated soils.
REFERENCES:
[1] A. Mottier, F. Mouchet, C. Laplanche, S. Cadarsi, L. Lagier, J-C. Arnault, H. Girard, V. Léon, E. Vazquez, C. Sarrieu, E. Pinelli, L. Gauthier, E. Flahaut, Nano Letters, 16 (6), (2016), 3514-3518, "Surface area of carbon nanoparticle: a dose-metric for a more realistic ecotoxicological assessment"
[2] L. Evariste, L. Lagier, P. Gonzalez, A. Mottier, F. Mouchet, S. Cadarsi, P. Lonchambon, G. Daffe, G. Chimowa, C. Sarrieu, A-M. Galibert, C. Matei Ghimbeu, E. Pinelli, E. Flahaut, L. Gauthier, Nanomaterials, 9, (2019), 584:1-16, "Thermal reduction of Graphene Oxide mitigates its in vivo genotoxicity toward Xenopus laevis tadpoles"
(Invited) Hybrid Van Der Waals Heterostructures: From Fundamentals to Applications
Authors: Orgiu Emanuele 
Published: July 2021

2D materials are held together by weak interplanar van der Waals (vdW) interactions. The incorporation of molecules in such materials holds an immense potential to understand and modify the fundamental physical properties of the pristine materials while creatin new artificial materials. Whilst nature offers a finite number of 2D materials, an almost unlimited variety of molecules can be designed and synthesized with predictable functionalities. The possibilities offered by systems in which continuous molecular layers are interfaced with inorganic 2D materials to form hybrid organic/inorganic van der Waals heterostructures (H-vdWH) are emphasized. Similar to their inorganic counterpart, the hybrid structures have been exploited to suggest novel device architectures. Moreover, specific molecular groups can be employed to modify intrinsic properties and confer new capabilities to 2D materials. In particular, I will highlight how molecular self-assembly at the surface of 2D materials can be mastered to achieve precise control over position and density of (molecular) functional groups, paving the way for a new class of hybrid functional materials.
In particular, within such vdW heterostructures, currently assembled by mechanical superposition of different layers, periodic potentials naturally occur at the interface between the 2D materials. These potentials significantly modify the electronic structure of the individual 2D components within the stack and their alignment, thus offering the possibility to build up hybrid and novel materials with unique properties.
Also, I will show how the presence of ordered supramolecular assemblies bearing different functional groups can modify the pristine Shubnikov-De Haas oscillations occurring in graphene.
Finally, an example will be given of how a carefully designed H-vdWH could be used for sensing of different biomarkers.
(Invited) Optical Properties and Active Plasmon Excitations in Nanocrystals and 2D Materials
Authors: Henrard Luc 
Published: July 2021

The control and tuning of the optical properties of materials and the localization of electromagnetic energy are long standing quests for scientists. Not only it allows to design new classes of adaptive devices such as smart windows but also to perform surface enhanced vibrational spectroscopies such a SERS. Behind all these applications, fundamental questions are still debated : what is the role of electron correlation in the optical response ? How to include to contribution of crystal field in the dielectric response of complex system ? How the local electro-magnetic field influence the optical absorption and the SERS activity ?
For metallic nanostructured systems, the optical properties are directly related to collective electronic excitation (plasmons) and they depend mainly on the composition, shape and size of the system. Doped semiconductors such as Indium Tin Oxide have been also shown to display active plasmon, i.e., optical excitations that can be controlled by an external stimulus such as static electric potential [1].
In 2D materials like graphene, the electrostatic doping is a commonly used to modify the optical response due to the low density of state at the Fermi energy. Moreover, topological corrugation, anisotropy [2], chemical doping [3] and electrostatic coupling in vanderwaals heterostructures plays very specific roles on the optical responses. Graphene nanodots and molecular PAH also supported plasmon excitation and electrochromic behavior.
In this presentation, based on numerical simulations, we analyze the optical properties of these compounds and we discuss the influence of electrostatic coupling and charging effects. We emphasized the role of the electron correlation and of the local field in classical, semi-empirical and ab-initio methods.
[1] A. Maho et al. Solar Energy Materials and Solar Cells 200 (2019) 110014
[2] B. Majerus et al. Phys. Rev. B 98 (2018) 125419
[3] F. Joucken et al. Phys. Rev. Mat. 3 (2019) 110301
(Invited) Scanning Gate Imaging of Charge Transport in Graphene Nanodevices
Authors: Hackens Benoit 
Published: July 2021

