MSc. Václav Knap, Ph.D.

Recycling lithium-ion batteries (LIBs) have become increasingly important in response to expanding electromobility. This paper is focused on evaluating the environmental impacts (EIs) of recycling pre-treatment of three types of LIBs with black mass as its product. A detailed gate-to-gate Life Cycle Assessment study was conducted to obtain EIs of the recycling process. The benefits of LIBs recycling pre-treatment and significant recovery of secondary aluminum for compared battery types are highlighted in the analysis. This paper points out that the varying chemistry of the compared LIBs does not affect the resulting EIs of the recycling pre-treatment procedures.

Electrochemical impedance spectroscopy (EIS) is a measurement method widely used for non-destructive analysis and diagnostics in various electrochemical fields. From the measured dependence of the battery impedance on the frequency, it is possible to determine the parameters of various equivalent electrical circuit models of the battery. The conventional method of battery measurement using single-sine EIS is currently one of the most widely used methods for the analysis of lithium-ion batteries. However, its most significant disadvantage is the relatively long measurement time. For this reason, there is a growing demand for faster methods using fast-Fourier transform or pseudo-random sequences. A description of various EIS methods applications is provided in this paper.

The development of new battery systems has been intensively pursued in an effort to increase energy densities. Lithium-sulphur batteries represent a group of next-generation batteries with high theoretical capacity and energy density. The electrochemical properties of lithium-sulphur batteries may be improved by the application of appropriate conductive and porous additives to sulphur in the cathode material. Recently, materials belonging to the group of metal-organic frameworks (MOFs) have been widely investigated as host materials for sulphur thanks to their unique porous structure. In this work, various types of MOFs (GaTCPP, MOF-76(Gd), MIL-101(Fe)-NH2) were applied to the cathode material. MOFs were activated or carbonized before cathode material preparation. The structure of activated GaTCPP showed the lowest capacity fading per cycle (0.07 %) from activated MOFs during cycling at 0.5 C for 200 cycles. The carbonization process may improve the electrochemical properties of the electrode material. The best electrochemical properties showed carbonized MOF-76(Gd), and the capacity fading rate per cycle was only 0.04 % despite 200 cycles at 0.5 C.

Despite great progress in lithium-sulfur (Li-S) batteries, the electrochemical reactions in the cell are not yet fully understood. Electrode processes, complex interfaces and internal resistance may be characterized by electrochemical impedance spectroscopy (EIS). EIS is a non-destructive technique and easy to apply, though there are challenges in ensuring the reproducibility of measurements and the interpretation of impedance data. Here, we present the impedance behavior of a 3.4 Ah Li-S pouch cell characterized by EIS. The impedance changes were analyzed over the entire depth-of-discharge, depth-of-charge, and at various temperatures. Based on the formation of intermediates during (dis)charging, the changes of resistances are observed. Overall, the increase in temperature causes a decrease in electrolyte viscosity, lowering the surface energy which can improve the penetration of the electrolyte into the electrode pores. Moreover, the effect of superimposed AC current during EIS measurement was analyzed, and the results show the dependence of the charge transfer resistance on superimposed AC current which was lower compared to steady-state conditions and consents with theory.

CubeSats, a branch of the space industry, has lately received great interest for being an affordable satellite platform. For proper functioning, they are nowadays practically dependent on Lithium-ion batteries as a power supply at moments, when there is not enough power generated by solar panels. Thus, batteries have to be thoroughly tested to ensure that they provide sufficient performance, lifetime and that they are safe. In other industry areas, such as electric vehicles, it is common to use mission profiles (often referred to as driving profiles) for battery testing to closely emulate conditions that are experienced in practice. However, mission profiles reflecting closely CubeSat conditions are not publicly available. Thus, this paper proposes a methodology to derive mission profiles, and resulting representative mission profiles, dedicated especially to battery testing. The proposed methodology is based on analyzed telemetry data from three GOMX CubeSats. At first, electrical current characteristics are obtained from the telemetry and are generalized across the satellites, to be subsequently used for the mission profile synthesis. The battery temperature is an important factor for the battery performance and lifetime, and it was identified to be very dynamic in CubeSats. Thus, a model describing battery temperature during their mission is proposed to enable generate realistic temperature mission profiles. Finally, the current and temperature profiles are synchronized to capture their mutual impact on the batteries, and they are formulated to be suitable for on-ground (laboratory) testing.

