Lithium-ion Battery Research Research Articles

New Uses Spur Lithium-Ion Battery Research and Development [Happenings

Reports on new uses for lithium ion batteries. Driven in part by increased interest in electrification of land transportation and by the increased use of wind-and solar generated electricity, lithium (Li)-ion battery research and development (R&D) is exploring many innovations. This article discusses potential new directions in the Li-ion battery industry. It starts with a few paragraphs about the basics of the technology and the evolution of the product line and then offers a discussion of future directions.

The Triple Helix within the lithium-ion battery research network: a case study of JCESR

The Triple Helix within the lithium-ion battery research network: a case study of JCESR

Experimental Combined Numerical Approach for Evaluation of Battery Capacity Based on the Initial Applied Stress, the Real-Time Stress, Charging Open Circuit Voltage, and Discharging Open Circuit Voltage

With the intensification of energy crisis, considerable attention has been paid to the application and research of lithium-ion batteries. A significant progress has also been made in the research of lithium-ion battery capacity evaluation using electrochemical and electrical parameters. In this study, the effect of mechanical characteristic parameter (i.e., stack stress) on battery capacity is investigated using the experimental combined numerical approach. The objective of the proposed approach is to evaluate the capacity based on the initial applied stress, the real-time stress, charging open circuit voltage, and discharging open circuit voltage. Experiments were designed and the data is fed into evolutionary approach of genetic programming. Based on analysis, the accuracy of the proposed GP model is fairly high while the maximum percentage of error is about 5%. In addition, a negative correlation exists between the initial stress and battery capacity while the capacity increases with real-time stress.

(Keynote) Tribute to Michel Armand: Lithium Metal Solid State Batteries from 1979 to 2019

Research on lithium metal combined with polymer electrolyte in lithium rechargeable batteries was started in 1979 by Michel Armand. Since that time, lithium battery research has expanded worldwide. Several new polymers, solid electrolytes and ionic liquids with improved conductivity were identified. These advances resulted from a better understanding of the major parameters controlling ion migration, such as favorable polymer structure, phase diagrams between solvating polymers and lithium salts, and the development of new lithium counter-anions. In spite of the progress so far, the quest for a highly conductive dry polymer at room temperature is still not available. However, effort is continuing, and all-lithium polymer battery (LPB) developers presently face the challenge of whether to heat the polymer electrolyte to enable high-power performance, as required for electric vehicles and energy storage. LPB developers have explored both the high-temperature and low-temperature options. The commercial use of lithium metal/polymer batteries has been delayed because of the adverse effects of dendrites on the surface of the lithium electrodes, and the difficulty in finding a polymer that has both the mechanical strength and ionic conductivity required in a solid electrolyte. However, recent strategies have emerged to overcome these difficulties, and now these batteries are currently an option for different applications, including electric cars. In this presentation, we review these strategies and discuss the different promising routes that should result in further progress on lithium metal/polymer batteries in the near future. This presentation also discusses the challenges and opportunities in developing thin lithium negative electrodes with stable SEI layers for three battery technologies using: All solid-state Li- batteriesRechargeable lithium batteries containing dry polymer and ionic liquid-polymer électrolytes Li-Sulfur batteries. In addition, we will discuss the safety of lithium, dendrite mechanism, interface phenomena, side reactions, protection of lithium metal, and lithium alloys that are relevant to lithium batteries. Acknowledgement: The author thanks the CETEES groups in Varennes Shawinigan teams for helpful discussion.

Exploration of Advanced Electrode Materials for Rechargeable Sodium‐Ion Batteries

AbstractAs the rapid growth of the lithium‐ion battery (LIB) market raises concerns about limited lithium resources, rechargeable sodium‐ion batteries (SIBs) are attracting growing attention in the field of electrical energy storage due to the large abundance of sodium. Compared with the well‐developed commercial LIBs, all components of the SIB system, such as the electrode, electrolyte, binder, and separator, need further exploration before reaching a practical industrial application level. Drawing lessons from the LIB research, the SIB electrode materials are being extensively investigated, resulting in tremendous progress in recent years. In this article, the progress of the research on the development of electrode materials for SIBs is summarized. A variety of new electrode materials for SIBs, including transition‐metal oxides with a layered or tunnel structure, polyanionic compounds, and organic molecules, have been proposed and systematically investigated. Several promising materials with moderate energy density and ultra‐long cycling performance are demonstrated. Appropriate doping and/or surface treatment methodologies are developed to effectively promote the electrochemical properties. The challenges of and opportunities for exploiting satisfactory SIB electrode materials for practical applications are outlined.

