bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low-Cost Alternatives to Pedot:PSS As Conducting Binders
Authors: Kuss Christian 
Published: February 2020

Pedot:PSS is a molecular level composite material of conjugated polymer (Pedot) and anionic polyelectrolyte, or polyanion (PSS). It is popular in organic electronics and as transparent conductor, because it is water dispersible, conductive and film-forming upon drying. For the same reasons, Pedot:PSS has previously been suggested as binder in lithium-ion batteries. However, its high cost is prohibitive for routine battery applications. This presentation discusses our exploration of chemically similar, but lower-cost molecular polymer composites of conjugated polymers and polyanions, to be used as lithium- and sodium-ion battery binders. Within these composites, the conjugated polymer serves to deliver electronic conductivity, whereas the polyanion allows dispersion of the composite, and provides strong adhesion to battery particles. We perform the oxidative polymerization in the presence of the polyanion, at which the polyanion backbone serves as polymerization template. In this way, the latter becomes a permanently intertwined polymeric dopant within the conjugated polymer.
We are presenting data on the electrochemical stability of these binders within typical battery environments and the dependence of electronic conductivity on composition and synthesis methods. Moreover, composite battery electrodes have been fabricated and electrode micro-structure and cycling performance data are presented. Examples are selected based on low-cost polymers of Pyrrole and Aniline, combined with non-traditional polyanion binders, such as Carboxymethyl Cellulose and Alginate.
The target of this work is to improve cycling performance of high-capacity, high-volume-change intercalation materials. In traditional composite lithium and sodium intercalation electrodes, such intercalation materials exhibit very little adhesive strength with the typical carbon conductive additive. By combining the adhesive and conductive additive within a single molecular composite binder, the conductor adheres directly to the intercalation material, accommodating volume changes more easily and improving lifetime of high capacity materials.
Insights into Electrolyte Decomposition Phenomena Utilizing Solid Phase Microextraction - Gas Chromatography - Mass Spectrometry in Combination with an in Situ Lithium Ion Cell
Authors: Horsthemke Fabian , Winkler Volker , Friesen Alex , Winter Martin , Nowak Sascha 
Published: February 2020

In the last decades, the interest in lithium ion battery (LIB) technology has been rising steadily and thereby the system became an important field for scientific research. Numerous techniques for post mortem analysis of battery materials have been reported in literature - ranging from surface investigation e.g. scanning electron microscopy (SEM) to the analysis of the emerging passivation layers or the investigation of the liquid electrolytes. The analysis of the LIB electrolytes is of special interest due to their instability at typical electrode potentials. Thereby the aging phenomena in the electrolyte, which is in contact with all parts of the LIB, are a good indicator for the cell status. However, the state-of-the-art sample preparation for electrolyte analysis requires the mechanical opening of the cell and subsequent electrolyte extraction.[1] Thus, the cells are destroyed during the sample preparation and it is not possible to achieve data for multiple different states-of-health (SOHs) of one specific cell. The gas chromatography - mass spectrometry (GC-MS) provides the option to analyze the gases above a heated sample making the typically applied carbonate solvents accessible. However, the sample heating is not compatible with the commonly applied conducting salt (LiPF6) and thereby introducing additional aging phenomena. Therefore, an automated sample pretreatment was considered, which was developed in the work group of Pawliszyn.[2] The Solid phase microextraction (SPME) in combination with GC-MS provides several benefits with regard to the LIB environment - namely the headspace sampling option, the preconcentration of volatile organic compounds at room temperature and the small amount of removed sample.[3]
This work reports on the development of a round cell (18650 format) for in situ investigations of the electrolyte. Proof of principle experiments have been executed with different setups relying on passive diffusion or utilizing a peristaltic pump for enhanced analyte uptake. Emerging decomposition products and consumed film forming additives have been analyzed at different SOHs. The cell response to the sampling procedure was investigated by C-rate tests, which did not show significant changes. Furthermore, the cell setup provides the possibility to investigate the electrolyte during charge / discharge operation, which might prove or disprove assumed changes in the electrolytes during cell operation.
[1] Mönnighoff, X. et al., Journal of Power Sources
2017,
352, 56-63.
[2] C. L. Arthur and J. Pawliszyn, Analytical Chemistry, 1990, 62, 2145-2148.
[3] Horsthemke, F. et al., RSC Advances
2017,
7 (74), 46989-46998.
Symmetric Cell Study of Ferri/Ferrocyanide Stability As a Flow Battery Active Material
Authors: Fell Eric M. , De Porcellinis Diana , Wong Andrew A. , Goulet Marc-Antoni , Aziz Michael J. 
Published: February 2020

