bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Carbon Doping of Nickel-Cobalt-Manganese Triple Hydroxides (NiCoMn-TH) on Its Electrochemical Capacitive Performance in Aqueous Electrolyte
Authors: Oyedotun Kabir Oyeniran
Published: February 2020

The study presents the synthesis and characterization of low cost mixed-metal hydroxides (NiCoMn-TH)/carbon composites via a simple and cost-effective low temperature stirring technique. The nickel-cobalt-manganese triple hydroxides and activated expanded graphite (NiCoMn-TH/AEG) composite electrode material provided a maximum specific capacity of 91.94 mAh g-1 corresponding to a specific capacitance of 525.5 F g-1 at a specific current of 1 A g-1 and a scan rate of 5 mV s-1, respectively measured in a three-electrode configuration using 1 M KOH aqueous electrolyte. Electrochemical measurements of the NiCoMn-TH/AEG composite material and C-FP selected as an asymmetric supercapacitor (SC), delivered a high energy density of 23.5 Wh kg-1 corresponding to a power density of 427 W kg-1 at a specific current of 0.5 A g-1. Interestingly, the assembled asymmetric SC, NiCoMn-TH/AEG //C-FP retained about 73 % of its initial capacitance corresponding to an energy density of about 14 Wh kg-1 with a power density of 592.9 W kg-1 at a floating test of 120 hours at a specific current of 1 A g-1. These excellent results suggest that this composite material has great potential for high performance electrode for supercapacitor applications.

Figure 1
Morphology Control of Zinc Electrodeposition By Surfactant Addition for Alkaline-Based Rechargeable Batteries
Authors: Shimizu Masahiro , Hirahara Koichi , Arai Susumu
Published: February 2020

Critical challenges have remained in practical realization of Zn-air batteries. Focusing on negative electrode, Zn grows in the form of mossy and dendrite structures in low and high current densities, respectively. The non-uniform Zn morphology prevents homogeneous Zn dissolution (discharge) reaction, which is responsible for deterioration of battery performance. In the present study, we used trimethyloctadecylammonium chloride (STAC / surfactants) as an inhibitor of the formation of mossy and dendrite Zn structures. The addition of surfactant to an electrolyte is not necessarily a new approach for improving Zn deposition morphology. However, the new insight in this study is that we found a leveling agent enabling to suppress the formation of not only mossy structure but also dendrite structure and highly flatten deposit in wide current densities (5−40 mA cm−2). The mechanism was systematically investigated by means of X-ray diffraction and measurements of zeta potential and kinetic current density for Zn-deposition. The obtained results indicate that quaternary ammonium cations (STAC) with bulky size adsorb to protrusions which are cause of shape change and suppress Zn deposition in the region to promote lateral growth. In charge−discharge test using an asymmetric Cu|Zn cell, Coulombic efficiency in an additive free electrolyte was less than 95%, whereas the addition of STAC with 1 mM achieved superior cycling performance without any capacity loss originated from the generation of dead Zn. These results demonstrate that the addition of STAC is a promising way of controlling Zn morphology and allows the efficient utilization of Zn metal electrode in large-scale batteries for important next-generation applications.

Figure 1
Opportunities for 3D Zinc Anode Architectures in Aqueous Batteries
Authors: Rolison Debra R. , Parker Joseph F. , Ko Jesse S. , Hopkins Brandon J. , Chervin Christopher N. , Long Jeffrey W.
Published: February 2020

Zinc-based batteries offer a compelling alternative to lithium-ion batteries thanks to nonflammable aqueous electrolytes augmented by the high energy density of Zn-based batteries. We recently demonstrated that fabricating dendrite-prone zinc into a monolithic porous, aperiodic architecture form-factor suppresses zinc migration and dendrite development. Three structural features of these emulsion–derived Zn "sponge" electrodes physically ensure dendrite suppression: (i) interconnected pathways that maintain long-range electronic conductivity within the electrode volume throughout charge–discharge; (ii) an electrified 3D interface that imparts more uniform current distribution; and (iii) confined internal void volume that controls Zn/Zn2+ precipitation/dissolution dynamics and product redistribution.

The Zn sponge anodes exhibit unprecedented cyclability at high depths-of-discharge (theoretical DODZn), increased specific capacity relative to conventional powder-bed Zn electrodes, and tens of thousands of cycles at low-DODZn pulse-power profiles, as recently demonstrated in prototype Ni–Zn cells [1]. This breakthrough enables the entire family of alkaline Zn batteries (Ni–Zn, Ag–Zn, MnO2–Zn, and Zn–air) to be reconfigured in extensively rechargeable forms, with energy and power characteristics that are competitive with Li-ion batteries.

Our second-generation emulsion protocol improves the volumetric density of the sponge thereby concomitantly improving the energy density and power density of the cell while adding mechanical ruggedness to the anode [2]. We have also introduced additional manufacturing flexibility to sponge fabrication. The potential paths forward for the development and transition of this safer energy-storage technology will be discussed.

[1] J.F. Parker, C.N. Chervin, I.R. Pala, M. Machler, M.F. Burz, J.W. Long, and D.R. Rolison, “Rechargeable nickel–3D zinc batteries: An energy-dense, safer alternative to lithium-ion.” Science, 356, 415–418 (2017).