Supplier Selection Model of the Lithium-ion Battery using Fuzzy AHP and Analysis of BOCR

Although the demand for the lithium-ion battery for electronic consumers and electric vehicles in Indonesia is high, there is no supplier coming from the local manufacturer. The proper selection of suppliers is required by some lithium-ion battery manufacturers (cells, modules, and packs), and Research and Development (R&D) center of the lithium-ion battery with the consideration not only in benefits and cost but also in opportunities and risks. It is important that experts assist the manufacturers and R&D to procure the lithium-ion (materials and cells), through transparent methods that seek a quantitative model to select the right supplier. The main objective of this study is to propose an analytical approach to select suppliers which incorporate Benefits, Opportunities, Costs and Risks (BOCR) concept that comply with the characteristics of the lithium-ion battery industries. A fuzzy Analytical Hierarchy Process (AHP) model is developed by accommodating the vagueness and inaccuracies of expert elections. The result of this research is development of the model obtained from 2 questionnaires given to the expert. Questionnaire 1 was made for the determination of criteria and sub-criteria, while Questionnaire 2 aims to perform pairwise comparisons of existing criteria and sub-criteria. In the selection of the lithium-ion battery suppliers, there are 11 criteria and 40 sub-criteria which are considered. Those criteria are divided into 4 merits and known for their respective global priorities.

Mapping of Inbound Flows in Supply Chain of Lithium-ion Industry in Indonesia

The demand for lithium battery is currently high from the consumer side due to the widespread application of lithium-ion battery for electronics (laptops, notebooks, mobile phones, street lighting) and electric vehicles (electric cars and electric motors). In Indonesia, the research and industrialization on lithium-ion battery have been conducted to develop products such as for electric vehicles and street lighting. On the other hand, the relationship between suppliers, producers, distribution channels, and consumers has not been mapped. This mapping is intended to provide an overview of the strength of suppliers, involved manufacturers, and to determine the readiness of the value chain of lithium-ion battery to perform mass production. The approach in the mapping uses primary data and secondary data for the initial stage of inbound flows in supply chain of lithium-ion industry in Indonesia. Primary data are obtained from the questionnaires, which adopted from the value chain lithium-ion battery research in USA adjusted for Indonesian context. Meanwhile, the secondary data derived from literature reviews. The respondents in the study are 11 institutions consisting of manufacturers and R&D of lithium-ion battery in Indonesia. The results obtained are supplier mapping that provides the flow of lithium-ion battery, cell, module, and pack as well as the producers and consumers. The results could also be utilized to identify the valuable metrics in the supply chain of lithium battery industry.