The attraction of aqueous organic redox flow batteries (AORFBs) lies in the potential for low mass-production cost and long lifetime of the organic reactants. To reach a cell potential greater than 1.0 V, several AORFBs have employed the ferri/ferrocyanide redox couple as a positive electrolyte (posolyte) in an alkaline full cell. Recent works [1,2] have reported significant amounts of capacity fade of this redox couple at high pH, attributed to an apparent chemical decomposition associated with cyanide ligand dissociation and subsequent irreversible hydroxylation of the iron complex.
An in-depth analysis of the chemical and electrochemical stability of ferri/ferrocyanide is performed utilizing a volumetrically unbalanced, compositionally-symmetric cell method [3]. The dependence on pH of the apparent interaction of carbonaceous electrodes with active species will be reported, and keys to suppressing electrolyte degradation will be discussed. The accuracy of electrochemical techniques (e.g. high-precision coulometry) and chemical characterization (e.g. NMR, UV-vis) to understand ferri/ferrocyanide degradation will also be compared. Collectively, these results will highlight opportunities for improving energy storage systems.
[1] J. Luo, A. Sam, B. Hu, C. DeBruler, X. Wei, W. Wang, and T.L. Liu, “Unraveling pH dependent cycling stability of ferricyanide/ferrocyanide in redox flow batteries”, Nano Energy
42, 215 (2017).
[2] J. Luo, B. Hu, C. Debruler, Y. Bi, Y. Zhao, B. Yuan, M. Hu, W. Wu, and T.L. Liu, “Unprecedented Capacity and Stability of Ammonium Ferrocyanide Catholyte in pH Neutral Aqueous Redox Flow Batteries”, Joule, in press (2018).
[3] M-A. Goulet, M.J. Aziz, “Flow Battery Molecular Reactant Stability Determined by Symmetric Cell Cycling Methods”, Journal of the Electrochemical Society
165, A1466 (2018).
Understanding Electrocatalytic Pathways in Complex Organic and Inorganic Composites in Aqueous and Non Aqueous Environments
Authors: Mukerjee Sanjeev , Jia Qingying 
Published: February 2020

There are very few techniques that lend themselves to rigorous requirements, where the individual role of different transition metal components of nano-phasic materials can be investigated in both amorphous and crystalline forms. We have validated a new analytical technique along with theoretical calculations, which enables the amount and specific adsorption site of species such as H, OH, O, CO, other C1 moieties and even anions such as bisulfate to be determined in situ on a metal surfaces using synchrotron XANES data. This technique, commonly called the ‘Delta Mu (∆μ) Technique’ can be taken in situ in both electrochemical cells and operating fuel cells, and can be obtained from a wide variety of transition metal surfaces and alloys,[3] including non-Pt based metal electrocatalysts with element specificity. EXAFS data taken concurrently provide information on the changes in short range atomic order around the absorber atom thereby providing structural information such as bond distances and coordination numbers (thereby information on average cluster size, homogeneity and surface segregation etc.).
In this part of the presentation among other things we will show in-situ XAS study of group of (Metal-Nitrogen-Carbon) MNC catalysts from perspective of metal center. We will demonstrate the presence of ORR active bio-mimetic porphyrin-like FeNx functionalities, as well as other forms of the metal which indicate no catalytic activity. The XAS in-situ studies will be combined with electroanalytical evaluations using cyclic voltammetry (CV) and square wave voltammetry (SWV). Further the factors governing the ORR activity at MNC centers, such as the Lewis basicity of the carbon support and the accompanying changes in the redox potential of the metal center will be discussed. This part of the presentation will bring together electrochemistry and XAS spectroscopy (including ∆μ) on effect of pH (inner and outer sphere charge transfer) and aqueous vs. non-aqueous electrolyte (concerted vs. non-concerted charge transfer).
Study of Sulfur-Based Electrodes By Operando Acoustic Emission
Authors: Lemarie Quentin , Idrissi Hassane , Alloin Fannie , Maire Eric , Thivel Pierre-Xavier , Roué Lionel 
Published: February 2020

