Electrodeposition of NiP composite coatings with nano and sub-micron sized SiC has been carried out to investigate the possibility of replacing hard chromium coatings. The composition and structure of the coatings were evaluated by energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analysis, respectively. Microhardness was measured by Vickers indentation and polarization measurements were carried out to study the corrosion behavior of the coatings. The results showed that submicron particles can be codeposited with a higher content as compared to nano sized ones. However, even if a smaller amount of the nano-sized SiC particles are incorporated in the coating, the contribution to an increasing microhardness was comparable with the submicron sized particles, which can be related to the higher density of codeposited particles. SiC particles did not change the anodic polarization behavior of NiP coatings in a 3.5% NaCl solution. Finally, the effect of heat-treatment on the coatings properties at 400 °C for 1 h was studied to investigate the contribution of particles and heat-treatment on hardness and corrosion properties. It was found that the heat-treatment doubled the microhardness and changed the anodic polarization behavior of the coatings from passive to active with respect to the as-plated conditions.
In this study, electrodeposition of Ni-P composite coatings has been carried out to investigate the possibility of replacing hard chromium coatings. Therefore, electrodeposition of Ni-P based composite coating with different SiC particle size (50 nm, 100 nm and 500 nm) or B4C (500 nm) was performed. The coating's composition was evaluated by energy dispersive spectroscopy (EDS), microhardness of the coatings was measured by Vickers indentor and polarization measurements were carried out to study the corrosion behavior of the coatings. The results showed that B4C particles can codeposit in higher percent respect to SiC ones. Ceramic particles increased microhardness of Ni-P coatings to 700HV0.01. The polarization behavior of all the coatings in 3.5% NaCl was similar in as plated state proving that particles did not hindered the passive behaviour. Finally, the effect of heat-treatment (at 400 ºC for 1 hour) on the coating's properties was studied to compare the contribution of particles and heat-treatment on mechanical and corrosion properties of the coatings. Heat-treatment increased the coating's microhardness and changed the anodic polarization behavior of the coatings respect to the as plated conditions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved.
The crystal structure of the title compound, [Ni3(C8H4O4)3(C3H7NO)4], is a two-dimensional coordination network formed by trinuclear linear Ni3(tp)3(DMF)4 units (tp = terephthalate = benzene-1,4-di-carboxyl-ate and DMF = di-methyl-formamide) displaying a characteristic coordination mode of acetate groups in polynuclear metal-organic compounds. Individual trinuclear units are connected through tp anions in a triangular network that forms layers. One of the DMF ligands points outwards and provides inter-actions with equivalent planes above and below, leaving the second ligand in a structural void much larger than the DMF mol-ecule, which shows positional disorder. Parallel planes are connected mainly through weak C-H⋯O, H⋯H and H⋯C inter-actions between DMF mol-ecules, as shown by Hirshfeld surface analysis.
The shipping industry is facing increasing pressure to cut emissions. Diesel-electric hybrid or fully electrical propulsion systems can offer significant savings in fuel consumption and reduce emissions. However, the use of energy storage battery systems on board vessels is introducing new fire hazards and advice on suitable fire extinguishing systems and agents is desired. In a series of tests, both total compartment application water spray and water mist systems and direct injection (using several different agents) into the module were evaluated in fire tests conducted to compare different fire extinguishing approaches for a fire in a battery cell. A test compartment was constructed to simulate a battery room and a commercially available lithium-ion (Li-ion) battery cell was positioned inside a cubic box that mimicked a battery module. By heating the battery cell, combustible gases were generated, and these gases were ignited by a pilot flame inside the simulated battery module. The tests indicated that fire extinguishment of a battery cell fire inside a battery module is unlikely when using total compartment water spray or water mist fire protection systems. The water droplets are simply not able to penetrate the battery module and reach to the seat of the fire. Direct injection of the fire extinguishing agent inside the battery module is necessary. The tests also showed that agents such as water and low-expansion foam, with a high heat capacity, provide rapid cooling and fire extinguishment. The reduced water surface tension associated with low-expansion foam may improve the possibilities for water penetration whilst agents with a high viscosity may not be able to spread to the seat of the fire. Agents with less heat capacity, such as high-expansion foam and nitrogen gas, provide less cooling but fire extinguishment can still be achieved if designed correctly.
