Electrochemical Storage Systems Research Articles

Battery and/or supercapacitor?—On the merger of two electrochemical storage system families

Similarities and analogies between materials, structures, operating and construction principles of secondary batteries and supercapacitors and their electrodes are presented, named and reviewed in context. On the material level several materials used both in batteries and supercapacitors are addressed, implications from observations made in one application for the other one are highlighted. On the electrode level a continuous change of architectural details is observed when going from an electrode with high charge storage capability to an electrode supporting high currents is detected, again this overlap provides instructive ideas for both fields. On the cell level combinations of electrodes from both fields yielding hybrid devices are an obvious outcome again with implications for both fields. Ideas and suggestions for further research and development based on a deeper exchange between both families are developed.

Lithium-Ion Batteries on Board: A Review on Their Integration for Enabling the Energy Transition in Shipping Industry

The emission reductions mandated by International Maritime Regulations present an opportunity to implement full electric and hybrid vessels using large-scale battery energy storage systems (BESSs). lithium-ionion batteries (LIB), due to their high power and specific energy, which allows for scalability and adaptability to large transportation systems, are currently the most widely used electrochemical storage system. Hence, BESSs are the focus of this review proposing a comprehensive discussion on the commercial LIB chemistries that are currently available for marine applications and their potential role in ship services. This work outlines key elements that are necessary for designing a BESS for ships, including an overview of the regulatory framework for large-scale onboard LIB installations. The basic technical information about system integration has been summarized from various research projects, white papers, and test cases mentioned in available studies. The aim is to provide state-of-the-art information about the installation of BESSs on ships, in accordance with the latest applicable rules for ships. The goal of this study is to facilitate and promote the widespread use of batteries in the marine industry.

Efficient electrochemical hydrogenation and dehydrogenation of quinoxaline over a dendritic structure P-WO3/NF electrode

Liquid organic hydrogen carrier (LOHC) has been recognized as a highly promising candidate for hydrogen storage materials in addressing hydrogen utilization issues. However, the hydrogenation and dehydrogenation of LOHC typically require noble metal catalysts and harsh reaction conditions. In this paper, we proposed an efficient reversible electrochemical hydrogen storage system based on a nitrogen heterocyclic organic hydrogen carrier, quinoxaline, in which water was used as the solvent and hydrogen source for quinoxaline hydrogenation, and a self-supporting dendritic P-WO3/NF electrode was employed as the electrocatalyst. The catalytic properties of P-WO3/NF for electrochemical hydrogenation of quinoxaline and dehydrogenation of 1,2,3,4-tetrahydroquinoxaline were studied in 1 M KOH solution under mild conditions. The results showed that the hydrogenation conversion of quinoxaline was 90%, the selectivity was 99%, and the dehydrogenation conversion of 1,2,3,4-tetrahydroquinoxaline was 100%, the selectivity was 100%. This indicates that the system has high conversion efficiency, outstanding selectivity, and good reversibility. Meanwhile, the P-WO3/NF electrode adapted to the system exhibited good catalytic stability. In addition, no pre-prepared external hydrogen was required in the electrochemical hydrogenation reaction involving water, which gave the system an excellent safety profile. The reversible electrochemical hydrogen storage system established by this work broadens the vision of LOHC in hydrogen storage applications.

Double-Layered Perovskite Oxyfluoride Cathodes with High Capacity Involving O-O Bond Formation for Fluoride-Ion Batteries.