The acoustic emission (AE) technique has been widely used since the 70’s for detecting anomalies such as leakages and cracks on large structure (e.g. bridges, pressure containers, and pipe lines). The analysis of the AE signals (transient elastic waves) can also be used to characterize the degradation mechanisms (crack growth, friction, delamination, matrix cracking, corrosion, etc) of various materials subjected to a stress by mechanical, pressure or thermal means. Recently, AE technique has also been used to evaluate the degradation of metal hydride electrodes for Ni-MH [1] and Si-based electrodes for Li-ion batteries [2,3]. Cracking of the active material and gas evolution are the main sources of AE signals identified in these studies.
In the present study, the AE technique is used for studying upon cycling the mechanical degradation of S-based electrodes for Li/S batteries. The AE signals were recorded by a piezoelectric transducer fixed on the back of the working electrode. S-based electrodes made with two different binders (PVdF vs. CMC) and two different current collectors (standard Al foil vs. porous 3D carbon paper) were studied. In all cases, AE signals were mainly detected during the first plateau of the first discharge, suggesting that the electrode degradation mostly occurs during the initial dissolution of the S8 particles. AE signals were also detected during a few subsequent cycles when CMC binder is used. This is attributed to a better propagation of the AE signals through the electrode thanks to an improved adhesion of the electrode to the current collector in comparison to PVdF binder. This is confirmed by further mechanical resistance testing (peel and scratch tests). The use of a carbon paper as a current collector combined to CMC binder greatly improves the electrochemical performance of the S electrode by preventing the collapse of the electrode upon cycling. This electrode also presents an increased amount of AE signals, suggesting that the carbon fibres of the C paper act as an AE waveguide.
This study demonstrated that AE could be used as an efficient tool to monitor the morphological degradation of S-based electrodes upon their cycling and offers relevant information for optimizing their formulation and architecture.

A. Etiemble, H. Idrissi, P. Bernard, L. Roué. New insights into the pulverization of
LaNi5-based alloys with different Co contents from electrochemical acoustic emission measurements. Electrochim. Acta 186 (2015) 112-116

A. Tranchot, A. Etiemble, P-X. Thivel, H. Idrissi., L. Roué. In-situ acoustic emission study of Si-based electrodes for Li-ion batteries, J. Power Sources 279 (2015) 259-266.

A. Tranchot, P-X. Thivel, H. Idrissi, L. Roué. Influence of the Si particle size on the mechanical stability of Si-based electrodes evaluated by in-operando dilatometry and acoustic emission. J. Power Sources 330 (2016) 253-260.

Figure 1
Zinc Oxide Nanoparticles Anchored Graphitic Carbon Nanofibers: Strategies for Improving Supercapacitive Performance
Authors: Dillip G.R. , Bai Fan , Joo Sang W. 
Published: February 2020

Graphitic carbon nanofibers (CNFs) decorated with ZnO nanoparticles (NPs) were synthesized by chemical co-precipitation method. This report demonstrates an effective strategy to intrinsically improve the conductivity and supercapacitive performance of the hybrids by inducing oxygen vacancies. Oxygen deficiency-related defect analyses were performed qualitatively as well as quantitatively using Fourier transform infrared spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. All of the analyses clearly indicate an increase in oxygen deficiencies in the hybrids with an increase in the vacuum-annealing temperature. At a current density of 3 A g-1, the hybrid electrode exhibited higher energy density (119.85 Wh kg-1) and power density (19.225 kW kg-1) compared to a control ZnO electrode (48.01 Wh kg-1 and 17.687 kW kg-1). The enhanced supercapacitive performance is mainly ascribed to the good interfacial contact between CNF and ZnO, high oxygen deficiency, and fewer defects in the hybrid. Our results are expected to provide new insights into improving the electrochemical properties of various composites/hybrids.
(1) Mefford, J. T.; Hardin, W. G.; Dai, S.; Johnston, K. P.; Stevenson, K. J. Nat. Mater.
2014, 13, 726-732.
(2) G.R. Dillip, A.N. Banerjee, V.C. Anitha, B. Deva Prasad Raju, S.W. Joo, and B.K. Min, ACS Appl. Mater. Interfaces 8, 5025 (2016).
(3) G.R. Dillip, A.N. Banerjee, V.C. Anitha, S.W. Joo, B.K. Min, S.Y. Sawant, and M.H. Cho, ChemPhysChem 16, 3214 (2015).
2 V Class Aqueous Sodium-Ion Batteries with Low Temperature Cycling Capabilities
Authors: Reber David , Kühnel Ruben-Simon , Battaglia Corsin 
Published: February 2020

