This PDF file contains the front matter associated with SPIE Proceedings Volume 10663, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

Regarding the field of energy storage, the design of new materials that are showing high ionic mobility together with being economic and environmental benign is crucial. Our research is focused on the synthesis by soft chemistry of new frameworks with large tunnels or layered structures in order to favor ionic mobility. We will discuss on our strategies to generate such original frameworks. We will focus on material for Na ion batteries based on manganese sodium oxides such as Na2Mn3O7.

Rechargeable magnesium (Mg) batteries are considered as potential post lithium batteries with different application. Due to natural abundance of Mg, batteries based on Mg metal as an anode are considered as sustainable batteries which with high specific theoretical capacity (2205 mAh/g and 3.832 mAh/cm3) and with a reduction potential of −2.356 V versus standard hydrogen electrode (NHE) puts a lot of motivation for their exploration and application. Metallic magnesium is known as a highly passivating metal and it requires a special attention to the electrolyte development. Recent progress in the field of non-nucleophilic electrolytes with high oxidative stability opens the possibility to employ these types of electrolytes with redox active organic materials where weak intermolecular forces enable the reversible electrochemical interaction of Mg cations coupled with fast diffusion. Organic polymers can be considered as a sustainable counterpart in the combination with Mg metal and that represents a robust approach towards sustainable Mg batteries with high power and good cycling properties. Another, even more attractive combination is magnesium sulfur battery, which is a combination of two highly abundant elements and it can provide higher energy density compared to current Li-ion batteries. Finally, problems related to high voltage insertion materials will be discussed within presentation.

Photoelectrochemical water splitting to generate hydrogen uses the renewable sources to meet the daily increasing energy demand. Lots of metal oxides have been investigated as photoanode in a photoelectrochemical cell, where hydrogen generation occurs on the metal counter electrode. Despite great efforts, the solar-to-hydrogen conversion efficiency is still not fully up to expectations. On the other side, p-type semiconductors can be employed to generate photoelectrons that directly reduce water on the photocathode to hydrogen. Copper based metal oxides, including binary and ternary oxides, represent a promising class of p-type semiconductors due to their low cost and abundance in the earth. From the perspective of photoelectrochemical energy applications, they typically have large photocurrent, higher conduction band level for large hydrogen evolution driving force, and very positive onset potentials as well. However, the fatal issues that copper-based metal oxides suffer are the stability and efficiency in the aqueous electrolyte solution. In our presentation, we will show our recent efforts in both experiment and theory to manipulate copper-based metal oxides from the perspectives of morphology, geometry and electronic band structure by passivating the surface, engineering electronic band structures, and optimizing hydrogen evolution co-catalysts with the aim to achieve the long-term photostability and improve the solar-to-hydrogen conversion efficiency. The resultant nanostructures could be used as photocathode in photoelectrochemical cell for solar hydrogen generation.

Deployment of micro-grids using renewable energy (solar and wind power) requires large-scale electrical energy storage (EES) systems. Currently, lithium-ion batteries (LIBs) are leading candidates for EES. High power density LIBs addressing intermittency of renewables use expensive lithium titanate as anode. Besides, lithium is a scarce resource. Sodium, on the other hand, is the sixth most abundant element on the Earth’s crust. Sodium-ion batteries (NIBs) operating at ambient temperature are expected to be durable, safe and inexpensive. Regardless of the relatively lower energy density of NIBs, they can effectively be employed in micro-grid applications, where the weight and footprint requirement are not severe. We present here recently developed non-flammable sodium-ion conducting glyme based electrolyte displaying excellent storage performance of low voltage anodes as well as high voltage cathodes for sodium-ion cells. Employing this liquid electrolyte, non-flammable sodium-ion cells (18650-type) have been fabricated using rhombohedral Prussian Blue analogoue1 or sodium vanadium phosphate as cathode and hard carbon as anode with energy density in the range 40 – 60 Wh/kg (kg refers to the total 18650 full cell weight) and impressive 4C rate performance. This ultra-safe commercial type sodium-ion cells have relatively higher energy density than the reported aqueous (non-flammable) commercial NIBs. We further present thermal (DSC analyses) and safety parameters (heat losses and internal resistance evaluations) of the above 18650 cells which help in developing thermal management systems for NIB packs for possible micro-grids (100-500 kWh) to address the intermittency of renewable energy.

In energy storage devices, materials evolve from their initial state either due to electrochemical reactions or instabilities at interfaces, and such transformations must be understood and controlled for improved electrochemical behavior. This manuscript discusses multiscale in situ techniques that are designed to reveal reaction mechanisms, degradation processes, and interfacial transformations in energy storage materials to guide the development of better batteries. Our recent work has used a combination of in situ transmission electron microscopy (TEM) and in situ X-ray diffraction/spectroscopy to elucidate phase transformation pathways in high capacity electrode materials for alkali ion batteries. For instance, Cu₂S electrode materials show similar global transformations during reaction with alkali metal ions, but the nanoscale reaction pathways differ significantly, which influences the electrochemical behavior. Other research is focused on using X-ray photoelectron spectroscopy (XPS) to understand reaction mechanisms at solid-state interfaces. Finally, synchrotron X-ray diffraction investigations have revealed strain evolution in individual alloying anode particles. This work demonstrates the importance of utilizing in situ techniques to understand dynamic processes in energy devices so as to guide the synthesis of new materials with high energy density and long lifetime.

