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Fiber‐reinforced composites are widely used in civil engineering, aerospace, automotive, and medical sectors. However, these composites undergo aging due to factors such as temperature, humidity, load, and so on, during their usage. As a result, their performance deteriorates, and predicting their durability under real service conditions is a significant challenge. In order to better understand the durability of fiber‐reinforced composites, this article summarizes their microscopic aging mechanism under natural aging conditions and analyzes the changing rules of tensile, bending, and shear properties of composites under seven typical climate types, including tropical desert climate, temperate continental climate, temperate oceanic climate, Mediterranean climate, seasonal climate, tropical rainforest climate, and seawater immersion. This article reviews various durability prediction models, such as the Arrhenius model, prediction models based on residual modulus of elasticity and residual strength, and median strength regression analysis. To enhance the accuracy of aging life prediction during the natural aging process of composites, it is important to consider the influence of loads under real service conditions, incorporate different climatic types, utilize comprehensive mechanical property indices, establish an equivalent conversion relationship between natural aging and accelerated aging, and create a database with unified test standards. Highlights: The aging mechanisms of FRP after exposure in natural aging environments are discussed.The tensile, bending, and shear properties of FRP after exposure under seven climate types are discussed.The predictive models are proposed for the FRP used in natural aging.The future research needs are proposed for the FRP used in natural aging. [ABSTRACT FROM AUTHOR]

Despite a substantial impact on various economic and cell technology factors, the influence of electrolyte quantities is rarely addressed in research. This study examines the impact of varying electrolyte quantities on cell performance and aging processes using three different electrolytes: LP57 (1 M LiPF6 in ethylene carbonate:ethyl methyl carbonate (EC:EMC 3:7 w/w), LP572 (LP57+2 wt.% vinylene carbonate (VC)) and LP57 + absVC (18.351 mg VC). Comprehensive analytical post mortem investigations revealed that continuous excessive electrolyte decomposition determines the performance of cells using LP57, leading to enhanced irreversible lithium‐ion loss and interphase thickening with increasing electrolyte volume. Impedance rise due to the growth of the interphase was also identified as the cause of degrading cell performance with rising amounts of LP572, attributed to an increasingly pronounced consumption of VC rather than electrolyte aging effects. By varying the electrolyte quantity while maintaining a constant amount VC within the cell system, the differences in cell performance were minimized, and observed deteriorating effects were suppressed. This study demonstrates the sensitive interdependence of electrolyte volume and additive concentration, practically affecting aging behavior. Comprehensively understanding the characteristics of each individual electrolyte component and tailoring the electrolytes to cell‐specific cell properties proves to be crucial to optimize cell performance. [ABSTRACT FROM AUTHOR]

The study explores the intricate biochemical mechanisms driving aging and their inferences for prolonged existence and to identify implicit remedial targets for interventions that promote healthier aging. A comprehensive literature investigation was conducted across different databases and search machines to identify material exploration papers, reviews, and studies concentrated on critical biochemical mechanisms driving aging. Data abstraction and synthesis were performed to organize findings into thematic sections, each devoted to a specific biochemical mechanism. The connection of these mechanisms and their relative influence on aging were investigated, and consequences for age-associated conditions and implicit strategies to enhance health span and lifetime were explored. The review highlights the pivotal function of cellular anility, genomic integrity, mitochondrial function, inflammation, genetics, epigenetic regulation, and nutrient seeing in shaping the aging process. Transcriptional processes, including RNA polymerase II extension speed and chromatin structure, are also intertwined in aging. Sirtuins, NAD, and circadian timepieces regulate lifetime and health span, while exercise and nutrition play pivotal functions in maintaining cellular health. Drugs targeting aging pathways and biomarkers for assessing aging processes show capacity. This study provides a comprehensive understanding of the molecular mechanisms underpinning aging and lifetime regulation, stressing the significance of interdisciplinary exploration in addressing the complex challenges of aging. The known biochemical mechanisms offer implicit remedial targets for interventions promoting healthier aging and extended life. Evolving trends and impending directions in longevity research are bandied, and limitations and challenges in deciphering exploration issues into practical interventions are addressed. [ABSTRACT FROM AUTHOR]

Abstract Despite a substantial impact on various economic and cell technology factors, the influence of electrolyte quantities is rarely addressed in research. This study examines the impact of varying electrolyte quantities on cell performance and aging processes using three different electrolytes: LP57 (1 M LiPF6 in ethylene carbonate:ethyl methyl carbonate (EC:EMC 3:7 w/w), LP572 (LP57+2 wt.% vinylene carbonate (VC)) and LP57 + absVC (18.351 mg VC). Comprehensive analytical post mortem investigations revealed that continuous excessive electrolyte decomposition determines the performance of cells using LP57, leading to enhanced irreversible lithium‐ion loss and interphase thickening with increasing electrolyte volume. Impedance rise due to the growth of the interphase was also identified as the cause of degrading cell performance with rising amounts of LP572, attributed to an increasingly pronounced consumption of VC rather than electrolyte aging effects. By varying the electrolyte quantity while maintaining a constant amount VC within the cell system, the differences in cell performance were minimized, and observed deteriorating effects were suppressed. This study demonstrates the sensitive interdependence of electrolyte volume and additive concentration, practically affecting aging behavior. Comprehensively understanding the characteristics of each individual electrolyte component and tailoring the electrolytes to cell‐specific cell properties proves to be crucial to optimize cell performance.