Electric propulsion using batteries as energy storage has the potential to significantly reduce emissions from shipping and thus the environmental impact. The battery type that is currently on the top of the agenda to be used for ship propulsion applications is Li-ion batteries. Li-ion batteries pose different safety issues than e.g. other propulsion technologies and other batteries such as lead-acid batteries. It is essential that the safety level on board, including fire safety, is maintained, when introducing electric propulsion with energy storage in batteries. This report discusses the different regulations and guidelines available today for fire safety of batteries on board in relation to current knowledge about Li-ion batteries. Also fire safety measures available on board ships today and their applicability for Li-ion batteries is discussed, as well as the different test methods available and their applicability. A workshop gathering different stakeholders from Sweden, Norway and Finland identified fire safety as the main challenge for the introduction of battery propulsion at sea. The workshop concluded that future work is desired in order to increase knowledge and to develop publicly available strategies, training and designs.
Experimental evaluation of several active anti-condensation methods for application in non-hermetic electronics enclosures was performed in harsh climatic conditions, including RH = 70% and T = 43 °C. The studied methods included blowing the air along the exposed surface, combination of blowing and air heating as well as local heating of the exposed surface in natural convection conditions. The purpose was to prevent/remove the dew on/from the exposed surface of a micro-condensation sensor. The difference between the methods was quantified in terms of time for dew removal. The power consumption aspects were discussed. A CFD based optimization methodology was developed to determine the heating profiles for the local anti-condensation PCB heater in a non-hermetic cabinet exposed to the quickly changing climatic conditions. The potential for 60% energy savings was revealed by simulation.
A mathematical model of a multi-phase power conversion system composed of modified bridge-elements (B-system) capable for parallel computation has been developed. Experimental validation on the example of a power system including a synchronous generator and an AC-DC rectifier has been performed. A mathematical algorithm for B-system assembly and steps to obtain mathematical model of the B-system have been developed. Integration of mathematical models of conversion system into the complete model of a multi-phase power system has been explained and evaluation of computational efficiency of parallel computation techniques for the developed model of an AC-DC-AC converter has been performed. The presented modelling method can be employed in the design phase of smart grids, for power quality and conducted emission analysis.
Rural electrification programs usually do not consider the impact that the increment of demand has on the reliability of off-grid photovoltaic (PV)/battery systems. Based on meteorological data and electricity consumption profiles from the highlands of Bolivian Altiplano, this paper presents a modelling and simulation framework for analysing the performance and reliability of such systems. Reliability, as loss of power supply probability (LPSP), and cost were calculated using simulated PV power output and battery state of charge profiles. The effect of increasing the suppressed demand (SD) by 20% and 50% was studied to determine how reliable and resilient the system designs are. Simulations were performed for three rural application scenarios: a household, a school, and a health centre. Results for the household and school scenarios indicate that, to overcome the SD effect, it is more cost-effective to increase the PV power rather than to increase the battery capacity. However, with an increased PV-size, the battery ageing rate would be higher since the cycles are performed at high state of charge (SOC). For the health centre application, on the other hand, an increase in battery capacity prevents the risk of electricity blackouts while increasing the energy reliability of the system. These results provide important insights for the application design of off-grid PV-battery systems in rural electrification projects, enabling a more efficient and reliable source of electricity.
The Eco-design directive issued by the European Commission has led to re-quirements on efficiency of power transformers. In the case of large power transformers used in grid applications, serious problems are encountered in establishing how reliable the loss measurements are. An effort is currently on-going within IEC to produce a documentary standard on “Rules for the determination of uncertainties in the measurement of the losses of power transformers”. An IEC standard should be clear and easy to understand by all users in the industry. Background theory and material, whilst necessary for understanding, is not required for the day-to-day application of the standard. This paper presents a more detailed background and theory on the measure-ment of transformer losses and how to quantify precision. The authors are all members of the IEC maintenance team working with the standard.