[2] J.S. Ko, A.B. Geltmacher, B.J. Hopkins, D.R. Rolison, J.W. Long, and J.F. Parker, ACS Appl. Energy Mater. (doi: 10.1021/acsaem.8b01946).
Discharge Capacity Improvement of Zinc-Air Battery Using Electrospun Polypropylene Nanofibrous Separator
Authors: Abbasi Ali , Hosseini Soraya , Han Siow Jing , Kheawhom Soorathep
Published: February 2020

Among metal-air flow batteries, zinc-air offers the advantages of low cost, high safety, environmental friendliness and high theoretical energy density. An electrolyte, as one of the main components in zinc-air batteries, are responsible for the transport of hydroxide ions between the cathode and the anode. A favorable electrolyte for alkaline zinc-air batteries should have high ionic conductivity, low zincate ion crossover, good electrochemical stability in caustic solutions and high electrical resistance. Commercially, microporous films of polyolefins, namely polyethylene and polypropylene, saturated with electrolyte are widely used as the separator. However, using the microporous commercial films with ordered structures in zinc-air batteries usually leads to low performances. Thus, non-ordered and layered-fibrous structures are suggested to improve the performance. Herein, separators based on electrospun polypropylene nanofibers were investigated. Electrospun syndiotactic polypropylene (s-PP) nanofibrous mat was fabricated using electrospinning technique. Granular s-PP was dissolved in a solvent mixture of decalin, acetone and DMF to the concentration of 7.5 wt%. The resulting solution was then electrospun under a controlled condition (Potential: 10.5 kV; Distance: 15 cm; flow rate: 0.8 ml/h). To examine electrochemical characteristics of electrospun s-PP nanofibers and Whatman filter paper as benchmark separator, a three-electrode configuration cell with a zinc working electrode and a platinum counter electrode was used. Furthermore, the performance of the separators was evaluated using a home-made tubular zinc-air battery with stagnant KOH electrolyte. Cyclic voltammetry elucidated higher and broader peak for zinc dissolution for the battery using nanofiber-based separator as shown in Figure 1. The galvanostatic discharge results showed that the battery using s-PP nanofibers exhibited more than 40% improvement in the discharge capacity compared to the Whatman filter paper. The results of this study show the potential of electrospun nanofibrous structures as separators in various types of battery systems.

Figure 1
Direct Sodium Hypophosphite Fuel Cell System
Authors: Nikoleishvili Paata , Kveselava Valentina , Kurtanidze Rusudan , Gorelishvili Giorgi
Published: February 2020

The goal of the presented project is development a new type of direct sodium hypophosphite fuel cell (DSHFC) System, with Sodium Hypophosphite direct oxidation at the CoB2O4 based anode.

Synthesized CoB2O4 was used as a catalyst of sodium hypophosphate oxidation [1,2]. CoB2O4 was annealed at 280˚C - 350˚C demonstrated best catalytic activity. In X-ray phase analysis of the sample show the X-ray diffraction pattern according to the ASTM standard of СoB2O4 (2.88,2.44, 2.03, 1.86 Å).

Sodium Hypophosphite is oxidized in alkaline media. Hypophosphite-ion is adsorbed at metal oxide CoB2O4 surface, hydrogen atom, which is connected with catalyst surface by covalent bond, attenuates P-H bond and finally cleaves it; hydrogen is replaced by hydroxide-ion of water (1, 2) which causes hypophosphite transformation in phosphate. The overall anodic reaction will be (3)

H2O=H++OH- (1)

H2PO2
-ads + OH-ads = H2PO3
-ads+ H++ 2e- (2)

NaH2PO2 + H2O = NaH2PO3 + 2H+ +2e- (3)

The DSHFC anode was made by next steps: the CoB2O4 powder and carbon black XC72 powder 1:3 were mixed in isopropanol alcohol, as a binder was used polytetrafluoroethylene suspension and sonicated during 30 min. A carbon felt was used as an anode substrate and catalytic layer was covered bay spry-gun and heated at 250 oC during 5 min. the figure 1 show the DSHFC construction. The fuel Cell is undivided. As a cathode was used ordinary gas diffusion electrode for O2 reduction. The Anode and the cathode geometric surface area was 4 cm2 (2cm X 2cm)

The Voltage –Ampere characteristics of the Direct Sodium Hypophosphite Fuel Cell was recorded with various concentrations of electrolyte X NaH2PO2 + Y NaOH, electrolyte was feed in to fuel cell by pump, oxygen to the cathode chamber was feed by air compressor (pressure 35-40 mm.H2O).Test were performed at room temperature. External load was changed from 10 000 Ω to 0.1 Ω. Current and voltage of DSHFC was recorded by multi-meters. In optimal conditions, electrolyte 1M NaH2PO2 + 2 NaOH, external load 1 Ω, the current density was 36 mA cm-1, the suitable power density was 13,5 mwt cm-1, open circuit potential was 1v

References

[1] Electroless plating: fundamentals and applications edited by G. O. Mallory, J. B. Hajdu

[2] P.O. Nikoleishvili, at all, Russian Journal of Electrochemistry, 2015, Vol. 51, No. 7, pp. 665–671

Figure 1
Going with the Flow: Novel Quinoidal Electrolytes for Redox Flow Batteries
Authors: Jethwa Rajesh Bharat , Zhao Evan Wenbo , Kerber Rachel Nathaniel , Jónsson Erlendur , Wright Dominic S. , Grey Clare P.
Published: February 2020