High capacity redox active materials are the building blocks for batteries and modern electrochemical conversion devices. Last couple of decades has witnessed tremendous progress in the area of rechargeable batteries for transportation, grid storage and consumer applications.1 The talk will provide an overview of the current R&D status of advanced batteries for electric vehicles followed by deep dive analysis of lithium-ion battery electrodes using X-ray synchrotron, micro-Raman and neutron spectroscopic and imaging methods. Specifically, the talk will cover recent work related to applying X-ray transmission imaging combined with near edge absorption spectroscopy (XANES) to study the evolution of chemical oxidation state of the transition metal (TM) cations accompanied by changes in the particle morphology for a number of lithium-ion cathode systems such as lithium-manganese rich NMC cathodes (LMR-NMC) and high capacity Li2Cu0.5Ni0.5O2 cathodes.2-4 Ex-situ and in-situ Raman and neutron imaging methods for studying micron scale inhomogeneties associated with high capacity battery electrodes such as silicon-graphite will also be presented.5-7 1. M. S. Whittingham, Chem. Rev. 104, 4271 (2004) 2. H. Dixit, J. Nanda et al, ACS Nano, 8 (12) 12710 (2014) 3. R. Ruther, J. Nanda et al. Chem. Mater. 29, 2997 (2017) 4. F. Yang, Y. Liu, J. Nanda et al. Nano Letts. 14, 4334, (2014) 5. J. Nanda, H. Bilheux, et al, J. Phys. Chem. C, 116, 8401 (2012) 6. R. Ruther, J. Nanda et al J. Phys. Chem. C 119, 18022 (2015) 7. H. Zhou, H. Bilheux, J, Nanda et al ACS Energy Letters, 1, 981 (2016)

Traditional thermoelectric device manufacturing uses machining, assembly, and integration steps which lead to material waste and performance limitations. The approach offers little flexibility in designing thermoelectric module geometry. Additive manufacturing can overcome these challenges, but it has not been demonstrated for inorganic thermoelectric materials, particularly those geared toward mid-/high-temperature applications. This work describes selective laser melting, an additive manufacturing process which locally melts successive layers of material powder to construct three-dimensional objects. The work shows the firstever demonstrations of selective laser melting applied to half-Heusler thermoelectric materials: ZrNiSn, and Hf_0.3Zr_0.7CoSn_0.3Sb_0.7/nano-Zr_O2. Laser processing parameters critically affects the formation and appearance of ingots, and we found laser energy density is useful but cannot be the single consideration for the SLM process. The fabricated ingots are generally porous with rough surfaces. They are characterized through powder XRD and TGA. The results consistently show that produced parts preserved most of the original chemical structures with small chemical changes due to decomposition and oxidation during the selective laser melting process. The work demonstrates selective laser melting is feasible for half-Heusler thermoelectric materials.

We report an all-polymer flexible piezoelectric fiber that uses both judiciously chosen geometry and advanced materials in order to enhance fiber piezoelectric response. The microstructured/nanostructured fiber features a soft hollow polycarbonate core surrounded with a spiral multilayer cladding consisting of alternating layers of piezoelectric nanocomposites (polyvinylidene enhanced with BaTiO3, PZT or CNT) and conductive polymer (carbon filled polyethylene). The conductive polymer layers serve as two electrodes and they also form two spatially offset electric connectors on the fiber surface designed for the ease of connectorization. Kilometer-long piezoelectric fibers of submilimeter diameters are thermally drawn from a macroscopic preform. The fibers exhibit high output voltage of up to 6V under moderate bending, and they show excellent mechanical and electrical durability in a cyclic bend-release test. The micron/nano-size multilayer structure enhances in-fiber poling efficiency thanks to the small distance between the conducting electrodes sandwiching the piezoelectric composite layers. Additionally, spiral structure greatly increases the active area of the piezoelectric composite, thus promoting higher voltage generation and resulting in 10-100 higher power generation efficiency over the existing piezoelectric cables. Finally, we weave the fabricated piezoelectric fibers into technical textiles and demonstrate their potential applications in power generation when used as a sound detector and a wearable textiles

One major challenge to the usability of IoT devices is limited onboard battery lifetime. Integrating an energy harvester to scavenge the energy from ambient sources is a viable green option. In recent 5 years, Triboelectric Nanogenerators (TENG) have gained attention for harvesting ambient vibration energy from sources ranging from ocean waves to human body motion due to their flexibility in the choice of materials and fabrication processes. However, due to the high nonlinearly varying impedance (typically in mega ohms) of TENG, standard full wave rectifier based AC to DC conversion for energy extraction is unable to provide a matching impedance needed for optimized energy transfer. In the presented work, Synchronous Charge Extraction (SCE), Parallel and Series synchronized switch harvesting on inductor (P-SSHI and S-SSHI) energy extraction circuits are mathematically modeled, analyzed, simulated, and compared with the standard full wave rectifier (FWR) circuit for the first time to the best of our knowledge. While the above-mentioned extraction schemes have been studied for piezoelectric transducers, the models (and gains) are different in the case of triboelectric transducers. For TENG with an area, 12 x 8 cm², surface charge density 8 μC=m², and subjected to vibration with 3 mm amplitude and 1 Hz frequency, energy gains of 2.8, 14.5, 385 over FWR were realized for P-SSHI, S-SSHI and SCE for a 5V battery load respectively. The above findings were also confirmed by SPICE-based circuit simulation.