Emissions reduction has been tightened worldwide, especially in automotive. Electric vehicles (EVs) are a suitable solution that can meet the strict requirements in CO2 production and high user torque and speed requests. Therefore, a significant increase in demand for EVs has occurred. This growing trend results in increased production of new vehicles, raw materials consumption, and the number of waste vehicles and batteries on the market. Solution methods are being sought: the recycling process is one of the most promising. This work provides a simplified overview of the economic evaluation of the recycling process of spent lithium-ion batteries from EVs in conditions of the Czech Republic. The described technique evaluates a combination of the pyrometallurgical and hydrometallurgical methods (with the process efficiency above 95 %) and the high quality of output products. Moreover, this work presents future scenarios considering the changes due to EU legislation.

This paper describes how to model a Lithium-ion battery's internal characteristics based on electrochemical impedance spectroscopy (EIS) data and their fitting into an Equivalent Circuit Model (ECM) using Python and the Jupyter development environment. The described method is used on an extensive dataset collected during an ageing campaign of lithium-ion batteries. The work aims to determine the correct values of ECM elements with satisfactory accuracy. The battery's ECM parameter interpretation provides essential information about its internal structure and mechanisms, which helps to understand its processes and estimate its future degradation. It was necessary to deal with two tasks: first, the processing of many measurements, and second, estimating the appropriate input parameters for the ECM. We have managed to practically automate the processing of more than one thousand files with measured data and design and gradually refine a method for estimating input parameters for ECM fitting.

Lithium battery diagnostics should comprehensively monitor battery status. To increase the level of diagnostics, it is necessary to expand with new parameters. The GITT method is used for the analysis of diffusion process. However, the method has drawbacks when applied to current electrode structures. They exhibit inconsistencies during their measurements and evaluation. Consequently, this work builts upon state-of-the-art and it proposes a new solution for determination of necessary relaxation time after a pulse to determine accurately a diffusion coefficient.

The popularity of CubeSats has grown in the last few years. CubeSats are small-sized, low-weight satellites commonly used in low Earth orbit for remote sensing or communications. Their most considerable benefits are their high flexibility, quick lead time, and significantly lower price than 'classical' satellites, due to their vast use of commercial off-the-shelf components. Lithium-ion batteries are being used as energy storage within these components. Batteries are necessary for the spacecraft; they supply energy when there is not enough generation from solar panels, especially during eclipses. The batteries undertake a series of operations during missions in various conditions that influence their lifetime and performance. The performance of these batteries can be modelled via an electrical-circuit model. Thus, a set of characterization and degradation tests considering cycling aging were performed to identify the cell behaviour throughout an expected battery life in a CubeSat. The aging trends of the battery model parameters based on the provided parametrization procedure were observed and evaluated. Moreover, the developed model reaches high accuracy for a mission profile with the root-mean-square-error below 9 mV.

During recent years, emissions reduction has been tightened worldwide. Therefore, there is an increasing demand for electric vehicles (EVs) that can meet emission requirements. The growing number of new EVs increases the consumption of raw materials during production. Simultaneously, the number of used EVs and subsequently retired lithium-ion batteries (LIBs) that need to be disposed of is also increasing. According to the current approaches, the recycling process technology appears to be one of the most promising solutions for the End-of-Life (EOL) LIBs—recycling and reusing of waste materials would reduce raw materials production and environmental burden. According to this performed literature review, 263 publications about “Recycling of Lithium-ion Batteries from Electric Vehicles” were classified into five sections: Recycling Processes, Battery Composition, Environmental Impact, Economic Evaluation, and Recycling & Rest. The whole work reviews the current-state of publications dedicated to recycling LIBs from EVs in the techno-environmental-economic summary. This paper covers the first part of the review work; it is devoted to the recycling technology processes and points out the main study fields in recycling that were found during this work.

