bluuebunny/crossref_metadata_2025 huggingface dataset:
3D Thermal Gradient of Li-Ion Prismatic Cell during High Current Discharge: A Numerical and Experimental Study
Authors: Raccurt Olivier , Geniès Sylvie , Bachir-Elezaar Kamel , Pham Quynh Trang , Coste Pierre , Daniel Lise , Montaru Maxime , Fiette Sébastien , Hergott Julien , Antunes Benoit
Published: May 2020

Thermal management of the Li-ion batteries is one of major challenges to manage the performances and safety of the cell [1][2]. In battery pack, cooling systems are required to manage the heat generation of the cells during the charge and discharge cycles. The heat generated by the electrochemical processes inside the cell depends on the materials properties, the internal electrical resistance of the cell and the applied current rate [3][4].

In this study, the thermal behaviour of a 25 Ah prismatic cell has been modelled by a 3D approach. From an ante mortem analysis, the structure and configuration of the cells were determined. From such analysis, a 3D model of the cell was constructed by ANSYS and STARCCM software. A thermal source has been imposed in the jelly roll to simulate the heat generation during electrochemical reactions. Different cooling strategies were simulated to determine the temperature profile inside the cell volume and on the external surface.

To validate the developed thermal model, electrochemical tests in charge and discharge at different C-rates (up to 5C) into a thermal chamber were used to study the evolution of the surface temperature of the cell over 35 measuring points. The experimental results show the presence of a temperature gradient on the surface of the cell during the discharge step. This gradient increase according to the discharge rate. This thermal behaviour observed by experiment was in agreement with the simulation results. In addition, the current work will discuss on the methodology to improve the sensitivity of the 3D thermal model. The comparison of different cooling strategies explored by simulation will be also presented and discussed.

References

[1] A. Mauger and C. M. Julien, “Critical review on lithium-ion batteries: are they safe? Sustainable?,” Ionics, vol. 23, no. 8, pp. 1933–1947, Aug. 2017.

[2] D. Lisbona and T. Snee, “A review of hazards associated with primary lithium and lithium-ion batteries,” Process Safety and Environmental Protection, vol. 89, no. 6, pp. 434–442, 2011.

[3] P. Wu, J. Romberg, X. Cheng, W. Hao, H. Si, H. Li, and X. Qiu, “A study on thermal runaway of commercial lithium-ion cells: influence of soc, cell chemistry and ageing status on safety performance,” Lecture Notes in Electrical Engineering, vol. 486, pp. 619–627, 2019.

[4] Y.-S. Duh, K. H. Lin, and C.-S. Kao, “Experimental investigation and visualization on thermal runaway of hard prismatic lithium-ion batteries used in smart phones,” Journal of Thermal Analysis and Calorimetry, vol. 132, no. 3, pp. 1677–1692, Jun. 2018.

Acknowledgement

The present work has been launched by FAURECIA Group and supported by CEA Liten
Development of Porous Electrode Theory to Accommodate Voltage Gradients and Nonlinearity
Authors: Turney Damon
Published: May 2020

Simulations of ionic and solvent mass transfer in electrolytes are typically based upon either i) the Poisson-Nernst-Plank equations with Fickian diffusion (Poisson-Fickian), or ii) the Newman-type porous electrode equations with Stefan-Maxwell transport (Newman-Stefan-Maxwell). Computational expense usually limits the Poisson-Fickian-type simulations to simple systems with only one or two phases, and one or two dimensions. Meanwhile the Newman-Stefan-Maxwell-type equations are explicitly only one-dimensional but are much easier to execute and can crudely handle more phases. This ease and flexibility made the Newman-Stefan-Maxwell approach popular over the past thirty years, and the Newman-type model continues to be popular with modern usage at current date.

The work presented here shows a further development of the Newman-Stefan-Maxwell equations that extend the Newman theory to i) simulate voltage and pressure gradients in the electrolyte that are significant when ionic concentrations are below ~2 Molar, and ii) include more accurate thermodynamics when describing the chemical potential of the species. The new equations are shown and justified. No significant increase in computational expense or model complexity is necessary for these improvements.

An additional predictor-corrector modelling scheme is shown for calculating the chemical composition at the particle-liquid interface, which allows for the overall model to be solved with explicit time-differencing without requiring extremely small time steps. The explicit time-differencing is advantageous because it discards the requirement to linearize all equations, and therefore allows for fully nonlinear charge-transfer equations to be tested with an arbitrary complexity desired.

The new model is capable of simulating one-dimensional full battery operation (anode, cathode, separator, electrolyte) with improved accuracy over the classical Newman-Stefan-Mawell model regarding spatio-temporal patterns of electrochemical potential, concentrations, and reaction rate. Some example applications are shown for CV cycling and galvanostatic cycling of: i) a 1 Molar Zn-MnO2 battery, ii) a EMImCl:AlCl3 aluminum-graphite battery. Additional systems are proposed for study where the voltage and pressure gradients are important to simulate.
NiFe2O4 Nanoparticles Anchored on Porous Graphene Sheets Offered Robust Electrochemical Performance for Supercapacitor Applications
Authors: Sethi Meenaketan , Shenoy U Sandhya , Bhat D Krishna
Published: May 2020