Battery-based electrochemical storage is particularly attractive because of its high energy efficiency and ease of deployment, and lithium-ion batteries (LIBs) are one of the most well developed. Sodium-ion batteries (SIBs), which replace lithium with abundant and inexpensive sodium, have received a great deal of attention recently. Nevertheless, several scientific challenges still need to be resolved before the performance of SIBs becomes competitive with that of LIBs. In particular, the higher negative redox potential of Na compared to that of Li results in lower cell voltages and consequently lower energy densities. Moreover, the larger size of Na+ relative to Li+ causes slower solid-state diffusion in the active materials and leads to lower energy efficiencies when the batteries are rapidly charged or discharged. High capacity electrode materials with fast solid-state kinetics are therefore required in order to compensate for these intrinsic limitations. In this talk, I will introduce low-vacancy, sodium manganese hexacyanomanganate (MnHCMn) as a viable cathode material for SIBs. The as-synthesized MnHCMn shows a monoclinic crystal structure composed of nonlinear Mn–N≡C–Mn bonds and containing eight large interstitial sites occupied by Na+ ions. Our experiments demonstrate a high specific capacity of 210 mAh g-1 and excellent capacity retention at high rates in a propylene carbonate electrolyte. We discovered a novel mechanism wherein small lattice distortions allow for the unprecedented storage of 50% more sodium cations than in the undistorted case. These results represent a step forward in the development of sodium-ion batteries. Due to the minimal hysteresis in the galvanostatic charge/discharge curves of the electrochemical cell using Prussian Blue open-framework structures, a different approach is to explore thermodynamic cycles as is common in thermomechanical engines. The thermogalvanic effect, the dependence of an electrode’s electrochemical potential on temperature, can be used for such cycles. In the second part of the talk, the electrochemical thermodynamic cycle for thermal energy harvesting will be introduced. By utilizing novel electrode materials, this system can achieve very high efficiencies at low temperature ranges.

Lithium ion batteries have reshaped our life with their omnipresence in portable electronics. However, increasing the specific energy of these batteries is reaching its limit and high-profile fire accidents (e.g. cell phones spontaneously combusting) cast doubt of their applications in electric vehicles and large-scale energy storage. Intrinsically safe batteries such as aqueous batteries and all-solid-state batteries are being actively studied in the battery community but also faced with several challenges. In this paper, we review our recent progress on the electrolyte-dictated materials design of organic redox materials as potent enablers for aqueous and solid-state electrolytes/batteries.

Safe, powerful and reliable lithium batteries are required for an extensive market penetration of electric vehicles and stationary energy storage systems. In operation, lithium batteries are continuously generating and dissipating heat. Therefore, an appropriate thermal management is necessary to provide best electrochemical cycling conditions and avoid battery performance losses and thermal runaway. The rational design of thermal management systems should be based on quantitative information for thermal behavior, heat generation and dissipation of batteries in operation. Both regular and irregular battery use as well as accidents have to be realistically simulated by experiments in the laboratory. Calorimetry and thermography are excellent analysis tools to provide data for batteries applied in different operation modes under various environmental conditions. Simultaneously, (hazardous) reactions of battery materials and correlated pressure changes can be analyzed. The thermal runaway with inflammation and even explosion of a Li-ion cell in a larger battery pack is the worst case scenario which must be avoided in commercial applications under all circumstances. In order to get more insight into the character of exothermic reactions, that trigger the thermal runaway, combined experimental and computer simulation approaches were used. Accelerating Rate Calorimeters (ARC) are perfect tools for in-operando investigations of the cells during electrochemical cycling under isoperibolic and adiabatic conditions and for so-called heat-wait-seek tests. Heating under adiabatic conditions will eventually either stop the cell from cycling or lead to thermal runaway depending on the cycling parameters

Future factories would be based on Industry 4.0 paradigm. Industrial Internet of Things (IIoT) represent a part of the solution in this field. As autonomous systems, powering challenges could be solved using energy harvesting technology. In the present research two alternatives energy input and management are combined on a single architecture. A minireactor and an indoor photovoltaic cell as energy harvesters and a double power manager with AC/DC and DC/DC converters controlled by a low power microcontroller. Furthermore, implementation of artificial intelligence techniques, allows a smart and optimal energy management. Finally, integration of these solutions makes IIoT self-powered devices.