Lithium-ion batteries (LIBs) are crucial for consumer electronics, complex energy storage systems, space applications, and the automotive industry. The increasing requirements for decarbonization and CO2 emissions reduction affect the composition of new production. Thus, the entire automotive sector experiences its turning point; the production capacities of new internal combustion engine vehicles are limited, and the demand for electric vehicles (EVs) has continuously increased over the past years. The growing number of new EVs leads to an increasing amount of automotive waste, namely spent LIBs. Recycling appears to be the most suitable solution for lowering EV prices and reducing environmental impacts; however, it is still not a well-established process. This work is the second part of the review collection based on the performed literature survey, where more than 250 publications about “Recycling of Lithium-ion Batteries from Electric Vehicles” were divided into five sections: Recycling Processes, Battery Composition, Environmental Impact, Economic Evaluation, and Recycling and Rest. This paper reviews and summarizes 162 publications dedicated to recycling procedures and their environmental or economic perspective. Both reviews cover the techno-environmental economic impacts of recycling spent LIBs from EVs published until 2021

Lithium-ion batteries (LIBs) are one of the most popular energy storage systems. Due to their excellent performance, they are widely used in portable consumer electronics and electric vehicles (EVs). The ever-increasing requirements for global carbon dioxide CO2 emission reduction inhibit the production of new combustion vehicles. Thus, the demand for EVs increases, as well as the number of spent LIBs. Due to increases in raw materials saving and reduction in energy and environmental impacts, recycling is one of the most promising solutions for end-of-life (EOL) treatment for spent LIBs. This work describes the first step in recycling the LIBs nickel-manganese-cobalt (NMC) based module from a full battery electric vehicle (BEV) holding its high recycling efficiency and considering the process costs and environmental impact. This paper is devoted to module-to-cell disassembly, discharge state characterization measurements, and material analysis of its components based on x-ray fluorescence (XRF) and diffraction (XRD).

The ever-increasing requirements for global carbon dioxide CO2 emission reduction decrease the production of new internal combustion engine vehicles (ICEVs). On the contrary, the demand for electric vehicles (EVs) increases along with the number of spent lithium-ion batteries (LIBs). Recycling LIBs seems to be one of the most promising options for end-of-life (EOL) treatment solutions; however, many process effects of currently used battery compounds are still being addressed, e.g., the safety and potential risks of wastewater, battery scrap, or leaks into the air. In this work, the LIB nickel-manganese-cobalt (NMC) cell electrolyte was characterized in wastewater using gas chromatography with mass spectrometry (GC-MS), inductively coupled plasma with optical emission spectrometer (ICP-OES), and the residues of toxic substances bound to nm-μm valuable metal particles in battery scrap were determined by x-ray fluorescence (XRF).

State-of-health (SOH) estimation is an essential but challenging functionality for batteries. In this work, a SOH estimation for Lithium-ion batteries in CubeSats is in focus. A proposed method is based on offline model parameter identification from satellite telemetry. Its laboratory performance was 2.26 % and 0.74 % root-mean-square-error for capacity and resistance, respectively.

CubeSats are on a rise as an agile and perspective satellite technology. They are small satellites of a standardized format, using commercial off-the-shelf (COTS) components, which reduces their manufacturing and lunching costs. Batteries are a key part of CubeSats with the task of providing energy whenever needed. Thus, the satellite lifetime is limited (partly) by battery life. Lithium-ion batteries, the state-of-the-art choice for CubeSats, are complex electrochemical systems, with their performance and lifetime behavior strongly influenced by the temperature. Thus, the battery temperature behavior in CubeSats is the focus of this work. Aspects of thermal environment and modelling of CubeSats and batteries are reviewed. Satellite’s telemetry is used to derive a temperature data-driven model for low Earth orbit conditions. This model is then convenient for generating test and simulation profiles reflecting realistic conditions that are used throughout the remaining work. A battery management system and its algorithms are one area that must be adapted to such dynamic temperature changes. Thus, a state-of-charge estimation method was developed and demonstrated against a CubeSat temperature profile. Another important area affected by temperature is battery lifetime. A set of calendar and cycling tests were performed and assessed to evaluate a cell’s capability to support five-years long commercial missions. Finally, as means to directly influence a battery temperature, heaters are commonly used. A model is developed for evaluating the heaters’ control, which should ensure better performance and lifetime of batteries in cold cases.

