bluuebunny/crossref_metadata_2025 huggingface dataset:
Glyme-Li Salt Solvate Ionic Liquids for Advanced Lithium Batteries
Authors: Watanabe Masayoshi
Published: February 2020

Certain molten complexes of Li salts and solvents can be regarded as ionic liquids. In this study, the local structure of Li+ ions in equimolar mixtures ([Li(glyme)]X) of glymes (G3:triglyme and G4: tetraglyme) and different Li salts was investigated to discriminate between solvate ionic liquids and concentrated solutions. Raman spectroscopic analysis allowed us to estimate the fraction of the free glyme in [Li(glyme)]X. The amount of free glyme was estimated to be a few percent in [Li(glyme)]X with perfluorosulfonylamide-type anions, and thereby could be regarded as solvate ionic liquids. Other equimolar mixtures of [Li(glyme)]X were found to contain a considerable amount of free glyme, and they were categorized as traditional concentrated solutions. The activity of Li+ in the glyme-Li salt mixtures was also evaluated by measuring the electrode potential of Li/Li+ as a function of concentration. At a higher concentration of Li salt, the amount of free glyme diminished in the solvate ionic liquids, leading to a drastic increase in the electrode potential. Unlike conventional electrolytes (dilute and concentrated solutions), the solvation of Li+ by the glyme forms stable and discrete solvate ions ([Li(glyme)]+) in the solvate ionic liquids. This anomalous Li+ solvation had a great impact on the electrolyte properties and electrode reactions, which enhanced the utility of the solvate ionic liquids in advanced lithium batteries such as Li-S batteries.
Probing Reactivity at the Electrode and Electrolyte Interface
Authors: Shao-Horn Yang
Published: February 2020

Understanding reactions at the electrode/electrolyte interface (EEI) is essential to developing strategies to enhance cycle life and safety of lithium batteries. There is limited understanding by what means different components are formed at the EEI and how they influence EEI layer properties for positive electrodes. High-capacity layered oxides, which can generate highly reactive species toward the electrolyte via oxygen anion redox, highlight the critical need to understand reactions with the electrolyte and EEI layers for advanced positive electrodes.
Ion Solvation Effects in the Nonaqueous Li-O2 Electrochemistry
Authors: McCloskey Bryan D
Published: February 2020

Multiple directions in battery research are now being pursued in hopes of advancing beyond the specific energy limits imposed by conventional Li-ion electrode materials.  For example, ‘beyond Li-ion’ battery chemistries, such as Li-O2, Li-S, and Mg-ion, are currently being explored as potential successors to Li-ion batteries given their very high theoretical specific energies; yet severe technical challenges have prohibited them from becoming a practical reality.  The objective of this presentation is to provide an assessment of such challenges, in particular, instabilities of the electrolyte and cathode, and Li2O2 electronic conductivity limitations, facing the nonaqueous Li-O2 battery cathode. Results will be presented on the characterization of the Li2O2 formation mechanism and how the mechanism can be manipulated through electrolyte engineering to potentially alleviate problems associated with Li2O2 deposition on the cathode.
Simple Metal Oxide as a New Cathode for Lithium Ion Batteries
Authors: Kang Kisuk
Published: February 2020

In our continuing efforts of redox composite electrode, we identify that simple metal oxides in the redox composite can function as execellent cathode for lithium ion batteries via a new lithium storage mechanism, so called "surface conversion reaction".
Silicon Foam Anode with Stabilized Interface for Lithium-ion Batteries
Authors: Ma Tianyi , Liu Yuan , Zhu Wentao , Qiu Xinping
Published: February 2020

Silicon has been regarded as an optimized anode material of LIBs1-4 due to its low discharge potential and high specific capacity. Challenges from the huge volume change during the alloying reaction of silicon with lithium still obstacle the application of silicon anode, since the huge volume change causes particle pulverization, electrode disintegration and the solid electrolyte interphase (SEI) film ceaseless growth.  Although some nano-structured silicon anode materials, such as hollow nanospheres, silicon core-hollow carbon shell nanocomposites, 1D hollow silicon nanotubes, showed the improved cycle performance. However, the ceaseless growth of SEI film is still absence of evidence. In this work, we report a facile approach to prepare silicon foam with hollow structure with a chemical vapor deposition (CVD). With the built-in space, this silicon foam presents remarkable capacity retention and fairly high coulombic efficiency. The method combining the electrochemical impedance spectroscopy with differential scanning calorimetry (DSC) to elucidate the SEI stability was developed, which confirm that silicon foam have more stabilized interface.

Reference:

1.             Huggins, R. A. J. Power Sources
1999, 81, 13-19.

2.             Park, C.-M.; Kim, J.-H.; Kim, H.; Sohn, H.-J. Chem. Soc. Rev.
2010, 39, (8), 3115-3141.

3.             McDowell, M. T.; Lee, S. W.; Nix, W. D.; Cui, Y. Adv. Mater.
2013, 25, (36), 4966-4984.

4.             Su, X.; Wu, Q.; Li, J.; Xiao, X.; Lott, A.; Lu, W.; Sheldon, B. W.; Wu, J. Adv. Energy Mater.
2014, 4, (1), 882-882.
Combining Reversible Oxygen Charge Transfer and Li-Excess to achieve High Capacity Cathodes
Authors: Ceder Gerbrand
Published: February 2020