Developing electrochemical high-energy storage systems is of crucial importance toward a green and sustainable energy supply. A promising candidate is fluoride-ion batteries (FIBs), which can deliver a much higher volumetric energy density than lithium-ion batteries. However, typical metal fluoride cathodes with conversion-type reactions cause a low-rate capability. Recently, layered perovskite oxides and oxyfluorides, such as LaSrMnO4 and Sr3Fe2O5F2, have been reported to exhibit relatively high rate performance and cycle stability compared to typical metal fluoride cathodes with conversion-type reactions, but their discharge capacities (∼118 mA h/g) are lower than those of typical cathodes used in lithium-ion batteries. Here, we show that double-layered perovskite oxyfluoride La1.2Sr1.8Mn2O7-δF2 exhibits (de) intercalation of two fluoride ions to rock-salt slabs and further (de) intercalation of excess fluoride ions to the perovskite layer, leading to a reversible capacity of 200 mA h/g. The additional fluoride-ion intercalation leads to the formation of O-O bond in the structure for charge compensation (i.e., anion redox). These results highlight the layered perovskite oxyfluorides as a new class of active materials for the construction of high-performance FIBs.

Synergistic Effect of CNT-TiO2 Catalyst and 3D Electrode Architecture for Electrochemical Performance in Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) are a potential electrochemical storage system for the future with high capacity (1675 mAh g−1) and energy density (∼2600 Wh kg−1). The poor conductivity of sulfur, polysulfide shuttle effect, and volume expansion of the sulfur cathode are the main hurdles to their commercialization. To mitigate these issues, this work represents a rational composite of hybrid multiwalled carbon nanotubes (MWCNT) -TiO2 high surface area carbon-sulfur composite (CTHS) onto a 3D carbon fiber (CF) based free-standing electrode (CTHS@CF) architecture. TiO2 can effectively anchor the polysulfides by chemical bonding and improve cyclability. MWCNTs and CFs are the effective electron transport materials that accelerate the redox kinetics of polysulfides. The electrochemistry of CTHS@CF reveals an excellent discharge capacity of 910 mAh g−1 (1st cycle) at 100 mA g−1 compared to the conventional aluminum-coated (CTHS@Al) of 532 mAh g−1. The CTHS@CF (at 300 mA g−1) displays 514 mAh g−1 (initial discharge) capacity with 83% capacity retention up to 100 cycles, whereas CTHS@Al shows 394 mAh g−1 with 44% capacity retention. Combining 3D electrode architecture with the metal oxide (TiO2) plays a vital role in the electrochemistry of LSBs by improving the stability of the battery’s cycle life and overall energy density.

Corrosion inhibition of polyelectrolytes to the Al anode in Al-air battery: A comparative study of functional group effect

Al-air battery is a promising alternative to electrochemical storage systems because of their high energy density and low cost. However, the hydrogen evolution corrosion in alkaline electrolytes is a major obstacle before this technology can be commercially viable. In this paper, three polyelectrolytes as corrosion inhibitors for pure Al anodes in KOH electrolytes are investigated by electrochemical methods, hydrogen evolution rate (HER) tests, weight loss measurements, and surface characterization. The Attenuated Total internal Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) and theoretical simulation results show that all the polyelectrolytes can be adsorbed on Al to form a protective barrier against the corrosive species. In particular, poly(allylamine) (PAH) exhibits the highest corrosion inhibition efficiency. Furthermore, galvanostatic discharge measurement reveals that the Al-air battery in PAH electrolyte exhibits the highest specific discharge capacity (1495.2 mA h g−1). Computational analysis shows that the inhibition performance depends on the frontier molecular orbital energy and adsorption energy.

Technical assessment of a stand-alone hybrid renewable system for energy and oxygen optimal production for fishes farming in a residential building using HOMER pro