Development of fifth‐generation technology leads to a growing demand for materials with exceptional thermal property, mechanical strength, and low dielectric loss. However, ensuring the broad application of such materials by comprehensively investigating their aging mechanisms and service lifetimes remains a challenge. In this work, we have developed a glass fiber (GF) reinforced liquid crystal polymer composite (GF/LCP) and conducted a thorough exploration of its aging mechanism, behavior, and service lifetime under thermal and oxidative conditions. On the basis of the general Arrhenius model, the composite maintains a high level of functionality for a remarkable 18 years at 150 °C and 1.5 years at 200 °C. Despite the extremely high thermal resistance of GF/LCP composite, the LCP matrix exhibits localized brittle fracture, and the main chains still undergo gradual degradation to generate phenolic groups, which ultimately leads to severe pulverization and mass loss. However, a high degree of connection maintenance between GF and LCP components is still reserved. This work provides a valuable reference for the reliable application of 5G materials under thermal and oxidative conditions. [ABSTRACT FROM AUTHOR]

The development of fifth‐generation technology has resulted in increased demand for materials with low dielectric losses and superior thermal and mechanical properties. However, ensuring the widespread use of such materials by investigating their aging mechanisms and operating lifetimes remains challenging. In this study, a glass‐fiber (GF)‐reinforced acrylate‐styrene‐acrylonitrile/polycarbonate (ASA/GF/PC) composite is designed and comprehensively investigated its aging behavior, mechanism, and service lifetime under long‐term hygrothermal conditions. Based on the general Peck model, the composite maintains a high level of quality for over 10 years, including under harsh conditions of 40 °C and 80% relative humidity. The aging mechanism is primarily ascribed to cracking between the GF fibers and matrix, the breaking of chemical bonds, the generation of new cross‐linked domains, and physical aging. These findings provide valuable insights into the long‐term utilization of ASA/GF/PC composites in harsh environments. [ABSTRACT FROM AUTHOR]

Aging is a complex journey shaped by interactions among mechanisms, biochemistry, physiology, and social habits. This review explores aging's core facets by uncovering the mechanisms driving cellular senescence, oxidative stress, telomere shortening, and mitochondrial dysfunction.The review also delves into the biochemistry and physiology of aging, shedding light on hormonal shifts, genetic influences, and immune system modifications that contribute to the aging process. It navigates the terrain of social habits linked to aging, considering the profound impact of dietary choices, physical activity, social engagement, and stress management.These elements intricately intertwine, emphasizing the holistic nature of aging. The complex interplay between mechanisms, biochemistry, physiology, and social habits underscores the need for a comprehensive understanding of aging that transcends single disciplines.Deciphering these factors underscores the significance of personalized approaches to healthy aging. Tailoring interventions to individual genetics, lifestyles, and health needs emerges as a critical strategy for optimizing well-being in later life.In conclusion, this review illuminates the multifaceted nature of aging, urging the embrace of complexity and interdependence. By fostering a holistic, personalized approach, individuals can navigate the aging journey with grace, vitality, and resilience.

Abstract Development of fifth‐generation technology leads to a growing demand for materials with exceptional thermal property, mechanical strength, and low dielectric loss. However, ensuring the broad application of such materials by comprehensively investigating their aging mechanisms and service lifetimes remains a challenge. In this work, we have developed a glass fiber (GF) reinforced liquid crystal polymer composite (GF/LCP) and conducted a thorough exploration of its aging mechanism, behavior, and service lifetime under thermal and oxidative conditions. On the basis of the general Arrhenius model, the composite maintains a high level of functionality for a remarkable 18 years at 150 °C and 1.5 years at 200 °C. Despite the extremely high thermal resistance of GF/LCP composite, the LCP matrix exhibits localized brittle fracture, and the main chains still undergo gradual degradation to generate phenolic groups, which ultimately leads to severe pulverization and mass loss. However, a high degree of connection maintenance between GF and LCP components is still reserved. This work provides a valuable reference for the reliable application of 5G materials under thermal and oxidative conditions.

Abstract The development of fifth‐generation technology has resulted in increased demand for materials with low dielectric losses and superior thermal and mechanical properties. However, ensuring the widespread use of such materials by investigating their aging mechanisms and operating lifetimes remains challenging. In this study, a glass‐fiber (GF)‐reinforced acrylate‐styrene‐acrylonitrile/polycarbonate (ASA/GF/PC) composite is designed and comprehensively investigated its aging behavior, mechanism, and service lifetime under long‐term hygrothermal conditions. Based on the general Peck model, the composite maintains a high level of quality for over 10 years, including under harsh conditions of 40 °C and 80% relative humidity. The aging mechanism is primarily ascribed to cracking between the GF fibers and matrix, the breaking of chemical bonds, the generation of new cross‐linked domains, and physical aging. These findings provide valuable insights into the long‐term utilization of ASA/GF/PC composites in harsh environments.

Precise prediction of lithium‐ion cell level aging under various operating conditions is an imperative but challenging part of ensuring the quality performance of emerging applications such as electric vehicles and stationary energy storage systems. Accurate and real‐time battery‐aging prediction models, which require an exact understanding of the degradation mechanisms of battery components and materials, could in turn provide new insights for materials and battery basic research. Furthermore, the primary barrier to meaningful artificial intelligence/machine learning for accelerating the prediction period is the exploitation of accurate aging mechanistic descriptors. This review comprehensively summarizes the evolution of deterioration mechanisms at the material and cell level in different environments and usage scenarios, including the intricate relationships between aging mechanisms, degradation modes, and external influences, which are the cornerstones of modeling simulation and machine learning techniques. Recent advances in electrochemical models coupled with internal battery degradation mechanisms as well as identification and tracking of aging parameters are shown, with particular emphasis on electrode balance and the anticipated trend of machine learning‐assisted reliable remaining useful life prediction. Precise simulation prediction of cell level aging will continue to play an essential role in advanced smart battery research and management, enhancing its performance while shortening experimental sequences. [ABSTRACT FROM AUTHOR]

Studying the mechanisms of aging is one of the most important goals of modern science. A significant amount of data on the processes associated with a decrease in the functional ability to regenerate, cell proliferation and resistance to adverse factors with age has been accumulated due to fundamental research. The aim of the review was to study the mechanism of drugs with the senolytic activity, to determine the main targets of their effect at the cellular level, and also to evaluate the prospects for their clinical use. The relevance of this topic is confirmed by the increasing number of clinical trials of senolytics, many of which have ambiguous results and require further analysis and elimination of revealed difficulties and shortcomings. We reviewed the literature on Pubmed and Scopus platforms over the past 10 years in order to find information about the mechanisms of senotherapy and the possibility of using senolytics in clinical medicine. The focus was on those senolytic drugs that were used in clinical studies. [ABSTRACT FROM AUTHOR]