The highest energy density cathode materials are currently found among the layered compounds based on Ni,Co and Mn, but achieving much more than 200mAh/g has become difficult.  Two new ideas are promising to obtain substantially higher cathode capacity:  1) By using a substantial amount of Li-excess, cathodes can be made tolerant to metal disorder thereby enabling the use of a much larger group of transition metals, while achieving capacities well above 200 mAh/g.  2) Reversible redox process that take place on the oxygen ions rather than on the transition metal ions are now well established and can reduce the transition metal content of cathode compounds.  I will explore the physics of both these new directions and demonstrate with several examples how they have enabled novel high-capacity cathodes.
Materials for High Energy Lithuim Ion Batteries
Authors: Kim Il-Seok
Published: February 2020

Advancement of smart electronics, evolution of wearable devices, and growing interest in electric vehicles have created significant needs for lithium-ion batteries (LIBs) with high energy density that provide longer usage time, smaller size, and extended driving range, respectively. Since its introduction to market in 1991, the energy density of lithium-ion batteries (LIBs) has increased significantly, which has been possible through innovation in materials technologies and cell engineering. To meet market’s expectation for LIBs as power sources for electric vehicles and next generation mobile devices, however, further breakthroughs are needed, especially in active materials. In this presentation, recent status and progress in active materials in commercial high energy density LIBs will be discussed.
Suppression of Polysulfide Transfer by Polypyrrole Modification on Cathode in Lithium-Sulfur Battery
Authors: Momma Toshiyuki , Nakamura Natsuki , Yokoshima Tokihiko , Nara Hiroki , Osaka Tetsuya
Published: February 2020

Sulfur is one of the candidates for cathode of Li battery to realize improved capacity of the cell. The issues to be solved are selection of electrolyte which is compatible to both of sulfur cathode and anode, and high solubility of polysulfides generated during the charge-discharge operation of cathode. The dissolved polysulfide into the electrolyte phase inside the battery leads chemical shortage between the cathode and the anode, i.e. the dissolved redox active polysulfide works as redox shuttle between the electrodes, and causes difficulty of charging and self-discharge. Some ideas to stop the dissolution of polysulfide are proposed, such as (1) apply sulfide organic  compound with high molecular weight or polymer as the cathode active material, (2) use insoluble solvent for electrolyte solution, (3) control the mass transfer of Li+ and polysurfide, and so on. For blocking the transfer of dissolved polysulfide, cell structure with the perm-selective membrane inserted the between the electrodes by placing in the electrolyte phase or by covering one of the electrode can be considered. In those cases, the perm-selective membrane should have the property of well-transporting of Li+ with low impedance beside the non-transfer of polysulfide. Since polysurfide has negative charge, cation exchange membrane would be the one of the candidates for the perm-selective membrane.

Ion exchange membrane is well known to be designed with polymer having anionic groups inside the matrix. Polypyrrole, which is known as a redox active polymer and is able to be formed as a sheet form on conducting substrate by electro-oxidative polymerization as anion doped state. Polypyrrole doped with anion having large size exhibit an interesting properties, such as cation exchange properties. For example, Polypyrrole doped with polyanion, such as polystyrenesulfonate acts as cation exchange membrane.

In this work, we prepared polypyrrole doped with soft/large anion by electropolymerization method forming directly onto the surfur-carbone composite cathode. The prepared polypyrrole film was confirmed to exhibit cation exchange properties, and the film prepared on S-C composite electrode was found to be formed with covering the S and C phase. The electrtode of S-C composite covered by polypyrrole exhibits discharge capacity of over 800 mAh/g(sulfur) at 0.1C-rate with the current efficiency of above 95% during the continuous charge-discharge cycling. The detailed battery performance of the polypyrrole coated S cathode and effect of polypyrrole formation condition to the the battery perrormance will be introduced.
Towards Na-ion and K-ion Batteries
Authors: Komaba Shinichi
Published: February 2020

We have been studing electrode and electrolyte materials for Li-ion batteries.  In the past 10 years, we have also studied the materials for Na-ion batteries.  Indeed we succeeded high-capacity or high-energy positive / negative electrode materials including binders and electrolytes.  Recently, we expand our research target to K-ion batteries, which is potentially expected to show higher-power and higher-voltage than those of Li- and Na-ion batteries.  We will talk about our recent achievement on electrode and electrolyte materials and surface chemistry for Na-ion and K-ion batteries and will discuss similarity and difference compared with Li-ion ones.
NMR Beyond Li: New Approaches in Studying Na, Mg and Li-air Batteries
Authors: Grey Clare P. , Liu Tao , Kim Gunwoo , Clement Raphaele , Allan Phoebe , Stratford Josh , Lee Jeongjae , Seymour Ieuan , Liu Zigeng
Published: February 2020

This talk will describe the use of NMR spectroscopy to characterize a series of “beyond-Li” electrode materials.  The NMR results are combined with complementary techniques such as pair distribution function analysis of (X-ray) scattering data.  In the sodium-ion battery case, 23Na NMR spectroscopy can be used to follow changes in local structure in a manner very similar to that performed on lithium-ion battery materials.  Our work using the method to study local structure and Na+ and electronic ordering in positive layered materials and intermetallic anodes will be described. 25Mg NMR is more challenging, but the use of DFT calculations to predict shift positions and help interpret the spectra speeds up the analysis considerably.  This will be illustrated for paramagnetic positive electrode materials.  The use of NMR and MRI (magnetic resonance imaging) to link structural changes with electrolyte concentrations will be demonstrated for lithium metal anodes.  Finally, new developments in the field of lithium-oxygen batteries will be described.  In particular NMR spectroscopy allows the different discharge products and many side-reactions to be followed.  For example, 1H and 7Li NMR spectroscopy can be used to separate Li2O2 from LiOH, allowing the formation and removal of LiOH to be quantified.  Our recent studies with LiI redox mediators and r-GO electrodes will be described.
Nanoscale Anode and Cathode Materials for (Li/Na/Mg/Al)-ion Batteries
Authors: Kovalenko Maksym V.
Published: February 2020