Electricity holds both economic significance and strategic importance in many regions globally. Persistent challenges related to electricity generation, encompassing aspects like availability, quality, and cost, have impeded the progress of nations for an extended period. While conventional electrochemical storage systems have been the benchmark, they are plagued by issues such as high expenses, technical limitations in power output, and restricted storage capacity. Power generation facilities come with their own array of problems, including noise pollution, environmental impacts, and suboptimal performance, exacerbating the existing concerns of reliability and maintenance. To navigate the path of sustainable global development amidst a sharp upswing in energy consumption, it becomes imperative to foster innovative energy solutions. Independent renewable energy systems (RES) represent a promising avenue for reshaping the prevailing reliance on conventional power grids. The Hybrid Renewable Energy System (HRES) deserves careful calibration, particularly considering the considerable load fluctuations and the need for cost efficiency. The study considers a standalone HRES in a residential area on Manoka Island, where fish farming is a primary activity. This dwelling exhibits a daily electricity consumption averaging at 9.28 kWh, with peak demand hitting 0.88 kW. To evaluate the suitability of the Hybrid Optimization Model for Electric Renewable (HOMER) program, the study investigates the optimal energy generation mix for both sustaining the fish farming industry and fulfilling the energy requirements of the chosen building. The optimization process identifies four key parameters that undergo thorough assessment in this analysis. Delving into the specifics, the study attains an impressive renewable fraction (RF) of 92.5% and achieves a Deficit of Power Supply Probability (DPSP) of 0%. Furthermore, the production of 50 kg of O2 and the emission of 1.69 kg of carbon annually prove adequate for constructing a reliable and environmentally sound energy system. In a broader sense, this research serves as a compelling case study, elucidating the concept of hybrid energy systems within the framework of eco-friendly and sustainable power generation. The study not only underscores the substantial potential of RES for the country but also constitutes a significant stride for researchers active in this field.

Unified model of lithium-ion battery and electrochemical storage system

Nowadays, energy storage systems are of paramount importance in sectors such as renewable energy production and sustainable mobility because of the energy crisis and climate change issues. Although there are various types of energy storage systems, electrochemical devices such as electric double layer capacitors (EDLCs), lithium-ion capacitors (LiCs), and lithium-ion batteries (LiBs) are the most common because of their high efficiency and flexibility. In particular, LiBs are broadly employed in many applications and preferred in the mobility sector, where there is a need for high energy and high power. To ensure good operating conditions for a battery and limit its degradation, it is important to have a precise model of the device. The literature contains numerous equivalent circuit models capable of predicting the electrical behavior of an LiB in the time or frequency domain. In most of them, the battery impedance is in series with a voltage source modeling the open circuit voltage of the battery for simulation in the time domain. This study demonstrated that an extension of a model composed exclusively of passive elements from the literature for EDLCs and LiCs would also be suitable for LiBs, resulting in a unified model for these types of electrochemical storage systems. This model uses the finite space Warburg impedance, which, in addition to the diffusion process of lithium\\lithium ions in the electrodes\\electrolyte, makes it possible to consider the main capacitance of the battery. Finally, experimental tests were performed to validate the proposed model.

Use of Physics-Based Models for Different Applications of Electrochemical Energy Storage and Conversion Devices