The high-rate discharging performance of lithium titanate batteries is a crucial aspect of their functionality. Under high-power demands, the discharge rate, which is defined as the ratio of discharge current to the maximum capacity, can exceed 50 C or higher. This study investigates the evolution of incremental capacity (IC) curves and frequency response characteristic of 2 Ah lithium titanate batteries subjected to aging cycles at 50 C. The results provide a new indicator to assess the fading of the state of health (SOH) of lithium titanate batteries during ultra-high-rate discharge cycles. [ABSTRACT FROM AUTHOR]

Aging is an irreversible physiological process in the human body, and the aging characteristics of the body that accompany this process also lead to many other chronic diseases, such as neurodegenerative diseases represented by Alzheimer's disease and Parkinson's disease, cardiovascular diseases, hypertension, obesity, cancer, and so on. The marine environment is highly biodiverse, the natural active products of these organisms constitute a vast treasure trove of marine drugs or drug candidates that play an essential role in disease prevention and treatment, and the active peptide products among them have received special attention because of their unique chemical properties. Therefore, the development of marine peptide compounds as anti-aging drugs is emerging as an important research area. This review highlights the currently available data on marine bioactive peptides with anti-aging potential from 2000 to 2022 by analyzing the prevalent aging mechanisms, critical aging metabolic pathways and well-established multi-omics aging characteristics, as well as grouping different bioactive and biological species lines of peptides from marine organisms and discussing their research modalities and functional characteristics. Active marine peptides is a promising topic to explore and to develop their potential as anti-aging drugs or drug candidates. We expect this review to be instructive for future marine drug development and to reveal new directions for future biopharmaceuticals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Combines fast-charging design with diagnostic methods for Li-ion battery aging. • Studies real-life aging mechanisms and develops a digital twin for EV batteries. • Identifies factors in performance decline and thresholds for severe degradation. • Analyzes electrode degradation with non-destructive methods and post-mortem analysis. The aging mechanisms of Nickel-Manganese-Cobalt-Oxide (NMC)/Graphite lithium-ion batteries are divided into stages from the beginning-of-life (BOL) to the end-of-life (EOL) of the battery. The corresponding changes in the battery performance across these stages have been analyzed, and a digital twin model is established to quantify the primary parameters that influence these aging mechanisms. Post-mortem analysis is applied to validate the results. This paper compares the aging mechanisms from BOL to EOL using two charging protocols: a multi-step fast charge protocol and a common constant-current fast charge protocol that applies the average current of multi-step currents. Notably, a transition from a linear to a non-linear degradation trend in capacity fade is observed, beginning from a 10% capacity reduction to EOL. From BOL to 10% degradation, the resistance of solid electrolyte interphase (SEI) grows steadily. The graphite anode's crack depth exhibits a significant increase, accompanied by an evident collapse of cathode materials in all the test cases following a 10% degradation until EOL. This phenomenon can be attributed to one primary reason—the expansion of the corresponding simulated resistance of charge transfer (R ct). Post-mortem analysis revealed the change in morphology, structure, and composition of various degradation conditions. This analysis proved that the primary driver of the linear aging stage is the SEI growth. Furthermore, it is evident that the transition to a non-linear aging degradation is dominated by electrode defects resulting from continuous mechanical stress during long-term aging. [ABSTRACT FROM AUTHOR]

In this study, we examined the aging characteristics of polyethylene (PE) and polylactic acid (PLA) microplastics (MPs), examining the adsorption behaviors and mechanisms concerning Cd(II) and Cr(VI) under both single and binary systems. The results revealed that aging treatment changed the physicochemical properties of MPs. The aging mechanisms of PLA and PE MPs were shown to be similar by the 2D-FTIR-COS study. These mechanisms involve the formation of oxygen-containing functional groups through the combination of carbon chain breakdown and oxygen. Aged MPs had a greater ability to adsorb metal ions than pristine MPs, with PLA MPs outperforming PE MPs. After 30 days of aging, Cd(II) adsorption increased by 40.61 % and 25.49 % for PE and PLA MPs, respectively, while Cr(VI) adsorption increased by 37.50 % and 69.29 %, respectively. The adsorption ability of PE and PLA MPs with Cd(II) or Cr(VI) under binary systems was less than that under single systems, with Cd(II) exhibiting more adsorption competitiveness than Cr(VI). Humic acid (HA), ionic species and strength, solution pH, and adsorption of Cd(II) and Cr(VI) were found to be significantly correlated. Further investigation into the adsorption mechanisms of Cd(II) and Cr(VI) on PE and PLA MPs revealed that pore-filling, electrostatic interactions, complexation, and hydrogen bonding play important roles in the adsorption process. The study's conclusions are crucial for assessing the risk associated with concurrent contamination by metal ions and microplastics. [Display omitted] • The carbon chains of PE and PLA MPs break during aging and combine with oxygen to form oxygen-containing functional groups. • The adsorption ability of PE and PLA MPs for Cd(II) and Cr(VI) was enhanced after aging. • Cd(II) exhibited greater adsorption competitiveness than Cr(VI) under binary systems. • Electrostatic interactions, complexation, and hydrogen bonding were the primary mechanisms of adsorption. [ABSTRACT FROM AUTHOR]

Using a series of electrochemical performance tests and post‐mortem analysis, herein, the performance and aging mechanisms of high‐nickel lithium‐ion batteries after accelerated aging at different discharge rates are investigated. The results show that the loss of lithium ions and the generation of a solid electrolyte interphase are the main causes for capacity fading at relatively low aging discharge rates. When the aging rate increases to 3 C, the performance of the battery deteriorates significantly, and structural damage becomes the main reason for attenuation, which means that the aging mechanism changed. It is expected that this investigation will improve the safety performance of the retired high‐nickel ternary lithium batteries. [ABSTRACT FROM AUTHOR]

Interfacial reactions in lithium‐ion batteries often involve gaseous reaction products. Mechanistic investigation of material degradation processes requires a technique to identify and quantify these gases in battery cells. On‐line electrochemical mass spectrometry (OEMS) is an operando gas analysis method that continuously samples the headspace of a custom battery cell. Real‐time gas analysis by quantitative OEMS was used to create mechanistic understanding of battery degradation reactions, some of which will be highlight in this article. [ABSTRACT FROM AUTHOR]