In the last few years the use of Li-ion batteries has increased rapidly, powering small as well as large applications, from electronic devices to power storage facilities. The Li-ion battery has, however, several safety issues regarding occasional overheating and subsequent thermal runaway. During such episodes, gas emissions from the electrolyte are of special concern because of their toxicity, flammability and the risk for gas explosion. In this work, the emissions from heated typical electrolyte components as well as from commonly used electrolytes are characterized using FT-IR spectroscopy and FT-IR coupled with thermogravimetric (TG) analysis, when heating up to 650 °C. The study includes the solvents EC, PC, DEC, DMC and EA in various single, binary and ternary mixtures with and without the LiPF6 salt, a commercially available electrolyte, (LP71), containing EC, DEC, DMC and LiPF6 as well as extracted electrolyte from a commercial 6.8 Ah Li-ion cell. Upon thermal heating, emissions of organic compounds and of the toxic decomposition products hydrogen fluoride (HF) and phosphoryl fluoride (POF3) were detected. The electrolyte and its components have also been extensively analyzed by means of infrared spectroscopy for identification purposes.
The European Machinery directive gives the requirements for safe machinery, and safe machine control, within the European Union. This report explains some of the requirements, especially for safety-related machine control systems. Practical examples with aspects on machine control are given in annexes to the report.
Automated Driving Systems (ADS) represent a key technological advancement in the area of Cyber-physical systems (CPS) and Embedded Control Systems (ECS) with the aim of promoting traffic safety and environmental sustainability. The operation of ADS however exhibits several uncertainties that if improperly treated in development and operation would lead to safety and performance related problems. This paper presents the design of a knowledge-base (KB) strategy for a systematic treatment of such uncertainties and their system-wide implications on design-space and state-space. In the context of this approach, we use the term Knowledge-Base (KB) to refer to the model that stipulates the fundamental facts of a CPS in regard to the overall system operational states, action sequences, as well as the related costs or constraint factors. The model constitutes a formal basis for describing, communicating and inferring particular operational truths as well as the belief and knowledge representing the awareness or comprehension of such truths. For the reasoning of ADS behaviors and safety risks, each system operational state is explicitly formulated as a conjunction of environmental state and some collective states showing the ADS capabilities for perception, control and actuations. Uncertainty Models (UM) are associated as attributes to such state definitions for describing and quantifying the corresponding belief or knowledge status due to the presences of evidences about system performance and deficiencies, etc. On a broader perspective, the approach is part of our research on bridging the gaps among intelligent functions, system capability and dependability for mission-&safety-critical CPS, through a combination of development- and run-time measures. © Springer Nature Switzerland AG 2018.
Vehicles may contain multiple antennas for different applications. Among all of them, Vehicle-to-Vehicle and Vehicle-to-Infrastructure (V2X) is one of the most recent applications. This new technology focuses on traffic safety and traffic efficiency. In this paper we present a new compact antenna module suitable for vehicular applications. This module could be easily integrated into the rear-spoiler on a vehicle. The module consists of two identical monopoles for V2X applications based on the IEEE 802.11p standard and two identical printed inverted F-antennas for Long-Term Evolution (LTE) communications. The evaluation of the proposed module is done by analyzing the simulated and measured antenna S-parameters, antenna efficiencies, radiation patterns, as well as by calculating the diversity performance. The results show that the antennas are well matched and well isolated for both LTE and V2X and exhibits a radiation pattern close to the desired omnidirectional in the horizontal plane for V2X. The two LTE antennas have radiation patterns that complement each other ensuring an omnidirectional coverage by combination. Furthermore the module presents good radiation efficiency for both LTE and V2X.
The Blue Move project aims to generate an increased demand for hydrogen as a fuel and investigate the business potential of heavy machinery in the Öresund-Kattegatt- Skagerrak (ÖKS) region, contributing for renewable energy in the transport sector to increase. The use of heavy machinery generates significant carbon dioxide emissions and local air pollution. By using machines with batteries and/or fuel cells instead of combustion engines, local air pollution and climate impact from the machines can be reduced. Electrification also reduces noise and vibration problems, contributing to an improved local and working environment. Customers' requirements are changing and within the near future some clients will only buy zero-emission vehicles. For example, many municipalities have high environmental targets and aim to be climate neutral and fossil fuel-free by 2030. Setting the requirements for public procurement, municipalities and regions become very important players in the process of converting to fossil fuel-free working machines. Electrification is on the rise and the development is fast, which, in addition to the environmental benefits, allows many benefits such as increased service life and a reduced number of components. The cost and character of the service of the vehicles will also change. The choice between electrical operation with batteries or with fuel cells depends on the cost, weight and space requirement for the current energy need. When operating on fuel cells, the heavy machinery can be quickly fueled, and it has an unchanged performance from full to empty tank. The use of fuel cells is also space-saving compared with fullelectric machines since areas for charging or battery change are not required. Today there are both battery and fuel cell - electric heavy machinery available on the market. This report gives an overview of available equipment, but also prototype and demo machines. Both a continued technical development and an increased market share for emission-free vehicles are required to meet future environmental goals. In order to achieve success, it is important that customers and manufacturers meet.