The inherent safety and potential cost-efficiency of rechargeable batteries based on aqueous electrolytes, led to their development as a large-scale energy storage option for grid applications enabling wide spread integration of renewables. In this field cost and safety are more important than energy density, which is why water based systems are a promising candidate. In recent reports, highly-concentrated electrolytes have been employed to extend the narrow electrochemical stability window of water (thermodynamically ~1.23 V) and stability windows beyond 3 V have been reported for lithium based systems [1]. Using 35 molal aqueous sodium bis(fluorosulfonyl)imide (NaFSI) solutions, we recently translated the concept to sodium-ion batteries and reported a stability window of 2.6 V on stainless steel current collectors [2]. However, all so called water-in-salt electrolytes reported to date suffer from crystallization at room temperature, which leads to premature cell failure.
We developed a ternary aqueous sodium-ion electrolyte based on NaFSI which is kinetically robust against crystallization and allows long term cycling at temperatures down to at least -10 °C. Addressing the raw materials supply chain as important challenge for scaling, we developed a 2 V class aqueous sodium-ion battery employing only abundant raw materials, namely NaTi2(PO4)3 [3] and Na3(VOPO4)2F [4] on the anode and cathode side, respectively. With 64 Wh kg-1, based on the active masses of both electrodes, this battery displays an energy density that is almost twice as high as that of previously reported aqueous sodium-ion batteries [5]. The cell displays excellent cycling stability at 30 °C with capacity retention of 85% after 100 cycles at C/5 and 77% after 500 cycles at 1C. At -10 °C, we obtain capacity retention of 74% after 500 cycles at C/5.
References:

Suo, L. et al. "Water-in-salt" electrolyte enables high-voltage aqueous lithium-ion chemistries. Science
350, 938 (2015).

Kühnel, R. S.; Reber, D.; Battaglia, C., A High-Voltage Aqueous Electrolyte for Sodium-Ion Batteries. ACS Energy Lett.
2, 2005 (2017).

Li, Z.; Young, D.; Xiang, K.; Carter, W. C.; Chiang, Y.-M., Towards High Power High Energy Aqueous Sodium-Ion Batteries: The NaTi2(PO4)3/Na44MnO2 System. Adv. Energy Mater.
3, 290 (2013).

Qi, Y.; Mu, L.; Zhao, J.; Hu, Y. S.; Liu, H.; Dai, S., Superior Na-Storage Performance of Low-Temperature-Synthesized Na3(VO(1-x)PO4)2F(1+2x) (0≤x≤1) Nanoparticles for Na-Ion Batteries. Chem. Int. Ed.
54, 9911 (2015).

Kumar, P. R.; Jung, Y. H.; Wang, J. E.; Kim, D. K., Na3V2O2(PO4)2F-MWCNT nanocomposites as a stable and high rate cathode for aqueous and non-aqueous sodium-ion batteries. Power Sources
324, 421 (2016).
Merging Flow and Non-Flow Batteries: K4fe(CN)6 Electrolyte – Ni(OH)2 Solid Material As Proof of Concept
Authors: Paez Teresa , Palma Jesus , Ventosa Edgar 
Published: February 2020

Ferrocyanide (FCY) based alkaline redox-flow batteries are considered promising alternatives to traditional redox-flow batteries that are based on high cost and strategic metals and corrosive acidic media. FCY has been used as active species in the positive side of a variety of redox-flow batteries, e.g. anthraquinone/FCY[1] and phenazines/FCY[2]. However, in all these cases, the energy density is limited by the low solubility of FCY in alkaline media (0.4 M equivalent to 10 AhL-1). In contrast, electroactive solid species that are frequently used in non-flow batteries are able to store more charge per unit volume than soluble electroactive species, e.g. Ni(OH)2 has a volumetric capacity of 1180 Ah·L-1 that is two orders of magnitude higher than that of a FCY solution. However, solid materials cannot be used in flow batteries as there is no electrical contact between the electrode and the solid located in the external tank.
In this talk, we will show that soluble electroactive species can be also used as molecular wiring to transport charges to high-energy solid materials confined in the external reservoir.[3] We demonstrate that by adding solid material in the reservoir, volumetric capacities of >25 AhL-1 are achieved (40% utilization rate of Ni(OH)2). We apply the concept in two types of FCY flow batteries: quinone/FCY and phenazines/FCY. For the latter, energy densities of >15 WhL-1 are demonstrated representing the highest value for an alkaline flow battery. This work open up the field for a new generation of batteries, which benefits from the advatages of flow and non-flow configurations.