This talk will present the application of physics-based models applied to two different electrochemical storage and conversion systems, viz. Li-ion batteries and Proton Exchange Membrane Fuel Cells (PEMFCs). Battery energy storage system (BESS) is becoming a crucial part of standalone renewable hybrid power systems due to the intermittent nature of power generation and for aiding in various operations like frequency regulation, voltage support, and peak shaving. The lithium-ion battery is a promising choice for BESS due to its high energy density, power density, operating voltage, negligible self-discharge, suitable operating temperature range, modularity, and reliability. A standalone renewable hybrid power system framework with lithium-ion battery energy storage is developed to investigate its performance using physics-based battery models. Power management and control strategies are developed for standalone renewable hybrid power systems. These control strategies can track the MPP of the solar cells and wind turbines while avoiding overcharging the battery and guaranteeing 0% dumping power under different ambient and working conditions. The battery is exposed to harsh ambient conditions in the real world, resulting in the dynamic and continuous capacity fade. A thermal management and control strategy is developed to analyze the effect of temperature on lithium-ion batteries' performance and degradation without using external cooling systems. Dynamic battery degradation analysis and life prediction are essential for better techno-economic estimation of renewable hybrid power systems. The impact of BESS size variation on degradation and the cost of energy generation is analyzed. The developed renewable hybrid power system framework is independent of location and system size and can be extended to incorporate other renewable energy generation sources and energy storage systems.The second part of this talk will focus on using physics-based models to understand the water dynamics and degradation mechanisms inside PEMFC, which is necessary for water management, long-life operation, and cost reduction. PEMFCs have emerged as an alternative green energy technology in various applications such as automobiles, portable and stationary applications, and auxiliary power supplies for space exploration missions. The cost and durability targets remain unmet largely, which restrains the commercialization of the PEMFCs. The major difficulty in modeling lies in the wide scale of dimensions from the millimeter level (flow channel) to the micron level (catalyst layer (CL) thickness). The multi-scale physics-based model enables the life cycle analysis of PEMFC under various operating conditions. The mass transport limitation is the major hurdle in performance enhancement for higher current density operations. It arises from the liquid water generated during the electrochemical reactions, which hinders the reaction sites of CL and oxygen transport reaction sites in the gas diffusion layer, resulting in performance deterioration. Many experimental studies reported the two-phase flow visualization techniques in PEMFCs, viz. neutron imaging, optical visualization, and X-ray radiography. However, the difficulties in conducting experiments for flow visualization and related parameters such as liquid volume fraction have encouraged researchers to adopt numerical simulations that are less expensive and computationally efficient. Understanding liquid water movement inside the cell at the micro-scale help to improve the PEMFC performance at the stack level. Here, we develop a comprehensive 3-D, multiphase, non-isothermal, steady-state physics-based model of the PEMFC that can closely approximate the liquid water flooding and membrane drying. The findings from this work can be used to design an efficient flow configuration and to study membrane deformation due to the shrinking-swelling under humidification and thermal cycling. The ultimate goal of the multi-scale model is to enhance the PEMFC stack output with less degradation.

Reversible electrochemical hydrogen storage of quinoxaline utilizing Pd/NF dual-function electrocatalyst under mild conditions

Nitrogen heterocyclic organics are promising hydrogen storage carriers with the advantage of being capable of large-scale transportation over long distances using existing oil and gas facilities. However, traditional methods for the hydrogenation and dehydrogenation of organic hydrogen carriers usually require high temperature and pressure conditions and external hydrogen supplies, which hinder their large-scale applications, as well as having certain safety risks. In this paper, a reversible electrochemical hydrogen storage system using quinoxaline as a hydrogen carrier was developed with potential for use at room temperature and atmospheric pressure. Experiments revealed that the hydrogenation conversion of quinoxaline reached 95% within 120 min at −0.20 V vs. RHE, and the dehydrogenation conversion of 1,2,3,4-tetrahydroquinoxaline reached 100% within 30 min at 1.30 V vs. RHE. This means that the system achieved quick and efficient reversible hydrogen storage. The Pd/NF dual-function electrode prepared by spontaneous redox reaction still showed high catalytic activity after 8 cycles, indicating its good long-term stability. The proton donor in the electrochemical hydrogenation process of quinoxaline was water, which completely eliminates the safety risk from the use of external hydrogen. This work provides a simple and reliable strategy for efficient hydrogen storage using nitrogen heterocyclic organics.

Energy yield estimation of on-vehicle photovoltaic systems in urban environments

Greenhouse gases from the propulsion systems of road transportations constitute a significant obstacle to achieve the Paris Agreement objectives. Nowadays, the substitution of conventional internal combustion engines with electric motors, along with electrochemical storage systems are the leading efforts to reduce the use of fossil fuels in road transportations. However, their limited driving range and the long charging times are the main technical factors that hinder the development of electromobility. Thus, energy harvesters and regeneration systems are increasingly incorporated in road vehicles, in order to increase their driving range. In this context, Vehicle Integrated and Applied Photovoltaics (VIAPVs) constitute an attractive prospect. The electricity yield for VIAPVs depends strongly on the route, the shadings due to the urban environment, the applied Maximum Power Point (MPPT) algorithm and the traffic conditions. In this paper, four commonly used commercial MPPT algorithms are experimentally evaluated, regarding their ability to extract the maximum available power simulating realistic city routes. The results show notable discrepancies in the performance of the studied algorithms, between terrestrial and VIAPV applications, highlighting the impact of poor MPPT performance in terms of power generation in moving vehicles.