We will discuss the utility of monodisperse metallic nanocrystals as model anode material for Li-ion, Na-ion and Mg-ion batteries. Furthermore, novel strategies for designing low-cost magnesium-ion and aluminum-ion batteries using metallic magnesium and aluminum as anodes and carbonous materials as cathodes will be presented as well.
Ionic Liquids - A Unique Palette to Create Advanced Electrolytes
Authors: Best Adam Samuel , Barghamadi Marzi , Bhatt Anand , Francis Candice , Hollenkamp Anthony F. , Huynh Thuy Diem , Mahon Peter , Musameh Mustafa , Ruether Thomas , Sharma Neeraj , Webster Nathan
Published: February 2020

The drive to identify high energy batteries remains an on-going challenge. There are two key R & D thrusts at this time – next generation Lithium-ion batteries that (i) require the use of intercalation materials that can operate high voltages (5 V vs Li|Li+) and (ii) alternative high energy density electrodes such as Sulfur (2567 Wh/kg) or the holy-grail for the field, an air breathing cathode (3505 Wh/kg). To harness these high energy densities Lithium metal anodes are required as one of very few alternatives. In both instances, there is a distinct need to develop electrolytes that are stable under strongly oxidising environments and strongly reductive environments, respectively.

To this end, CSIRO has been actively researching ionic liquid electrolytes as an option to replace aprotic solvent based electrolytes in batteries. Ionic liquids have some unique properties in terms of negligible vapor pressure, relatively high conductivity, wide electrochemical windows and high thermal decomposition temperatures. This makes them ideally suited to a range of electrochemical storage devices, specifically those that are being targeted at this time.

(i) High voltage lithium-ion batteries require electrolytes that are stable in contact with intercalation cathode at potentials > 4.5 V (vs Li|Li+) and do not cause Al current collector corrosion. To-date, there are very few materials that can achieve both of these goals. We will describe work we have been undertaking to determine failure modes of both active materials and electrode structures and the role of the electrolyte in solving these issues.

(ii) Although a 10 fold increase in specific energy is possible with recent advances in Li-Sulfur (2567 Wh / kg) technologies, there are several challenges in the development of these devices. The most vexing of these challenges is the generation of lithium polysulfides which are highly prone to irreversibly move into the electrolyte media. These can have deleterious effects on the performance of the device such as reduced capacity and cycle-life. To overcome this problem, numerous different approaches have been trialled to “lock” S within a conductive structure / matrix whilst still making it available to lithium ions from the electrolyte to form the required lithium polysulfides that deliver the high capacity of the device.

At CSIRO, we have been looking at a range of different methodologies to understand the formation of polysulfides both in the electrolyte and the cathode and then examine various methods to keep them electrically connected within the cathode. In this presentation, we will highlight our work methods to prevent polysulfide dissolution via changes to the electrolyte and the effect on cycling and in-situ studies at the Australian Synchrotron.
Ab-Initio MD Simulations of Redox Reactions of Liquid Electrolytes and SEI Formation
Authors: Tateyama Yoshitaka
Published: February 2020

Atomistic understanding of solid electrolyte interphase (SEI) formed at the interface between electrode and liquid electrolyte is still an issue of greatest importance. However, difficulties in experimental in-situ observations and simulations considering the liquid dynamics (fluctuation) and reaction have inhibited elucidation of physics and chemistry of SEIs. We have addressed such unresolved issues by means of accurate large-scale ab-initio molecular dynamics (AIMD) samplings and free energy calculations on supercomputers.

 The SEI formation is initiated by electrochemical decomposition of the electrolyte molecules such as solvents and additives. Slight change of the electrolyte component often exhibits a large impact on the SEI quality. We first examined the reductive decomposition of the electrolyte molecules at charging (reductive) environment, using a typical electrolyte with ethylene carbonate (EC) solvents and vinylene carbonate (VC) additives. We carried out AIMD free energy calculations for possible decomposition pathways, and found that VC passivation to EC anion radical is a more appropriate mechanism than the conventional scenario with sacrificial reductive decomposition of VC (Fig. (a))1. This novel mechanism can explain the decrease of irreversible capacity and the CO2 evolution with a small amount of VC additives observed experimentally.

 Next, we extracted stable organic SEI film components (SFCs) from the products of the reductive decompositions of the electrolyte. We then investigated the characteristic of the probable SFC amorphous aggregates on the adhesion to the graphite electrode and the interfacial electronic states. The results showed that the SFC aggregates have characters of “unstable adhesion” to the graphite surface and “high electronic insulation”. With these results, we discussed that a near-shore aggregation mechanism of SFCs is promising for the SEI film formation.2 Very recently, we examined inorganic SFCs as well to elucidate their roles in the SEI formation.3 These new findings with supercomputer simulations give important perspectives for more efficient and reliable batteries.

1. K. Ushirogata, K. Sodeyama, Y. Okuno, Y. Tateyama, J. Am. Chem. Soc.
135, 11967-11974 (2013).

2. K. Ushirogata, K. Sodeyama, Z. Futera, Y. Tateyama, Y. Okuno, J. Electrochem. Soc.
162, A2670-2678 (2015).

3. Y. Okuno, K. Ushirogata, K. Sodeyama, Y. Tateyama, submitted.

Figure (a) Proposed role of VC additive in reductive decomposition of the EC-based electrolyte. (b) Schematic picture of the near-shore aggregation mechanism for SEI formation on a graphitic electrode.

