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![FIGURE 3. Li-ion battery with arc tab [15].](profile/Xingyan-Yao/publication/331146992/figure/fig9/AS:733542359236609@1551901535127/Li-ion-battery-with-arc-tab-15_Q320.jpg)
![FIGURE 4. Li-ion battery with arc tab [15].](profile/Xingyan-Yao/publication/331146992/figure/fig10/AS:733542359257089@1551901535151/Li-ion-battery-with-arc-tab-15_Q320.jpg)
![FIGURE 6. Li-ion battery tab with overcurrent protection [18].](profile/Xingyan-Yao/publication/331146992/figure/fig12/AS:733542359261184@1551901535201/Li-ion-battery-tab-with-overcurrent-protection-18_Q320.jpg)
Lithium-ion (Li-ion) batteries play a vital role in today’s portable and rechargeable products, and the cylindrical format is used in applications ranging from e-cigarettes to electric vehicles due to their high density and power. The tabs that connect the electrodes (current collectors) to the external circuits are one aspect of cylindrical batter...
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Batteries are a popular and important item that are utilized as energy sources in a variety of applications. The rise of electric vehicles in the twenty-first century has increased its importance. A battery's state of charge (SoC) is critical information. It is vital to estimate SoC with a reasonable degree of precision. During charge and discharge...
Citations
... The global cylindrical lithium battery pack market is projected to grow at a Compound Annual Growth Rate of 19 % between 2023 and 2028 [4][5][6]. Cylindrical cells are highly favored among different lithium-ion cell types due to their exceptional mechanical stability, high specific power, and ease of manufacturing [7][8][9][10]. Most producers employ steel cases with a Nickel coating for their cylindrical cells, offering high mechanical strength, long life cycle time, and good corrosion resistance [11][12][13]. ...
Until today, disassembling cylindrical 18650 cells commonly involved using a pipe cutter and pliers, with a risk of short-circuiting and mechanical damage to the electrode materials. This study presents a novel laser ablation assisted disassembly method with X-ray and optical validation for opening cylindrical battery cells without damaging the jelly roll. The objective is to develop a safe, efficient, and reproducible approach for cell disas-sembly enabling post-mortem analysis of failure mechanisms and investigation of aging effects. X-ray and tube micrometer measurements are used to estimate the cell wall thickness, with good agreement between the two methods. Laser ablation is calibrated to determine the optimal number of laser cycles for achieving the desired ablation depth. In situ temperature measurements are conducted. Various cooling parameters are investigated, maintaining the cell temperature within a safe range of 17 °C to 35 °C during operation. The temperature remains significantly below the reported onset temperature of 57 °C for solid electrolyte interphase (SEI) decomposition. Depth analysis and surface morphology are conducted using confocal microscopy with inter-ferometry and a fully automated digital microscope system. The cells are disassembled within an inert argon atmosphere. Challenges such as redeposition of ablated material and side trench formation are addressed. Overall, this method offers a safe, reproducible and efficient approach for opening cylindrical battery cells. This innovative approach fills a gap in the literature and contributes to advancements in failure analysis and degradation research for the benefit of cell producers, testing laboratories and research institutes.
... A tab is welded to the current collector, which acts as a bridge that connects the electrode to the external circuit. The material, location, and number of tabs affect the performance of the cell in terms of uniform current distribution, heat generation and ohmic resistance [21]. The anode and cathode electrodes are separated by a porous polymer sheet called the separator. ...
... Other techniques, such as spray coating or doctor-blad coating, may also be used. The coating thickness ranges from 70 µm to 350 µm and i measured using X-ray reflectivity (XRR) [21]. The coating speed, coating width and preci sion of the slurry pump define the thickness accuracy, homogeneity, and surface qualit (blowholes, particles) of the coating [12]. ...
... Other techniques, such as spray coating or doctorblade coating, may also be used. The coating thickness ranges from 70 µm to 350 µm and is measured using X-ray reflectivity (XRR) [21]. The coating speed, coating width and precision of the slurry pump define the thickness accuracy, homogeneity, and surface quality (blowholes, particles) of the coating [12]. ...