Nickel as a key element in the future energy

The review discusses the complex properties of nickel and its role as a critical element for ensuring a confident transition to a new technological paradigm from fossil fuels in favor of using advanced electrochemical storage and energy conversion systems. The main classes of nickel-containing materials of the positive electrode (cathode) for metal-ion batteries are discussed, the place of nickel among other 3<i>d</i>-metals used in the industry of electrochemical energy storage is determined. The main methods and approaches for the synthesis of state-of-the-art and next generation cathode materials based on layered Ni-containing oxides are presented. The crystal and electronic structures of these materials, including their evolution in the process of (de)intercalation of alkali metal cations, are considered in the context of their electrochemical properties. The most acute problems facing modern materials science on the way to commercialization and industrial production of new generation highenergy density cathode materials are determined. At the end of the review, promising directions for the further development of nickelcontaining cathode materials are outlined.<br> The bibliography includes 252 references.

Insights into the Modification of Carbonous Felt as an Electrode for Vanadium Redox Flow Batteries.

The vanadium redox flow battery (VRFB) has been regarded as one of the best potential stationary electrochemical storage systems for its design flexibility, long cycle life, high efficiency, and high safety; it is usually utilized to resolve the fluctuations and intermittent nature of renewable energy sources. As one of the critical components of VRFBs to provide the reaction sites for redox couples, an ideal electrode should possess excellent chemical and electrochemical stability, conductivity, and a low price, as well as good reaction kinetics, hydrophilicity, and electrochemical activity, in order to satisfy the requirements for high-performance VRFBs. However, the most commonly used electrode material, a carbonous felt electrode, such as graphite felt (GF) or carbon felt (CF), suffers from relatively inferior kinetic reversibility and poor catalytic activity toward the V2+/V3+ and VO2+/VO2+ redox couples, limiting the operation of VRFBs at low current density. Therefore, modified carbon substrates have been extensively investigated to improve vanadium redox reactions. Here, we give a brief review of recent progress in the modification methods of carbonous felt electrodes, such as surface treatment, the deposition of low-cost metal oxides, the doping of nonmetal elements, and complexation with nanostructured carbon materials. Thus, we give new insights into the relationships between the structure and the electrochemical performance, and provide some perspectives for the future development of VRFBs. Through a comprehensive analysis, it is found that the increase in the surface area and active sites are two decisive factors that enhance the performance of carbonous felt electrodes. Based on the varied structural and electrochemical characterizations, the relationship between the surface nature and electrochemical activity, as well as the mechanism of the modified carbon felt electrodes, is also discussed.

Multi criteria decision making for the most suitable combination of energy resources for a decentralized hybrid energy solution with green hydrogen as the storage option

Decentralized hybrid renewable energy systems are emerging as possible solutions for remote locations not feasible for grid power. However, such systems always need a storage device to bridge the gap between demand and supply during its operation. Electrochemical storage systems are currently the most common devices for this purpose. An alternative novel process to meet this gap between the demand and supply of power may be to generate hydrogen with excess renewable power during off-peak load. Produced green hydrogen may be used by fuel cells to generate electricity subsequently to compensate for the gap during peak load. However, practical suitability of acceptance of these alternative options will depend on economic feasibility including risk in return on investment. This is explored through comparative evaluation of these options with relative assessment of a few indicative parameters including uncertainties. These parameters are fuel consumption, cost of electricity, net present cost, financial risk and renewable fraction with full load meeting. As projects with new technologies have generally associated risk with return on investment, a Monte Carlo Simulation is also done to assess and compare the uncertainties of different options. As the five different evaluation criteria do not converge to the same best solution, finally a multi-criteria decision-making approach is adopted to decide the acceptable solution. The sensitivity analysis is also performed to examine the robustness of the decided solution. The analysis results show that the combination of photovoltaic-wind-generator-Lithium-ion is techno-economically acceptable with a moderate risk and a significant renewable share. Corresponding values of different parameters are: cost of electricity-$0.159/kWh, net present cost - $4,24,568, fuel consumption- 2628L/year, renewable fraction- 96.5%, and standard deviation–0.45% respectively. Though the methodology is generic, the study is demonstrated with data of a remote Indian village.