A Facile solvothermal method is used for the synthesis of porous graphene − NiFe2O4 (PGNF) nanocomposite. Thorough elemental, diffraction, microscopic and spectroscopic studies confirmed the formation of PGNF composite in which, the NiFe2O4 nanoparticles are covered over the porous graphene (PG) surface strongly depicting the formation of composite structure. Among the obtained composites, the 10 PGNF composite showed a high surface area of 107 m2 g-1, with large pore volume which will be favorable for the charge storage property. Utilizing the material as an electrode for supercapacitors in a 2 M KOH aqueous electrolyte, the electrode displayed a high capacity value of 1465.0 F g-1 at a scan rate of 5 mV s-1, and 1320.0 F g-1 (594 C g-1) at a current density of 1 A g-1, along with high capacitance retention rate of 94 % after 10000 discharge cycles. The fabricated symmetrical supercapacitor device by using the best performed electrode (10 PGNF), displayed a high capacitance value of 303 F g-1 at a scan rate of 5 mV s-1, with 96 % initial capacitance retention value after a long 10000 discharge cycles along with a good energy density of 5.5 Wh kg-1 while maintaining a high power density of 1008.0 W kg-1 at a current density of 4 A g-1, and still produces an energy density of 4.0 Wh kg-1 at a high power density of 3600.0 W kg-1 at the applied current density of 14 A g-1. The superior results showed by the material is mainly due to the inclusion of PG having high surface area and pore volume, in addition to that NiFe2O4 nanoparticles presence also increased the electronic conductivity by acting as spacer to keep the neighboring sheets apart along with it has maintained the mechanical strength during continuous electrochemical redox process. Thus, we believe that the increased electrochemical performance is mainly due to the synergetic effect of the materials which not only provided enough electroactive channels for the smooth passage of electrolyte ions but also maintained the hybrid structure intact in the ongoing electrochemical process. The obtained result supports the promising utility of this material for future electrochemical energy storage devices.

Keywords: Porous graphene, NiFe2O4 nanoparticles, composite, specific capacitance, cyclic stability.
Fabrication and Evaluation of Two-Dimension Perovskite LED Devices with p-Xylylenediamine As Ligand
Authors: Xiu Zhaohong
Published: May 2020

Halide perovskite nanocrystals (HPNCs) are promising materials for optoelectronic devices. However, HPNCs suffer severely from chemical and phase instabilities in relation to the common capping ligands, such as oleic acid and oleylamine, which encapsulates the NCs and forms an insulating layer, precluding their utilities in optoelectronic devices. In addition, despite` significant advancements in the development for applications of light-emitting diodes (LED) based on HPNCs, especially for green LEDs, device performances are still far from meeting application requirements, particularly when red LEDs are needed. To overcome these limitations, for the first time, the present paper reports the fabrication and evaluation of two-dimension (2D) perovskite LED devices with p-xylylenediamine as ligand by using a postsynthesis passivation process. Our passivated HPNCs exhibit narrow red photoluminescence with exceptional quantum yield (close to unity) and substantially improved stability. The passivated NCs enabled us to realize much purer and brighter red LED devices with a narrower band and full width at half maximum of 37 nm, surpassing by far LEDs made from the nonpassivated NCs.
WITHDRAWN: V2O5 Film Embedded Carbon Fiber Paper Synthesized By Sol Process As Highly Pseudocapacitive Electrode for Energy Storage
Authors: Azadian Farshad , Rastogi Alok C
Published: May 2020

This abstract has been withdrawn at the request of the authors.
Quantifying Intercalation Pseudocapacitance Using Single Nanoparticle Electro-Optical Imaging
Authors: Sambur Justin , Evans Russel Colby
Published: May 2020

Understanding the correlated dynamics between atoms, electrons, and ions in solids is critical to the holistic design of energy storage materials. A critical requirement for electrochemical energy storage is to transport electrons and guest ions (e.g., Li+, Na+) in and out of a host lattice. Intercalation pseudocapacitors exhibit unusual charge dynamics in that they store charge throughout the bulk, improving energy density, but do so via a fast capacitor-like intercalation process that is not limited by solid-state diffusion, improving rate. The physical principles and materials chemistry properties that govern and promote fast ion transport in pseudocapacitors is not entirely understood. One major challenge is to quantify the surface and/or bulk sites that participate in the pseudocapacitive charge storage process. Here we show how single particle electro-optical imaging and theoretical analyses can distinguish diffusion-limited and pseudocapacitive energy storage processes in single nanoparticles. Electro-optical measurements quantify redox changes in the solid electrode that have the same scaling relations in time, potential, etc. as the electrochemical scaling relations for pseudocapacitance. We quantify the fraction of surface and bulk sites that charge/discharge with pseudocapacitive signatures and defind structure/property relationships that give rise to enhanced pseudocapacitive contributions.

Figure 1
(Invited) A New Family of Lithium-Rich Layered Sulfides (Li[LitTi1-t]S2, 0 < t ≤ 0.33) Belonging to the LiTiS2 – Li2TiS3 System
Authors: Delmas Claude , Flamary Florian , Boulineau Adrien , Martinez Hervé , Suchomel Matthew , Pecquenard Brigitte , Le Cras Frederic
Published: May 2020

Li-rich layered oxide (Li[LixM1-x]O2, (M = Mn, Ni, Co,...) positive electrode materials are considered as a key component for next generation lithium ion batteries, as they display outstanding specific energy originating from a combination of additional lithium de-intercalation and the unusual oxidation of oxygen anions.