Safety-critical systems are subject to rigorous assurance and certification processes to guarantee that they do not pose unreasonable risks to people, property, or the environment. The associated activities are usually complex and time-consuming, thus they need adequate support for their execution. The activities are further becoming more challenging as the systems are evolving towards open, interconnected systems with new features, e.g. Internet connectivity, and new assurance needs, e.g. compliance with several assurance standards for different dependability attributes. This requires the development of novel approaches for cost-effective assurance and certification. With the overall goal of lowering assurance and certification costs in face of rapidly changing features and market needs, the AMASS project has created and consolidated the de-facto European-wide open solution for assurance and certification of critical systems. This has been achieved by establishing a novel holistic and reuse-oriented approach for architecture-driven assurance, multi-concern assurance, and for seamless interoperability between assurance and engineering activities along with third-party activities. This paper introduces the main elements of the AMASS approach and how to use them and benefit from them.
Blue Move har utarbeidet en rapport som belyser 12 ulike muligheter for produksjon, industri, lagring og distribusjon av hydrogen i ØKS-regionen.
Rapporten belyser ogs viktigheten av lav elavgift for hydrogenproduksjon gjennom beregninger gjort for en nyetablert hydrogenstasjon.
Interreg-prosjektet Blue Move arbeider for å fremme økt bruk av fornybar energi som erstatning for fossile drivstoff i ØKS-regionen. Mulighetsstudien som er samlet i denne rapporten ser nærmere på hvilke produksjonsmetoder som er mest relevante, relatert til tilgjengelig fornybar kraft. Videre beskriver den hvordan hydrogenet kan anvendes utover veitransport, og på hvilken måte det kan ha betydning for veitransport at det også kommer andre anvendelsesområder.
Today, embedded systems across industrial domains (e.g., avionics,automotive) are representatives of software-intensive systems with increasingreliance on software and growing complexity. It has become critically importantto verify software in a time, resource and cost effective manner. Furthermore,industrial domains are striving to comply with the requirements of relevantsafety standards. This paper proposes a novel workflow along with tool supportto evaluate robustness of software in model-based development environment,assuming different abstraction levels of representing software. We then showthe effectiveness of our technique, on a brake-by-wire application, byperforming back-to-back fault injection testing between two differentabstraction levels using MODIFI for the Simulink model and GOOFI-2 for thegenerated code running on the target microcontroller. Our proposed method andtool support facilitates not only verifying software during early phases of thedevelopment lifecycle but also fulfilling back-to-back testing requirements of ISO 26262 [1] when using model-based development.
Hardware realization of safety functions, in safety related machinery control systems can, according to EN ISO 13849-1, be realized as one out of five distinct designated architectures. This report gives examples and guidance for choosing a designated architecture which fulfills the required risk reductive measure of the safety function.
An experimental mean curve and a design fatigue curve corresponding to 95% survival probability were derived from realistic fatigue experiments on a non-welded water pressurized piping component with primarily focus on high cycle fatigue. The components were subjected to a synthetic variable amplitude bending deformation. Comparison with the results obtained for a similar piping component with a circumferential butt weld allowed the determination of an experimental fatigue strength reduction factor. Comparison with the fatigue procedure and design curve in ASME BPVC Section III allowed to quantify its conservatism with regards to accounting for the presence of a weldment and more generally transferability. © 2017 The Authors.
Automated road transport is regarded as a key enabler for sustainable transport. One example is the use of small automated buses as a supplement to already existing public transport services. There are several manufacturers of these kind of buses, and field trials are in progress.
The goal of the pre-project is to evaluate the feasibility and criteria for transport with automated buses in two middle-sized Nordic municipalities, Lørenskog in Norway and Borås in Sweden, by analyzing at least two different test-cases in each location. Feasibility, adaptation to existing traffic and conditions for public acceptance are described. The pre-project concludes that automated buses are possible in these two municipalities. Further test and demonstrations should be made.