Critical Indicator Determining the Discharge Capacity of Li-Oxygen Batteries

Li-O2 battery is one of the possible candidates for future energy devices and has attracted much attention in the beyond lithium ion battery research field.1-3 Despite its specific high energy capacity, many obstructions, including lower capacity, impede their use for practical applications. In typical Li-O2 batteries, Li metal and carbon were applied as the anode and the cathode materials, respectively, and the Li2O2 is formed as the discharge product and deposited on the cathode. As Li2O2 shows inherent low electron conductivity,4,5 once the positive electrode was fully covered with the deposition, it inhibits the continuous discharging and then the discharge potential is suddenly dropped. Several strategies such as control of the solubility of LiO2, which is an intermediate in the discharge reaction, have been studied with interest for sustainable discharge. It is known that Donor Number (DN), the indicator of Lewis basicity of solvents, highly influences on the solubility of LiO2.6 The electrolytes with higher DN solvents enhance the discharge capacity of Li-O2 batteries, because solubility of LiO2 is increased and Li2O2 is formed in the solution (solution pathway). In contrast, Li2O2 is formed on the cathode surface in solvents of lower DN (surface pathway). The effect of additives in solvents on enhancing the solubility of LiO2 was also reported,7-9 however, the understanding of the underlying principles that determine the discharge capacity is still limited. Herein we present an alternative indicator to DN that controls the discharge capacity in the Li-O2 batteries. We focused on the effect of the range of combinations of cathode substrates and electrolytes on the discharge capacity. When we used Au-mesh as cathode, higher discharge capacity was obtained in a higher DN of dimethyl sulfoxide (DMSO) electrolytes (LiTFSI in DMSO) than that obtained in a lower DN of acetonitrile (MeCN) electrolyte, as reported previously.6 However, interestingly, higher capacity was obtained in the MeCN electrolytes when a carbon material was applied as the cathode. Through these experiments, we also found that the negative differential resistance (NDR), which appears when the coverage of the inhibitor on the electrode depends on the potential of the electrode, is a critical indicator determining the discharge capacity of Li-O2 batteries. The NDR in the oxygen reduction reaction (ORR) potential region implies that LiO2 works as an inhibitor of ORR. The higher discharge capacity can be obtained when the ORR proceeds at higher potential than NDR region, because LiO2 is desorbed from the electrode and the solution pathway is promoted. Our results indicate that this correlation between the NDR and the discharge capacity is generally applied to Li-O2 battery system. 1) Abraham, K.M. et. al. J. Electrochem. Soc. 143, 1-5 (1996).2) Ogasawara, T. et. al. J. Am. Chem. Soc. 128, 1390-1393 (2006).3) Luntz, A.C. & McCloskey, B.D. Chem. Rev. 114, 11721-11750 (2014).4) Viswanathan, V. et al. J. Chem. Phys. 135, 214704 (2011).5) Luntz, A.C. et al. J. Phys. Chem. Lett. 4, 3494-3499 (2013).6) Johnson, L. et al. Nat. Chem. 6, 1091-1099 (2014).7) Aetukuri, N.B. et al. Nat. Chem. 7, 50-56 (2015).8) Burke, C.M. et. al. PNAS 112, 9293-9298 (2015).9) Matsuda, S., Uosaki, K. & Nakanishi, S. J. Power Sources 356, 12-17 (2017).

High Throughput Experimental Methodologies for Accelerating Solid State Lithium-Ion Battery Development

Breakthrough in lithium-ion battery technology is crucial for modern sustainable energy applications, especially the electric vehicles. Compared to conventional lithium-ion battery with liquid electrolyte, solid state battery with solid inorganic electrolyte or flexible composite electrolyte possesses the advantages of higher energy density, higher working voltage, non-flammability, and lithium dendrite prevention [1, 2]. One of the main challenges of developing this next generation of batteries is to find the optimized structure and composition of solid electrolyte material, which usually has a ternary, quaternary, or even more complex composition. High throughput experimental methodologies, in which dozens of parallel experiments are carried out with small sample quantities per experiment, can greatly accelerate new material discovery and process optimization for solid electrolyte and solid state lithium ion battery development.To support this high-throughput experimental demand, the experimental instrument must meet requirements such as maximizing productivity through parallel experiments and automation, working with small amount of sample per experiment, and compatibility with Ar gas glove box operation. MTI Corporation (Richmond CA, USA) strive to provide highly efficient and economical experimental equipment and solutions for high throughput battery development. In this work, MTI Corporation¡¯s efforts on developing high throughput experimental solutions for solid state lithium-ion battery are discussed.The first step is solid inorganic electrolyte powder synthesis and pellet fabrication. For solid dispensing, four or more dispensing heads and balances, with one dispensing head for each solid electrolyte component, are integrated with a carousel type sample changer for automatic powder dispensing of 32 electrolyte powder samples. Next, the powder samples are ball milled in a planetary ball mill with 4 sets of 4 cavities milling jars for totally 16 parallel experiments. Then, the electrolyte powders are pressed into pellets for coin cell assembly using a hydraulic press with carousel type 16-sample changer. The powders and pellets are sintered, annealed, or quenched in a compact, 16-channel tube furnace up to 1700 ¡ãC with quenching option.Novel sintering techniques, such as spark plasma sintering (SPS) [3] and hydrothermal-assisted cold sintering process (CSP) [4], are employed for solid inorganic electrolyte sintering. These techniques, whether for the fast processing time of spark plasma sintering, or the low temperature processing capability of cold sintering process, open up possibilities of low cost, rapid fabrication of solid electrolytes, cathode pellets, or even the whole solid electrode-electrolyte stack [3].Solid inorganic electrolyte is usually too brittle for practical use. Composite electrolyte, which is made by embedding solid inorganic electrolyte powder in flexible polymer electrolyte, is a promising solution. By varying the ratio between inorganic and polymer components, a balance between electrical and mechanical properties can be achieved [4, 5]. The process of composite electrolyte fabrication starts with powder and liquid dispensing. For liquid dispensing, an automatic pipette robot with integrated XYZ stage is used for dispensing organic solvents and liquid electrolytes. The as-prepared high viscosity samples are mixed in a planetary centrifuge mixer for mixing 6 samples of 5 ml in one run. With addition of a 4-channel film applicator, existing doctor blade coater can be modified into high throughput equipment. The as-prepared sample with four strips of different composite electrolytes can be passed onto hot calendar machine or hot press for solvent evaporation and thickness reduction, and coin cell die cutter for high throughput preparation of composite electrolyte discs.Finally, the solid electrolyte powder and discs are analyzed by a compact X-ray fluorescence (XRF) spectrometer integrated with a XY sample stage for high throughput composition characterization. 32 samples can be qualitatively and quantitatively analyzed in one auto run. For high throughput assembling of coin cells, one route is to use an automatic coin cell crimper machine to facilitate coin cell assembling process. The other route is to use multiple split cells with quick, easy, repeatable assembling for parallel comparison of different solid electrolyte materials. This further saves time and labor by eliminating the coin cell crimping step.In conclusion, high throughput experimental solutions accelerate new material discovery and process optimization for solid state lithium ion battery research. Existing experimental techniques are modified for high throughput application by smart design of sample fixture, by integration, and by automation. Novel processing methods, such as spark plasma sintering and cold sintering, enable reduced processing time and low production cost.