Recently we have extended these studies to the homologous titanium sulfides belonging to the LiTiS2 – Li2TiS3 system. Layered Li2TiS3 was obtained for the first time by direct reaction of Li2S on TiS2. Its structure is similar to the Li2MnO3 one, with a small amount of stacking faults. Overlithiated compositions (Li[LitTi1-t]S2, (0 < t ≤ 0.33)) were synthesized by direct synthesis from Li2TiS3 and LiTiS2 and structurally characterized. While LiTiS2 exhibits the O1 type sulfur packing, all compositions with ~0.08 < t ≤ 0.33 exhibit the O3 type sulfur packing like the homologous oxides.

High resolution HAADF images recorded for the Li2TiS3 end-member reveal that lithium and titanium are fully ordered within the [Li1/3Ti2/3]S2 slabs of the typical honeycomb lattice usually observed for Li-rich layered oxides. Nevertheless, stacking faults are observed along the hexagonal C axis. In the Li[LitTi1-t]S2, (0.08 < t ≤ 0.33) solid solution the honeycomb ordering is observed only in some domains thank to the departure from the ideal ratio required for the ordering.

The electrochemical studies shows that up to 1.1 Li per Li[LitTi1-t]S2 can be reversibly cycled with a negligible irreversibility. The high capacity (≈240 mAh/g) and the shape of the charge curves suggest that Ti3+ ions are oxidized in a first step and the S2- ions in a second step to form S2
2- ions. The very small irreversibility results from the easy oxidation of S2- ions, which does not induce any sulfur release from the particle surface and subsequent structural densification. The XPS study of the deintercalated material confirms the formation of S2
2- species.

Contrary to oxides, there is a very small fading and voltage decay upon cycling. This behavior suggests that there is no significant structure modification as it is observed in lithium-rich oxides. In a particular composition range, they exhibit high electrochemical performance with a reversible capacity and an energy density exceeding respectively 265 mAh·g-1 and 600 Wh·kg-1, a very low irreversible capacity in the first cycle, fast activation and a limited voltage decay.

Their operation potential within the electrochemical stability window of sulfide-based fast ionic conductors makes them promising cathode materials for all-solid-state lithium and Li-ion batteries.
(Invited) Deep Analysis of Lithium Metal Anodes for Rechargeable Batteries
Authors: Bouchard P , Guerfi A , Chisu K , Cho M , Trudeau M , Zaghib K
Published: May 2020

The commercial use of lithium metal batteries was delayed because of dendrite formation on the surface of the lithium electrode, and the difficulty finding a suitable electrolyte that has both the mechanical strength and ionic conductivity required for solid electrolytes. Recently, strategies have developed to overcome these difficulties, so that these batteries are currently an option for different applications, including electric cars. Deep analysis of lithium metal by XPS, In situ SEM, SEM, TEM and Raman spectroscopy will be showed. In this work, we review these strategies, and discuss the different routes that are promising for progress in the near future.
Improving the Efficient of Porphyrin-Based Organic Solar Cell
Authors: Cuesta Virginia , de la Cruz Pilar , Sharma Ganesh , Langa Fernando
Published: May 2020

The optical and electrochemical properties of porphyrins can be tailored by changing the central metal and functionalization of the periphery, being excellent candidates as donors for Organic Solar Cells (OSCs). In the early years, the PCE values of OSCs based on porphyrins were very low, but by structural modifications, we achieve efficiencies in the range of 9-10%. In this presentation, I´ll show our recent work in design, synthesis and application of A−π−D−π−A and D−π−A−π−D porphyrin-based small molecules for efficient OSCs (»10%).

Figure 1. A−π−D−π−A and D−π−A−π−D porphyrin-based small molecules

References

1. 1. V. Cuesta, M. Vartanian, P. d. l. Cruz, R. Singhal, G. D. Sharma and F. Langa, J. Mater. Chem. A, 2017,
5, 1057-1065.

2. S. Arrechea, A. Aljarilla, P. de la Cruz, M. K. Singh, G. D. Sharma, F. Langa. J. Mater. Chem. C,
2017, 5, 4742.

3. 5. M. Vartanian, R. Singhal, P. de la Cruz, S. Biswas, G. D. Sharma and F. Langa, ACS Appl. Energy Mater.
2018, 1, 1304.

4. 6. M. Vartanian, P. de la Cruz, F. Langa, S. Biswas, G. D. Sharma. Nanoscale,
2018, 10, 12100-12018.

5. M. Vartanian, R. Singhal, P. de la Cruz, G. D. Sharma, F. Langa, Chem. Commun, 2018, 54,14144-14147.

6. V. Cuesta, R. Singhal, P. de la Cruz, G. D. Sharma, F. Langa, ACS Mater. Interfaces, 2019, 11, 7216-7225.

Figure 1
Acroleylcorroles
Authors: Paolesse Roberto , Caroleo Fabrizio , Di Zazzo Lorena , Nardis Sara , Petrella Greta , Cicero Daniel Oscar
Published: May 2020

Corrole continues to attract the interest of different research groups, since this macrocycle shows peculiar and intriguing characteristics, which open its application in different fields.

For this reason, the functionalization of the corrole is a fundamental step for the optimization of the macrocycle features for the target application.

We have been interested in the introduction at the peripheral positions of the corrole ring of acroleyl groups by Vilsmeier reaction, because they can allow the preparation of hybrid materials by grafting the corrole derivative onto poly-acrolein microballs. These hybrid materials have been successfully exploited to develop chemical sensors.

The regioselectivity of the Vilsmeier reaction strongly depends on the corrole structure and in the case of the free base the macrocyclic inner core showed an unexpected reactivity.