Redox flow batteries are growing in interest as potential systems for electrochemical energy storage at the grid-level, where high cycle number durability, long calendar life, high efficiency, low cost and fast response times are required.1,2 However, due to current issues of low energy density3–5 and high capital costs3,4 the industrial implementation has been slow. Electrolytes are a topic of active research aiming to increase the energy density while reducing the cost. Battery energy density can be increased by expanding the voltage window, or by minimising the mass and/or volume of the electroactive species per electron transferred6 which opens up many avenues through which novel electrolytes can be explored. Previous examples of electrolytes for flow batteries have included a variety of metal-based systems and a range of organic molecules.7,8 Of these, quinones are a common electroactive class of organic molecules that have been investigated and offer fast kinetics, high tunability and low cost.8 In the current work, benzoquinone derivatives were synthesised and investigated as potential anolytes for redox flow batteries. Benzoquinone has a higher aqueous solubility and a lower molecular weight than anthraquinone, but it is less stable electrochemically.8 The derivatised quinones explored in this work are anticipated to benefit, in comparison to previous anthraquinones, from a higher energy density through greater solubility and lower cost. Electrochemical screening was carried out using cyclic voltammetry as an initial test of redox properties and stability. Selected molecules that exhibited favourable behaviour were then run in a full cell on a lab-scale and through the aid of in situ NMR spectroscopy, the behaviour of the species under cycling conditions was investigated. Density functional theory modelling was used to complement the analysis.

Weber, A. Z. et al. Redox flow batteries: A review. J. Appl. Electrochem.
41, 1137–1164 (2011).

Gyuk, I. et al.
Grid Energy Storage. (2013).

Potash, R. A., McKone, J. R., Conte, S. & Abruña, H. D. On the Benefits of a Symmetric Redox Flow Battery. J. Electrochem. Soc.
163, A338–A344 (2016).

Wang, W. et al. Recent progress in redox flow battery research and development. Adv. Funct. Mater.
23, 970–986 (2013).

Alotto, P., Guarnieri, M. & Moro, F. Redox flow batteries for the storage of renewable energy: A review. Renew. Sustain. Energy Rev.
29, 325–335 (2014).

Armand, M. & Tarascon, J. M. Building better batteries. Nature
451, 652–657 (2008).

Noack, J., Roznyatovskaya, N., Herr, T. & Fischer, P. The Chemistry of Redox-Flow Batteries. Angew. Chemie - Int. Ed.
54, 9776–9809 (2015).

Ding, Y., Zhang, C., Zhang, L., Zhou, Y. & Yu, G. Molecular engineering of organic electroactive materials for redox flow batteries. Chem. Soc. Rev.
47, 69–103 (2017).
Fabrication of High Performance Asymmetric Energy Storage Device with WO3@Graphene By Electrochemical Exfoliation Method
Authors: Das Himadri Tanaya
Published: February 2020

The demand for batteries and supercapacitors on a single platform has been building up for decades now. The demand for supercapacitors stems from its peak power densities and long-term cycle life. However, transition metal oxides have high theoretical specific capacity to store charge but it drawbacks due to its low electronic conductivity and capacity fading with number of cycles. To overcome these usually metal oxides are embedded with the conductive matrix. The conductive matrix like graphene not only provides path for easy electron movement it also increases the surface area for higher interaction of active electrode materials with electrolyte. Hence it attracts active research pursuits in synthesizing low cost effective electrode materials.

In this work, we report a facile and economic approach to produce tungsten oxidenanospheres embedded in graphene sheets (WO3@G) powders with an improved electrochemical activity.The method consists of exfoliation of graphite cardboard at constant voltage of 10 V in a metal sulphate bath. This ultimately yields black flakes like powders. The WO3@G powders' crystallinity was characterized by XRD which confirmed. The FE-SEM and TEM reveals the formation of nanospheres embedded on the graphene nanosheets. A comparison of the physical and chemical properties was intended with different concentrations of metal sulphate salt solutions. Interestingly, it was found that the yield of graphene also depends on the concentrations of salt bath. The Raman spectroscopy reveals the few exfoliated layers of graphene. We have examined the electrochemical activity of these different electrode materials by studying the supercapacitors properties like cyclic voltammetry, charge-discharge profiles and electrochemical impedance spectroscopy. Thus, we have reached a cheap and effective yield of promising candidate for the electrode materials for energy storage devices. The WO3@G positive electrode was assembled with graphene as negative electrode, sandwiched by gel-electrolyte. These prototype devices were capable of powering consumer electronics applications.
Influence of Water on the Properties of Protic Ionic Liquids
Authors: Stettner Timo , Ray Promit , Kirchner Barbara , Balducci Andrea
Published: February 2020

Protic ionic liquids (PILs) represent an interesting subclass of Ionic Liquids (ILs), with properties suitable for the realization of different kinds of electrochemical energy storage devices. [1-2] PIL have been proposed as electrolytes for electrochemical double layer capacitors (EDLCs) and lithium-ion batteries (LIBs) [ref]. In the case of EDLCs the use of these ILs appears not to be particularly advantageous due to the presence of a proton on their structure, limiting the operative voltage, and their relative high viscosity, limiting the power performance of these devices. In the case of LIBs, to the contrary, the presence of the proton has a positive influence on the lithium coordination and on the performance at high current densities of IL-based LIBs. [3].

The influence of the water content on the chemical-physical properties of PILs have been investigated in the past, and it has been found that even a few hundred ppm of residual water are strongly changing the properties of these ILs, e.g. they might significantly lower the melting point of PILs. Nevertheless, the impact of the water content on the electrochemical performance of electrochemical energy storage devices containing PILs as electrolytes has not been investigated in detail. These important aspects should be investigated because it could supply valuable information about the development of PIL-based devices.

In this paper we report about the influence of water on the properties of the PIL butylpyrrolidinium bis(trifluoromethylsulfonyl)imide (PyrH4TFSI) containing different amounts of water (0, 1, 2, 3.8 wt%). The viscosity, ionic conductivity, density and electrochemical stability of these PIL have been investigated in detail. Furthermore, the mixtures were utilized as electrolytes for EDLCs containing activated carbon-based electrodes, as well as for LIBs containing graphite anodes and lithium iron phosphate (LFP) cathodes.