• Different types and contents of the hydrolysis stabilizers were added to settle the hydrolysis problem of PET. • To shorten the time of accelerated aging test, pressure cooker test was conducted on PET samples with hydrolysis stabilizers as an alternative to damp heat test. • The aging mechanisms of PET and the effect of hydrolysis stabilizers were comprehensively studied using various characterization methods, particularly ATR-FTIR in a quantitative manner. Polyethylene terephthalate (PET) is extensively utilized in various industries due to its good properties. However, as a kind of polyester, PET is apt to hydrolysis when exposed to moisture and heat, which severely affects its performance and service life. Hence, the incorporation of hydrolysis stabilizers is a common mitigation method. In this work, the PET specimens modified by two types of hydrolysis stabilizers were subjected to the pressure cooker test to evaluate the improvement effect, and the resultant changes in appearance, mechanical properties, and thermal characteristics were studied. Additionally, the crystallinity and infrared peaks were detected to assess the effectiveness of the hydrolysis stabilizers and to reveal the aging mechanisms of PET. The results indicated that PET underwent three distinct aging processes during the pressure cooker test, including crystallization, water plasticization and hydrolysis, and the inhibitory effect of the hydrolysis stabilizers mainly reflected in the crystallization and hydrolysis processes while the effectiveness depended on their types and concentrations. [ABSTRACT FROM AUTHOR]

The high-rate discharging performance of lithium titanate batteries is a crucial aspect of their functionality. Under high-power demands, the discharge rate, which is defined as the ratio of discharge current to the maximum capacity, can exceed 50 C or higher. This study investigates the evolution of incremental capacity (IC) curves and frequency response characteristic of 2 Ah lithium titanate batteries subjected to aging cycles at 50 C. The results provide a new indicator to assess the fading of the state of health (SOH) of lithium titanate batteries during ultra-high-rate discharge cycles.

The UV durability of carbon fiber composites has been a concern. In this work, UV irradiation on carbon fiber-reinforced polymer (CFRP) materials was performed using an artificial accelerated UV aging chamber to investigate the effect of UV exposure on carbon fiber composites. UV aging caused some of the macromolecular chains on the surface resin to break, resulting in the loss of small molecules and loss of mass. After 80 days of UV irradiation exposure, a significant decline in the macroscopic mechanical properties occurred in the longitudinal direction, with the largest decrease of 23% in longitudinal compressive strength and a decreasing trend in the transverse mechanical properties at the later stage of aging. The microscopic mechanical properties of the CFRP specimens were characterized using nanoindentation, and it was found that UV aging had an embrittlement effect on the matrix, and its hardness/modulus values were higher than the initial values with UV exposure. The fibers were less affected by UV irradiation. [ABSTRACT FROM AUTHOR]

Aging is an irreversible physiological process in the human body, and the aging characteristics of the body that accompany this process also lead to many other chronic diseases, such as neurodegenerative diseases represented by Alzheimer’s disease and Parkinson’s disease, cardiovascular diseases, hypertension, obesity, cancer, and so on. The marine environment is highly biodiverse, the natural active products of these organisms constitute a vast treasure trove of marine drugs or drug candidates that play an essential role in disease prevention and treatment, and the active peptide products among them have received special attention because of their unique chemical properties. Therefore, the development of marine peptide compounds as anti-aging drugs is emerging as an important research area. This review highlights the currently available data on marine bioactive peptides with anti-aging potential from 2000 to 2022 by analyzing the prevalent aging mechanisms, critical aging metabolic pathways and well-established multi-omics aging characteristics, as well as grouping different bioactive and biological species lines of peptides from marine organisms and discussing their research modalities and functional characteristics. Active marine peptides is a promising topic to explore and to develop their potential as anti-aging drugs or drug candidates. We expect this review to be instructive for future marine drug development and to reveal new directions for future biopharmaceuticals.

• Final morphology determined by maximum melt amount formed within deposit. • Change from skeletal to molten morphology if melt fraction exceeds about 30 wt-% • Formation of skeletal morphology accelerated by presence of small amounts of melt. • Deposit ageing behaviour tightly linked to deposit melting. The initial melting behaviour of synthetic ash deposits, with a focus on how the amount of melt formed, affects the final deposit morphology, was studied. Binary and ternary reciprocal deposits were exposed to a temperature gradient with varying exposure time, steel temperature, and furnace temperature. Two different archetype deposit morphologies emerged. The final deposit morphology was identified to depend on the amount of melt formed during the experiment. A skeletal deposit morphology developed in systems with less than 30 wt-% melt. Short-term experiments proved that the formation of the skeletal structure is accelerated by the presence of melt, accumulating at contact points of distinct particles. If melt fractions exceeded 30 wt-%, a molten morphology developed, as the amount of melt present was sufficient to fill the pores within the deposit. For molten deposits of ternary reciprocal systems, enrichment of K in the formed melt and concurrent movement toward the steel was observed. The results confirmed a deposit ageing mechanism that has been proposed earlier, based on full-scale superheater deposit samples. The experiments showed that deposit melting and ageing behaviour are strongly connected, as the two identified morphologies differed in their ageing behaviour. The presented results improve the understanding of the initial melting behaviour of deposits and illustrate the connection between deposit morphology and deposit ageing. The results can be utilised as input data for deposition models and help in predicting the final deposit morphology and its associated ageing behaviour, aiding boiler operators and manufacturers dealing with deposit-related issues. [ABSTRACT FROM AUTHOR]