The characterization of these species, together the applications of the functionalized corroles will be presented and discussed.
Host-Guest Chemistry of Porphyrins in Liquid Crystalline Macrocycles
Authors: Tanaka Kentaro
Published: May 2020

Structurally well-defined macrocyclic molecules have great potential to accommodate specific guest molecules in the hollow. Recently, we have reported a series of macrocycles which are composed of four carbazoles connected with four salphen ligands1, four dibenzothiophenes connected with four salen ligands2, or four diindrocarbazoles connected with four salphen ligands3 (MC1, MC2 and MC3, respectively). The macrocycles with appropriate peripheral alkyl chains and their tetranuclear metal complexes with square planar metal ions showed thermotropic columnar liquid crystalline properties1,2. These macrocycles stacked to form columns inside the fluid materials. Especially, the giant macrocycle MC3 contained a square hollow with a diagonal of 2.5 nm. This giant macrocycle has the largest inner cavity among known discrete shape-persistent macrocycles that exhibit thermotropic LC properties. The size and shape of the hollow structure make it interesting for molecular inclusion applications. For example, MC3 molecule can accommodate a tetrapyridylporphyrin inside the hollow to afford a planar conjugate, and the conjugate showed liquid crystalline behavior.

Reference:

[1] S. Kawano, Y. Ishida, and K. Tanaka, J. Am. Chem. Soc.
2015, 137, 2295.

[2] Kawano, S.; Hamazaki, T.; Suzuki, A.; Kurahashi, K.; Tanaka, K. Chem. Eur. J.
2016, 22, 15674-15683.

[3] Kawano, S.; Kato, M.; Somiya, S.; Nakayama, M.; Onoe, J.; Tanaka, K. Angew. Chem. Int. Ed.
2018, 57, 167–171.

Figure 1
Quadrupolar Cyclopenta[Hi]Aceanthrylene-Based Electron Donor-Acceptor-Donor Conjugates: Charge Transfer Versuscharge Separation
Authors: Guldi Dirk M.
Published: May 2020

Cyclopenta[hi]aceanthrylene (CPA) has been functionalized at two of its positions with electronically-inert trimethylsilylethynyl (1), as well as electron donating 4-ethynyl-N,N-dimethylaniline (2), ethynyl Zn(II)phthalocyanine (3), and ethynyl Zn(II)porphyrin (4) units. Consistent with X-ray crystal structures of 2 and 4, analyses of absorption and fluorescence of 2-4 prompt to strong electronic communication between CPA and the peripheral units, affording quadrupolar electron donor-acceptor-donor charge transfer conjugates. By virtue of their quadrupolar/dipolar charge transfer characters in the excited state, 2-4 exhibit fluorosolvatochromism. Transient absorption spectroscopy confirmed delocalized quadrupolar ground states and formation of weakly solvent stabilized quadrupolar singlet excited states. The latter transform into strongly stabilized dipolar excited states before deactivating to the ground state in 2 and give rise to a fully charge separated state in 3 and 4.
Positively and Negatively Charged Porphyrin Metal Complexes That Form Ion-Pairing Assemblies
Authors: Maeda Hiromitsu
Published: May 2020

An ordered arrangement of π-electronic species is crucial for the fabrication of functional organic materials such as organic electronic devices including field-effect transistors, light-emitting diodes, and photovoltaic cells. Synergetic uses of electrostatic interactions and other noncovalent interactions, including π–π stacking, is very important for the alignment of π-electronic charged species (cations and anions) and the formation of dimension-controlled assemblies including fiber and sheet solid materials, supramolecular gels, and liquid crystals.[1,2] An advantage of using electrostatic interactions is the formation of various ion-pairing materials by combining constituent π-electronic ions: for example, ten kinds of cations and ten kinds of anions are mixed to ideally provide one hundred kinds of ion pairs. Furthermore, assembling modes can be modulated by constituent ions as well as by the environment, thus exhibiting particular properties according to the arrangement of charged building units even in an ion pair. In this study, porphyrin–AuIII complexes were found to act as π-electronic cations which can combine with various counteranions, including π-electronic anions such as negatively charged porphyrin metal complexes. In the solid-state and soft materials, the formation of assemblies with contributions of charge-by-charge and charge-segregated assemblies, whose ionic components were highly organized by π–π stacking and electrostatic interactions, depended on the geometries and electronic states of constituent ionic species.[3,4]

References

1. Reviews: a) Haketa, Y.; Maeda, H. Bull. Chem. Soc. Jpn.
2018, 91, 420; b) Haketa, Y.; Urakawa, K.; Maeda, H. to be submitted.

2. Recent examples: a) Maeda, H.; Takeda, Y.; Haketa, Y.; Morimoto, Y.; Yasuda, N. Chem. Eur. J.
2018, 24, 8910; b) Maeda, H.; Okubo, T.; Haketa, Y.; Yasuda, N. Chem. Eur. J.
2018, 24, 16176; c) Yamakado, R.; Ishibashi, H.; Motoyoshi, Y.; Yasuda, N.; Maeda, H. Chem. Commun.
2019, 55, 326; d) Yamakado, R.; Haketa, Y.; Hara, M.; Nagano, S.; Seki, T.; Maeda, H. Chem. Commun. Chem. Commun.
2019, 55, 10269.

3. a) Haketa, H.; Bando, Y.; Sasano, Y.; Tanaka, H.; Yasuda, N.; Hisaki,I.; Maeda, H. iScience
2019, 14, 241; b) Tanaka, H.; Haketa, Y.; Yasuda, N.; Maeda, H. Chem. Asian J.
2019, 14, 2129; c) Tanaka, H.; Haketa, Y.; Bando, Y.; Yamakado, R.; Yasuda, N.; Maeda, H. to be submitted.