The results of this study indicate that small amounts of water have a significant impact on the overall transport properties and stability of PyrH4TFSI. Moreover, they also show that the performance of EDLCs and LIBs containing PyrH4TFSI as electrolyte are considerably changing depending on the water content of the PIL.

Literature:

[1] Menne, Electrochem. Commun. 2013, 31, 39-41.

[2] Vogl, Journal of Materials Chemistry A 2016, 4, 10472-10478.

[3] Brandt, Electrochim. Acta 2013, 108, 226-231.

Figure 1
(Invited) Hard Chemistry: Solid State Electrolytes and Anode Protection for Solid State Lithium and Sodium Batteries
Authors: Nazar Linda F , Kaup Kavish , Zhou Laidong , Kochetkov Ivan , Zhang Zhizhen , Park Kern Ho
Published: February 2020

The development of safe and high-performance all-solid-state batteries (ASSB) is contingent on creating fast ion conductors that combine high ionic conductivity with good ductility and chemical stability in a large voltage window, while - especially - mastering the interface of the solid electrolyte with the electrode materials. This presentation will examine ways to address these factors with new materials within the crystalline and glassy alkali thiophosphate families, while also shedding light on new design concepts for ion conductivity.

The talk will cover an overview of the state-of-the art in the field, followed by recent findings in our laboratory. Significant increases in conductivity of thiophosphate-halide argyrodites, above that of the parent Li6PS5Cl phase, have been attained by both tuning composition and developing “clean” solution-engineering processing routes to these materials to create materials that exhibit ion conductivities above 1 mS/cm together with good chemical stability. An understanding of superionic conductivity in these and related crystalline and glassy alkali thiophosphates has been achieved using a combination of structural elucidation via single crystal X-ray/powder neutron diffraction, ion conductivity mechanisms via impedance studies and the maximum entropy method, 7Li MAS/PFG NMR, and ab initio molecular dynamics simulations. We correlate crystal structure with ionic conductivity to understand how cation disorder and a frustrated energy landscape affects the conductivity and activation energy. Last but not least, the talk will highlight our work on in-situ Li-ion conductive protective films for lithium metal batteries
(Invited) Solbat: The Solid-State Metal-Anode Battery Project within the Faraday Institution
Authors: Pasta Mauro
Published: February 2020

Attempts to realize an all solid-state battery have been made for several decades without success. Traditionally the focus has been on the conductivity of the solid electrolyte but in truth this is the least important challenge. The barriers to achieving an all solid-state battery lie with the interfaces between the electrolyte and the two electrodes, the mechanical properties of the solid electrolyte, and in how devices might ultimately be fabricated. Simply using traditional approaches or attempting to fabricate new devices will not deliver success. The SOLBAT project within the Faraday Institution, the UK’s independent institute for electrochemical energy storage science and technology, aims at understanding the fundamental science underpinning the manifold scientific and technological impediments to the practical development of solid-state batteries. We identified four main areas of study: anode interfaces, cathode interfaces, electrolyte discovery, and cell fabrication, summarized in the following figure. Responding to the recognition of the above challenges, we have assembled a team with the expertise and critical mass to solve these key barriers. Led by Oxford, the team is composed of 19 co-investigators from 6 UK institutions (Liverpool, Cambridge, Sheffield, Glasgow, St. Andrews, and UCL), 19 postdocs and 7 PhD students who are all working together to tackle the aforementioned issues. In my presentation, I will summarize the scientific highlights from the first year of the SOLBAT project and the overall scientific direction.

Figure 1
(Invited) NMR Studies of Li Metal Dendrite Formation and Coatings
Authors: Marbella Lauren E , Emge Steffen , Grey Clare P.
Published: February 2020

All solid-state batteries (ASSBs) potentially offer safe electrochemical energy storage as they do not require the liquid organic electrolyte. However, in order to achieve high energy densities that are competitive with conventional lithium ion cells, Li metal anodes are required. Even when nominally pin-hole free ceramic membranes are used, issues surrounding Li microstructural growth and subsequent cell death persist, particularly at high current densities. The use of 7Li magnetic resonance chemical shift imaging to track Li microstructural growth in solid electrolytes will be discussed in this talk. Applications to garnet solid-electrolyte will be described.

We follow the early stages of Li microstructural growth during electrochemical cycling – from the formation of Li on the electrode surface to dendritic Li connecting both electrodes in a symmetrical cell and correlate these changes with electrochemistry (e.g. short circuiting). At low current densities, 7Li MRI detects the formation of Li microstructures in cells before obvious electrochemical signatures indicating their presence are observed.
Nanofluid Reinforced Polymer Electrolytes for Safe and High Energy Density Secondary Lithium Batteries
Authors: Bose Pallab , Deb Debalina , Bhattacharya Subhratanu
Published: February 2020