Combined hybrid energy storage system and transmission grid model for peak shaving based on time series operation simulation

This study proposes a combined hybrid energy storage system (HESS) and transmission grid (TG) model, and a corresponding time series operation simulation (TSOS) model is established to relieve the peak-shaving pressure of power systems under the integration of renewable energy. First, a linear model for the optimal operation of the HESS is established, which considers the different power-efficiency characteristics of the pumped storage system, electrochemical storage system, and a new type of liquid compressed air energy storage. Second, a TSOS simulation model for peak shaving is built to maximize the power entering the grid from the wind farms and HESS. Based on the proposed model, this study considers the transmission capacity of a TG. By adding the power-flow constraints of the TG, a TSOS-based HESS and TG combination model for peak shaving is established. Finally, the improved IEEE-39 and IEEE-118 bus systems were considered as examples to verify the effectiveness and feasibility of the proposed model

Parameter Estimation of the Randles Equivalent Electrical Circuit Using Only Real Part of the Impedance

Electrical impedance spectroscopy (EIS) has been widely used in the modeling and analysis of various electrochemical and energy storage systems. Parameter estimation of the equivalent electrical circuit is usually performed with personal computer (PC)-based software platforms that are not commonly available onsite. Such an approach introduces a lag between measurement and maintenance actions. In this article, we present a method for in situ parameter estimation of the Randles circuit ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}$ </tex-math></inline-formula> - <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\textit {RC}}$ </tex-math></inline-formula> equivalent model). Our method overcomes the shortcoming of the iterative and PC-based estimation approaches since there is no need for an initial guess provided by the user. The low complexity of our approach enables the implementation on cost-effective microcontroller-based portable systems. The proposed method has been validated with simulations and with experimentally obtained data. In the simulation part, we used both the noiseless and noisy data, while in the experimental part, we used impedance data obtained from a dummy circuit created with discrete components, as well as bioimpedance of apple slices. The obtained results are compared with desktop-based Multiple Electrochemical Impedance Spectra Parameterization (MEISP) software. Finally, reliable and accurate estimations with a board based on the ATmega2560 microcontroller confirmed the hypothesis of suitability for implementation on embedded hardware.

Comparative Analysis of Lithium-Ion and Lead–Acid as Electrical Energy Storage Systems in a Grid-Tied Microgrid Application

Microgrids (MGs) are a valuable substitute for traditional generators. They can supply inexhaustible, sustainable, constant, and efficient energy with minimized losses and curtail network congestion. Nevertheless, the optimum contribution of renewable energy resource (RER)-based generators in an MG is prohibited by its variable attribute. It cannot be effectively deployed due to its application’s power quality and stability issues. Therefore, an energy storage system is employed to alleviate the variability of RERs by stabilizing the power demand against irregular generation. Electrical energy storage systems (EESSs) are regarded as one of the most beneficial methods for storing dependable energy supply while integrating RERs into the utility grid. Conventionally, lead–acid (LA) batteries are the most frequently utilized electrochemical storage system for grid-stationed implementations thus far. However, due to their low life cycle and low efficiency, another contending technology known as lithium-ion (Li-ion) is utilized. This research presents a feasibility study approach using ETAP software 20.6 to analyze the performance of LA and Li-ion batteries under permissible charging constraints. The design of an optimal model is a grid-connected microgrid system consisting of a PV energy source and dynamic load encompassed by Li-ion and LA batteries. Finally, the comparative study led to significant conclusions regarding the specific attributes of both battery technologies analyzed through the operation, revealing that Li-ion is a more conducive energy storage system than LA.

