bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dually Li Ion/Electron-Conductive Materials for Polymer-Based, Printable Lib Electrodes
Authors: McDonald Michael Blaine , Hammond Paula T 
Published: February 2020

Limitations in lithium ion batteries (LIBs) reside foremost in their 1) energy capacity, and 2) size and configuration modulation. Polymer properties are generally attractive for next-generation electronics due to their flexibility, facile tunability with known chemistry, and processability. Specialized polymers, such as conjugated polymers, are electrically conductive, while others, such as poly(ethylene oxide) (PEO), form matrices suitable for Li ion transport. Inert polymers such as poly(ethylene) and poly(propylene) are fabricated to form ordered porous electrode separators (‘Celgard’) that are typically wetted with liquid electrolyte to form lithium polymer batteries. In this work, the desired properties of polymers are bestowed unto LIBs via the modification of these preformed polymer separators, which are used as the skeletons for all-polymer, wet-fabricated LIBs.
First, commercial separators were infiltrated with PEO in place of toxic, flammable solvents to form the solid state electrolyte. For the electrodes, previously, conducting polymers (CPs) have been shown to act as a binding materials to not only adhere active material, but form conductive pathways to bulk charge collectors for Li ion cathodes such as LiFePO4. Herein, the brittle, usually carbon-based scaffolds and binders are removed to form entirely conducting polymer bulk electrodes that are flexible. Active cathode (LiCoO2) and anode (graphite, Si) microparticle materials are incorporated to optimize battery capacity by exploiting excessive polyanion dopant in the commercially available CP suspension PEDOT:PSS as a dispersing agent, yielding “LIB electrode inks” that are printable onto the solid electrolyte support.
Transport of Li ions through the polymer matrix to access active material is systematically investigated both by forming a porous polymer network akin to carbon paper electrodes, and by fabricating composites of PEDOT:PSS with PEO. The mixtures are optimized for electronic conductivity, Li ion conductivity, and capacity through control of the active material content. All-polymer thin LIBs can then be entirely fabricated through wet deposition across the commercial separator scaffold and demonstrate behavior consistent with the current rigid LIB configurations. This novel configuration juxtaposes the all-polymer printed LIB, where dispersions consisting of PEDOT:PSS-PEO and active material as electrodes and a solution-based polymer electrolyte are wet-cast onto a substrate layer-by-layer.
Prussian Blue Analog Batteries on Thread Substrates for Wearable Electronic Applications
Authors: Kim Andrew , Biswas Shaurjo , Gupta Tanya , Steingart Daniel A 
Published: February 2020

Flexible, wearable electronics are starting to reach mass consumer markets but an adequate solution to power these devices remains a challenge. The size constraints in traditional mobile devices impose a premium on high energy density batteries to capitalize on limited space. These energetically dense systems often require bulky, rigid casings for robust protection against fire and chemical hazards. Thus we target energy storage in textiles, where size constraints are less stringent, battery real estate is scalable to requirements, and safer materials may be used.
We demonstrate a zinc/Prussian blue analog battery on a thread/fiber architecture that can be woven into clothing/textiles. First, we show a cell that consists of a copper hexacyanoferrate (CuHcf) cathode dyed or coated on to conductive carbon fibers and a counter zinc electrode, suspended in a sodium-rich agarose hydrogel electrolyte at neutral pH. Agarose is a seaweed based gel known to conduct ions such as Na+. We introduce sodium salt loaded agarose gels as a potential high rate battery electrolyte. Preliminary charge/discharge tests of the 1.7 V cells in a flooded 2 cell setup show an initial specific discharge capacity of 51 mAhr/g of CuHcf, and 43 mAhr/g after 25 cycles. Further optimization is likely to improve cycle life significantly.
Next, we demonstrate simple woven structures with CuHcf and Zn coated threads with Agarose/Na+ electrolyte as a proof of concept towards realizing wearable and washable electronics. We characterize the physical properties of the fiber electrodes and gel electrolyte with SEM, stress loading, and washing with sodium salt based laundry detergents. A range of electrochemical characterization is performed on the woven structures to analyze their cycle life, energy and coulombic efficiencies and specific capacities.
Baseline Si Electrode Fabrication and Performance for the Battery for Advanced Transportation Technologies Program
Authors: Jia Zhe 
Published: February 2020