Any theory suggesting an adaptive meaning for aging implicitly postulates the existence of specific mechanisms, genetically determined and modulated, causing progressive decline of an organism. According to the subtelomere–telomere theory, each telomere is covered by a hood formed in the first cell of an organism having a size preserved at each subsequent duplication. Telomere shortening, which is quantitatively different for each cell type according to the telomerase regulation, causes the hood to slide on the subtelomere repressing it by the telomeric position effect. At this point, the theory postulates existence of subtelomeric regulatory sequences, whose progressive transcriptional repression by the hood should cause cellular alterations that would be the likely determinant of aging manifestations. However, sequences with characteristics of these hypothetical sequences have already been described and documented. They are the [sub]TElomeric Repeat-containing RNA (TERRA) sequences. The repression of TERRA sequences causes progressively: (i) down- or up-regulation of many other regulatory sequences; (ii) increase in the probability of activation of cell senescence program (blockage of the ability to replicate and very significant alterations of the cellular functions). When cell senescence program has not been triggered and the repression is partial, there is a partial alteration of the cellular functions that is easily reversible by telomerase activation. Location of the extremely important sequences in chromosomal parts that are most vulnerable to repression by the telomeric hood is evolutionarily unjustifiable if aging is not considered adaptive: this location must be necessarily adaptive with the specific function of determining aging of the cell and consequently of the whole organism. [ABSTRACT FROM AUTHOR]

The capacitance of Lithium-ion Capacitors (LiCs) highly depends on their terminal voltage. Previous research found that it varies in a nonlinear manner with respect to the voltage. However, none of them modeled the capacitance evolution while considering the physicochemical phenomena that happen in a LiC cell. This paper focuses on developing a new capacitance model that is based on the Stern model of the electrochemical double layer capacitance. The model accounts for the asymmetric V-shape of the C(V) curve, which reflects the variation of the capacitance with respect to the voltage. The novelty of this study concerns the development of a model for LiCs that relies on the fundamental theory of Stern for the differential capacitance. The basic model of Stern is modified in order to account for the hybrid physicochemical structure of LiCs. Moreover, the model was applied to three aged cells to which accelerated calendar aging tests were applied at three voltage values: 2.2, 3 and 3.8 V. A drift of the voltage corresponding to the minimum capacitance was detected for the aged cells. This voltage is related to the neutral state of the positive electrode. The main cause of this phenomenon concerns the loss of lithium ions from the negative electrode of a LiC. In addition, capacitance values decreased after aging, showing an eventual blocking of the pores of the positive electrode. Therefore, the analysis of the C(V) curve was found to be an interesting tool for the interpretation of aging mechanisms. [ABSTRACT FROM AUTHOR]

Operation temperature is known to be one of the most impacting parameters for aging of Li-ion batteries under cycling conditions. While Li plating usually dominates aging at low temperatures, Solid-Electrolyte-Interphase (SEI) growth often dominates aging at elevated temperatures. The longest cycle life for Li-ion batteries is observed at the crossover temperature of both aging mechanisms at around 25 °C. We introduce aging color maps to show changes in the aging rate during battery aging. Reconstructed 3-electrode full cells with Li reference electrode show that the prolonged CV phase during charging at low temperatures counteracts Li plating by an increasing anode potential. Thirty-six temperature variations during cycling between 0 °C and 45 °C were studied to investigate the temperature path dependence of battery aging. The permutability of aging temperatures is analyzed by means of commutators. It turns out that aging at elevated temperatures is only slightly affected by previous aging processes and aging at lower temperatures with Li plating accelerates itself. Previous high temperature cycling decelerates Li plating and shifts its onset to lower temperatures, leading to a new and improved optimum cycling temperature of 20 °C. Differential voltage analysis and Post-Mortem analysis were performed to identify the underlying aging mechanisms. [Display omitted] • Aging color maps illustrate changing aging rate. • Cyclic aging at elevated temperatures is little affected by previous aging. • Low temperature cycling with Li plating accelerates further Li plating. • Aging at high temperatures shifts onset of Li plating to lower temperatures. • Permutability of aging temperatures is analyzed by means of commutators. [ABSTRACT FROM AUTHOR]

The high-rate discharging performance of a lithium titanate battery is one of its main properties. In conditions that require ultra-high-rate discharging, a lithium titanate battery can be discharged continuously at a current of 50 C (50 times of its maximum capacity) or higher. In this paper, we take cylindrical steel shell lithium titanate cells as the research object and perform aging cycles at 66 C on these cells. The ultra-high-rate discharging cycles cause a rapid high-power capacity fading while the available capacity at normal current rate is not affected. The capacity at 66 C decreases to 80% of initial value in 10 cycles. This paper also analyzes the aging process of a lithium titanate battery at high-rate discharging with incremental capacity (IC) analysis, and presents the aging behavior of lithium titanate battery qualitatively, which is inconsistent with existing research. We attribute the aging mechanism of ultra-high-rate discharging cycles to the decrease of ionic mobility and increase of polarization resistance. Mechanical damage is observed in the CT scan of an aged cell, which we presume to be the result of rapid strain of cathode material.

Abstract Lithium-ion batteries with Li 4 Ti 5 O 12 (LTO) negative electrodes have been recognized as a promising candidate over graphite-based batteries for the future energy storage systems (ESS), due to its excellent performance in rate capability, cycle life and inherent safety. Accurate identification of battery degradation mechanisms is of great significance for reliable management and sustainable capability of ESS. Unfortunately, only a few quantitative analysis regarding LTO batteries are drawn at extreme conditions including designed overcharge and cycling at high temperatures. In this paper, cyclic aging behaviors of commercial LTO batteries are investigated at room temperature (RT) by applying incremental capacity and differential voltage techniques. A typical sketch of regional divisions among the voltage curve of a LTO battery is presented to explain the effects induced by different degradation modes on battery performance. The results imply that the loss of active material in the positive electrode occupies at least 83% and 81% of the total capacity loss under cycling at 10C and 5C respectively, while pure loss of lithium inventory is detectable when cycling at 5C rather than at 10C. Depth of discharge is further considered as the dominant stress of LTO batteries during the high-rate operation at RT. Highlights • Study of cyclic aging of commercial 10 Ah LTO batteries at room temperature. • Illustration of LTO batteries performance upon high-rate cycling. • Impact analysis of different aging mechanisms on battery behaviors. • Identification and quantitative analysis of major mechanism for capacity fade of battery. • Detailed discussion of C-rate effect on battery aging phenomenon. [ABSTRACT FROM AUTHOR]