Progress on the failure analysis of lithium battery

The failure problems, associated with capacity fade, poor cycle life, increased internal resistance, abnormal voltage, lithium plating, gas generation, electrolyte leakage, short circuit, battery deformation, thermal runaway, etc., are the fatal issues that restrict the performances and reliabilities of the lithium batteries. The main tasks of failure analysis of lithium batteries are to accurately diagnose, which is vital for revealing the failure modes or failure mechanisms. These information has profound significance for improving the performances and technology of lithium batteries. In order to have a comprehensive understanding of the recent progress on failure analysis research of lithium batteries, the failure analyses from the respect of definition, phenomenon, reason, analysis content, process, difficulty, etc. are briefly reviewed. We hope this review will helpful to the researchers engaged in the field of failure analysis as well as battery field.

Innovating Safe Lithium-Ion Batteries Through Basic to Applied Research

This paper for inclusion in the special issue provides a brief synopsis of lithium-ion battery safety research efforts at the Naval Research Laboratory (NRL) and presents the viewpoint that lithium-ion battery safety is a growing research area for both academic and applied researchers. We quantify how the number of lithium-ion battery research efforts worldwide has plateaued while publications associated with the safety aspect of lithium-ion batteries are on a rapid incline. The safety challenge creates a unique research opportunity to not only understand basic phenomena but also enhance existing fielded system through advanced controls and prognostics. As the number of lithium-ion battery safety research contributions climbs, significant advancements will come in the area of modeling across multiple time and length scales. Additionally, the utility of in situ and in operando techniques, several performed by the NRL and our collaborators, will feed the data necessary to validate these models. Lithium-ion battery innovations are no longer tied to performance metrics alone, but are increasingly dependent on safety research to unlock their full potential. There is much work to be done.

Surface/Interfacial Structure and Chemistry of High-Energy Nickel-Rich Layered Oxide Cathodes: Advances and Perspectives.

The urgent prerequisites of high energy-density and superior electrochemical properties have been the main inspiration for the advancement of cathode materials in lithium-ion batteries (LIBs) in the last two decades. Nickel-rich layered transition-metal oxides with large reversible capacity as well as high operating voltage are considered as the most promising candidate for next-generation LIBs. Nonetheless, the poor long-term cycle-life and inferior thermal stability have limited their broadly practical applications. In the research of LIBs, it is observed that surface/interfacial structure and chemistry play significant roles in the performance of cathode cycling. This is due to the fact that they are basically responsible for the reversibility of Li+ intercalation/deintercalation chemistries while dictating the kinetics of the general cell reactions. In this Review, the surface/interfacial structure and chemistry of nickel-rich layered cathodes involving structural defects, redox mechanisms, structural evolutions, side-reactions among others are initially demonstrated. Recent advancements in stabilizing the surface/interfacial structure and chemistry of nickel-rich cathodes by surface modification, core-shell/concentration-gradient structure, foreign-ion substitution, hybrid surface, and electrolyte additive are presented. Then lastly, the remaining challenges such as the fundamental studies and commercialized applications, as well as the future research directions are discussed.