Baseline Si electrodes were developed and characterized based on Si nanomaterials. Si with a designed nanostructure has attracted much attention as potential anode materials for lithium-ion batteries due to its high gravimetric specific capacity. Because of a resulted poor tap density of Si from the electrode while using nano-sized Si and also from including other additives like conductive carbon and binder, it is difficult to maintain a high loading of active materials at the anode side in lithium-ion batteries.
In this report, we aim to investigate how the thickness of Si-based electrode influences the cycling performance, rate performance and impedance. We also discuss the variation of gravimetric, area and volumetric capacity along with increasing of electrode thickness. It is found that with a thinner electrode of 7 mm the volumetric capacity could reach up to 920 mAh cm-3 but a poor area capacity of 0.7 mAh cm-2, while a thicker one of 33 mm enables to provide a high area capacity up to 1.5 mAh cm-2 and gives a volumetric capacity less than 500 mAh cm-3. A cell operated under 0 °C shows a gravimetric capacity of 2000 mAh g-1 after 60 cycles.
FeWO4 As Electrode Material for High Volumetric Capacitance Supercapacitors
Authors: Brousse Thierry , Favier Frederic , Goubard Nicolas , Crosnier Olivier , Payen Christophe 
Published: February 2020

The volumetric capacitance of supercapacitors is one of the limiting factors of today’s stationary applications. Further research on new materials with improved storage properties is necessary to meet the requirements concerning high-performance energy storage devices while considering a reasonable manufacturing cost and a low environmental impact. In order to meet those requirements, our interest has focused on high-density oxides operating in aqueous electrolytes.
Metal tungstates (M2+WO4) represent an important group of inorganic high-density oxides with excellent functional and electronic properties. Iron tungstate (FeWO4), crystallizes in the wolframite-type structure, characterized by distorted [MO6] and [WO6] octahedra. It is well known for its magnetic, photocatalytic and photoluminescence properties and has recently been studied in lithium-ion batteries but its electrochemical properties in supercapacitors have not yet been reported. FeWO4 has been synthesized via various low-temperature methods (polyol-mediated, hydrothermal synthesis…) in order to obtain high specific surface area nanoparticles which have been characterized and electrochemically tested as supercapacitor electrode materials in aqueous electrolytes. Concomitantly, zinc tungstate was synthesized by the same method. Specific surface area ranging from 10 to 80 m2/g have been achieved.
The different oxides have been tested in neutral aqueous based electrolytes (LiNO3 5M). ZnWO4 does not show any sign of electrochemical activity whatever the potential window. FeWO4 exhibits a typical pseudocapacitive behavior i.e. CVs without any redox peaks but typical rectangular shape. The material exhibits very promising properties that seem to be due to Fe2+/Fe3+ surface redox reactions and are closely related to its specific surface area. The synthesis conditions, materials characterizations and electrochemical performance will be detailed in the presentation. For FeWO4 obtained by polyol-mediated synthesis, a high volumetric capacitance of 210 F.cm-3 was measured at 20 mV.s-1 with less than 5% fade over 10 000 cycles. Furthermore, unlike most previously investigated iron based electrodes, a unique pseudocapacitive behavior emphasizes the role of the crystallographic structure.
Capacitive Deionization Process Via Nano-Titanium Carburizing Electrode
Authors: Wang Li , Zhou Yun 
Published: February 2020