Figure 1
Ceramic Interface (Ceramic Coated Separator) and Li-Ion Safety/Performance
Authors: Zhang Zhengming John
Published: February 2020

One of the great innovations in Li-ion batteries: ceramic interface via ceramic coated separator made the transition of its polymer based separator to ceramic coated (interface) separators during the last a couple of years. Nearly 90% Li-ion batteries in consumer electronics and 2nd generation EDV are using ceramic coated separators today. This ceramic interface via ceramic coated separator greatly enhanced Li-ion energy density (reduced oxidation of separators that enable the use of high voltage cathodes), greatly improved battery safety (reduce the thermal propagation to avoid serious thermal runaway) and battery life (ceramic react with oxidized electrolytes, H2O and HF that continuously purifies the electrolyte). The development, mechanism, specific ceramic interfaces and battery results will be presented and discussed.
Systematic Binder Design in High Capacity Silicon Anodes
Authors: Choi Jang Wook
Published: February 2020

Polymeric binder has turned out to be very critical for stable operation of high capacity silicon (Si) anodes, as the binder could stabilize the electrode films even during the large volume change of Si. In this talk, I will present novel approaches for functional binder design. They include 1) the use of mussel-inspired catechol functional group, 2) multi-dimensional cross-linkable hydrogen bonding network, 3) self-healing polymer network, and 4) host-guest interaction network. The series of these investigations suggest the usefulness of noncovalent polymer interactions and the future role of supramolecular chemistry in the binder design.
A Cost Efficient Silicon-Carbon based Anode Material for Lithium-Ion Batteries
Authors: Voje Jorunn , Kirkengen Martin
Published: February 2020

Silicon as anode material for Li-ion batteries is interesting due to its very high theoretical capacity. However, the positive ability to accommodate up to four lithium ions per silicon atom has a corresponding downside in the extreme changes occurring in the battery, usually leading to rapid degradation. A silicon-carbon composite made by a cost-effective and environmental-friendly production of the raw materials has been tested. The effect of silicon quality, as chemical composition and particle size as well as binder composition and electrolyte additives, have been examined. Post mortem studies were performed to understand the mechanisms. The tests showed more than 1200 cycles of a 600 mAh/g total anode.
Oxygen Electrochemistry in Aprotic Li-Air Batteries
Authors: Peng Zhangquan
Published: February 2020

As a promising candidate for next generation energy storage system, Li-air battery has generated a great deal of interest over the past decade. However, realization of the practical Li-air battery is a formidable challenge, and is impeded by some fundamental key issues including the degraded capacity, limited cycle life, notoriously low round-trip efficiency and limited stability of battery components, which are currently being tackled by numerous approaches. From the viewpoint of fundamental study, a better understanding of the oxygen electrode reactions in aprotic electrolyte will be beneficial to the realization of Li-air batteries with improved electrochemical performances. Here, a mechanistic study of oxygen electrochemistry in aprotic Li+ electrolyte has been conducted using Raman spectroelectrochemistry coupled with density functional theory calculations. By spectroscopic identification of oxygen intermediates under various operating conditions, different routes for Li2O2 formation have been revealed.
Can We Control Polysulfide Formation and Migration?
Authors: Dominko Robert
Published: February 2020

Polysulfide dissolution and the correlated parasitic reactions are two major reasons for the capacity fading in the Li-S batteries. By understanding the mechanism of the electrochemical reactions in this system, one can introduce appropriate modifications in the components design which can effectively suppress or completely stop polysulfide migration or even their formation. In this talk a special attention will be paid to development of iono selective membranes designed and optimized for use in the Li-S batteries. Additionally, mechanism(s) of Li-S battery operation will be discusses based on the analytical work using operando XAS and UV-Vis measurements.
Multi-Scale Characterization of Electronic and Ionic Limitations to Power Performance of Composite Electrodes Toward Ultra-High Surface Capacities
Authors: Lestriez Bernard , Etiemble Aurelien , Besnard Nicolas , Jimenez-Manero Pablo , Tran-Van Pierre , Dubrunfaut Olivier , Gaubicher Joël , Guyomard Dominique , Badot Jean-Claude , Maire Eric
Published: February 2020

By using a set of advanced techniques such as the broad band dielectric spectroscopy, X-Ray and FIB-SEM computed tomography, it will be described which factor(s) (material properties, engineering parameters) mainly influence the rate discharging behavior of NMC- or LFP-based composite electrodes. This fundamental understanding will be rationalized to disclose ultra-high surface capacities electrodes (more than 10 mAh / cm²) with reasonable rate performance.
One-Step Pyro-Synthetic Strategy of LiFePO4-Li3V2(PO4)3 Nanocomposite with a High Energy Density for Lithium-Ion Batteries
Authors: Jo Jeonggeun , Song Jinju , Kim Sungjin , Alfaruqi Muhammad Hilmy , Kim Seokhun , Kim Yeoeun , Nam Sukyung , Kim Jaekook
Published: February 2020

In commercially available Li-ion cells, cobalt-based oxide is utilized as the cathode material, but its high cost and low thermal stability prohibit the large-scale use such as Energy Storage Systems (ESS) and Electric Vehicles (EV). Lithium iron phosphate (LiFePO4) and lithium vanadium phosphate (Li3V2(PO4)3) exhibit good thermal stability and high operating voltage, which make them the most promising cathode candidates so far. Despite of their advantages, LiFePO4 and Li3V2(PO4)3 also have some drawbacks. For instance, LiFePO4 has a stable voltage platform and its cyclic attenuation rate is almost negligible, but its relatively low capacity and low voltage limit its energy density and consequently limits its use. Li3V2(PO4)3 has a higher voltage, however, it  suffers from its stepped voltage platforms and severe cycle attenuation. In order to combine the advantages from both materials, many research groups have attempted by designing hybrid materials since the doping approach can only improve the main material without combining the advantages of two different active materials.