Lifetime of energy storage systems is a key factor that is extremely influenced by the operating conditions. For this reason, lithium-ion batteries (LiBs) and supercapacitors (SCs) were subjected to accelerated aging tests in several previous research in order analyze their lifespan. Lithium-ion capacitors (LiCs), which fall in between LiBs and SCs, are still considered as a novel technology. Their behavior during accelerated aging tests is not yet well studied in the literature. This paper focuses on studying the degradation of their properties during floating aging. Eighteen samples were tested under three different voltage values and two different temperatures over 12 months. Cells that were discharged to the minimum voltage showed a severe capacitance decrease that was much higher than the one of fully charged cells. The best storage voltage of LiCs was found to be 3 V, which is equivalent to a half charging state. The hybrid structure of LiCs was found to be the major cause of this change in behavior during aging at different voltages. Mechanisms that affect the electrodes and the internal composition of the cells in the diverse conditions were analyzed and predicted. [ABSTRACT FROM AUTHOR]

Lithium-ion Capacitors (LiCs) that have intermediate properties between lithium-ion batteries and supercapacitors are still considered as a new technology whose aging is not well studied in the literature. This paper presents the results of accelerated aging tests applied on 12 samples of LiCs. Two high temperatures (60 °C and 70 °C) and two voltage values were used for aging acceleration for 20 months. The maximum and the minimum voltages (3.8 V and 2.2 V respectively) had different effects on capacitance fade. Cells aging at 2.2 V encountered extreme decrease of the capacitance. After storing them for only one month at 60 °C, they lost around 22% of their initial capacitance. For this reason, an aging model was developed for cells aging at the lowest voltage value to emphasize the huge decrease of the lifetime at this voltage condition. Moreover, two measurement tools of the capacitance were compared to find the optimal method for following the evolution of the aging process. It was proved that electrochemical impedance spectroscopy is the most accurate measurement technique that can reveal the actual level of degradation inside a LiC cell. [ABSTRACT FROM AUTHOR]

The capacitance of Lithium-ion Capacitors (LiCs) highly depends on their terminal voltage. Previous research found that it varies in a nonlinear manner with respect to the voltage. However, none of them modeled the capacitance evolution while considering the physicochemical phenomena that happen in a LiC cell. This paper focuses on developing a new capacitance model that is based on the Stern model of the electrochemical double layer capacitance. The model accounts for the asymmetric V-shape of the C(V) curve, which reflects the variation of the capacitance with respect to the voltage. The novelty of this study concerns the development of a model for LiCs that relies on the fundamental theory of Stern for the differential capacitance. The basic model of Stern is modified in order to account for the hybrid physicochemical structure of LiCs. Moreover, the model was applied to three aged cells to which accelerated calendar aging tests were applied at three voltage values: 2.2, 3 and 3.8 V. A drift of the voltage corresponding to the minimum capacitance was detected for the aged cells. This voltage is related to the neutral state of the positive electrode. The main cause of this phenomenon concerns the loss of lithium ions from the negative electrode of a LiC. In addition, capacitance values decreased after aging, showing an eventual blocking of the pores of the positive electrode. Therefore, the analysis of the C(V) curve was found to be an interesting tool for the interpretation of aging mechanisms.

A laboratory study was carried out to investigate the chemical composition of aged aromatic secondary organic aerosol (SOA) formed from the photoxidation of p‐xylene in the presence of ammonia (NH3). The experiments were conducted by irradiating p‐xylene/CH3ONO/NH3 air mixtures without and with NO in a home‐made smog chamber. The particulate products of aged p‐ xylene SOA in the presence of NH3 were measured by UV–vis spectrophotometry, attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy, and aerosol laser time‐of‐flight mass spectrometry (ALTOFMS) coupled with the fuzzy C‐means (FCM) clustering algorithm. The experimental results show that NH3 does not alter the gas–particle partitioning in the photoxidation of p‐xylene without NO and that 2,5‐dimethylphenol is the predominant NH3‐aged p‐xylene SOA without NO. However, NH3 has a significant promotional effect on the formation of organonitrogen compounds in the OH‐initiated oxidation of p‐xylene with NO. Organic ammonium salts such as ammonium glyoxylate and p‐methyl ammonium benzoate, which are formed from NH3 reactions with gaseous organic acids, were detected as the major particulate organonitrogen products of NH3‐aged p‐xylene SOA with NO. 1H‐Imidazole, 4‐methyl‐1H‐imidazole, and other imidazole products of the heterogeneous reactions between NH3 and dialdehydes of p‐xylene SOA were newly measured. The possible reaction mechanisms leading to these organonitrogen products are also discussed and proposed. The formation of imidazole products suggests that some ambient particles containing organonitrogen compounds may be the result of this mechanism. The results of this study may provide valuable information for discussing anthropogenic SOA aging mechanisms. [ABSTRACT FROM AUTHOR]

In this paper, we present an accuracy-aware operating voltage management unit to improve the lifetime of processors by considering the error-resilient nature of some applications. This unit is placed in the power management unit of the processor and its operation is based on the aggressive operating voltage reduction during the runtime of error resilient applications. This unit determines the operating voltage of the processor based on the type of the running application, the predefined minimum acceptable quality, and the operating voltage level specified by the dynamic voltage frequency scaling controller of the processor power management unit. The determined operating voltage by this unit results in lifetime improvement and power reduction at the cost of timing violations that are tolerable by error-resilient applications. In addition, the proposed unit dynamically adjusts the minimum acceptable operating voltage based on the impact of aging mechanisms. The aging mechanisms considered in this work include Negative Bias Temperature Instability, Hot Carrier Injection, Time Dependent Dielectric Breakdown, Thermal Cycling, Electro-Migration, and Stress Migration. The efficacy of the proposed operating voltage management is investigated by applying it to some exact and error-resilient applications. The results show that the proposed unit lead to, on average, 38.82% lifetime improvement as well as 41.8% power consumption reduction. [ABSTRACT FROM AUTHOR]