Quantum transport in nanodevices is usually probed thanks to measurements of the electrical resistance or conductance, which lack the spatial resolution necessary to probe local-scale electron behaviour. Here, we will discuss how to get real-space local information on peculiar quantum transport phenomena inside graphene constrictions. The results were obtained using low temperature scanning gate microscopy (SGM), which consists in mapping the electrical conductance of a device as an electrically-biased sharp metallic tip scans in its vicinity [1].
If the tip-induced perturbation is relatively small, SGM is an imaging technique giving access to the local density of states inside mesoscopic devices [2]. Here, we will focus on the regime of large tip-induced perturbation. This regime is particularly interesting in the case of graphene: depending on tip voltage and tip-sample distance, one can tune the shape, size, and smoothness of the moving scattering region associated with the tip, and eventually create a moving circular pn-junction within the device. We use this moving pn-junction to probe peculiar aspects of relativistic charge carrier dynamics within graphene devices: Klein tunnelling and current focusing and defocusing [3], Fabry-Pérot interferometry [4], signatures of whispering gallery modes [5] and tunneling between counterpropagating quantum Hall edge states [6]. This work unlocks new possibilities in the field of electron optics in graphene.
[1] M.A. Eriksson et al., Appl. Phys. Lett. 69, 671 (1996); M. Topinka et al., Science 289, 671 (2000).
[2] F. Martins et al., Phys. Rev. Lett. 99, 136807 (2007) ; M. Pala et al., Phys. Rev. B 77, 125310 (2008).
[3] B. Brun et al., Phys. Rev. B 100, 041401 (2019).
[4] B. Brun et al., 2D Materials, 7, 025037 (2020).
[5] B. Brun et al., submitted.
[6] N. Moreau et al., submitted.
(Invited) Alteration of the Electrical Transport in Carbon Nanotube Network Field-Effect Transistors Using Polymer Encapsulants and Gate Dielectrics
Authors: Lapointe Francois 
Published: July 2021

Enriched semiconducting single-walled carbon nanotubes (SWCNTs) inks of high purity opens a wealth of possibilities for device fabrication using printing techniques and solution processes. [1] Logics, displays, sensors and large-scale integrated circuits [2] appear to be within reach. For those promises to concretize, a better control over parameters such as carrier type and mobility, operation power and device-to-device variability is needed. Beside the ambient effect (notably water and oxygen) on the transport of carbon nanotube network field-effect transistors (CNN-FETs), the nature of the surrounding materials (as a passivation layer or as a gate dielectric) appears to play a crucial role in determining the device's characteristics.
Firstly, we have tested a large number of polymeric materials as the bottom gate in three-terminal CNN-FETs. We have found that the transport characteristics parameters such as the threshold voltage and the hysteresis are affected by the chemical nature of the polymer. [3] Subjecting those CNN-FETs with various gate dielectrics to a series of volatile analytes, we observed drastically different responses which suggests the usefulness of polymer gate dielectric variations in cross-reactive sensors arrays.
Secondly, polymeric materials were used as an encapsulant over bottom gate CNN-FETs. [4] A smooth and continuous variation of the threshold voltage has been achieved by using a series of poly(styrene–co–2-vinyl pyridine) copolymers with different monomer ratios. A surface charge density measurement methodology has been developed to rationalize the threshold voltage variations upon encapsulation with various polymers. Finally, we explored the use of n-doping molecules blended with polymer encapsulants as an efficient way to obtain n-type transport characteristics. This strategy is further used in the implementation of simple p-n junctions showing a modest rectification.

References

[1] Bati, A. S. R. et al. Recent Advances in Applications of Sorted Single‐Walled Carbon Nanotubes. Adv. Funct. Mater.
29 1902273 (2019)
[2] Hills, G. et al. Modern Microprocessor Built from Complementary Carbon Nanotube Transistors. Nature
572 595–602 (2019)
[3] Lapointe, F. et al. Carbon Nanotube Transistors as Gas Sensors: Response Differentiation Using Polymer Gate Dielectrics. ACS Appl. Polym. Mater.
1 3269-3278 (2019)
[4] Lapointe, F. et al. Polymer Encapsulants for Threshold Voltage Control in Carbon Nanotube Transistors. ACS Appl. Mater. Interfaces
11 36027-36034 (2019)