1,182 research outputs found

    NASA Aerospace Flight Battery Program: Generic Safety, Handling and Qualification Guidelines for Lithium-Ion (Li-Ion) Batteries; Availability of Source Materials for Lithium-Ion (Li-Ion) Batteries; Maintaining Technical Communications Related to Aerospace Batteries (NASA Aerospace Battery Workshop)

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    This NASA Aerospace Flight Battery Systems Working Group was chartered within the NASA Engineering and Safety Center (NESC). The Battery Working Group was tasked to complete tasks and to propose proactive work to address battery related, agency-wide issues on an annual basis. In its first year of operation, this proactive program addressed various aspects of the validation and verification of aerospace battery systems for NASA missions. Studies were performed, issues were discussed and in many cases, test programs were executed to generate recommendations and guidelines to reduce risk associated with various aspects of implementing battery technology in the aerospace industry. This document contains Part 1 - Volume I: Generic Safety, Handling and Qualification Guidelines for Lithium-Ion (Li-Ion) Batteries, Availability of Source Materials for Lithium-Ion (Li-Ion) Batteries, and Maintaining Technical Communications Related to Aerospace Batteries (NASA Aerospace Battery Workshop)

    End User Acceptance - Requirements or Specifications, Certification, Testing

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    NASA follows top level safety requirement of two-failure tolerance (t hree levels of controls or design for minimum risk) to all catastroph ic hazards in the design of safe li-ion batteries for space use. ? R igorous development testing at appropriate levels to credible offnominal conditions and review of test data. ? Implement robust design con trols based on test results and test again to confirm safety at the a ppropriate levels. ? Stringent testing of all (100%) flight batteries (from button cells to large batteries)

    Towards Better Understanding of Failure Modes in Lithium-Ion Batteries: Design for Safety

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    In this digital age, energy storage technologies become more sophisticated and more widely used as we shift from traditional fossil fuel energy sources to renewable solutions. Specifically, consumer electronics devices and hybrid/electric vehicles demand better energy storage. Lithium-ion batteries have become a popular choice for meeting increased energy storage and power density needs. Like any energy solution, take for example the flammability of gasoline for automobiles, there are safety concerns surrounding the implications of failure. Although lithium-ion battery technology has existed for some time, the public interest in safety has become of higher concern with media stories reporting catastrophic cellular phone- and electric vehicle failures. Lithium-ion battery failure can be dangerously volatile. Because of this, battery electrochemical and thermal response is important to understand in order to improve safety when designing products that use lithium-ion chemistry. The implications of past and present understanding of multi-physics relationships inside a lithium-ion cell allow for the study of variables impacting cell response when designing new battery packs. Specifically, state-of-the-art design tools and models incorporate battery condition monitoring, charge balancing, safety checks, and thermal management by estimation of the state of charge, state of health, and internal electrochemical parameters. The parameters are well understood for healthy batteries and more recently for aging batteries, but not for physically damaged cells. Combining multi-physics and multi-scale modeling, a framework for isolating individual parameters to understand the impact of physical damage is developed in this work. The individual parameter isolated is the porosity of the separator, a critical component of the cell. This provides a powerful design tool for researchers and OEM engineers alike. This work is a partnership between a battery OEM (Johnson Controls, Inc.), a Computer Aided Engineering tool maker (ANSYS, Inc.), and a university laboratory (Advanced Manufacturing and Design Lab, University of Wisconsin-Milwaukee). This work aims at bridging the gap between industry and academia by using a computer aided engineering (CAE) platform to focus battery design for safety

    Optimal cell tab design and cooling strategy for cylindrical lithium-ion batteries