Molecular Layer Deposition for Applications in Lithium-Ion Batteries

Molecular layer deposition (MLD) of hybrid organic-inorganic thin films called titanicones, vanadicones, tincones, and alucones was investigated for electrode and solid electrolyte applications in lithium-ion batteries. The titanicone, vanadicone and tincone films were studied as electrode materials, both as anodes and cathodes. Novel MLD processes were developed for these materials and were based on an alkylamine metal precursor (TDMAT, TEMAV, TDMASn) and glycerol (GL) as the organic reactant. Linear and self-limited growth could be achieved for these metalcones in a broad temperature range with temperature-dependant growth rates ranging from 0.2 to 1.3 Å/cycle. Film growth was studied in situ with spectroscopic ellipsometry (SE) and infrared spectroscopy (FTIR). The as-deposited films appeared to be electrochemically inactive in all cases. A post-deposition heat treatment up to 500°C in either inert (helium) or oxidizing (air) atmosphere was able to electrochemically activate the films. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) measurements showed that all carbon was removed during calcination in air and that the films crystallized. However, annealing in inert atmosphere conserved the carbon content of the film and thus the films remained amorphous. The performance with increasing charging and discharging rate, and cyclability of the heat-treated MLD electrodes was tested against their respective metal oxide references. The He-annealed metalcones emerged from these tests as the best performing electrodes at higher rates (left and middle figures) and with improved capacity retention and stability during repeated charging and discharging. The transformation of alucone films, deposited with the TMA and ethylene glycol (EG) or GL process, into porous aluminium oxide was examined. Porous, non-conducting materials are interesting for lithium-ion battery research since they may serve as the matrix template for solid composite electrolytes. Calcination in air and water etching proved to be the most successful methods. For the calcination treatment, a clear relation was found between the ramp rate during both heating and cooling and the resulting porosity of the film (right figure). The aging behaviour of the films in ambient atmosphere was also investigated with FTIR and showed that the films deposited with EG decompose in a matter of only a few hours, as opposed to those deposited with GL. Figure 1

High throughput materials research and development for lithium ion batteries

Development of next generation batteries requires a breakthrough in materials. Traditional one-by-one method, which is suitable for synthesizing large number of sing-composition material, is time-consuming and costly. High throughput and combinatorial experimentation, is an effective method to synthesize and characterize huge amount of materials over a broader compositional region in a short time, which enables to greatly speed up the discovery and optimization of materials with lower cost. In this work, high throughput and combinatorial materials synthesis technologies for lithium ion battery research are discussed, and our efforts on developing such instrumentations are introduced.

Characterization and Model of Piezoelectrochemical Energy Harvesting Using Lithium ion Batteries

Although lithium ion battery research often focuses on electrochemical properties, lithium ion intercalation materials are also mechanically active. Essentially, these materials exhibit a mechanical-electrochemical coupling such that when a stress is applied, the voltage of the battery increases. In this work, we develop a model to study and predict the effectiveness of intercalation materials as mechanical energy harvesters. Specifically, we show that a lithium ion battery harvester can be modelled as a simple circuit and that we can make both qualitative and quantitative predictions about the effectiveness of a battery material given its intrinsic mechanical and electrochemical properties. The measured efficiency of our system, calculated from the energy output and total work input, is 0.012 ± 0.004%, and our model predicts that the maximum theoretical efficiency of the system is 2.9 ± 0.5%. In the future, this model will help us develop and study other intercalation materials that will bring the measured efficiency closer to our proposed theoretical maximum.

Activated Carbon Based Quasi-Reference Electrodes for Unconventional Lithium-Salt Containing Organic Electrolytes