Cylindrical lithium-ion batteries are widely used in consumer electronics, electric vehicles, and energy storage applications. However, safety risks due to thermal runaway-induced fire and explosions have prompted the need for safety analysis methodologies. Though cylindrical batteries often incorporate safety devices, the safety of the battery also depends on its design and manufacturing processes. This study conducts a design and process failure mode and effect analysis (DFMEA and PFMEA) for the design and manufacturing of cylindrical lithium-ion batteries, with a focus on battery safety.
... For thermal studies using a 2D electrochemical model, comprehensive summaries of the various multiscale and multidimensional modelling concepts were published by Xu et al. [28] and Ye et al. [29], which can be considered very detailed summaries of the FEA of batteries in 2D. Numerous authors have investigated cylindrical cells in 2D to model cell failures [30,31] and optimise the cooling [32]. On the other hand, some other researchers have studied pouch cells in 2D [33] and 3D [34][35][36] finite element environments. ...
The specificities of temperature-dependent electrochemical modelling strategies of 18650 Li-ion batteries were investigated in pseudo-2D, 2D and 3D domains using finite element analysis. Emphasis was placed on exploring the challenges associated with the geometric representation of the batteries in each domain, as well as analysing the performance of coupled thermal-electrochemical models. The results of the simulations were compared with real reference measurements, where temperature data were collected using temperature sensors and a thermal camera. It was highlighted that the spiral geometry provides the most realistic results in terms of the temperature distribution, as its layered structure allows for a detailed realisation of the radial heat transfer within the cell. On the other hand, the 3D-lumped thermal model is able to recover the temperature distribution in the axial direction of the cell and to reveal the influence of the cell cap and the cell wall on the thermal behaviour of the cell. The effect of cooling is an important factor that can be introduced in the models as a boundary condition by heat convection or heat flux. It has been shown that both regulated and unregulated (i.e., natural) cooling conditions can be achieved using an appropriate choice of the rate and type of cooling applied.
... Additionally, placing the tabs on different sides could prevent manufacturing process defects coming from overlapping tabs [50,51]. It can be inferred that adding more tabs might bring more homogenous current distribution and reduce the temperature gradient inside the battery. ...
... Methods like computed tomography (CT) imaging, which enables the non-destructive detection and investigation of inhomogeneities, can be carried out on a random basis. While several authors [1][2][3][4][5][6][7][8][9][10][11][12] have shown the general applicability of CT imaging to detect manufacturing defects such as foreign matter contamination (FMD) or anode-cathode misalignments, further investigations are needed to determine the limits of defect detectability. The aim of this work is the controlled reproduction of typical cell production defects in different gradations and the assessment of detectability, with the help of CT imaging. ...
Realising an ideal lithium-ion battery (LIB) cell characterised by entirely homogeneous physical properties poses a significant, if not an impossible, challenge in LIB production. Even the slightest deviation in a process parameter in its production leads to inhomogeneities and causes a deviation in performance parameters of LIBs within the same batch. The greater the number and/or intensity of inhomogeneities, the more they need to be avoided. Severe inhomogeneities (defects), such as metal particle contamination, significantly impact the cell’s performance. Besides electrical measurements, image-based measurement methods can be used to identify defects and, thus, ensure the production quality and safety of LIBs. While the applicability of computed tomography (CT) as an image-based measurement method for detecting defects has been proven, the limitations of this method still need to be determined. In this study, a systematic analysis of the capabilities of CT imaging was conducted. A multilayer pouch cell without an electrolyte was reassembled with several defects on one of the middle anodes. To investigate the boundaries of CT, defects such as a partial and complete removal of the coating, a cut, or a kink, as well as particle contaminations of various sizes and materials (aluminium, copper, iron) were chosen. By comparing the CT images of the cell using laser scanning microscope images of the defective anode, it could be proven that all selected defects except the kink were detectable.
... Lithium-ion batteries are manufactured in various geometries including prismatic, pouch, coin, and cylindrical [1][2][3]. The cylindrical type of lithium-ion battery, especially the one with 18 mm diameter and 65 mm length (18650 lithium-ion battery, 0 refers to the cylindrical shape) are widely used in flashlight, vaping devices, laptop, and even Tesla electric vehicles [4]. The 18650 cylindrical lithium-ion battery has a capacity in the range of approximately 2200 mAh to approximately 3300 mAh [5][6][7]. ...