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    The ability to correctly predict the behavior of lithium ion batteries is critical for safety, performance, cost and lifetime. Particularly important for this purpose is the prediction of the internal temperature of cells, because of the positive feedback between heat generation and current distribution. In this work, a comprehensive electro-thermal model is developed for a cylindrical lithium-ion cell. The model is comprehensively parameterized and validated with experimental data for 2170 cylindrical cells (LG M50T, NMC811), including direct core temperature measurements. The validated model is used to study different cell designs and cooling approaches and their effects on the internal temperature of the cell. Increasing the number of tabs connecting the jellyroll to the base of the cylindrical-can reduces the internal thermal gradient by up to 25.41%. On its own, side cooling is more effective than base cooling at removing heat, yet both result in thermal gradients within the cell of a similar magnitude, irrespective of the number of cell tabs. The results are of immediate interest to both cell manufacturers and battery pack designers, while the modelling and parameterization framework created is an essential tool for energy storage system design

    An investigation into the sustainable lithium battery pack design

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    The global demand for electricity is rising due to the increased electrification of multiple sectors. Whereof electrical vehicles are becoming increasingly popular. In addition, the European Parliament issued a ban on emission vehicles by 2035. Lithium-ion batteries have become one of the main energy storage solutions in modern society. Where the production and use is expected to continuously increase in the near future. However, the handling of end-of-life lithium-ion batteries must be addressed considering that a massive number of lithium batteries that are not refurbished for second life systems will retire and enter the waste stream at the same rate just at a delay of 8-15 years. Furthermore, the process of EV battery pack repair is currently unutilized except for some trial facilities. While the second life of EV batteries just recently started to exploit the energy and economics that went into battery production by utilizing the remaining battery capacity. While The optimization of recycling processes and technologies, and the current recycling are still under development. This thesis demonstrates the need for design changes in mass production to facilitate battery repair and the possibility of introducing second life battery systems. In addition to making further development of recycling methods possible. The four pillars of this thesis are safety, second life, recycling, and mass production. This study contributes to this by identifying factors that affect these pillars in relation to lithium-ion battery packs. This is achieved by a systematic literature review and applying a PEST analysis (political, economic, social, and technological factors). Followed by implementations based on a SWOT (strengths, weaknesses, opportunities, and threats) analysis meant to challenge the current norms in li-ion battery pack production. Furthermore, this thesis presents comprehensive results and a discussion of the interconnection and the contradictory design optimization for the four pillars. The results indicate that given the proper incentives, industry norms can change to better accommodate the complete life cycle of the lithium-ion battery. Ultimately allowing for battery pack repairs, better conditions for the profitability of second life, and the development of more efficient recycling processes

    Advanced characterisation techniques for battery safety assessment

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    The need to shift to cleaner energy sources is imperative. Battery technology is considered a highly promising technology to successfully bring about this shift. It has already been implemented in numerous ways and features in our day-to-day lives; from mobile phones to homes. Recently, concerns regarding their safety have increased and as a result, governments have boosted research efforts in this area, with the added urge to work collectively with industry partners and regulatory bodies. These cells are prone to undergo catastrophic failures as a result of a series of exothermic reactions (thermal runaway) that can be triggered by several methods. Many research efforts have been made to understand this phenomenon from various perspectives: material selection, mechanical design, mitigation or preventative measures. This thesis shows how we can begin to comprehend this complexity and apply it to advancing existing battery safety assessment techniques. Through thermal analyses and multi-scale X-ray CT imaging, the correlations between heat generation and battery architecture are addressed. In this work, for the first time, differential scanning calorimetry was used to measure heat signals from full cells, high aspect ratio battery samples were imaged and a custom-built calorimeter chamber was developed to provide operando images and heat measurements of cells undergoing thermal failure. The results obtained from the methodologies and techniques established in this work have advanced our understanding of how various battery material morphologies and architectures behave under certain stresses. In turn, these findings can aid not only in the development and manufacture of safer lithium-ion batteries but also in the standardisation of testing standards, and improvement of failure mitigation strategies