Capacitive deionization (CDI) technology is an economical and effective electrosorption desalination method. In Capacitive deionization process, the feed solution flows through high adsorption capacity electrodes in which the anions and cations from the salty water are adsorbed on the charged electrodes. Two methods of chemical deposition and high vacuum magnetron sputtering are used for the preparation of nano-titanium carburizing electrode (named C1-TiO2and C2-TiO2). This paper apply the prepared nano-titanium carburizing electrode to the construction of a CDI desalination reactor. This paper focuses the desalination of capacitive deionization (CDI), investigates the influence of electrode material on adsorption capacity. By comparing the adsorption capacity of different kinds of electrode material, combined with physical and chemical characteristic and electrochemical analysis, the paper choose the optimal electrode material for capacitive deionization. The results show that under the same conditions, the adsorption capacity of nano-titanium carburizing electrode named C2-TiO2 up to 9.61mg/g.
In the capacitive deionization process by the selected nano-titanium carburizing electrode, the most optimal processing parameters of CDI in the research are operating voltage of 1.4 V, flow rate of 10 mL/min and plante spaceing of 4 mm. The kinetics analysis demonstrated that the electrosorption of NaCl on electrodes during dealing different concentration of NaCl solutions and different operating voltages followed pseudo-first-order model. The ion electrosorption on the electrodes can be represented by the Langmuir equation. This phenomenon indicating that the monolayer adsorption was primary during the electrosorption process. The experiment of adsorption-desorption in desalination process presented a better reversibility of nano-titanium carburizing.
Quaternized Graphene Oxide-Based Supercapacitor Electrode
Authors: Movil-Cabrera Omar , Staser John A 
Published: February 2020

Electrochemical capacitors (supercapacitors) have received considerable attention as promising energy storage devices for applications including transportation, load leveling, and personal electronic devices. Common features among electrochemical capacitors are high power density and cycle life, and although they may differ with respect to electrode material, most electrochemical capacitors employ some type of high surface area carbon electrode. With the emergence of graphene (a single atom thick layer of carbon), some recent attention has focused on using this material as a supercapacitor electrode with generally promising results. In this paper, we present novel quaternized graphene oxide-based supercapacitor electrodes. We compare these materials to unmodified graphene oxide. Our results indicate the functionalized graphene oxide materials exhibit higher capacity than unmodified graphene oxide, leading us to conclude that these materials may be suitable for supercapacitor electrodes. In addition, we show that the functionalized graphene oxide materials exhibit a mix of double-layer and pseudocapacitance, which ultimately could further enhance material capacity.
(Invited) Dynamic Behaviour of Electric Double Layer Capacitors
Authors: Madabattula Ganesh , Kumar Sanjeev 
Published: February 2020

Electrical double layer capacitors (EDLCs) store energy by accumulating ions in electrolyte at electrode-electrolyte interface in the form of a double layer (DL) in porous electrodes. As electrochemical reactions are not involved, EDLCs find use in devices requiring energy at high rates, such as in hybrid electric vehicles, high power electric tools, and emergency power banks. Highly non-linear decrease in cell voltage with time and decreased availability of stored charge at high discharge rates, observed experimentally, are major technical issues though. We present here results of our probe into these limitations by requiring a transport model to quantitatively explain a large body of experimental data available on variation of cell voltage with discharge time at different electrolyte concentrations and discharge currents, charge redistribution and voltage recovery of EDLC during relaxation, and other characteristics. The model utilizes experimentally measured variation of electrolyte conductivity with salt concentration to make predictions for EDLC characteristics. In order for the model to consistently explain all the known experimental findings, it requires that (i) the double layer capacitance must vary with local potential difference and electrolyte concentration, (ii) it must decrease with an increase in local voltage drop, (iii) it must vary with local salt concentration in the same manner as bulk conductivity does, and (iv) ionic conductivity in pores of carbon electrodes must be an order of magnitude smaller than the reduced conductivity of electrolyte in porous media, as captured by the correlations available in the literature. While it is known that double layer capacitance in porous media is understood only poorly, to the best of our knowledge, this is the first time that model based probe has clearly and ambiguously brought out unexpected dependence of capacitance on various parameters.
Highly Porous Carbon Nanospheres and Carbon Foams for Supercapacitors Using Facile Spray Pyrolysisand One-Pot Reaction
Authors: Wang Chengwei , O'Connell Michael J. , Chan Candace K. 
Published: February 2020