... Cylindrical batteries, in contrast, generally have shorter tabs that are positioned 180°away from each other, and are connected to opposing terminal ends. [29] Tab position and design can significantly impact the performance and safety of a cell as it can impact the chance of short circuits. [29] In addition, the temperature around the tab is often much higher during cycling than other areas due to the current concentration around the metal fixtures. ...
... [29] Tab position and design can significantly impact the performance and safety of a cell as it can impact the chance of short circuits. [29] In addition, the temperature around the tab is often much higher during cycling than other areas due to the current concentration around the metal fixtures. [29] As a result, the same macroscopic structural damage that batteries experience upon cycling may not be consistent with supercapacitor failure. ...
... [29] In addition, the temperature around the tab is often much higher during cycling than other areas due to the current concentration around the metal fixtures. [29] As a result, the same macroscopic structural damage that batteries experience upon cycling may not be consistent with supercapacitor failure. ...
Owing to a reputation for long lifetimes and excellent cycle stability, degradation in supercapacitors has largely been overlooked. In this work, we demonstrate that significant degradation in some commercial supercapacitors can in fact occur early in their life, leading to a rapid loss in capacitance, especially when utilized in full voltage range, high charge‐discharge frequency applications. By using a commercial 300 F lithium‐ion pseudocapacitor rated for 100,000 charge/discharge cycles as an example system, it is shown that a ∼96 % loss in capacitance over the first ∼2000 cycles is caused by significant structural and chemical change in the cathode active material (LiMn2O4, LMO). Multi‐scale in‐situ and ex‐situ characterization, using a combination of X‐ray computed tomography, Raman spectroscopy and X‐ray photoelectron spectroscopy, shows that while minimal material loss (∼5.5 %), attributed to the dissolution of Mn²⁺, is observed, the primary mode of degradation is due to manganese charge disproportionation (Mn³⁺→Mn⁴⁺+Mn²⁺) and its physical consequences (i. e. microstrain formation, particle fragmentation, loss of conductivity etc.). In contrast to prior understanding of LMO material degradation in battery systems, negligible contributions from cubic‐to‐tetragonal phase transitions are observed. Hence, as supercapacitors are becoming more widely utilized in real‐world applications, this work demonstrates that it is vital to understand the mechanisms by which this family of devices change during their lifetimes, not just for lithium‐ion pseudocapacitors, but for a wide range of commercial chemistries.
... Cylindrical Li-ion battery cells consist of (i) a jelly roll, a wound composite consisting of a cathode, an anode, and two separators, and (ii) a cell housing consisting of a can and a cap [9]. Current and heat transport between the jelly roll and the cell housing is traditionally conducted by contacting elements called tabs [10]. These are metal strips usually made of copper or nickel for contacting the anode and aluminum for contacting the cathode. ...
... The tabs are joined to the collector foils by ultrasonic welding. The welding geometry and all other design features, such as location, shape, size, and tabs' number, differ significantly between the various cell designs and manufacturers [10]. The classical tab design shows design heterogeneities caused by extended electrical and thermal transport paths [11,12]. ...
Battery cells are the main components of a battery system for electric vehicle batteries. Depending on the manufacturer, three different cell formats are used in the automotive sector (pouch, prismatic, and cylindrical). In the last 3 years, cylindrical cells have gained strong relevance and popularity among automotive manufacturers, mainly driven by innovative cell designs, such as the Tesla tabless design. This paper investigates 19 Li-ion cylindrical battery cells from four cell manufacturers in four formats (18650, 20700, 21700, and 4680). We aim to systematically capture the design features, such as tab design and quality parameters, such as manufacturing tolerances and generically describe cylindrical cells. We identified the basic designs and assigned example cells to them. In addition, we show a comprehensive definition of a tabless design considering the current and heat transport paths. Our findings show that the Tesla 4680 design is quasi-tabless. In addition, we found that 25% of the cathode and 30% of the anode are not notched, resulting in long electrical and thermal transport paths. Based on CT and post-mortem analyses, we show that jelly rolls can be approximated very well with the Archimedean spiral. Furthermore, we compare the gravimetric and volumetric energy density, the impedance, and the heating behavior at the surface and in the center of the jelly rolls. From the generic description, we present and discuss production processes focusing on format and design flexible manufacturing of jelly rolls.