4. Assemblies of anionic porphyrins: Sasano, Y.; Haketa, Y.; Tanaka, H.; Yasuda, N.; Maeda, H. Chem. Eur. J.
2019, 25, 6712.
Pyrolysis of Self-Assembled Metalloporphyrins Toward ORR and/or CO2RR
Authors: Song Yujiang
Published: May 2020

Oxygen reduction reaction (ORR) and carbon dioxide reduction reaction (CO2RR) are of particular interest for energy conversion and storage and have drawn a lot of recent attentions. It is obvious that efficient electrocatalysts are highly needed to selectively accelerate the ORR and CO2RR at a low overpotential. Metalloporphyrins and the derivatives represent an important type of non-precious metal electrocatalysts (NPMEs). Herein, we introduce the synthesis of several types of metalloporphyrin-based NPMEs by pyrolysis of self-assembled porphyrins in the presence or absence of carbon supports. As-prepared NPMEs with core-shell structure or flower-like structure exhibit excellent performance toward ORR and CO2RR. This study shows that porphyrin-based materials may play an import role in the field of clean and renewable energy.

Keywords: oxygen reduction reaction, CO2 reduction reaction, metalloporphyrins, self-assembly, pyrolysis

References:

[1] Li, J.; Song, Y. J.; et al.
Adv.Funct. Mater. 2017, 27: 1604356.

[2] Cong, Y. Y.; Song, Y. J.; et al.
Nano Energy 2018, 44: 288.

[3] Zhang, X.; Song, Y. J.; et al. Chem. Commun. 2019, 55:5659.

[4] Xie, Y.; Song, Y. J.; et al. ACS Appl. Mater. Interfaces 2019, 11: 34203.

[5] Li, J.; Song, Y. J.; et al. J. Catal. 2019, 378: 113.
Application of Saddle-Distorted Porphyrins to Dioxygen Reduction
Authors: Kojima Takahiko
Published: May 2020

Efficient and selective dioxygen (O2) reduction is an important process in biological dioxygen activation and also in fuel cells to gain a chemical potential. So far, O2 activation has been achieved using transition-metal complexes as observed in that by metalloenzymes such as cytochrome P-450. However, organic molecules have scarcely used for O2 reduction probably due to instability during redox reactions under oxic conditions. We report herein the utilization of diprotonated and saddle-distorted porphyrins for photocatalytic O2 reduction and unprecedented interconversion between O2 and H2O2.

The photocatalytic O2 reduction was performed using diprotonated dodecaphenylporphyrin (H4DPP2+) as a photocatalyst, 10-methyl-9,10-dihydroacridine (AcrH2) as a two-electron donor in CH3CN in the presence of CH2ClCOOH as a proton source.1 Under photoirradiation at 480 nm, H2O2 was produced in turnover number of > 3000 and turnover frequency of 500 h–1 in the yield of 99% and the quantum yield of 12%. The efficiency is the highest among porphyrin photocatalysts reported so far. This is due to a low energy level of the triplet excited state of H4DPP2+ to avoid energy transfer to 3O2 for the formation of 1O2.

On the other hand, an N22, N23-dimethylated H2DPP derivative (Me2Por) reacted with excess H2O2 to afford the corresponding isophlorin derivative (Me2IPh) and O2.2 The isophlorin derivative conversely reacted with O2 to form the dimethylated porphyrin and H2O2. This reversibility has been gained due to a small Gibbs free energy difference between the two states, Me2Por + H2O2 and Me2IPh + O2, and minimizing activation energy of the reaction. The hydrogen-bond formation, which is facilitated by the saddle distortion of the porphyrin to fix the direction of protons or lone pairs of the pyrroles, between Me2Por and H2O2 and between Me2IPh and O2 plays indispensable roles in each process to promote proton-coupled electron transfer. The interconversion can be repeated by converting the atmosphere between O2 and Ar at least 11 times without losing activity due to the robustness of the dimethylated porphyrin.

References

1. Aoki, W. Suzuki, H. Kotani, T. Ishizuka, H. Sakai, T. Hasobe, T. Kojima, Chem. Commun.
2019, 55, 4925.

2. W. Suzuki, H. Kotani, T. Ishizuka, T. Kojima, J. Am. Chem. Soc.
2019, 141, 5987.
Sensing and Catalytic Properties of Oxoporphyrinogens
Authors: Hill Jonathan P. , Chahal Mandeep Kaur , Payne Daniel , Labuta Jan , Matsushita Yoshitaka , Ariga Katsuhiko , Karr Paul , D'Souza Francis
Published: May 2020

Simple oxoporphyrinogen (OxP) derivatives are excellent colorimetric sensors for a variety of analytes including anions, acidity and enantiomeric excess. More recently, this family of compounds has grown to include rim-functionalized compounds, which also exhibit colorimetric properties. In this work, we have prepared differently rim-functionalized OxPs and we will present their properties with respect to sensing, including selective anion binding, ion pair sensing and coupled sensing of other important polluting species. The sensing properties of OxPs rely on intermolecular hydrogen bonding interactions which, in turn, imply their possible applications in organocatalysis. These properties will be described with an emphasis on the identity of macrocyclic substituents, and how catalytic activity of the OxP macrocycles is established. Structural aspects of OxPs influencing their sensing and organocatalytic activities will be discussed.
Investigation By NMR Spectroscopy of the Structural Characteristics of Modified Oligo-Nucleotides with Pendant Porphyrins
Authors: Solladie Nathalie
Published: May 2020