Introducing Spectrophotometry for Quality Control in Lithium‐Ion‐Battery Electrode Manufacturing

The demand for electrochemical storage systems is increasing due to their conventional use in mobile applications and potential as energy storage devices in power generation and electromobility. Due to its comparatively low weight and high energy density, the lithium‐ion battery is one of the most widely used electrochemical storage devices. Battery cell production consists of a complex process chain with a large number of interdisciplinary processes. Each process step has specific requirements for the product. Different process parameters are essential in each step and require unique control measurements to ensure the quality of the intermediate product. To identify critical parameters, an understanding of the potential effects of different process parameters and the relationship between structural characteristics and end product properties must be gained. Therefore, herein, spectrophotometry concerning its application in lithium‐ion battery production is investigated. Individual process steps in electrode production are carried out to establish a correlation between intermediate product properties and measured color values. The influences of the powder components, the dispersion, and coating process are discussed. Based on the experiments carried out in this study, the suitability of spectrophotometry as an indirect measurement method of intermediate product properties is demonstrated.

Study on applications of radio frequency nano antenna energy conversion and supercapacitors

In this paper, the study on applications of radio frequency nano antenna energy conversion and supercapacitors is presented. Radio Frequency (RF) signals are a form of electromagnetic radiation with wavelengths greater than 3 meters. Initially used in wireless communication devices like radios and walkie-talkies, RF signals have found their way into energy conversion and storage applications. When RF signals are received by an antenna with coupled capacitors and a rectifier circuit, they generate a potential difference of a few millivolts. This potential difference can be used as a stable source of energy to power low-voltage applications through ambient RF radiation, and excess energy can be stored in electrochemical storage systems like supercapacitors and lithium-ion batteries. While this technology is currently limited to low-power applications, it has immense potential in various fields such as medicine, automotive industry, military applications, and more. Researchers are currently working to improve the energy density of supercapacitors by modifying their electrode materials using nanotechnology. One promising material is lignin, derived from wood fibers, which has shown great performance in tests and is expected to be a low-cost solution for high-performance batteries and supercapacitors. As the renewable energy sector continues to advance, we can expect to see more useful applications based on RF nano antennas and micro/nano-sized supercapacitors. The work done &amp; presented in this paper is the result of the mini-project work that has been done by the first sem engineering students of the college and as such there is little novelty in it and the references are being taken from various sources from the internet, the paper is being written by the students to test their writing skills in the starting of their engineering career and also to test the presentation skills during their mini-project presentation. The work done &amp; presented in this paper is the report of the assignment / alternate assessment tool as a part and parcel of the academic assignment of the first year subject on nanotechnology &amp; IoT.

Sepiolite as a novel polysulfide trapper for energy applications: an electrochemical, X-ray spectroscopic and DFT study.

Capacity retention is a critical property to enhance in electrochemical storage systems applied to renewable energy. In lithium-sulfur (Li-S) batteries, the capacity fade resulting from the shuttle effect of polysulfides is a major obstacle to their practical application. Sepiolite, an eco-friendly earth-abundant clay with suitable surface chemistry for anchoring and retaining various molecules and structures, was studied as a cathode additive to mitigate the shuttle effect using experimental and theoretical approaches. Electrochemical measurements, spectroscopy, and ab initio calculations were performed to describe the mechanism and interfaces involved in polysulfide retention using 2 wt% of sepiolite as an additive in Li-S batteries. The results showed that the addition of sepiolite significantly improved the capacity retention during battery cycling. Spectroscopic analysis revealed that the effective sepiolite-polysulfide interface was governed by oxidized sulfur species. Additionally, ab initio studies showed a highly exothermic adsorption both inside and outside the sepiolite pore. This study demonstrates the potential use of eco-friendly, low-cost, non-toxic, natural, and abundant materials as additives to increase capacity retention.