Idling periods are a major part of the Lithium-ion battery operation. Due to parasitic reactions, the battery capacity is decreasing and self-discharge occurs over time. Thus, in order to predict the battery lifetime and optimize its operation, it is required to capture this behavior. In this study, two different storage periods of 2 and 6 months were investigated and used to develop and validate models dedicated to reversible and irreversible capacity loss. It has been observed that while for the shorter storage period, the self-discharge rate does not change significantly, for the longer storage period it decreased during aging. Moreover, the degradation rates vary significantly for various time scales at low temperature, while at medium and high temperatures they are matching closely for 2- and 6-months periodic storage.

Nano-satellites are a rapidly developing field of the space industry. Their structure and environmental conditions impose requirements for their functioning and reliability. One of key systems to keep nano-satellites in operation is the energy storage, often in a form of batteries, which supplies power, when there is not enough generation from solar panels. Thus, it is desirable to monitor the battery states, such as the state-of-charge (SOC). This topic was investigated in connection to other applications as electric vehicles or stationary storage; however, their working conditions are different from nano-satellites’. We propose a SOC estimation method, which takes into account these conditions, especially wide and rapidly changing temperature. The SOC is estimated through an unscented Kalman filter (UKF), which uses open-circuit voltage as pseudo-measurement, obtained from an online parameter identification method. Furthermore, to achieve a high accuracy SOC estimation, various open-circuit voltage models and characterization test procedures were evaluated. Finally, the SOC root mean square error of 0.53% was reached for a rapid temperature varying nano-satellite mission profile with thermal gradient of 22.4°C/hour by using an extended Kalman filter for online parameter identification and UKF for SOC estimation, based on the analytical OCV model characterized from quasi open-circuit voltage test.

Nowadays, Lithium-ion batteries are as the most preferable technology for consumer electronics. They found their way also to electric vehicles or even satellites, mainly due to their high energy density and long life. In the applications, the batteries require a battery management system for safe and optimal operation. Often, state estimation functionalities (as state-of-charge or state-ofhealth) require a running battery model. Therefore, an electrical circuit model (ECM) that accurately captures a battery behavior in suitable complexity is needed. This paper presents a three steps parametrization technique of ECM for Lithium-ion batteries based on laboratory experiments. Furthermore, an analysis of SOC and temperature dependence of battery parameters has been conducted. The developed ECM is validated, and its accuracy is evaluated by Root Mean Square Error (RMSE) and Maximal Absolute Error (MaE).

Much attention has been paid to rechargeable lithium-sulfur batteries (Li–SBs) due to their high theoretical specific capacity, high theoretical energy density, and affordable cost. However, their rapid c fading capacity has been one of the key defects in their commercialization. It is believed that sulfuric cathode degradation is driven mainly by passivation of the cathode surface by Li2S at discharge, polysulfide shuttle (reducing the amount of active sulfur at the cathode, passivation of anode surface), and volume changes in the sulfuric cathode. These degradation mechanisms are significant during cycling, and the polysulfide shuttle is strongly present during storage at a high state-of-charge (SOC). Thus, storage at 50% SOC is used to evaluate the effect of the remaining degradation processes on the cell’s performance. In this work, unlike most of the other previous observations that were performed at small-scale cells (coin cells), 3.4 Ah pouch Li–SBs were tested using cycling and calendar aging protocols, and their performance indicators were analyzed. As expected, the fade capacity of the cycling aging cells was greater than that of the calendar aging cells. Additionally, the measurements for the calendar aging cells indicate that, contrary to the expectation of stopping the solubility of long-chain polysulfides and not attending the shuttle effect, these phenomena occur continuously under open-circuit conditions.