Exerting control over the position and distance of the porphyrins along a specifically designed oligonucleotidic scaffold was our main goal over the past years. Indeed, in naturally occurring light-harvesting complexes, biopolymer scaffolds hold pigments at intermolecular distances that optimize photon capture, electronic coupling, and energy transfer. We thus focused on the synthesis of four uridine-porphyrin conjugates (a monomer, dimer, tetramer and octamer) dedicated to adopt a pre-organized conformation with face-to-face porphyrins, and capable to self-organize in a stable sandwich type complexe with bidentate base such as DABCO. Using a similar strategy as the one used in antisense research, an artificial nucleotidic backbone was built from modified deoxy-uridine units linked with a more rigid linker than the phosphodiester moieties found in natural oligonucleotides. Antisense research uses modified oligonucleotides, less flexible than natural strands, to pre-organize the system toward the obtaining of stable double helices between synthesized and natural oligonucleotides. A modified oligonucleotidic backbone was here used to target a parallel conformation of the porphyrins appended to each deoxy-uridine moiety. To provide a rigid environment for the porphyrins, the uridine units were coupled in 3’-5’ stepwise fashion using ether-ester type of spacer of suitable length, and porphyrins were anchored to the uridine by means of robust carbon-carbon bonds.

To investigate the conformation of our four uridine-porphyrin conjugates, they were subjected to a comprehensive conformational analysis by using NMR spectroscopy. The collected NOE NMR data highlighted characteristic and strong interactions indicating that the glycosidic angle between the ribose and uracil base is anti. In order to further invastigate the conformation of this family of molecules, NMR experiments were carried out at variable temperature. At low temperature, the signals of the porphyrinic protons decoalesce showing two sets of b-pyrrolic protons. Similar observations are made for the signals corresponding to the sugar moieties and especially the H1’ protons, indicating molecular motions within our porphyrin-uridin arrays. These results testify in favor of the existence of a dynamic process between C3’-endo and C2’-endo conformations.

We thus document the fact that the choice of rigid spacers is not the only way to pre-organize bis-porphyrins, and that some well-chosen nucleosidic linkers offer an interesting option for the synthesis of such devices. Furthermore, the chirality and enantio-purity of the nucleosidic linkers paves the way toward the selective complexation of enantio-pure bidentate guests and the resolution of racemates.

Acknowledgements

This work was supported by the CNRS and the French Ministry of Research.

References

1. Merkas, M. Zinic, R. Rein, N. Solladié, J. Porphyrins Phthalocyanines
2019, 23, 797-812.

Figure 1
Phthalocyanines for Photodynamic Therapy
Authors: Dominguez Ana Belen , Fonseca Alba , Rahali Asma , Almeida Veronica , Revuelta Miguel Angel , de la Escosura Andres , Rodriguez-Morgade M. Salome , de la Torre Gema , Duran Gonzalo , Garcia-Iglesias Miguel , Torres Tomas
Published: May 2020

Photodynamic therapy combines light, molecular oxygen and a PS for the production of reactive oxygen species (ROS), such as singlet oxygen (1O2) and free radicals, leading to oxidative stress and eventual cell death. Phthalocyanines (Pcs) fulfil many of the requirements to be applied as photosensitizers for singlet oxygen generation.1,2 However, a major drawback of these compounds is their low solubility in physiological media. Functionalization of the macrocycle at the peripheral and/or axial positions with appropriate hydrophilic functions provides compounds with an enhanced solubility in water. In this respect, several strategies have been adopted to increase the hydrophilicity of Pcs and make them more bio-compatible, like their functionalization with charged groups,3 aminoacids4 or carbohydrates.5 The introduction of such entities at Pc axial positions reduces the aggregation of the macrocycles in solution, thus improving their 1O2 generation efficiency. For recent work of our group, see reference 1 and articles cited therein.

1Almeida-Marrero V, van de Winckel E, Anaya-Plaza E, Torres T and de la Escosura A. Chem. Soc. Rev., 2018; 47: 7369-7400. 2Dąbrowski JM, Pucelik B, Regiel-Futyra A, Brindell M, Kyzioł A, Stochel G, Macyk W and Arnaut LG. Coord. Chem. Rev., 2016; 325: 67-101. 3Setaro F, Ruiz-González R, Nonell S, Hahn U and Torres T. J. Inorg.
Biochem., 2014; 136: 170-176. 4Chen Z, Zhou S, Chen J, Deng Y, Luo Z, Chen H, Hamblin MR, and Huang M. ChemMedChem, 2010; 5: 890-898. 5Alvarez-Mico X, Calvete MJF, Hanack M, Ziegler T. Tetrahedron Lett., 2006; 47: 3283-3286.
(Invited) New Electrode and Electrolyte Approaches for Rechargeable Li-S Battery
Authors: Liu Gao
Published: May 2020