Using lithium metal anode comprising remarkably high theoretical capacity with lowest negative electrochemical potential is an attractive way to increase the low energy density of current lithium-ion batteries.However, the application of lithium metal in presence of conventional organic-solvent-based electrolytes is hindered by severe safety concerns such as leakage, electrode corrosion, flammability and the inevitable growth of lithium dendrite in the electrolytes during repeated Li deposition/dissolution processes. In this concern, gel polymer membranes as both separators and electrolytes have enabled tremendous recent research interest to achieve safer, high-energy density rechargeable batteries.Extending the research further, a novel class of nanocomposite gel polymer membrane electrolytes is prepared by blending poly(vinylideneﬂuoride-co-hexaﬂuoropropylene) copolymer with a unique class of reinforcing agent, a highly conducting ionic liquid-based nanofluid, followed by soaking the resulted membranes into lithium salt dissolved liquid electrolyte. The conductivity of the nanofluids is optimized by dispersing different wt% of surface functionalized TiO2 nanoparticles in N-alkyl-N-butyl pyrrolidinium bis (trifluoromethylsulfonyl) imide (Pyr14TFSI) ionic liquid host. The best-conducting electrolyte containing 50wt% nanofluid shows excellent electrode/electrolyte interfacial stability when used in Li/LiFePO4 cell and delivers a discharge capacity of ~155 mAh g-1 at 25 °C at a considerably higher current density of 35 mAg-1. Excellent rate performance with superior capacity retention of the cell as compared to that comprising bare PY14TFSI ionic liquid reinforced gel polymer electrolyte indicates tremendous application potentiality of this novel class of electrolyte for safe and high energy density secondary lithium batteries.
Extraction Effect of Ni-Zn By Electrodeposition from Aqueous Acid Solutions
Authors: Addi Yassine
Published: February 2020

The electrodeposition of Zn-Ni is classified by Brenner (1) as anomalous codeposition, because zinc, the less noble metal, is preferentially deposited to nickel the more noble metal. The inhibition of H+ reduction occurs with increasing Zn ions concentration in solution (2). Anomalous codeposition is favored in chloride medium and inhibited in boric acid (3).

The reaction kinetic of Zn-Ni codéposition was investigated in acid solutions .The effects of solution composition and pH were analyzed. The inhibition of H+ reduction occurs with increasing Zn ions concentration in solution. Increasing pH values causes Zn deposition during Ni-Zn codeposition. Anomalous codeposition is favored in chloride medium and inhibited in boric acid. When alloy deposition becomes the main process, the interfacial pH is governed by the individual metal deposition that controls the kinetic behavior. The interfacial pH increases during separate Ni deposition, meaning that it occurs with simultaneous consumption of H+. Anomalous codeposition process is not due to a saturation of species at the electrode surface. Results show that it is possible to obtain alloys rich in either nickel or zinc , from an acidic solution,depending on the Ni/Zn concentration ration. For Ni/Zn concentration ratios in the range of 1-5, zinc rich alloys are obtained despite Zn is the less noble metal and even when it is present lower concentrations than nickel. For the highest Ni/Zn concentrations ratio ≥100, the formation of the alloy occurs by a normal deposition, resulting in Ni-rich alloys.

Boric acid extends the proton discharge potential to more cathodic values. Thus it can reduce anomalous codeposition since the presence of 0,8M of acid reduces the intensity of the peak corresponding to δ phase that is rich in zinc and enhances the intensity of γ phase containing more nickel than the δ phase.
Enhanced Cyclability of Li-Metal Batteries Using Aromatic Porous Layer
Authors: Woo Jung-Je , Jang Il chan , Song Jinju , Kim Hyun-Kyung , Choi Sunghun
Published: February 2020

The high capacity and low potential make Li-metal ideal anode material for high energy density batteries. However, its poor cyclability and safety issue prevent the practical use of Li-metal for rechargeable batteries. The degradation of Li-metal is mainly caused by dendrite formation of deposited Li and decomposition of liquid electrolyte at the interface between Li-metal and a separator. We modified the interfacial structure using aromatic porous layer (APL) to form stable SEI layer and minimize dendritic growth of Li-metal. Without APL, the surface of SEI/Li-meal was rough, and there were small cracks. However, APL led to formation of smooth SEI/Li-metal surface. In addition, the use of APL changed the structure of Li dendrite from a sharp needle-like shape to a blunt flower-like shape, which reduces the problematic electrolyte decomposition reaction. For this reason, APL improved cycling efficiency of Li dendrite. We tested a NMC/Cu cell to investigate the cycling efficiency of Li-dendrite. The cell assembled with APL showed 2 times higher efficiency compared to that of normal NMC/Cu cell. Due to stable interface between Li-metal and separator, the cyclability of a NMC/Li-metal cell with APL was remarkably improved. After 100 cycles, the residual capacity of the APL cell was 3 times higher than that of the conventional NMC/Li-metal cell.
Impact of Processing Conditions on Oxygen Vacancies in Ga-Doped Li7La3Zr2O12 Solid Electrolyte Using Tof-SIMS
Authors: Nabi Nomaan , Aguadero Ainara
Published: February 2020

Currently a vast amount of research into fast lithium ion conductors is taking place for application into solid electrolytes. The most attractive compositions being from the garnet family with the chemical composition of Li7La3Zr2O12 [1]. LLZO has high lithium ion mobility at room temperature, a large electrochemical window which allows high voltage cathodes to be employed and good stability with lithium metal anodes. Typically, LLZO is doped at the lithium position with donor cations these include Al3+and Ga3+ which provide stability of the cubic crystal phase thus allowing Li+ mobility in three dimensions. The mobility for Ga-LLZO has been reported to be above 10-3 S.cm-1 [2], [3] this is the composition that will be mainly focused on in the poster.

Preliminary investigations have shown that due to lithium loss during high processing temperatures oxygen vacancies are formed because of the charge compensation mechanism[4]. The quantification of oxygen vacancies as an affect of the processing conditions and it effect on the conductivity of oxygen and lithium ions have been investigated in this work using electrochemical impedance spectroscopy and cell cycling.

The affect of different densification atmospheres (Ar, Vac, and O2) on oxygen vacancies are measured using 18O isotopic labelling coupled with the Time of Flight Secondary Ion Mass Spectrometer (ToF-SIMS) to assess which results in a higher degree of oxygen defects. This work will be correlated with lithium defect chemistry and mobility to understand the lithium critical current density for dendrite growth which are detrimental to battery life.