A comprehensive performance evaluation is required to find an optimal battery for the battery energy storage system. Due to the relatively less energy density of lithium iron phosphate batteries, their performance evaluation, however, has been mainly focused on the energy density so far. In this paper, a multifaceted performance evaluation of lithium iron phosphate batteries from two suppliers was carried out. A newly proposed figure of merit, that can represent charging / discharging energy efficiency and thermal performance, is proposed. The figure of merit allows designers to conveniently select a battery with a higher round-trip efficiency and require less cooling load for the battery energy storage system. Temperature distribution characteristics, which can affect the accuracy of state prediction and lifespan, have been evaluated with a high-performance infrared camera. Even though the energy density of a certain battery is relatively lower, it has been confirmed that it could show better round-trip energy efficiency and thermal performance through the evaluations. It is revealed by structural analysis with three-dimensional X-ray computed tomography scanning that this performance difference is related to the tab design and package inside the batteries. Moreover, a temperature monitoring methodology to minimize temperature measurement errors in the battery management systems is proposed.

CubeSats and small satellite solutions are increasing in popularity as they enable a fast, cheap, and agile way for satellite applications. An essential component of nearly every satellite is the energy storage device, which is practically equal to a battery. Consequently, an overview of past, present, and future battery technologies for CubeSats is presented. CubeSats use typically commercial off-the-shelf (COTS) batteries. They are not primarily dedicated to space, so their suitability to the space environment needs to be evaluated. Batteries are also considered as potentially dangerous goods. Thus, there are guidelines and standards that specify safety criteria and tests for the batteries in order to be allowed for transportation and launch. Furthermore, the character of satellites' missions determines their demand on batteries in terms of current rates, depth-of-discharge, and lifetime. Thus, these expectations are discussed. A market survey was also carried out to identify currently available commercial battery solutions and their parameters. This work summarizes the status, requirements, and the market situation of batteries for CubeSats.

There is an increasing number of CubeSats being launched on the Earth's orbit. They are typically based on commercial off-the-shelf batteries that are not primarily designed for space applications. Thus, their actual degradation in this environment needs to be considered, compared to on-ground laboratory conditions. In this work, a model-based method is introduced for tracking the change in battery model parameters, including the battery capacity. The method is based on collected telemetry data and it covers specific and variable battery temperature conditions in CubeSats. However, it is shown that the method is sensitive to telemetry quality, regarding sample resolution and sample loss. Thus, the used settings could not determine battery degradation trends with high confidence. Nevertheless, steps for improvement were identified that shall increase the accuracy of the results in future work.

Mission design and spacecraft design are challenging activities, which have to be carefully conducted in order to achieve a successful mission for a nano-satellite. In NewSpace, especially in the area of nano-satellites, there is a strong drive towards agile and quickly market deployed products. Typically, commercial-off-the-shelf (COTS) batteries are used and their manufacturers rarely provides specifically needed information about them. Thus, it is necessary for the nano-satellite developer to assess the battery performance and lifetime, on their own, in order to support an accurate mission/spacecraft design. In the proposed approach, the possible degradation factors and their feasible ranges were firstly considered, in order to limit the test requirements, and the selected degradation tests were performed. The scope of battery performance indicators analysis was limited to battery capacity and resistance. Their change and sensitivity were evaluated in relation to calendar aging, considering temperature and state-of-charge factors, and to cycling aging, considering temperature and cycle depth factors, and to radiation aging. Afterwards, the identified degradation rates were used for lifetime modelling. The resulting lifetime model had 0.69% and 0.81% root-mean-square-error, compared to the experiment, for the prediction of capacity and resistance, respectively.

In today's applications, batteries, in the role of electricity storage, have a significant and irreplaceable place. Lithium-ion (Li-ion) batteries have become the most popular technology. When using them, great importance is placed on safety and therefore it is necessary to monitor their condition. Since it is a complex electrochemical system and it is practically possible to measure only their electrical quantities and temperature, their diagnostics becomes a challenging task. With regard to the internal process of lithium ion diffusion, new diagnostic methods using short current pulses to detect a change in the diffusion process, which changes with the age of the battery, are presented. Two methods will be presented here, which seem to be very promising for the analysis of the diffusion process. The first results show positive conclusions.