The safety of Li-ion batteries is the most critical of many important characteristics and must be carefully considered. However, depending on the aging conditions, safety of batteries can change drastically. We had recently introduced ARC-MS as a new tool for safety investigations, which is an updated accelerating rate calorimeter (ARC) combined with a mass spectrometer (MS). Additionally, our ARC-MS setup is equipped by seven more low cost sensors (temperature, voltage, resistance, audio, strain, and transmitted and reflected ultrasound). In this paper, the dependence of safety on the dominant aging mechanism as a function of aging temperature, and state-of-health (SOH) is investigated on the example of 3.3 Ah commercial pouch cells. The ambient temperature during aging has a strong influence on the dominant aging mechanism (Li plating or SEI growth) of this cell as shown by Arrhenius plots of the aging rate and Post-Mortem analyses (ICP-OES, SEM, EDX, Hg porosimetry, STA) of aged cells. Our in-depth evaluation shows that different sensors can provide indications of safety relevant events (onset of swelling, onset of self-heating, cell venting, stable exothermic reactions, separator melting, and thermal runaway) in the cells independently. Combining these low-cost sensors might be a solution for detection of unsafe cells in applications. [Display omitted] • ARC tests on commercial pouch cells aged at various temperatures to different SOH. • Correlation of dominant aging mechanism with safety and sensor data. • Safety decreases for low temperature aging and increases for high temperature aging. • Better understanding of ongoing processes through combination of multiple sensors. • Indicators for unsafe behavior from low cost sensors. [ABSTRACT FROM AUTHOR]

• Primary aging mechanism changes from "dead lithium" to SEI growth at low temperature. • "Dead lithium" causes more capacity fading than SEI growth at low temperature cycle. • Plated lithium is inhomogeneity during long low temperature cycle. • Plated lithium is consumed at high temperature cycle after low temperature cycle. • Charge current affects battery aging at high temperature after low temperature most. Lithium plating is an important issue for lithium-ion battery safety and cycle life that can be caused by cycle at low temperature. In this study, we investigated battery aging over an extended low-temperature cycle and at high temperature after the low-temperature cycle. Nondestructive and destructive analysis methods were used to study battery electrochemical dynamics and changes to the materials, and the results indicated that battery aging over the extended low-temperature cycle could be divided into two stages. The mechanism of the first stage is that of "dead lithium," which causes significant capacity fading, whereas that of the second stage is solid electrolyte interphase (SEI) growth. It was also found that plated lithium accelerates battery aging at high temperature; part of it is intercalated into anode, another part of it reacts with the electrolyte, thus consuming the plated lithium. Thus, electrolyte decomposition and SEI growth are the primary aging mechanisms at high temperature after low-temperature cycling. The plated lithium content and charge/discharge rate affected plated lithium consumption during the high-temperature cycle. Plated lithium was not depleted for the battery with significant amounts of plated lithium or upon charging with high current and discharging with both high and low current when the state of health (SOH) decreased to 70%. The factors affecting battery aging ranked in order of importance are charge current > plated lithium content > high temperature > discharge current. [Display omitted] [ABSTRACT FROM AUTHOR]

Lithium-ion Capacitors (LiCs) that have intermediate properties between lithium-ion batteries and supercapacitors are still considered as a new technology whose aging is not well studied in the literature. This paper presents the results of accelerated aging tests applied on 12 samples of LiCs. Two high temperatures (60 °C and 70 °C) and two voltage values were used for aging acceleration for 20 months. The maximum and the minimum voltages (3.8 V and 2.2 V respectively) had different effects on capacitance fade. Cells aging at 2.2 V encountered extreme decrease of the capacitance. After storing them for only one month at 60 °C, they lost around 22% of their initial capacitance. For this reason, an aging model was developed for cells aging at the lowest voltage value to emphasize the huge decrease of the lifetime at this voltage condition. Moreover, two measurement tools of the capacitance were compared to find the optimal method for following the evolution of the aging process. It was proved that electrochemical impedance spectroscopy is the most accurate measurement technique that can reveal the actual level of degradation inside a LiC cell.

The ammonium sulfate ((NH4)2SO4) seed aerosols commonly found in the Chinese urban atmosphere could affect the formation and aging of secondary organic aerosols (SOA). Aging of aromatic SOA is performed using UV-irradiation of 1,3,5-trimethylbenzene (135-TMB)/CH3ONO/NO/air mixtures with high concentrations (∼100 аg/m3) of (NH4)2SO4 seeds in the laboratory chamber in this study. The particulate products of SOA were measured using an aerosol laser time-of-flight mass spectrometer (ALTOFMS) in real-time, and fuzzy c-means (FCM) was applied to the mass spectra organic species for clusters. Experimental results indicated that methylglyxoal, 2-methyl-4-oxo-2-pentenal, 4-methyl-1H-imidazole, 4-methyl-imidazole-2-acetaldehyde, and other imidazole derivative compounds are the principal products in the aged particles. Imidazole compounds that can absorb solar radiation effectively were newly detected in the aged 135-TMB SOA with high concentrations of (NH4)2SO4 seed aerosols. These would provide new information for discussing the 135-TMB SOA aging mechanism. [ABSTRACT FROM AUTHOR]

Inorganic aerosols such as (NH 4 ) 2 SO 4 , NaNO 3 and CaCl 2 are commonly present in the Chinese urban atmosphere. They could significantly affect the formation and aging of ambient secondary organic aerosols (SOA), but the underlying mechanisms remain unknown. In this work we studied SOA formation from the photooxidation reaction of 1,3,5-trimethylbenzene (135-TMB) with 100 μg/m 3 of the above three types of inorganic aerosols as seeds in a laboratory chamber. We focused on the aging products of SOA particles by exposing them to high levels of oxidizing hydroxyl radicals (OH). The particulate products of SOA were measured using an aerosol laser time-of-flight mass spectrometer (ALTOFMS) and Fuzzy C-Means (FCM) were applied to organic mass spectra for clustering. In the presence of (NH 4 ) 2 SO 4 seeds, 4-methyl-1H-imidazole, 4-methyl-imidazole-2-acetaldehyde and other imidazole derivative compounds formed from reactions of NH 4 + with methylglyoxal were detected as new aged products. We also observed aromatic nitrogen-containing organic compounds as the major aged products in the presence of NaNO 3 seeds as a consequence of reaction with OH and NO 2 radicals, which were generated by UV irradiation of acidic aqueous nitrate, inducing nitration reactions with phenolic compounds. As CaCl 2 has the strongest hygroscopic properties of the three salt particles tested, the greater water content on the surface of the aerosol may facilitate the condensing of more gas-phase organic acid products to the hygroscopic CaCl 2 seeds, forming H + ions that catalyze the heterogeneous reaction of aldehydes, products of photooxidation of 135-TMB, and forming high-molecular-weight (HMW) compounds. These results provide new insight into the aromatic SOA aging mechanisms. [ABSTRACT FROM AUTHOR]