References

[1] R. Murugan, V. Thangadurai, and W. Weppner, ‘Fast Lithium Ion Conduction in Garnet-Type Li7La3Zr2O12 **’, Angew. Chem. Int. Ed., vol. 46, pp. 7778–7781, 2007.

[2] C. Bernuy-lopez, W. Manalastas, J. Miguel, A. Aguadero, F. Aguesse, and J. A. Kilner, ‘Atmosphere Controlled Processing of Ga-Substituted Garnets for High Li-Ion Conductivity Ceramics’, Chem. Mater., vol. 26, pp. 3610–3617, 2014.

[3] D. Rettenwander et al., ‘Structural and Electrochemical Consequences of Al and Ga co-substitution in Li La Zr O Solid Electrolytes Structural and Electrochemical Consequences of Al and Ga co- substitution in Li7La3Zr2O12 Solid Electrolytes’, Chem. Mater., vol. 28, pp. 2384–2392, 2016.

[4] M. Kubicek et al., ‘Oxygen Vacancies in Fast Lithium-Ion Conducting Garnets’, Chem. Mater., vol. 29, p. 7189−7196, 2017.
Ethylene Vinyl Acetate: An Alternative Aqueous Binder in Positive Electrode for Lithium-Sulfur Batteries
Authors: Di Carli Mariasole , Tarquini Gabriele , Aurora Annalisa , Della Seta Livia , Prosini Pier Paolo
Published: February 2020

We have optmized the electrode blend composition and tape preparation for Li-S batteries. Ethylene vinyl acetate (EVA), an hydro dispersible polymer was employed as a binder. This allows an aqueous preparation route for the composite cathode, promoting a more eco-friendly and economical productive process. Various conductive substrates have been compared: the EVA based blend have been deposited on aluminium, carbon paper and carbon cloth sheets. The electrode morphology of the electrode was evaluated by scanning electron microscopy (SEM) and thermal stabilitiy was tested by TGA. Electrochemical testing was performed in coin cells by using lithium metal as the counter and the reference electrodes. Among the others, the electrodes realized by using ketjen black carbon and EVA showed higher specific capacity and Coulombic efficiency, of 900 mAhg-1 after 50 cycles and 99 %, respectively. This study showed that EVA represents a promising binder for the development of high capacity Li-S batteries.
Chitosan Modified with Reduced Graphene Oxide Binder for Lithium-Sulfur Battery
Authors: Kim Soochan , Yoo Gayeon , Cho Misuk , Lee Youngkwan
Published: February 2020

The lithium-sulfur battery is a great promising candidate for next generation high energy density batteries. However, the poor conductivity of sulfur and the dissolution of soluble molecular intermediates (lithium polysulfide) interrupt practical application. To address this issue, the chitosan modified with reduced graphene oxide (Chitosan/rGO) was prepared as a binder in order to improve the electrical conductivity of sulfur and suppress the dissolution of lithium polysulfide into the electrolyte. The positively charged amino group in chitosan readily binds with negatively charged surface of rGO. The high conductivity of rGO provided facile pathway for electron and ion transport and the polar functional groups in chitosan could trap the lithium polysulfide due to their high affinity which was carefully confirmed by cyclic voltammetry. The chitosan/rGO binder with optimized composition showed enhanced initial discharge capacity, 1342 mAh g-1 at 0.05 C and the reversible specific capacity after 100 cycles was 856 mAh g-1 at 0.2 C. These are attributed to synergistic effect between chitosan and rGO. This work offers a simple and effective ways for improving the capacitive performance of Li-S batteries for practical applications.
Rare-Earth Metal Doping into Lithium Stuffed Garnet-Type Electrolytes for Next Generation, Solid State, Lithium Ion Batteries
Authors: Stockham Mark , Dong Bo , Slater Peter Raymond
Published: February 2020

Lithium stuffed garnet-type materials are promising candidates for solid state electrolytes to be used in next generation, all solid state, lithium ion batteries. However, despite significant work, there are still issues to solve, such as improving the conductivity, preventing Li dendrite growth, and reducing the electrolyte/electrode interfacial resistance. There is consequently a need to investigate additional doping strategies in these garnet materials.

This work investigates doping a variety of rare-earth metals into the garnet type Li5+yLa3(Nb/Ta)2-xLnxO12 (Ln = rare earth metal, 0 > x = < 2), in order to both increase the Li content and the unit cell size, so as to enhance the Li ion conductivity. We also investigate the effect of this doping strategy on the reaction with moisture. The possible incorporation of such dopants into the high Li content Li7La3(Zr/Hf)2O12 systems is also investigated.
Heterogeneous Nucleation and Interfacial Modification of Electrodeposited Lithium
Authors: Steingart Daniel , Koel Bruce E. , Chang Wesley
Published: February 2020

There has been a recent resurgence in research on high energy density lithium metal batteries (LMBs). The successful commercialization of rechargeable LMBs requires an improved understanding of the fundamental nucleation and growth processes for electrodeposited lithium metal. These fundamental studies necessitate the use of anode-free or nearly-anode-free cells which are able to deliver the maximum theoretical capacity of lithium. Past reports in the literature tend to use significantly excess lithium, which is not representative of a practical lithium metal cell. In this work, we examine the electrodeposition of thin film (< 30 um) uniform columnar lithium directly on various current collectors. We determine the effect of both the substrate and the electrolyte interface which allow us to control the length scales of the electrodeposited lithium. The substrate overpotential has an inverse relation to the columnar diameters, but it appears that the most dominant effect comes from the composition and distribution of solid-electrolyte-interphase (SEI) components. We find that for thin film electrodeposited lithium, the columnar length scale has a minor effect on the cycling performance, whereas increasing the thickness from 5 to 10 um and fluorinating the interface appear to improve cycling performance. This work presents improved cycling performance and morphological control (via modification of bulk interfaces) of electrodeposited columnar lithium.