When arguing safety foran autonomous road vehicle it is considered very hard to show that the sensing capability is sufficient for all possible scenarios that might occur. Already for today’s manually driven road vehicles equipped with advanced driver assistance systems (ADAS), it is far from trivial how to argue that the sensor systems are sufficiently capable of enabling a safe behavior. In this paper, we argue that the transition from ADAS to automated driving systems (ADS) enables new solution patterns for the safety argumentation dependent on the sensor systems. A key factor is that the ADS itself can compensate for a lower sensor capability, by for example lowering the speed or increasing the distances. The proposed design strategy allocates safety requirements on the sensors to determine their own capability. This capability is then to be balanced by the tactical decisions of the ADS equipped road vehicle.
Ground reflection is the major contributor to measurement uncertainty in the characterization of Radar Cross-Section (RCS) of automotive targets. In this paper we present a study of the influence of ground reflection on RCS measurements of large targets - such as real vehicles or surrogate objects - performed on flat outdoor test ranges. The influence of ground reflection and several means to reduce this effect are investigated and compared. Results are derived with theoretical formulas and simple models.
The 77 GHz radar is a crucial sensor in the Advanced Driver Assistance System (ADAS) and Autonomous Driving (AD) system due to its ability to detect and track objects at distances up to 200 meters. To ensure high reliability of the radar function, extensive testing with soft surrogate targets is needed. However, the radar response of a surrogate target may differ from that of real targets, causing unexpected reactions of the ADAS and AD functions in real traffic situations. The first project goal was therefore to develop and validate realistic soft surrogate targets, a work which was performed in several steps. First radar reference targets were designed and verified. Secondly procedures for calibration of automotive radars were developed. Finally, a thorough investigation on Radar Cross Section (RCS) characterization methods for large test objects on the test track was conducted resulting in several measurement setups and measurement procedures including uncertainty analysis. Now, with the ability to perform repeatable and reliable RCS characterizations, several real and surrogate targets were characterized and work on improving RCS profile of surrogate targets were conducted.Strong competition in the automotive industry and the need to validate more and more complex functions (including autonomous drive) drives the development of virtual test methods. The ability to test the ADAS or AD functions virtually early in the development will save considerable time and cost. However, there were no such tools available with full radar simulation in-loop available prior to the project, which was the reason for the second goal of this project: an ADAS/AD system simulation tool-chain with radar simulation in-loop.The HiFi Radar Target project (diarienr. 2015-04852) was an FFI project within the Electronics, Software and Communications program. After prolongation it was a 30-month project that started 2015-12-31 and ended 2018-06-30. The project had a total budget of 15.9 MSEK.
Transparent materials are essential in everyone’s life. They enable daylight to reach the interior of buildings, thereby contributing to both our physical and mental well-being; they are the primary component for communication via optical fibers and a key component in electronic devices such as protective cover and/or dielectric material; and they enable clean energy production through solar panels or algae reactors by acting as protective and light transmitting barriers. Adding functions to transparent materials in an intelligent way creates further opportunities to use and enhance the beneficial impacts of transparency. The concept Transparent Intelligence covers transparent materials and products with integral intelligent functions – passive, active or interactive. By using Transparent Intelligence it is possible to embrace many of the societal challenges that we are facing today. The concept can be divided into five broad industrial sectors: Built Environment, Information and Communication Technologies (ICT), Solar Energy, Mobility, and Materials. A perspective on how Transparent Intelligence can improve the sustainable development of our world will be presented, using examples of electrochromic windows for energy-efficient buildings, photocatalytic coatings for improved indoor air quality, transparent conductive coatings for antennas, bandpass filters for mobile phone indoor coverage, UV down-converting components for efficient solar energy, hygienic surfaces for infection mitigation on electronic devices, printed electronics for sustainable glass packaging, and IR-reflecting coatings for fire safety.
Automated vehicles are not supposed to fail at any time or in any situations during driving. Thus, vehicle manufactures and proving ground operators are challenged to complement existing test procedures with means to systematically evaluate automated driving. In this paper, we explore software related challenges from testing the safety of automated vehicles. We report on findings from conducting focus groups and interviews including 26 participants (e.g., vehicle manufacturers, suppliers, and researchers) from five countries.