References

Lin, K. et al. Alkaline quinone flow battery. Nat. Energy
349, 1–4 (2015).

Hollas, A. et al. A biomimetic high-capacity phenazine-based anolyte for aqueous organic redox flow batteries. Nat. Energy
3, 508–514 (2018).

Ventosa, E.; Paez, T.; Palma, J, Redox flow battery for energy storage, European Patent Application,
EP18382971

Figure 1. a Scheme of a redox-flow battery based on the use of ferrocyanide-Ni(OH)2 in the positive container. b Reversible stored charge during the first 20 cycles of a 2,6-dihydroxi- anthraquinone // ferrocyanide flow battery in the absence (black circles) and in the presence (red circles) of solid Ni(OH)2 in the external positive container.

Figure 1
(Invited) Redox Contributions to the Behaviour of Electrochemical Capacitors
Authors: Donne Scott W 
Published: February 2020

The use of electrochemical capacitors is expanding rapidly in the electronics industry due to their excellent performance characteristics, including high specific power and cyclability. However, their specific energy, and hence cost per unit energy, is somewhat limited, thus prompting significant global research to address this shortcoming.
Energy storage in these systems is a combination of electrical double layer formation, or charge separation at the electrode-electrolyte interface, and pseudo-capacitance, which is based on facile redox reversible reactions at this interface. One of the key characteristics of these systems is the relative contributions that these processes make to overall charge storage.
Much ado has been made about the contributions that redox processes made to pseudo-capacitive electrode performance. Many apparently similar materials such as RuO2, MnO2 and NiOOH contribute charge through redox processes at the electrode surface; however, their performance can be quite different depending on the electrode material itself and the conditions under which it is cycled. The typical response for an electrochemical capacitor electrode is a box-like voltammogram; however, materials such as these have a basis of such behaviour, but may also include distinct redox peaks within the voltammogram.
Here we will examine the role that the redox mechanism for these pseudo-capacitive materials has on electrode performance, as well as investigate its impact on electrode properties, in particular crystal size. Outcomes will allow further differentiation of materials used in electrochemical capacitors.
Electrochemical Analysis of Garnet-Type Solid Electrolytes – Effect of Dopants on Li-Conductivity and Dendrites Formation
Authors: Pesci Federico M , Brugge Rowena H , Cavallaro Andrea , Aguadero Ainara 
Published: February 2020

The development of solid state lithium-metal batteries (SSLB) is a key requirement to enable the use of energy storage systems with high energy and power densities in the automotive sector. Garnet-type solid electrolytes are considered suitable electrolytes candidates for SSLB due to their stability against lithium metal and high ionic conductivity at room temperature (10-3 S cm-1). Currently their use is limited because of their short life-time due to high interfacial resistance between electrode and electrolyte, and to the formation of lithium dendrites.1 A better understanding of the transport properties and the mechanism of dendrites formation in garnet type electrolytes is therefore required in order to develop solid electrolytes with a long enough life-time to be employed in commercial systems.
In this work, alongside to an extended and systematic electrochemical characterisation of garnet-type electrolytes by Electrochemical Impedance Spectroscopy (EIS),2 we employed cubic Al- and Ga- doped Li7La3Zr2O12 (LLZO) as solid electrolytes in symmetrical cells and we investigated the formation of dendrites as a result of electrochemical cycling. We suggest that the presence of local chemical inhomogeneities promoted by the type of dopants used to stabilise the cubic phase might greatly affect the critical current density (CCD) for the dendrites formation and propagation.3 This is of fundamental importance for the development of solid state batteries based on LLZO.

1 A. Sharafi et al., J. Power Sources,
2016, 302, 135–139

2 F. M. Pesci et al., Manuscript in preparation

3 F. M. Pesci et al.
, J Mater. Chem. A,
2018
, 6, 19817-19827