Figure 1
Phenothiazine-Based Redox Polymers As Cathode-Active Materials in Li/Organic Batteries
Authors: Kolek Martin , Otteny Fabian , Perner Verena , Esser Birgit , Winter Martin , Bieker Peter
Published: February 2020

The rising demand for energy storage is increasing the research on so-called next generation or beyond lithium ion battery technologies.[1] The most promising candidates are lithium metal-based batteries (LMBs) with the Li/S battery as the most advanced example.[2] Even though LMBs show a high energy storage ability, the sluggish kinetics combined with safety concerns keeps the field open for alternative battery principles. One of these are organic-based materials which offer a great opportunity for the next generation of energy storage.[3] Their energy densities are mostly lower compared to their inorganic counterparts, but the ability of fast electron transfer and therefore high kinetics leads to an increased power density (e.g. 33.6 kW kg−1[4] vs. common battery materials, e.g. 4.75 kW kg−1[5]).

Redox polymers are one of the most versatile organic-based materials for energy storage as they show decreased solubility and offer countless possibilities for modifications of the polymeric backbone and the side chains, while the polymer itself can be conjugated or non-conjugated.[6]

Herein, we present a non-conjugated redox polymer with a substituted poly(vinylene) backbone.[7] The redox active side chain consists of a methyl phenothiazine moiety and undergoes an one-electron transfer process during oxidation and forms a radical cation. This oxidation is accompanied by an anion insertion into the polymeric structure.

Due to a π-π-interaction between the side chains this polymer is able to enable long-term cycling with increased C-rates resulting in an ultra high cycling stability of 10,000 cycles with a capacity retention of 93%. In this work, we will describe these interactions and verify them with spectroscopic methods like EPR- and X-ray photoelectron spectroscopy (XPS). Additionally, density functional theory calculations (DFT) are shown which support the strong stabilizing effect of the π-π-interactions in this organic material.[7] Beside the mechanistic studies on molecular scale, we will comment further on the mechanism on the macroscopic electrode level. Here, we performed microscopic (SEM, LSM) and spectroscopic experiments (XPS, UV/Vis) to uncover the unique cycling behavior of PVMPT.[8] Finally, we will present an approach to increase the cycling capacity of the material and discuss the influence on the stabilizing interactions.[9]

References:

[1] Chu, S. et al., Nat. Mater. 2016, 16, 16.

[2] Placke, T. et al., J Solid State Electrochem
2017, 21 (7), 1939-1964.

[3] Schon, T. B. et al., Chem. Soc.
Rev. 2016, 45 (22), 6345-6404.

[4] Ni, W. et al., RSC Advances
2015, 5 (12), 9221-9227.

[5] Agostini, M. et al., Sci. Rep.
2017, 7 (1), 1104.

[6] Muench, S. et al., Chem. Rev.
2016, 116 (16), 9438-9484.

[7] Kolek, M. et al., Energy Environ. Sci.
2017, 10 (11), 2334-2341.

[8] Kolek, M. et al., Chem. Mater.
2018, 30 (18), 6307-6317.

[9] Otteny, F. et al., Adv. Energy Mater.
2018, 8, 1802151.
(Invited) Understanding the Factors Affecting the Performance of Li-Metal/Garnet Interfaces with Surface Analysis Techniques
Authors: Brugge Rowena H , Pesci Federico M , Cavallaro Andrea , Chater Richard John , Aguadero Ainara
Published: February 2020

Garnet-type electrolytes have received great attention in the development of the next generation of solid state batteries based on Li-metal anodes because of their adequate Li conductivity (greater than 1 mS cm-1 at room temperature)1–3 and stability against Li metal4. However, their applicability has been hindered due to major issues related to stability and degradation phenomena that need understanding and addressing.

The wide-ranging literature and lack of consensus with respect to the performance of garnets, in terms of Li conductivity (mS-10mS reported), polarisation resistance with Li metal (kW-W) and critical current density for dendrite formation (mA-mA) can be correlated to a lack of consistency in controlling the processing conditions for the material. This has a knock-on effect on the microstructure, local chemical composition of bulk, surfaces and grain boundaries and can also induce degradation phenomena such as segregation of secondary phases or moisture reactivity. All these parameters have a direct impact on the Li-ion dynamics in these systems, leading to significant implications on the cell performance in terms of power density and cycle life.

In this work, we use a combination of 6Li-isotopic labelling, surface analysis techniques and electrochemistry to understand factors limiting the performance of garnet electrolytes when using Li metal as an anode. Three main effects will be discussed here; first, we analyse the effect of Li-H exchange due to moisture reactivity on the Li mobility at the interface with Li metal and in the bulk of the electrolyte5; second, we study the effect of local chemical inhomogeneity on the critical current density for dendrite formation6 and finally, we analyse possible ways to reveal Li-ion mobilities within grain, grain boundaries and interfaces using 6Li isotopic labelling and in situ techniques.

Our main results highlight the complexity of these systems and propose new in situ techniques to gain a deeper understanding of the processes taking place. In this regard, we introduce a novel and beyond state of the art dual secondary ion mass spectrometer (SIMS) aimed at innovative 3D chemical and microstructural analysis with in operando capabilities.

(1) Bernuy-lopez, C. et al.
Chem. Mater.
2014, 26, 3610–3617.