In this work, we focus on obtaining nanostructured materials as well as hybrid materials by using pyro-synthetic method which is very effective for production of highly crystalline carbon coated nanomaterials under very short reaction times in open-air conditions. Further, the pyro-synthetic route using polyol medium will be beneficial for producing nanomaterials in terms of time and cost effectiveness because the combustion strategy is also applied to this strategy. Moreover, poly alcohols or polyols such as ethylene glycol and di/tri/tetra ethylene glycol can play multi-roles of a solvent, a reducing agent and a carbon source.

We have successfully synthesized 0.66LiFePO4•0.33Li3V2(PO4)3 nanocomposites with high crystallinity by one-step pyro-synthetic strategy using the polyol at low temperature. The as-prepared sample without any additional heat treatment showed average particle size of about 30 – 60 nm and spherical shape as observed by SEM studies. After moderate heat-treatment was applied, the particle sizes of 0.66LFP•0.33LVP increased due to crystal growth of monoclinic phase of LVP accompanied by particle agglomeration. When tested for lithium-ion cell, the nanoparticles composite electrode demonstrated impressive electrochemical properties with enhanced energy density. Furthermore, it showed high reversible capacity of 145.65 mAh g-1 at 0.1C and exhibited remarkable capacity of 119 mAh g-1 at 6.4C. After cycled at 6.4C, the electrode can recover to 85% of its initial capacity when the current density returned back to 0.1C indicating the excellent rate capabilities of the present electrode.
Porous TiO2 Electrodes Prepared By a Rapid Pyro-Synthesis for Advanced Lithium-Ion Batteries
Authors: Mathew Vinod , Gim Jihyeon , Oh Yunpyo , Alfaruqi Muhammad Hilmy , Song Jinju , Kim Sungjin , Jo Jeonggeun , Vu Thi Trang , Kim Seokhun , Lee Seulgi , Kim Jaekook
Published: February 2020

In this study, anatase-type titanium dioxide (TiO2) anodes were prepared by a polyol-assisted pyro-synthetic process followed by mild annealing in the range of 300 to 600 °C. The XRD studies confirmed the formation of anatase-type TiO2 and the Scherrer formula aided in establishing the average crystallite size to be less than 50 nm for all of the prepared samples. Electron microscopy studies revealed the average particle-size to be in the range between 5 and 50 nm whereas the adsorption studies demonstrated the mesoporous characteristics of all the prepared samples and the 500 °C electrode, in particular, exhibited tri-porosity. This unique tri-porous feature in combination with the sufficiently high particle crystallinity appears to contribute to the impressive electrochemical lithium storage (154.7 and 116.4 mAh g-1 at 3.2 and 6.4 C, respectively) in the 500 °C electrode. Furthermore, the pyro-synthetic strategy aids in developing nanostructured battery electrodes with porous morphologies and appears promising to be developed as an energy saving process for large-scale applications.
Running a Battery Lab with Low Cost Raspberry Pi's
Authors: Beattie Shane D
Published: February 2020

Building a battery R&D lab is expensive.  One of the largest capital costs is battery cyclers.  High accuracy battery cyclers can cost >$4000/channel.  A well-equipped lab requires hundreds of channels, costing hundreds of thousands of dollars.  These costs are prohibitive, which ultimately slows the discovery of new battery chemistries. 

To reduce the cost of performing research and accelerate the discovery of new materials a low cost battery cycler has been created.  A galvanostatic battery cycling daughter board has been designed that plugs directly into a Raspberry Pi (Figure 1).  The Raspberry Pi battery cycler behaves similar to commercially available cyclers (Figure 2).  The user can define: upper/lower cut off voltage, constant current charge/discharge, data save intervals and cycle number.  At scale, the unit cost is <$100/channel.  Substantially cheaper than comparable battery cycling hardware. 

The circuit was tested by cycling a commercial coin cell on the Raspberry Pi battery cycling hardware, then switching the cell to a commercial Maccor 4000 channel and comparing the results.  Data in Figure 2 shows that the performance of the Raspberry Pi circuit is very similar to a Maccor 4000.  

The Raspberry Pi battery cycling system has the following characteristics:

Low cost (< $100/channel)

Built in temperature sensors

Modular (all channels are independent)

Record data vs. time (text files) and ‘push’ data to a central server in real time

Compact and headless operation (operates over wifi, no mouse/keyboard/monitor required)

Galvanostatic charge/discharge cycling: ±5 V range, 1 uA – 10 mA, up to 0.1% accuracy

Auxiliary voltage measurements (e.g. temperature, pressure, humidity, strain, volume) synchronized with cycling data

Figure 1
Printed Cellulose Nano Fiber Separator and Its Application to All Printed Supercapacitor
Authors: Kang Heuiseok , Rho Yoonsoo , Lee Sangho , Hwang Jun Young
Published: February 2020

Electro-chemical energy devices like batteries and supercapacitors require separators. Separator prevents direct electrical current between the anode and cathode, but it provides ion path between two electrodes by keeping the electrolyte in it. To meet these two conflicting functionalities, thin porous membrane is used for the separator. The separator is usually made from polymers such as PP, PE or cellulose and provided as a ready made sheet.