The technology in the area of automated vehicles is gaining speed and promises many advantages. However, with the recent introduction of conditionally automated driving, we have also seen accidents. Test protocols for both, conditionally automated (e.g., on highways) and automated vehicles do not exist yet and leave researchers and practitioners with different challenges. For instance, current test procedures do not suffice for fully automated vehicles, which are supposed to be completely in charge for the driving task and have no driver as a back up. This paper presents current challenges of testing the functionality and safety of automated vehicles derived from conducting focus groups and interviews with 26 participants from five countries having a background related to testing automotive safety-related topics. We provide an overview of the state-of-practice of testing active safety features as well as challenges that needs to be addressed in the future to ensure safety for automated vehicles. The major challenges identified through the interviews and focus groups, enriched by literature on this topic are related to 1) virtual testing and simulation, 2) safety, reliability, and quality, 3) sensors and sensor models, 4)required scenario complexity and amount of test cases, and 5)handover of responsibility between the driver and the vehicle. © 2017 IEEE.
RF power amplifier demonstrators containing each one GaN-on-SiC, HEMT, CHZ015AQEG, from UMS in SMD quad-flat no-leads package (QFN) were subjected to thermal cycles (TC) and power cycles (PC) followed by electrical, thermal and structural evaluation. Two types of solders i.e. Sn63Pb36Ag2 and lead-free SnAgCu (SAC305) and two types of TIM materials (NanoTIM and TgonTM 805) for PCB attachment to liquid cold plate were tested for thermomechanical reliability. Changes in electrical performance of the devices namely reduction of the current saturation value, threshold voltage shift, increase of the leakage current and degradation of the HF performance were observed as a result of an accumulated current stress during PC. No significant changes in the investigated solder or TIM materials were observed.
The RF power amplifier demonstrators containing each one GaN-on-SiC, HEMT, CHZ015A-QEG, from UMSin SMD quad-flat no-leads package (QFN) were subjected to thermal cycles (TC) and power cycles (PC) andevaluated electrically, thermally and structurally. Two types of solders, Sn63Pb36Ag2 and lead-free SnAgCu(SAC305), and two types of TIM materials, NanoTIM and TgonTM 805, for PCB attachment to the liquid cold platewere tested for thermo-mechanical reliability. Changes in the electrical performance of the devices, namely thereduction of the current saturation value, threshold voltage shift, increase of the leakage current and degradation ofthe HF performance were observed as a result of an accumulated current stress during PC. No significant changes inthe investigated solder or TIM materials were observed.
Lithium-ion (Li-ion) batteries offer great energy and power densities accompanied with long battery life time. However, if a mechanical fault occurs or the batteries over-heat, the flammable electrolyte of the Li-ion battery may pose a risk. For Eurotransport, colleagues from the SP Technical Research Institute of Sweden (SP) and Chalmers University of Technology explore further, identifying the risks involved with electric buses.
Lithium-ion battery fires generate intense heat and considerable amounts of gas and smoke. Although the emission of toxic gases can be a larger threat than the heat, the knowledge of such emissions is limited. This paper presents quantitative measurements of heat release and fluoride gas emissions during battery fires for seven different types of commercial lithium-ion batteries. The results have been validated using two independent measurement techniques and show that large amounts of hydrogen fluoride (HF) may be generated, ranging between 20 and 200 mg/Wh of nominal battery energy capacity. In addition, 15-22 mg/Wh of another potentially toxic gas, phosphoryl fluoride (POF3), was measured in some of the fire tests. Gas emissions when using water mist as extinguishing agent were also investigated. Fluoride gas emission can pose a serious toxic threat and the results are crucial findings for risk assessment and management, especially for large Li-ion battery packs.
Safety issues concerning the use of large lithium-ion (Li-ion) batteries in electrified vehicles are discussed based on the abuse test results of Li-ion cells together with safety devices for cells. The presented abuse tests are: overcharge, short circuit, propane fire test and external heating test (oven). It was found that in a fire, cells with higher state of charge (SOC) gave a higher heat release rate (HRR), while the total heat release (THR) had a lower correlation with SOC. One fire test resulted in a hazardous projectile from a cylindrical cell. In the fire tests, toxic gas emissions of hydrogen fluoride (HF) were measured for 100%, 50% and 0% SOC.