Metallic lithium is the most frequently employed reference electrode in lithium ion battery research, but its high reactivity limits its utilization mainly to conventional carbonate based electrolytes. Novel concepts, like hybrid battery/supercapacitor devices, are often based on electrolytes with high ionic conductivity (e.g., acetonitrile). The utilization of these electrolytes brings up its own challenges as fundamental electrochemical characterizations are drastically aggravated by the high reactivity towards lithium metal. An alternative to Li/Li+ reference electrode for TEA-BF4 containing organic electrolytes is PTFE bound activated carbon as was shown in 2009.1 However, the latter approach yielded a pronounced drift of the reference electrode potential over time when a lithium-salt was employed. This effect is only poorly understood so far and a stable reference electrode for such systems is in high demand. Based on these issues, we provide a comprehensive study to establish (modified) carbon as a stable quasi-reference electrode for advanced lithium-salt containing electrolytes.2 In our work, we investigate the suitability of different carbons as quasi-reference electrodes (QREs) for lithium-salt containing electrolytes. As a reference point, we directly use the lithium intercalation/de-intercalation reaction of nanoparticulate Li4Ti5O12. Low surface area carbon-based QREs are impaired by high rates of potential shift (140 mV after 5 d). All high surface area carbon-based QREs show very low, uniform, and reproducible rates of potential shift (40-50 mV after 5 d). Only a negligible influence of carbon pore size distribution, electrolyte solvent, and binder on the reference electrode stability was observed. A distinct influence of the electrolyte anion on the quasi-reference electrode stability was found (Figure 1). The stability of pristine activated carbon decreases in the following order LiTFSI>LiClO4>LiPF6>LiBF4. We also studied the influence of carbon modification on the QRE stability. Activated carbon was de-functionalized (thermal annealing in vacuum or hydrogen) and functionalized (HNO3 treated) in order to unveil coherences of reference electrode stability with surface functional groups. The potential shift of activated carbon is drastically suppressed if the carbon surface is saturated by oxygen and nitrogen functional groups (Figure 2). After 15 days, the potential of heavily functionalized activated carbon is only marginally altered by 10 mV. Therefore functionalized activated carbon is a well suited quasi-reference electrode for the electrochemical characterization of Li-salt containing electrolytes which are not stable versus lithium metal.

Transferring the Incremental Capacity Analysis to Lithium-Sulfur Batteries

With a growing amount of battery applications in today’s world, there is a large interest into the methods of detecting, estimating, and analyzing the battery degradation. Consequently, many different health detection and estimation methods and techniques have been proposed. This is also the case of the incremental capacity analysis (ICA) 1 method, which receives a significant interest in the Lithium-ion (Li-ion) batteries research and development fields. The method offers the possibility to analyze the ageing processes (e.g. loss of lithium inventory, loss of active material and kinetic changes) of Li-ion batteries and also has the potential to be implemented into a battery management system 2. However, what is the suitability of this method for emerging battery technologies, such as Lithium-Sulfur (Li-S)? Li-S batteries differ in many aspects from Li-ion batteries, as for example discussed in 3, fact which in some cases prevents a straightforward transfer of the methods and approaches to be applied on them. Already at the method applicability, the first difference and challenge can be spotted by comparing the charging and discharging voltage profiles of the Li-ion and Li-S batteries, as illustrated in Figure 1. In the case of the Li-ion batteries, the curves are strictly monotonous, while the typical Li-S voltage discharging curve has a ‘dip’ between the high- and low- voltage plateaus. Moreover, the Li-S charging curve can be monotonous or it can have a ‘bump’ (high internal resistance) at the beginning of the charging phase, as shown in Figure 2, according to the charging conditions and the previous history. Furthermore, the two chemistries are driven by different mechanisms. The Li-ion batteries work based upon an intercalation mechanism, where the ions travel directly between the electrodes. On the other hand, the Li-S batteries belong to the “solution chemistries”, where reduction and oxidation reactions of several stages of polysulfide species take place during charging and discharging 4. Therefore, analyzing the incremental capacity (IC) curves should be done carefully by considering the aforementioned differences. In this work, the IC curves were derived based on the approach presented in 2, where the battery voltage profile is divided into smaller voltage intervals, which are used to count the capacity increase. However, if it would be applied directly, the change of trend in the voltage would not be reflected and the change of the capacity, in the area marked by grey in Figure 2, would be computed wrongly and assigned to a different voltage value. Therefore, we propose at first to split the voltage curves into monotonic parts, as illustrated by the critical points A, B, C and D in Figure 2. These monotonous parts are evaluated separately to obtain appropriate dQ/dV values and later on they are composed together. Accordingly, the ICA technique is applied to the charging and discharging voltage profiles of the Li-S battery at various temperatures and by different currents to see the trends and understand their behavior, an example of the IC curves is shown in Figure 3. This methodology is further used to identify and assess the ageing mechanisms in Li-S batteries during both calendar and cycle ageing conditions. Moreover, the suitability of the ICA applied to the Li-S batteries for state-of-health estimation is explored. 1. M. Dubarry, V. Svoboda, R. Hwu, and B. Yann Liaw, Electrochem. Solid-State Lett., 9, A454–A457 (2006). 2. X. Han, M. Ouyang, L. Lu, J. Li, Y. Zheng, and Z. Li, J. Power Sources, 251, 38–54 (2014). 3. K. Propp, M. Marinescu, D. J. Auger, L. O’Neill, A. Fotouhi, K. Somasundaram, G. J. Offer, G. Minton, S. Longo, M. Wild, and V. Knap, J. Power Sources, 328, 289–299 (2016). 4. M. Wild, L. O’Neill, T. Zhang, R. Purkayastha, G. Minton, M. Marinescu, and G. J. Offer, Energy Environ. Sci. (2015). Figure 1