Due to their unique properties, high surface area carbon nanomaterials such as carbon nanotubes and
graphene have been widely used in energy storage applications. However, it is still difficult and
expensive to synthesize carbon nanotubes and graphene at large-scales. Hence, there is still a need for
the development of low-cost and facile synthesis techniques for porous carbon materials with highly
accessible surface areas.
A facile and solution-based, spray pyrolysis synthesis technique which was used to synthesize individual
carbon nanospheres with specific surface area (SSA) up to 1106 m2/g using a novel ZnO catalyzed
reaction. The carbon nanosphere diameters were tunable from 10 nm to several micrometers by varying
the precursor concentrations. Solid, hollow, and porous carbon nanospheres were achieved by simply
varying the ratio of catalyst and carbon source without using any templates. When evaluated as
supercapacitor electrode materials, specific capacitances of up to 112 F/g at a current density of 0.1 A/g,
were observed, with no capacitance loss after 20,000 cycles. The performance of the carbon
nanospheres as electrodes in Li-ion batteries were also investigated.
The direct pyrolysis of sugar and zinc nitrate mixtures was employed to obtain foam-like carbons with
specific surface area (SSA) up to 2340 m2/g without using any hard templates. The role of the ZnO
nanoparticles formed from the decomposition of zinc nitrate and the effects of high temperature
annealing on the formation of the high SSA carbon foams were systematically studied. Due to the facile
and quick reaction conditions, these carbon foams carbons could be easily synthesized at a large scale.
When used as supercapacitor electrode materials, a specific capacitance up to 280 F/g was achieved at
current density of 0.1 A/g, and still remained as high as 207 F/g even at a high current density of 10 A/g.
References:
C. Wang, Y. Wang, J. Graser, R. Zhao, F. Gao, M.J. O’Connell, ACS Nano, 7, 11156-11165 (2013).
V. Etacheri, C. Wang, M.J. O’Connell, C.K. Chan, V.G. Pol, J. Mater. Chem. A, 3, 9861-9868 (2015).
C. Wang, M.J. O’Connell, C.K. Chan, ACS Appl. Mater. Interfaces, 7, 8952 (2015).
Structure-Directed CNT Arrays As Micro-Supercapacitor Electrodes and the Effect of Geometry on Electrolyte Selection
Authors: Nicol Katherine T , Hill Justin J 
Published: February 2020

The demand for power-dense and energy-dense storage devices is growing rapidly. While supercapacitors offer high power density, improving the energy density can be obtained by precisely tuning the electrode nanostructure and pairing it with the appropriate electrolyte. Multi-walled carbon nanotubes (MWNTs) are a promising electrode material for EDLCs because of their high electrical conductivity, chemical stability and exceptionally high surface area. Until single walled carbon nanotubes can be produced as solely conductive structures, low-diameter MWNTs offer the best properties with regard to carbon-based EDLC electrode materials. When MWNTs are fabricated in anodic aluminum oxide templates, a MWNT is grown within each nanopore, resulting in an ultra-high density vertically-aligned array. Vertically-aligned MWNTs offer numerous benefits, such as directed charge transport and high density packing, leading to a higher active surface area and better rate capabilities than observed with randomly-dispersed networks. We have demonstrated the fabrication and performance of these electrodes in non-pseudocapacitive supercapacitors with both organic and ionic liquid electrolytes. While these benefits are beneficial for all capacities of supercapacitors, they are increasingly important in the production of micro-supercapacitors, when it is essential to use all device volume efficiently. Despite the benefits, this highly oriented electrode design combined with the remnants of the template can lead to unique current distributions and behaviors in a coin cell test set-up. We will discuss the differences in electrochemical capacitive behavior of traditional and our anisotropic electrodes. There exists unique stability criteria in nanostructured domains that must be considered when designing this electrochemical system - specifically the current and potential distribution due to the MWNT curvature and constant phase element behavior. Through thorough characterization of the electrode structure and electrolyte behavior, we have successfully demonstrated cells with a projected energy and power density of 108 Wh/kg-carbon and 768 kW/kg-carbon.
Freestanding Graphene/Carbide Derived Carbon Films As High-Performance Electrodes for Electrochemical Capacitors
Authors: Alhabeb Mohamed , Beidaghi Majid , Van Aken Katherine L , Gogotsi Yury 
Published: February 2020