In this paper, a printed separator is proposed. With a printed separator, the battery and supercapacitor manufacturing process can be improved greatly since the electrode is also manufactured by printing. Futhermore, on-demand printed battery or supercapacitor can be easily manufactured, which are required in the wearable device industries.

First, we have made a cellulose nano fiber ink from the purified cellulose powder. The powder is mixed with IPA and processed in the high pressure homogenizer to get a colloid ink. The more we process the solution in the homogenizer, the finer fiber we get. In this paper we have used an ink containing few tens nm thickness fiber.

To make a membrane from the colloid ink, we have used the Musashi dispenser which is adequate to print high viscous ink. A drop-on-demand printing method is used since the colloid ink cause clogging in a continuous printing mode. In the drop-on-demand mode, basically, three processing parameters directly affect the membrane thickness; dispensing pressure, dispensing time, and drop spacing. Among them, the drop spacing is the easiest parameter to control the membrane thickness.

Finally, all printed supercapacitor has been manufactured. On a aluminium foil, activated carbon is printed using screen printer and the cellulose nano fiber ink is printed using dispenser. The final separator thickness is about 14 µ. The capacitance of the capacitor with the printed separator is about 184 F/g, which is slightly larger than the one with the commercial separator.

Fig.1 Cyclic voltammetry for the capacitor with commercial and printed separator

Figure 1
Flow-Assist Free Zn/NiOOH Battery Prepared By Electrodeposition
Authors: Korzhynbayeva Kuralay , Hara Toru , Belgibayeva Ayaulym , Moldabayeva Azhar , Bakenov Zhumabay
Published: February 2020

Non-flammable, high durability and low cost battery is required for smart grids applications. Zinc-based rechargeable batteries such as zinc–nickel oxide systems are one of the most attractive energy storage systems for such applications due to the advantages of zinc as low cost, abundance, and low toxicity. Higher energy density in terms of both weight (Whkg−
1) and volume (WhL−
1) is also expected compared with conventional batteries such as nickel–metal hydride [1]. The primary issue limiting use of zinc anodes in rechargeable batteries is the short cycle life caused by dendrite formation upon cycling causing short circuiting [2,3]. In order to solve this problem flow-assisted Zn/NiOOH batteries have been suggested, but this battery needs flowing KOH aqueous electrolyte solution to suppress Zn whisker growth [4].  

In current work, a novel flow-assist free battery was developed to meet the requirements for above mentioned applications. This battery was prepared by electrodeposition of NiOOH cathode and anode, and using an aqueous electrolyte.

Electrodeposition is one of the most economical and facile technique for producing metal/hydroxide electrodes, which used in this work to prepare both NiOOH and Zn electrodes. The electrodes were directly electrodeposited onto three-dimensional carbon fiber paper (CFP) substrates. Both electrodeposited electrodes were characterized by scanning electron microscopy (SEM, Fig. 1) and X-ray diffraction (XRD) which confirmed formation of NiOOH and Zn, respectively.  

Galvanostatic charge-discharge tests conducted at 0.05 C rate showed that the prepared NiOOH cathode delivers a discharge capacity of 250 mAh/g when used with the electrodeposited Zn anode. Further details of the work will be presented at the meeting.

Acknowledgements

This work was supported under the Technology Commercialization Project (Grant # OK_653) supported by the World Bank and the Government of the Republic of Kazakhstan, and a research Grant #3756/GF4 from the Ministry of Education and Science of Kazakhstan.

References

[1]Y. Ito, M. Nyce, R. Plivelich, M. Klein, D. Steingart, S. Banerjee J. of Power Sources 196 (2011) 2340

[2] R.D. Naybour, J. Electrochem. Soc. 116 (1969) 520.

[3] R.Y. Wang, D.W. Kirk, G.X. Zhang, J. Electrochem. Soc. 153 (2006) C357.[4] G. Bronoel, A. Millot, N. Tassin, J. Power Sources 34 (1991) 243.

Figure 1
Lioh and Li2CO3 Removal By a Dry Process Using Atmospheric Pressure Plasma
Authors: Seok Dong Chan , You Seungryul , Jung Yong Ho
Published: February 2020

LiOH and Li2CO3 are impurities remaining in NCM (Ni, Co, Mn Oxide) cathode powder in its manufacturing. As the sources of battery swelling, they need to be removed to a very low level from the cathode material. The existing technique for removing these impurities is wet washing with such as water. N2 and NF3 mixed gas from a multi layered DBD (Dielectric Barrier Discharge) plasma can remove the LiOH and Li2CO3 in dry environment. We monitored the reaction product gas coming from the conversion reaction by QMS residual gas analyzer. The O2 and CO2 concentration was increased in the conversion reaction of LiOH and Li2CO3 respectively. The addition of little amount of H2 gas into the mixed gas increased the dissociation rate of the NF3 molecule. In that condition, the O2 concentration was decreased in LiOH conversion whereas the CO2 concentration was steeply increased in Li2CO3 conversion. This plasma process could remove up to 80% of impurities of LiOH and Li2CO3 from 622 NCM powder in just one minute.
Investigation of Solid Electrolyte Interface Formation for Battery Optimization and Safety
Authors: Parker Adrian , Mu Richard , Hargrove Samuel Keith
Published: February 2020

There is considerable interest and demand in lithium-ion batteries for electric and hybrid vehicles, satellite, defense, and military applications in addition to the need for laptops, cell phones, and other portable devices. Battery performance - the capacities and lifetimes and safety, depend largely on the formation and development of the solid electrolyte interface (SEI) layer. Battery manufacturers and end users have expressed a real need for reduction of time needed for initial SEI formation and maturation/stabilization of lithium-ion batteries. In order to sustain and increase quality, each battery produced must go through initial charge/discharge cycles and shelf time. This can take up to one month for large-scale batteries. Standard constant current/constant voltage (CC/CV) charging practices are safer, but extend charging times and do not fully utilize active materials.