The understanding of the aging behavior of lithium ion batteries in automotive and energy storage applications is essential for the acceptance of the technology. Therefore, aging experiments were conducted on commercial 18650-type state-of-the-art cells to determine the influence of the temperature during electrochemical cycling on the aging behavior of the different cell components. The cells, based on Li(Ni 0.5 Co 0.2 Mn 0.3 )O 2 (NCM532)/graphite, were aged at 20 °C and 45 °C to different states of health. The electrochemical performance of the investigated cells shows remarkable differences depending on the cycling temperature. At contrast to the expected behavior, the cells cycled at 45 °C show a better electrochemical performance over lifetime than the cells cycled at 20 °C. Comprehensive post-mortem analyses revealed the main aging mechanisms, showing a complex interaction between electrodes and electrolyte. The main aging mechanisms of the cells cycled at 45 °C differ strongly at contrast to cells cycled at 20 °C. A strong correlation between the formed SEI, the electrolyte composition and the electrochemical performance over lifetime was observed. [ABSTRACT FROM AUTHOR]

Silicone sealing material, because of their excellence performance, are gradually replacing traditional materials and widely used in various sealing devices. They are known for their aging and degradation problems, stockpile reliability problems and service life, and hence they became a focus of attention. In this paper, thermal oxidation aging test, XPS and NMR analysis are used to analyze the aging mechanism of silicone rubber. Then the FEM contact model before aging and after aging is developed to study the influence of aging on sealing performance. The results show that hardness and compression set increases with aging of silicone rubber; more surface roughness and aging can lead to a degradation of sealing performance. It helps staff to estimate the sealing performance of silicone rubber in further research. [ABSTRACT FROM AUTHOR]

• Increase in average deposit Cl content with time via diffusional vapour transport. • Formation of Cl and K rich layer on steel surface due to deposit ageing. • Sulfation of alkali chloride in deposits at low SO 2 concentration in the gas phase. • Increased deposit corrosiveness through local elemental enrichment and decreased T 0. Probe deposit samples of 1, 5, and 8 weeks exposure time were collected from the superheater area of a Finnish kraft recovery boiler. Deposit cross-sections were analysed regarding their morphology and chemical composition using SEM/EDXA. Morphological differences along the probe's circumference were observed due to different prevailing deposition mechanisms. Overall enrichment in the deposit Cl content with increasing exposure time was observed. The Cl enrichment proceeds via diffusion of Cl-vapours from the flue gas into the deposit. Two deposit ageing mechanisms were identified within the deposit samples. First, alkali chloride layers formed on the furnace-facing side of deposit particles and also directly on the steel surface as a result of deposit ageing. Second, within the 5 and 8-week probe samples, sulfation of alkali chloride within the inner regions of the deposits was observed. Analysis of the local first melting temperature of the deposits showed a significant decrease within the Cl and K-rich layer adjacent to the steel surface, implying an increased risk for melt formation, and thus corrosion, in the direct vicinity of the steel. [ABSTRACT FROM AUTHOR]

The aim of this work is the design of an algorithm for on-board determination of the actual capacity of a lithium iron phosphate (LFP) cathode-based lithium-ion battery for electric vehicle applications. The presented approach is based on the detection of the predominant aging mechanisms (in terms of loss of lithium and loss of active material in both electrodes) by determining the single electrode voltage curves. The information related to the characteristic length and position of the voltage plateaus, which can be gathered during battery operation, can be used to obtain the actual aging state of the cells. The length of the plateaus depends on the respective position that the voltage curves of the single electrodes have in relation to each other. Relating the change of the plateau characteristics to the possible aging mechanisms allows the determination of the actual battery aging state in terms of total cell capacity. The work presents a possible implementation of an algorithm for capacity determination based on the described methodology. The algorithm is validated with various differently aged LFP cells. Furthermore, the work discusses the ability of the method to detect the actual battery capacity if the characteristics of only part of the quasi-OCV (open circuit voltage) curve are detected. Achieved accuracy and existing limitations are described and discussed in detail. [ABSTRACT FROM AUTHOR]

Lithium-ion (Li-ion) batteries widely used in electric vehicles (EVs) and hybrid EVs (HEVs) are insufficient for vehicle use after they have degraded to 70% to 80% of their original capacity. Battery lifespan is a large consideration when designing battery packs for EVs/HEVs. Aging mechanisms, such as metal dissolution, growth of the passivated surface film layer on the electrodes, and loss of both recyclable lithium ions, affect the longevity of the Li-ion battery at high-temperature operations. Even vehicle maneuvers at low temperatures (T < \mbox0\ ^\circ\mboxC) contribute to battery lifetime degradation, owing to the anode electrode vulnerability to other degradation mechanisms such as lithium plating. Nowadays, only a few battery thermal management schemes have properly considered low-temperature degradation. This is due to the lack of studies on aging of Li-ion batteries at subzero temperature. This paper investigates how load cycle and calendar life properties affect the lifetime and aging processes of Li-ion cells at low temperatures. Accelerated aging tests were used to determine the effect of the ambient temperature on the performance of three 100-Ah LiFeMnP04 Li-ion cells. Two of them were aged through a normalized driving cycle at two temperature tests ( -\mbox20\ ^\circ\mboxC and 25 °C). The calendar test was carried out on one single battery at –20 °C and mid-range of state of charge (50%). Their capacities were continuously measured every two or three days. An aging model is developed and added to a preliminary single-cell electrothermal model to establish, in future works, a thermal strategy capable of predicting how the cell ages. This aging model was then validated by comparing its predictions with the aging data obtained from a cycling test at 0 °C. [ABSTRACT FROM PUBLISHER]