New Weakly-Coordinating Hückel-Type Anions for Applications in Battery Electrolytes

Lithium-ion batteries are nowadays the most popular energy storage technology. A raising number of research investigates the development of modern batteries, while the market of secondary lithium batteries is still growing. This creates problems with disposal of expired batteries, as many electrolyte components comprise fluorine. Unfortunately, global lithium resources are not sufficient to fulfill these demands. Therefore, studies on batteries which are alternative to lithium-based energy sources are conducted intensively. A natural candidate to replace lithium is sodium. Most of lithium-ion batteries research focuses on development of electrode materials. However, apart from electrodes, a key component of Li-ion batteries is electrolyte. Electrolyte limits critical battery properties, such as safety, thermal stability, battery lifetime and internal resistance of a cell. Conventional electrolytes consist of lithium salt, solvent (or solvents mixture) and additives. Since both solvents and additives are well developed and not problematic, in this work we have focused on lithium salts. Among all lithium salts that can be used in large scale manufacturing, LiPF6 is used almost exclusively. Even considering all its advantages, LiPF6has numerous drawbacks, too. These include low thermal stability, moisture sensitivity and toxic and corrosive products evolution upon decomposition [1]. In the recent years many studies on new lithium salts have been published, however none of them has been introduced widely to the market so far [2]. Therefore, there is a substantial need for new ideas in this field. Our approach was to design new anions for lithium and sodium salts tailored particularly for Li-ion and Na-ion battery electrolytes. The concepts that we have chosen were aromatic anions and anions based on aliphatic chain with conjugated double bonds, that allows π-electrons as well as negative charge delocalization. Application of this ideas should lead to a highly stable and weakly-coordinating anion. As a result we have synthesized novel lithium and sodium salts. Salts show excellent thermal stability as proven with means of TGA and DSC. Electrochemical stability tests have shown up to 5 V window width. Conductivity of the electrolytes containing those new salts have been examined in propylene carbonate, typical battery mixtures and polymer matrix. Outstanding conductivity values has been reached – up to 10 mS cm-1 for liquid and over 1 mS cm-1for solid polymer electrolytes have been observed at the room temperature. Finally, to evaluate compatibility with electrode materials, cycling experiments have been performed both with commercial and custom made electrodes. In conclusion, we have synthesized and thoroughly tested a few lithium and sodium salts for applications in non-aqueous electrolytes for modern batteries. Obtained results exhibited clearly that presented salts would be successfully applied in lithium-ion and sodium-ion batteries improving their performance, safety and environmental friendliness.

High Throughput Experimental Solutions for Solid State Lithium-Ion Battery Research