A strong demand for low-cost and high-energy-density rechargeable batteries has spurred lithium-sulfur (Li-S) rechargeable battery research. First, sulfur is an abundant and low-cost material. Second, the Gibbs energy of the lithium (Li) and sulfur reaction is approximately 2,600 Wh/kg, assuming the complete reaction of Li with sulfur to form Li2S, more than five times the theoretical energy of transition metal oxide cathode materials and graphite coupling. With these advantages, Li-S batteries could be both high energy density and low cost, satisfying demand in energy storage for transportation application. The major obstacle is the loss of sulfur cathode material as a result of polysulfide dissolution into common electrolytes, which causes a shuttle effect and significant capacity fade. The polysulfide shuttle effect leads to poor sulfur utilization and fast-capacity fade, which have hindered widespread use of rechargeable Li-S batteries. Here, we present a body of work on both electrode materials design and synthesis, electrode fabrication and novel electrolyte materials for Li-S rechargeable batteries. We report the development of new electrode materials, electrolytes and additives for Li-S battery. The properties of the combined electrode and electrolyte stabilized polysulfides, and promoting the polysulfide affiliation with the electrode substrate to prevent polysulfide dissolution.
(Invited) Thermal Safety Aspects of Li-Metal Batteries
Authors: Puthusseri Dhanya , Manikandan P. , Pol Vilas G.
Published: May 2020

For last three decades, Li-ion batteries are the energy storage device of choice; however, the limited theoretical capacity hampers its wide adaption in many applications. Li metal batteries (LMBs) encompassing a lithium metal anodes with sulfur/layered oxide-based cathode material (Li-S and Li-NMC532) provide a sustainable possibility to improve energy/power density. However, thermal safety and overall stability issues continues to hinder its use in practical applications. In spite of the significant effort to alleviate the cycle life of LMBs, the thermal safety aspects of these systems remain unknown, therefore could lead to thermal runaway under extreme conditions. This talk will provide an understanding of the thermal stability of LMBs from materials level to cell level. The amount of exothermic heat generated for Li-NMC (2.9 KJ/g) and Li-S (188 J/g) from the coin cell DSC analysis shows amplified safety risk in Li-NMC532 batteries.
(Invited) Stabilization of High Capacity Anodes for High-Energy-Density Batteries
Authors: Wang Donghai
Published: May 2020

Li metal and Li-alloy based anode materials are the most promising anodes for next-generation Li batteries. The poor interfacial stability of the anode materials during electrochemical cycling has been the primary issues hindering their practical application. In this talk, I will present a strategy to reinforce the SEI on Li metal by employment of a polymer composite with desired properties including good tolerance to the Li-based material volume change and efficient surface passivation against electrolyte penetration. The strategy works via introducing multiple functional components into the polymer composite which can bond to the Li-based material surface to participate in the formation of the SEI. The reinforced SEI shows much better stability than the SEI generated by electrolyte additive strategy. The approach can be also extended to Si based anodes to similarly improve interface stability and thus cycling stability. Second, I will present an approach of structured host for Li metal to promoting uniform Li plating/stripping at high deposition capacity and current density. This approach uses a polymeric sponge to promote electrokinetic effects so as to alter Li-ion transport properties and reduce concentration polarization for Li plating/striping. High efficiency cycling of Li metal was achieved and demonstrated in Li metal battery cells at low N/P ratio and high deposition capacity and current densities.
The Bonding Nature and Adhesion of Li and Polyacrylic Acid (PAA) Coating for Li Dendrite Prevention
Authors: Yang Chi-Ta , Lin Yu-Xiao , Qi Yue
Published: May 2020

Vehicle electrification requires lithium ion batteries (LIB) with higher energy density to make possible the extended driving range at a lower cost. One promising approach is to adopt the lithium metal as the anode due to its ultrahigh capacity and lowest reduction potential; however, Li dendrite growth is an inevitable bottleneck that can lead to capacity loss and short circuit. It is recently shown that Li polyacrylic acid (Li-PAA) polymer as a passivation layer can exhibit high elasticity, high binding, and excellent stability to mitigate the Li dendrite growth during Li plating/stripping processes. However, the experimental limitation to the measurement of the interfacial adhesion of the interface of Li metal and PAA polymer, Li/PAA(polymer), and other polymer-based passivation layers has retarded the coating design. The uncertainty of the PAA structures (crystalline, semicrystalline, or amorphous) due to varied polymer preparation techniques and post-preparation conditions also limits direct calculation of the work of adhesion/separation using density functional theory (DFT) calculations. In this work, from atomistic understandings of the bonding nature at the Li/PAA interface, we have proposed a strategy to quantify the interfacial adhesion (work of separation) of the Li/PAA(polymer) based on simpler Li/PAA(oligomer) interfaces using DFT calculations. A total of fifteen interfaces of Li/PAA(tetramers), Li/PAA(hexamers), and Li/PAA(nanomers) were studied. It was found that the delamination of Li/PAA(oligomer) interfaces is affected by: a) the O atoms in PAA bonding with multiple surface Li atoms, b) the chemical reactions, including H incorporation into the Li substrate and surface LiOH from COOH reacting with Li surface, leading to the enhanced ionic Li-O bonding, and c) the interactions of ionized Li (incorporated into the PAA oligomers) with the surrounding metallic Li atoms on the surface. The characteristic interfacial bonding energy is then obtained based on the most likely delamination configuration and by fitting the corresponding work of separation using two approaches: as a function of the number of bonding O and as a function of the number of LiO bonds and ionized Li atoms. The areal density associated with the interfacial bonding is obtained from the practical PAA density and statics of the DFT results as well. The interfacial adhesion of Li/PAA(polymer) is quantified to be 0.97 J/m2, and is found to be comparable to that of Li/Li2O interface and much larger than Li/LiF and Li/Li2CO3 interfaces. We attribute the high interface adhesion of Li/PAA(polymer) to the high density of open O atoms of PAA, allowing more Li-O bonds across the Li/PAA interface. This study provides a strategy to estimate the adhesion of artificial polymer-based passivation layers on Li metal, which is expected to contribute to the development of polymer-based coatings for the Li dendrite growth mitigation in LIBs.
Wirelessly Rechargeable Printed Solid-State Supercapacitors for Continuous Operation of Smart Contact Lenses
Authors: Ahn David Byungsun , Park Jihun , Kim Joohee , Cha Eunkyung , Bae Byeong-Soo , Park Jang-Ung , Lee Sang-Young
Published: May 2020