In an effort to reduce the maturation time, we have changed the initial protocol from CC/CV to a pulsed protocol, and the goal is to develop, implement, test, and evaluate specific pulsing parameters to optimize SEI formation time. Experimental cells have been fabricated using a split-cell setup. These cells were charged and discharged using both CC/CV and pulsed methods, and then subjected to electrochemical impedance spectroscopy (EIS) for comparative analysis. Data retrieved during EIS analysis showed a high degree of complexity and unpredictability. Thus, current research endeavors, to be presented in the poster, include new battery array designs and employ various optical techniques used to correlate changes in the SEI layer to changes in the impedance spectra. With high precision control of battery fabrication parameters, meaningful comparative investigation of battery cell structures, charging/discharging histories, systematic characterization and analysis, it may be possible to provide knowledge of how the SEI layer and dendrites form. It will then be possible to provide “design rules” to effectively address battery performance and safety issues.
Electrode/Electrolyte Interface Contact Improvement of All Solid State Lithium Ion Batteries By Additional "Buffer Layer"
Authors: Sang Lingzi , Nuzzo Ralph G. , Gewirth Andrew A
Published: February 2020

Solid state electrolytes (SE) are believed to be the ultimate solution for the current electrode dissolution (and other stability) problems encountered in Li-ion batteries. The safety enhancements that would be engendered by a viable technology based on non-flammable solid-phase electrolyte materials cannot be overstated and would have transformational impacts.  Some of the currently developed bulk type solid state Li ion conductors exhibit comparable Li ionic conductivity as liquid electrolyte. However, poor interface contact remains to be a critical issue when assemble solid electrolyte into a useful all solid state battery. Assembly of bulk solid electrolyte into a battery usually requires deformation of interfaces between electrolyte and two electrodes high pressures to achieve good interface contact. This process is hard to handle and less reproducible. In order to avoid the high pressure press and achieve better reproducibility a liquid electrolyte based buffer Li-ion transport layer was applied at interfaces to bridge these interfaces. Results show that the cell impedance reduced by up to two orders of magnitude with the interface buffer layer.
Characterization of the Cathode Electrolyte Interface in Lithium Ion Batteries By Desorption Electrospray Ionization Mass Spectrometry (DESI-MS)
Authors: Liu Yao-Min , Nicolau Bruno G. , Gewirth Andrew A
Published: February 2020

The solid electrolyte interface (SEI) formed via electrolyte decomposition on the anode of lithium ion batteries is largely responsible for the stable cycling of conventional lithium ion batteries. Similarly, there is a lesser-known analogous layer on the cathode side of a lithium ion battery, termed the cathode electrolyte interface (CEI), whose composition and role are debated. To confirm the existence and composition of the CEI, desorption electrospray ionization mass spectrometry (DESI-MS) is applied to study common lithium ion battery cathodes. As a surface ionization method, DESI does not require matrix addition or high-energy radiation, reducing the perturbation of the surface. We observe CEI formation on both LiMn2O4 and LiCoO2 after running half-cells using 1 M LiPF6 or LiClO4 in ethylene carbonate (EC) with dimethyl carbonate (DMC). Intact poly(ethylene glycol) dimethyl ether is identified as the electrolyte degradation product on the cathode surface by the high mass-resolution Orbitrap mass spectrometer after five cycles between 3.5 and 4.5 V vs. Li/Li+. When EC is paired with ethyl methyl carbonate (EMC), poly(ethylene glycol) dimethyl ether and poly(ethylene glycol) methyl ethyl ether are found on the surface simultaneously. The presence of ethoxy and methoxy end groups indicates both methoxide and ethoxide are produced and involved in the process of oligomerization. Au surfaces cycled under different electrochemical windows as model systems for Li-ion battery anodes are also examined. Interestingly, the identical oligomeric species to those found in the CEI are found on Au surfaces after running five cycles between 2.0 and 0.2 V vs. Li/Li+ in half-cells. These results show that DESI-MS provides intact molecular information on battery electrodes, enabling deeper understanding of the SEI or CEI composition.

Figure 1
Evaluation of Electrolytes for Si-Based Negative Electrodes
Authors: Yang Li , Cai Mei , Lu Peng , Dai Fang , Jiang Meng , Xiao Qiangfeng , Verbrugge Mark W , Ruthkosky Marty
Published: February 2020

In this work, different promising electrolyte salts, solvents and additives have been evaluated for nano-silicon (nano-Si) negative-electrode materials. For a wide range of solvents and salts used to formulate electrolytes, we found that fluoroethylene carbonate (FEC) is important for good Si-electrode performance. The combination of FEC with dimethyl carbonate (DMC) gives the best electrochemical performance. We provide arguments to support our perspective that the superior solubility of the salts and FEC decomposition products in DMC leads to a more protective solid-electrolyte interphase (SEI). Consistent with this view, some SEI-forming precursors such as VC, LiBOB, LiODFB, if added in relatively large quantities (>2wt%), have deleterious effects on Si electrode performance due to competitive reactions with FEC decomposition, which, in the absence of such precursors, can form a more robust SEI on Si.
Dendrite Growth Processes Monitored in Situ with MRI
Authors: Jerschow Alexej , Grey Clare P. , Ilott Andrew , Chang Hee Jung , Trease Nicole M.
Published: February 2020

We will describe our work on the development of techniques for assessment of Li-ion batteries and battery materials via magnetic resonance imaging (MRI). The goal of these studies is to analyze battery degradation and energy storage mechanisms in situduring charging or discharging conditions by imaging changes in both the electrolyte and the electrodes in a noninvasive fashion.