... The first step for manufacturing a cylindrical cell is mixing and coating [257]. The cathode electrode is made of active materials such as LiCoO 2 , LiFePO 4 , or LiMnO 2 , whereas the anode electrode is either carbon or graphite [260]. ...
... In order to create a reel with a cylindrical mandrel, the second step involves loading the winding machine with both electrode strips [257]. As a result, before the strips are utilized, the winding machine functions automatically [259]. ...
The global population has increased over time, therefore the need for sufficient energy has risen. However, many countries depend on nonrenewable resources for daily usage. Nonrenewable resources take years to produce and sources are limited for generations to come. Apart from that, storing and energy distribution from nonrenewable energy production has caused environmental degradation over the years. Hence, many researchers have been actively participating in the development of energy storage devices for renewable resources using batteries. For this purpose, the lithium-ion battery is one of the best known storage devices due to its properties such as high power and high energy density in comparison with other conventional batteries. In addition, for the fabrication of Li-ion batteries, there are different types of cell designs including cylindrical, prismatic, and pouch cells. The development of Li-ion battery technology, the different widely used cathode and anode materials, and the benefits and drawbacks of each in relation to the most appropriate application were all thoroughly studied in this work. The electrochemical processes that underlie battery technologies were presented in detail and substantiated by current safety concerns regarding batteries. Furthermore, this review collected the most recent and current LIB recycling technologies and covered the three main LIB recycling technologies. The three recycling techniques—pyrometallurgical, hydrometallurgical, and direct recycling—have been the subject of intense research and development. The recovery of valuable metals is the primary goal of most recycling processes. The growth in the number of used LIBs creates a business opportunity to recover and recycle different battery parts as daily LIB consumption rises dramatically.
... This has led to extraordinary cycle life performance at high current rates [66]. Also, the rather large rated capacity while also achieving a high power capability is realized by adding silicon oxide (SiO x ) particles to the graphite anode (referred to as SiC), which has been increasingly added to pure graphite anodes in the past because it provides a high specific capacity in comparison to graphite (3579 mAh∕g compared to 372 mAh∕g) [67]. Therefore, it has the ability to compensate for negative effects on the cell's energy density of more power-oriented electrode designs. ...
... The lithium-ion cell is fast charged between 10% and 80% SOC, because it has been reported that low operating voltages (low lithiation stages of the SiC anode) may lead to severe aging due to rapid volume expansion [69] and should be avoided. Also, the used model reached large errors due to the strong hysteresis behavior of the cell, which may be also traced back to the different lithiation speeds of silicon and graphite at low SOC [67]. Furthermore, the charging current is initially limited to 15 A to account for the model validation boundary as discussed earlier and also to avoid excessive inhomogeneous heat generation in the lithium-ion cell. ...
The observed shift to a fully electrified transport sector with steadily increasing sales of battery electric vehicles has led to their wider use under demanding operation conditions, e.g., more frequent fast charging due to a higher degree of utilization with an increased share of operation under low ambient temperatures. These critical edge cases have to be precisely controlled by the battery management system to avoid accelerated battery aging and, in the worst case, safety-critical battery failure events. In this article, we present a model-based, health-aware fast charging strategy for current control of lithium-ion batteries to prevent the onset of non-linear aging and to prolong the cycle life. An electrochemical model of reduced order is used to avoid non-linear aging due to lithium plating. The model is regularly updated alongside the state-of-health of the battery to account for the rise of resistance. Extensive cycle life results reveal that the charging time can be significantly reduced while the cycle life can be prolonged compared to conventional charging. As the strategy is based on an electrochemical model of reduced order, inheriting the physics of lithium-ion batteries, the results can be easily transferred to other cell chemistries and/or formats.