(2) El Shinawi, H.; Janek, J. J. Power Sources
2013, 225, 13–19.

(3) Rettenwander, D et al.
Inorg. Chem.
2014, 53 (12), 6264–6269.

(4) Thangadurai V., D. et al. J. Phys. Chem. Lett., 2015, 6, 292–299.

(5) Brugge R. et al. Chem. Mater. 2018, 30, 3704

(6) Pesci F. et al. J. Mat. Chem A. 2018, 6, 19817
Solid-State Lithium and Li-Ion Batteries with Solid Nano-Composite Electrolytes
Authors: Debucquoy Maarten , Mees Maarten J. , Sagara Akihiko , Remizov Sergey , Chen Xubin , Gandrud Knut Bjarne , Put Brecht , Kaneko Yukihiro , Vereecken Philippe M.
Published: February 2020

Solid electrolytes with a Li-ion conductivity exceeding 1 mS/cm are a prerequisite to enable solid-state Li-ion batteries. In solid composite electrolytes (SCEs), the interface between an ionic conductor and a dielectric matrix can be engineered to enhance this ionic conductivity. The solid composite electrolyte developed at imec contains a monolithic, mesoporous, silica matrix filled with a non-volatile ionic liquid and an organic Li-salt. This composite material is made by a sol-gel process, similar to that for ionogels, with that difference that no acid is used but water. The resulting aqueous gel is carefully dried from water and solvents, resulting in the solid nano-composite electrolyte where the ionic liquid and the lithium salt are confined in the pores and channels of the mesoporous silica matrix. The slow sol-gel reaction and drying allows the adsorption of an ordered molecular layer on the fully hydrolyzed silica surface. Interfacial ice layers induce strong adsorption and ordering of the ionic liquid molecules through H-bonding, rendering them immobile and solid-like as for the interfacial ice layer itself. The dipole over the adsorbate results in solvation of the Li+ ions for enhanced conduction. We demonstrate that when the silica surface is appropriately hydroxylated, the Li-ion conductivity of the nano-SCE can be several times higher than that of the pure ionic liquid electrolyte itself. By this process solid nano-SCEs with conductivities between 0.4 and 8 mS/cm have been synthesized, using TFSI- and FSI-based ionic liquid electrolytes.

Battery cells can be made by impregnating the liquid sol-gel precursor solution inside the powder-based electrodes, very similar to the application of liquid electrolytes. As our precursor solution does not contain corrosive acid compounds such as formic acid, which is typically proposed as catalyst in literature recipes, we can deposit the solution directly on and into the porous electrodes. The sol-gel reaction and drying take place in-situ inside the electrodes allowing the nano-SCE to fill the empty spaces and providing an all-around contact with the active material. As such, we are able to realize functional solid-state cells with the TFSI- and FSI-based nano-SCE. Not only low voltage cells with LFP and LTO electrodes, but also high voltage cells with NCA and Li metal or Li alloy electrodes are demonstrated (Fig 1a and b). C-rate and cycling performance of these solid-state cells with the nano-SCE are given.

Figure 1
Lithium Metal Protection through Flexible Composite Electrolyte with Immobilized Anions
Authors: Zhang Qiang
Published: February 2020

Li metal electrode is regarded as a “Holy Grail” anode for next-generation batteries due to its extremely high theoretical capacity and lowest reduction potential. Unfortunately, uncontrolled dendrite growth leads to serious safety issues. This work realizes a dendrite-free Li metal anode by introducing anion-immobilized composite solid electrolyte, where anions are tethered to polymer chains and ceramic particles. Immobilized anions contribute to uniform distribution of Li ions and dendrite-free Li deposition. The flexible electrolyte can be applied in all-solid-state Li metal batteries with excellent specific capacities. This work demonstrates a concept to adjust ion distribution based on solid-state electrolytes for safe dendrite-free Li anodes, paving the way to practical Li metal batteries.

References

1. Zhao CZ, Zhang XQ, Cheng XB, Zhang R, Xu R, Chen PY, Peng HJ, Huang JQ, Zhang Q. Proceedings of the National Academy of Sciences of the United States of America (PNAS) 2017, 114, 11069-11074.

2. Zhao CZ, Chen PY, Zhang R, Chen X, Li BQ, Zhang XQ, Cheng XB, Zhang Q. Science Advances 2018, 4, eaa3446.

3. Zhang XQ, Zhao CZ, Huang JQ, Zhang Q. Engineering 2018, 4, 831-847.

4. Yan C, Yao YX, Chen X, Cheng XB, Zhang XQ, Huang JQ, Zhang Q. Angewandte Chemie International Edition 2018, 57, 14055–14059.
CORP: Using transgenic mice to study skeletal muscle physiology
Authors: Mobley C. Brooks , Vechetti Ivan J. , Valentino Taylor R. , McCarthy John J.
Published: February 2020

The development of tissue-specific inducible transgenic mice has provided a powerful tool to study gene function and cell biology in almost any tissue of interest at any given time within the animal’s life. The purpose of this review is to describe how to use two different inducible transgenic systems, the Cre-loxP system and the Tet-ON/OFF system, that can be used to study skeletal muscle physiology. Myofiber- and satellite cell-specific Cre-loxP transgenic mice are described as is how these mice can be used to knockout a gene of interest or to deplete satellite cells in adult skeletal muscle, respectively. A myofiber-specific Tet-ON system is described as is how such mice can be used to overexpress a gene of interest or to label myonuclei. How to effectively breed and genotype the transgenic mice are also described in detail. The hope is this review will provide the basic information necessary to facilitate the incorporation of tissue-specific inducible transgenic mice into a skeletal muscle research program.