In situ NMR/MRI have proven to be a useful tool to probe the structure of Li-ion batteries during real-time charge and discharge.  Ex situ studies of batteries are limited by self-relaxation of the electrode materials before a measurement can be obtained. The application of advanced magnetic resonance techniques, such as MRI and complex NMR experiments, in situ has the potential to monitor dynamics and visually monitor changes in functioning electrochemical systems in real time. The functionality of some energy storage devices where only the electrolyte is involved in the electrochemical process (such as supercapacitors) can only be studied in situ, as the electrolyte concentration gradients will relax as a potential is removed from the cell. Here we present techniques for in situ MRI of batteries and supercapacitors and discuss findings obtained from these studies [1,2]. It will be discussed how the rf field is perturbed by the presence of conducting materials in the probe [2], how susceptibility shifts can be used for assessing the morphology of microstructure buildup on electrodes [3]. The location and concentration of both cations and anions can be followed separately [4]. Figure 1 shows 3D images of Li metal obtained from an intact cell, at different times after initiation of charging, and Figure 2 shows both electrolyte and electrode 7Li images which are used to test dendrite growth models such as the Chazalviel model [5].

1.         S. Chandrashekar, N. M. Trease, H. J. Chang, L.-S. Du, C. P. Grey, A. Jerschow, Nat. Mater., 2012,

11, 311-315.

2.         A. J. Ilott, S. Chandrashekar, A. Klöckner, H. J. Chang, N. M. Trease, C. P. Grey, L. Greengard, A. Jerschow, J. Magn. Reson.
2014, 245, 143–149.

3.         H. J. Chang , N. M. Trease , A. J. Ilott , D. Zeng , L.-S. Du , A. Jerschow, C. P. Grey, J. Phys. Chem. C, 2015, 119, 16443−16451.

4.         A. J. Ilott, N. M. Trease, C. P. Grey, A. Jerschow, Nat. Comm. 5, 2014, 4536.

5.         H. J. Chang, A. J. Ilott, N. M. Trease, M. Mohammadi, A. Jerschow, C. P. Grey, J. Am. Chem. Soc. 2015, 137, 15209−15216.

Figure 1
Thermal Stability and Decomposition of Lithium Bis(fluorosulfonyl)Imide (LiFSI) Salts
Authors: Kerner Manfred , Plylahan Nareerat , Scheers Johan , Johansson Patrik
Published: February 2020

Lithium-ion batteries (LIBs) working at high temperature (HT) (80–150°C) (HT-LIBs) should have a number of intrinsic advantages such as high ionic conductivities, fast electrode kinetics, etc. An HT-LIB could at a vehicle systems level reduce the cooler size, as compared to using conventional LIBs. To comply with HT conditions, however, all parts of the battery have to be thermally stable, to not become a security problem or deteriorated. The most often used LIB electrolyte salt (LiPF6) is unstable at temperatures >60°C [1] and hence it is crucial to explore alternative lithium salts.

The lithium bis(fluorosulfonyl)imide (LiFSI) salt has been suggested as a possible replacement for LiPF6due to an improved thermal stability, high ionic conductivities and electrochemical stabilities in LIB electrolytes [2,3]. However, some contradictory results exist with respect to its promising thermal stability and non-corrosiveness [4,5].

We have investigated three commercial LiFSI salts and compared their properties with focus on thermal stability and phase transitions – including a vibrational spectroscopy based assessment of salt purity and decomposition products [6]. The salts were found to differ significantly in their thermal stabilities as determined by both dynamic and isothermal TGA. The FT-IR spectra of the salts are close to identical, but several additional bands were identified in the Raman spectra of the least stable salt. The latter allows for a discussion of the origin and role of salt impurities for the observed thermal (in-)stability. Furthermore, by adding each salt to the ionic liquid 1-ethyl-3-methylimidazolium FSI (EMIFSI), Li0.1EMI0.9FSI electrolytes were obtained. Galvanostatic cycling and linear sweep voltammetry were both performed to elucidate the influence of the impurities on the electrochemical performance.

[1] S.F. Lux, I.T. Lucas, E. Pollak, S. Passerini, M. Winter, R. Kostecki, Electrochem. Commun. 14 (2012) 47.

[2] H.-B. Han et al.J. Power Sources 196 (2011) 3623.

[3] L. Li, S. Zhou, H. Han, H. Li, J. Nie, M. Armand, Z. Zhou, X. Huang, J. Electrochem. Soc. 158 (2011) A74.

[4] K. Kubota, T. Nohira, T. Goto, R. Hagiwara, Electrochem. Commun. 10 (2008) 1886.

[5] A. Abouimrane, J. Ding, I.J. Davidson, J. Power Sources 189 (2009) 693.

[6] M. Kerner, N. Plylahan, J. Scheers, P. Johansson, submitted

Figure 1: The thermal stabilities of three commercial LiFSI salts.

Figure 1