Breakthrough in lithium-ion battery technology is crucial for modern sustainable energy applications. Compared to conventional Lithium-ion battery with liquid electrolyte, solid state battery with solid ceramic electrolyte or polymer electrolyte possesses the advantages of higher working voltage, non-flammability, and lithium dendrite prevention [1, 2]. High-throughput methodologies, which enable rapid materials screening and rapid process optimization, are finding its applications in solid state Lithium-ion battery development. To support this high-throughput research, the experimental instrument must meet requirements such as maximizing productivity through parallel experiments and automation, compatibility with Ar gas glove box operation, high resistance to corrosion, and working with small amount of sample per experiment. MTI Corporation (Richmond CA, USA) strive to provide highly efficient and economical experimental equipment and solutions for high throughput battery development. In this work, MTI’s efforts on developing experimental instrumentations for high throughput research of solid state Lithium-ion battery are discussed. MTI’s high throughput experimental solution for solid state Lithium-ion battery is outlined in Fig. 1. First step is the solid electrolyte synthesis and preparation. MTI provides complete solution for ceramic powder synthesis, from solid / liquid dispensing, high throughput milling / mixing, to multi-channel heat processing with high throughput tube furnace. After the high throughput solid electrolyte powder synthesis, MTI’s 6-position, 10 ton max electric hydraulic press and 4-channel, 1” OD tube furnace up to 1700 ºC allow for a high throughput process of conventional sintering method. Novel sintering techniques, such as spark plasma sintering (SPS) [3] and hydrothermal-assisted cold sintering process (CSP) [4], are also supported by MTI’s instruments. These techniques, whether for the fast processing time of spark plasma sintering, or the low temperature processing capability of cold sintering process, open up possibilities of low cost, rapid fabrication of solid electrolytes, cathode pellets, or even the whole solid electrode-electrolyte stack [3]. Fast solid electrolyte material screening is possible with combinatorial deposition methods. Combinatorial sputtering deposition systems, which uses substrate mask and multiple deposition sources with adjustable tilt and power, are utilized to create compositional spreads and deposit ternary more complicated thin film composition libraries for ceramic electrolyte [5]. An example is MTI’s combinatorial magnetron sputtering system with 5 independent sputtering sources and rotatable 16-sample mask. Combinatorial spray pyrolysis allows rapid screening of ceramic-polymer composite electrolytes. With MTI’s 6-channel combinatorial ultrasonic spray pyrolysis system, various polymer hosts, liquid electrolytes, and ceramic solid electrolyte powder suspensions are concurrently pumped and mixed at different ratios, and sprayed onto the heated stage. By varying the ratio between polymer electrolyte and ceramic electrolyte, a balance between composite electrolyte‘s electrical and mechanical properties can be achieved through the high throughput screening [4, 6]. Second step is rapid composition characterization of the as-synthesized solid electrolyte powder using high throughput, automatic X-ray fluorescence (XRF) instrumentation. MTI’s 32-sample high throughput XRF spectrometer station integrates a compact XRF spectrometer and a high precision XYZ stage with an Ar gas glove box for quick and easy composition analysis from element Ne to Pu. Finally, the as-prepared solid electrolytes are assembled with electrodes in split cells for high throughput electrochemical testing. MTI’s 8-channel coin split cell kit allows for easy parallel comparison of multiple cells. Temperature dependent testing is of great interest as improved ionic conductivity is usually observed at elevated temperatures. Moreover, to ensure good interfacial contact between electrode and solid electrolyte, a sufficient compressive pressure needs to be applied on the split cell to confine the volume expansion during charge-discharge cycles [7]. In this effort, MTI has developed a battery dilatometer with adjustable compressive pressure, and a heatable lab press for electrochemical testing under controlled pressure and temperature. [1] Li J, Ma C, Chi M, Liang C, Dudney NJ. Adv. Energy Mater. 2015;5:1401408. [2] Kim JG, Son B, Mukherjee S, Schupper N, Bates A, Kwon O, et al. J. Power Sources 2015;282:299. [3] Kali R, Mukhopadhyay A. J. Power Sources 2014;247:920. [4] Guo J, Berbano SS, Guo H, Baker AL, Lanagan MT, Randall CA. Adv. Funct. Mater. 2016;26:7115. [5] Beal MS, Hayden BE, Le Gall T, Lee CE, Lu X, Mirsaneh M, et al. ACS Comb. Sci. 2011;13:375. [6] Zhao Y, Huang Z, Chen S, Chen B, Yang J, Zhang Q, et al. Solid State Ionics 2016;295:65. [7] Piper DM, Yersak TA, Lee SH. J. Electrochem. Soc. 2013;160:A77. Fig. 1. MTI’s high throughput experimental solution for solid state Lithium-ion battery research. Figure 1

X-Ray Tomography for Lithium Ion Battery Research: A Practical Guide

X-ray tomography has emerged as a powerful technique for studying lithium ion batteries, allowing nondestructive and often quantitative imaging of these complex systems, which contain solid components with length scales spanning orders of magnitude and which are in-filled with liquid electrolyte. Over the past decade, X-ray tomography has allowed interrogation of structure and material composition, providing quantitative or qualitative insight into battery operation and degradation. In this review, we first provide an overview of X-ray tomography and explore what types of experiments can yield insight into open questions in the lithium ion battery research field. In the second half of the review, we discuss the aspects a researcher must consider, and we summarize challenges and approaches to sample preparation, experimental setup, and data analysis. Finally, we describe both outstanding challenges and promise in using X-ray tomography for lithium ion battery research.