Commercial 6.8 Ah lithium-ion cells with different ageing/status have been abused by external heating in an oven. Prior to the abuse test, selected cells were aged either by C/2 cycling up to 300 cycles or stored at 60 °C. Gas emissions were measured by FTIR and three separate vents were identified, two well before the thermal runaway while the third occurred simultaneously with the thermal runaway releasing heavy smoke and gas. Emissions of toxic carbon monoxide (CO), hydrogen fluoride (HF) and phosphorous oxyfluoride (POF3) were detected in the third vent, regardless if there was a fire or not. All abused cells went into thermal runaway and emitted smoke and gas, the working cells also released flames as well as sparks. The dead cells were however less reactive but still underwent thermal runaway. For about half of the working cells, for all levels of cycle ageing, ignition of the accumulated battery released gases occurred about 15 s after the thermal runaway resulting in a gas explosion. The thermal runaway temperature, about 190 °C, varied somewhat for the different cell ageing/status where a weak local minimum was found for cells cycled between 100 and 200 times.
This report presents a general and broad risk assessment and construction guidelines for lithium-ion battery systems used in electrified vehicles, from the perspectives of fire and gas release. General types of Li-ion battery systems and electrified vehicles, ranging from light to heavy-duty vehicles, are included. The findings in the report are based on results obtained in the project “Safer battery systems in electrified vehicles – develop knowledge, design and requirements to secure a broad introduction of electrified vehicles”, conducted between the years 2012-2017 and lead by RISE Research Institutes of Sweden. The guidelines focus on both how to design the battery system and on how to integrate and place the battery in the vehicle in order to increase the safety in terms or fire and gas release.
Overcurrent abuse has been performed on commercial 48 Ah primary prismatic zinc (Zn)–Air battery cells with full air supply as well as with shut-off air supply. Compared to other battery technologies, e.g., lithium-ion batteries, metal–air batteries offer the possibility to physically stop the battery operation by stopping its air supply, thus offering an additional protection against severe battery damage in the case of, e.g., an accidental short circuit. This method may also reduce the electrical hazard in a larger battery system since, by stopping the air supply, the voltage can be brought to zero while maintaining the energy capacity of the battery. Measurements of Overdischarge currents and current cut-off by suffocation have been performed to assess the safety of this type of Zn–air battery. The time to get to zero battery voltage is shown to mainly be determined by the volume of air trapped in the cell.
In the eyes of industrialists, scientists often exaggerate the economic potential of their findings. The industrialists know that developing a new technology to production is associated with uncertainty and risks. To elucidate the challenges faced by the surface treatment industry, this paper discusses aspects that should be considered when making innovation out of promising research results. The Technology Readiness Level (TRL) metric for assessing maturity of a technology is discussed and exemplified. Additional risks of fluid character such as legislation, price of raw material and customer expectations are also discussed. Even though, the subject is of general relevance, the present discussion refers to surface technology and examples are given from copper plating of printed circuit boards, and durable and cost-efficient coatings on electrical connectors.
Backshoring of production to Western Europe has become an increasingly important trend after decades of offshoring. The subject is introduced by a general discussion followed by a specific analysis of the Nordic surface finishing industry. The main finding is that production quality is the main driver for backshoring of surface finishing. .
The Assaf panel arrangement was used for evaluating pulse reverse plating processes and optimisation of the throwing power (TP) of complex three-dimensional (3D) geometries. Two different electroplating processes were investigated: an acid copper bath and a cyanide silver bath without additives. It has not been possible to establish a direct correlation factor for TP obtained with the Assaf panel and the 3D objects included in the trials. Nevertheless, the Assaf panel was found to be a useful tool for preliminary process parameter optimisation. The copper bath needs agitation to deposit coatings of good quality, whereas the silver bath obtains the best throwing power without agitation. The latter is probably due to inhibition by adsorbed cyanide.
The influence of electroplating parameters on throwing power (TP) is studied in additive-free silver cyanide solutions under direct current and pulse reverse electroplating conditions. It is found that the best TP is obtained when no agitation of the electrolyte is applied. The most important parameters for controlling the TP are the cathodic current density, the anodic to cathodic charge ratio, and the ratio between the anodic and cathodic current densities. Guidelines for process optimisation are given.
mCBEEs is an acronym for: Advanced integrative solutions to Corrosion problems beyond micro-scale: towards long-term durability of miniaturised Biomedical, Electronic and Energy systems. It is a doctoral student training network funded by the European Commission under the Marie Sklodowska-Curie Action scheme in the same way as the recently reported training network SELECTA that is focusing on smart electrodeposited alloys for environmentally sustainable applications.1.