    Acoustic and X-ray Chacterisation of Lithium-Ion Battery Failure

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    Lithium-ion batteries have become synonymous with modern consumer electronics and potentially, are the cornerstone to development of integrated electrified infrastructure that can support a clean and renewable national energy grid. Despite the widespread applications due to the favourable performance parameters, recent events have elevated the safety concerns associated with lithium-ion batteries. However, there is great difficulty in rapid diagnostic analysis outside specialised laboratories which can hinder the review of functional safety- and novel energy dense- materials for lithium-ion energy storage. The dynamic evolution of internal architectures and novel active materials across multiple length scales are investigated in this thesis; with in-situ and operando acoustic spectroscopy (AS) via ultrasonic time of flight (ToF) probing, high speed synchrotron X-ray imaging, computed tomography and fractional thermal runaway calorimetry. The identification of characteristic precursor events such as gas-induced delamination in degradation mechanisms before eventual failure by AS; is correlated with X-ray imaging and post-mortem computed tomography (CT), highlighting the potential for battery management systems. Mitigation and prevention of failure with plasticized current collectors and thermally stable cellulose separators was also investigated at multiple length scales, with the transient mechanical structure compared with their commercial counterparts in cylindrical cells. Further work investigating the robustness of acoustic spectroscopy and polymer current collectors were applied to pure silicon nanowire negative electrodes. The studies reported in this thesis assess novel materials in lithium-ion batteries, and the potential impact of the work is highlighted. Development of AS via ToF probing offers another unique and field deployable insight allowing more complete and comprehensive understanding of batteries as they continue to evolve in complexity. Lithium-ion failure characterisation techniques and literature have evolved and provided insights into the function of polymer current collectors in different cell formats and chemistries. Findings presented in this thesis are anticipated to augment future inherently safer battery design and characterisation of lithium-ion energy storage thermal runaway

    An insight into the errors and uncertainty of the lithium-ion battery characterisation experiments

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    Errors and uncertainty within the experimental results have long-term implications in lithium-ion battery research. Experimental directly feed into the development of different battery models, thus having a direct impact on the accuracy of the models, which are commonly employed to forecast short to long term battery performance. The estimations made by such models underpin the design of key functions within the BMS, such as state of charge and state of health estimation. Therefore, erroneous experimental results could evolve into a much larger issue such as the early retirement of a battery pack from the end-use application. For original equipment manufacturers (OEM), such as automotive OEMs this may have a significant impact, e.g. high warranty returns and damage to the brand. Although occasionally reported in published results, currently, little research exists within the literature to systematically define the error and uncertainty of battery experimental results. This article focuses on the fundamental sources of error and uncertainty from experimental setup and procedure and suggests control measures to remove or minimize the contributions from the sources identified. Our research shows that by implementing the control measures proposed, the error and uncertainty can be reduced to around 0.6%, from the figure of around 4.0%

    Multiphysics Based Thermal Modeling of a Pouch Lithium-Ion Battery Cell for the Development of Pack Level Thermal Management System

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    The design and impact of in-situ and operando thermal sensing for smart energy storage

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    Lithium-ion is increasingly the technology of choice for battery-powered systems. Current cell performance monitoring, which relies on measurements of full cell voltage and sporadic surface temperature, does not provide a reliable information on the true internal battery state. Here, we address this issue by transforming off the shelf cells into smart systems by embedding flexible distributed sensors for long-term in-situ and operando thermodynamic data collection. Our approach, which enables the monitoring of the true battery state, does not impact its performance. In particular, our results show that this unprecedented methodology can be used to optimise the performance and map the safety limits of lithium-ion cells. We find that the cell core temperature is consistently and significantly higher than the surface temperature, and reveal a breach of safety limits during a rapid discharge test. We also demonstrate an application of a current considerably higher than the manufacturers’ specification, enabling a significant decrease in charging time, without compromising the cell’s thermal stability. Consequently, this work on cell instrumentation methodology has the potential to facilitate significant advances in battery technology
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