Recent advances in smart contact lenses are essential to the realization of medical applications and vision imaging for augmented reality through wireless communication systems. However, previous research on smart contact lens has been driven by external electrical wired systems or wireless power transfer with temporal and spatial restrictions, which can limit their continuous use. Therefore, an essential prerequisite for electronic smart contact lenses is their monolithic integration with energy storage devices. However, conventional rigid, large sized, and fixed-shaped energy storage devices are not suitable for the soft, smart contact lens. Here, we demonstrate a new class of wirelessly-rechargeable solid-state supercapacitors directly printed on smart contact lenses. Supercapacitors are known to exhibit long cycle lives and high-power density, which are suitable for consistent fast wireless charging and discharging for operating the electronic devices in the smart contact lens. The arc-shaped form factor and limited area of the printed supercapacitor require a high-precision microscale direct ink writing (DIW) process and tailored component inks. The printed solid-state supercapacitor integrated smart contact lens show great potential as an effective/scalable platform for wearable electronics with continuous operation.
Lithium Carbonate as a Corrosion Inhibitor for Mg Alloy Sheet Metal Product
Authors: Kish Joseph , Zaghloul Basem , Glover Carol , Scully John R.
Published: May 2020

Reducing the overall mass of transportation vehicles by the use of strong lightweight materials is arguably the best enabling means to improve fuels efficiency and, thus reduce harmful emissions. Wrought Mg alloys with high specific strength, stiffness and warm formability (ZE alloys) provide enabling opportunities as an integral part of lightweight multi-material structural assemblies to achieve this goal. One key technical issue preventing widespread implementation of Mg alloy components is the high rate of dissolution (corrosion) in aqueous environments. This is driven in large part by the inherent reactivity of Mg (lowest standard reduction potential among industrial engineering metals), the high rate of the hydrogen evolution reaction that dominates the cathodic process and the tendency of the native oxide surface film to breakdown and be replaced with a significantly thicker and much less protective corrosion product film. Dissolved Li2CO3 (aq) is being evaluated as an effective corrosion inhibitor for bare Mg alloy sheet metal product (AZ31B and ZEK100) when immersed in 0.1 M NaCl (aq) as a precursor to the development of a conversion coating technology. The extent of corrosion protection is being determined at various Li2CO3 levels (mM) by making volumetric H2 gas evolution and mass loss measurements as a function of immersion time. Complementary potentiodynamic polarization measurements are being conducted to determine the manner in which dissolved Li2CO3 (aq) affects the global anodic and/or cathodic processes that control corrosion. SVP measurements are being made to resolve and track changes in the localized filament corrosion and associated cathodic activation resulting from effective inhibition of dissolved Li2CO3 (aq). Both surface analysis by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) examination of FIB-prepared cross-sections are being utilized to determine the film chemistry and local fine-scale structure involved in the filament corrosion and associated cathodic activation if and when it develops with time. A similar set of measurements is being made with Li(OH)2 (aq) additions (at equivalent pHs) to determine the specific role of Li+ (aq) and CO3
2− (aq) ions in providing improved corrosion control. This paper presents and discusses the results within the context of developing a self-healing conversion coating layer for inclusion in automotive paint schemes.
Embedded Ocv Based Model for State of Health Monitoring in a BMS
Authors: Radhakrishnan Karthik Narayanan , Prosser Ryan , Patel Yatish , Offer Gregory James
Published: May 2020

Lithium ion batteries degrades with time. Battery diagnostics links observable changes in cell parameters to changes that have occurred inside the cell. More accurate diagnosis means a better insight into these internal changes which can aid in predicting failure modes, remaining life, aide in optimising future use.

In the case of electric vehicles, an on-board battery management system (BMS) could implement these diagnostic techniques to give real time information on the internal state of the pack. It can then dynamically adjust parameters such as state of charge (SOC) window, maximum power and maximum allowable temperature to optimise performance and pack longevity.

Models capable of predicting Li-ion battery health with higher accuracy are highly advanced, and computationally exhaustive requiring complex physics-based models or equivalent circuit models (ECM) that require exhaustive parameter fitting. Other techniques require measurements or hardware which are not available in typical applications and so are only suited to lab-based diagnostics.

Current diagnostic techniques are not suitable for in-situ applications; either the BMS does not have the computational capacity to run the models, or the measurements required are not available outside a laboratory environment. In this work, we propose an Open Circuit Voltage (OCV) based model that predicts the degradation of a cell accurately without needing extensive computational capacity.

This model has been embedded in a microcontroller with limited computing power which could form part of the BMS system that better predicts the state of health of the cell. The model uses the open circuit potentials of each electrode and fits them to the full cell voltage in order to identify the degradation modes. Typical modes include Loss of Lithium (LLI) and Loss of Active Material from either electrode (LAM).

The model does not require the solving of concurrent complex equations or the fitting of extensive parameters to an equivalent circuit whilst still being able to provide accurate insight into the cell’s internal changes.

Results from this work demonstrate the usefulness of such a system in electric vehicle and paves the way for implementation of smarter BMS in electric vehicles by manufacturers. This unlocks the potential to predict and increase the longevity of a battery pack whilst still providing optimal performance to the vehicle.