Freestanding films of reduced graphene oxide (rGO) have attracted much attention as electrodes for electrochemical capacitor, especially for flexible device applications. However, graphene paper electrodes are usually limited in thicknesses to less than 10 μm, as increasing the electrode thickness hinders its performance due to restacking of rGO sheets and slow diffusion of ions [1]. To prevent this problem, carbon nanoparticels such as carbon nanotubes (CNTs) are frequently used as nanospacers between the rGO sheets to increase the electrolyte accessibility and electronic conductivity of the films [2]. However, CNTs have a much lower capacitance compared to rGO and their addition limits the overall capacitance of the freestanding electrodes.
In this study, for the first time, we have used highly porous carbide derived carbon (CDC) nanoparticles as spacer between graphene sheets and fabricated thick rGO/CDC hybrid electrodes. The electrodes were made by thermal reduction of GO/CDC papers fabricated by vacuum-assisted filtration of aqueous solutions of GO and CDC containing 10, 20, and 30 wt. % of CDC. Utilizing the high surface area and conductivity of rGO and the accessible pores of the CDC [3], the hybrid electrodes showed specific capacitances as high as 200-210 F/g at a high scan rate of 100 mV/s in an aqueous electrolyte. The addition of CDC between the rGO layers increases the accessibility of active material to the electrolyte ions and we observed good performance of the electrodes with the thickness of 40-50 μm.

References:

1. Oh, Y.J., et al., Oxygen functional groups and electrochemical capacitive behavior of incompletely reduced graphene oxides as a thin-film electrode of supercapacitor. Electrochimica Acta, 2014. 116: p. 118-128.
2. Wang, Y., et al., Preventing Graphene Sheets from Restacking for High-Capacitance Performance. Journal of Physical Chemistry C, 2011. 115 (46): p. 23192-23197.
3. Chmiola, J., et al., Anomalous increase in carbon capacitance at pore sizes less than 1 nanometer. Science, 2006. 313 (5794): p. 1760-3.
Environmental Friendly Electrode Preparation for Hybrid Battery-Supercapacitors Based on Li3V1.95Ni0.05(PO4)3/C and Activated Carbon
Authors: Meuser Carmen , Tran Hai-Yen , Secchiaroli Marco , Dsoke Sonia , Wohlfahrt-Mehrens Margret 
Published: February 2020

In the last years, hybrid battery-supercapacitors have been a rising interest toward the improvement of both the energy density and power density in comparison to the classical systems [1]. By using Li-insertion materials and activated carbon it is possible to develop high energy and high power density Li-ion supercapacitors. Among the various numbers of Li-ion materials, Li3V1.95Ni0.05(PO4)3/C shows excellent performances at very high C-rates, with very high specific discharge capacity (93 mA h g-1 at 100 C) and a capacity retention of 97% after 1000 cycles [2]. Most of the currently used Li-ion battery electrodes are based on poly(vinylidene difluoride) (PVDF) due to its good electrochemical stability and binding capability within the electrode composite. However, the cost and the environmental impacts of these widely used PVDF based electrodes are still a concern in the battery industry. Thus, lot of effort has been put toward the pursuit of an environment-friendly, cost-effective binder for lithium-ion batteries, such as carboxymethyl cellulose (CMC) and polyacrylic acid (PAA) [3].In this study, the effect of CMC and PAA binders in the battery-like counter part on the mechanical and electrochemical behaviour in the hybrid battery-supercapacitor electrodes is explored (see Table 1). In particular, Li3V1.95Ni0.05(PO4)3/C has been studied both as high energy and high power anode and cathode, between 3.0-1.5 and 3.0-4.3 V vs. Li+/Li. Commercial activated carbon (AC) (Haycard) and LP30 (Merck) has been used as counter electrode and electrolyte, respectively. Furthermore, the functionalization of PAA during the electrode preparation will be investigated and shown during the presentation.

Table 1. Electrode compositions.

Compositions
Active material LVNP / wt.%
Conductive agent Super P / wt.%
Binder /wt.%

1
80
10
9% CMC + 1% SBR

2
85
5
9% CMC + 1% SBR

3
86
5
9% PAA

References

[1] D. Cericola, R. Kötz, Electrochim. Acta 72 (2012) 1–17.
[2] M. Secchiaroli, G. Giuli, B. Fuchs, R. Marassi, M. Wohlfahrt-Mehrens, S. Dsoke, DOI: 10.1039/c5ta00976f.
[3] J. Chong, S. Xun, H. Zheng, X. Song, G. Liu, P. Ridgway, J. Q. Wang, V. S. Battaglia, J. Power Sources 196 (2011) 7707– 7714.

Acknowledgments

Financial support from the German Federal Ministry of Education and Research (BMBF) under the grant 03EK3021 is gratefully acknowledged.