Longer Life Research Articles

Redo Aortic Valve Replacement After Prior Transcatheter versus Surgical Aortic Valve Replacement: Insights from Western Experience

Introduction: The demand for reoperation on the aortic valve in Albania is rising, mirroring the increasing average age of the population and the subsequent rise in patients requiring aortic valve surgery. This trend underscores the need for this informative article, which aims to provide insights into the risks and outcomes of aortic valve reoperations, particularly in light of efforts by interventional cardiologists to expand the indications for TAVR to younger and lower-risk patients. Data from the Society of Thoracic Surgeons (STS) National Database reveal results that warrant attention, with concerns over reoperations after TAVR growing, mainly due to the uncertain feasibility of repeat TAVR. This article presents a novel perspective on the risks associated with surgical aortic valve replacement (SAVR) after prior TAVR or SAVR. It underscores the urgent need to develop an optimal strategy for managing these patients and offers fresh insight. Material and Methods: Our research, based on a comprehensive analysis of data from the Society of Thoracic Surgeons in the USA's 10-year database, included individuals who underwent bioprosthetic SAVR following prior TAVR and/or SAVR. Our analyses, which included total and isolated SAVR groups, focused on the primary outcome of operative mortality, ensuring the reliability and thoroughness of our study. Results: The study included 31,106 patients who underwent SAVR. Among them, 1,126 had prior TAVR (TAVR-SAVR), 674 had undergone SAVR followed by TAVR and SAVR (SAVR-TAVR-SAVR), and 29,306 had undergone prior SAVR (SAVR-SAVR). Matched analysis for isolated SAVR cases showed a 1.74-fold higher operative mortality for TAVR-SAVR than SAVR-SAVR (P = 0.020). In our center, 5 cases have been performed in the last two years with excellent results, no losses, and operating times close to the first-time interventions. Conclusions: This study's findings significantly contribute to the field. They could influence clinical practice, particularly for patients with longer life expectancies and anatomy unsuitable for TAVR. They suggest an initial SAVR approach may provide better results even in necessary surgical re-interventions on the aortic valve.

Cohabitation and Mortality Across the Life Course: A Longitudinal Cohort Study with Swedish Register-Based Sibling Comparisons

Research has shown that married individuals live longer lives than unmarried women and men. A smaller number of studies have included non-marital cohabitation and have found that their mortality falls between the married and other unmarried groups. There are indications that the cohabiting population is diverse in terms of mortality risk, yet very little is known about how the association is related to age and stages of the life course. Sweden is a forerunner in family trends, and this is the first study that examines cohabitation and mortality in a Swedish context. Using Swedish register data for the years 2012–2017, we investigated how different partnership statuses are related to mortality for men and women at different ages (N = 5,572,011). We also examine whether the association between cohabitation and mortality is similar after accounting for family-of-origin effects through the use of a sibling comparison design. Our findings confirmed the notion of cohabiters as a diverse group whose relative mortality risk differs depending on the timing of cohabitation. Never-married cohabiters had a mortality risk similar to married couples at younger ages and a gradually increased risk with age. Divorced and widowed cohabiters exhibited an age gradient in the opposite direction. Future research should consider how the context of cohabitation changes across the life course.

Superlongevity and African Ethics

ABSTRACTI apply African moral precepts to the topic of ‘superlongevity’. I make the case that African theories give rise to three specific sorts of moral concern about life extension that are distinct from similar objections in Western literature: first, superlongevity presents a challenge to identity; second, significantly longer lives face increased challenges to their meaningfulness; third, life extension may be socially divisive, undermining key tenets of sharing a way of life and communing harmoniously with others. Although these distinctive concerns are significant, I claim that their strength as objections to superlongevity depends heavily on the distribution of life extension technologies. Moreover, since African theories typically hold that moral excellence correlates with increasing age, they provide a prudential and moral incentive to live longer to develop personhood.

Association between activity quotient and cause-specific mortality - A prospective cohort study of 0.5 million participants in Asia.

Regular physical activity (PA) is important for reducing the risk of chronic diseases and improving overall health. Activity Quotient (AQ) is a novel metric that translates heart rate during PA into a weekly score, providing an objective measure of an individual's PA. We prospectively examined the association of AQ with cancer and cardiovascular (CVD) mortality outcomes, the two major causes of death, in a Taiwanese population. A cohort of 515,608 healthy adults (52 % women) enrolled in a standard medical screening program was followed for mortality outcomes. The weekly AQ score of each participant was estimated based on self-reported PA intensity and weekly duration, and placed into six categories (0, ≤50, 51-99,100-149, 150-199, or ≥ 200 AQ per week). We used multivariable Cox proportional hazard models adjusted for potential confounders to estimate the hazard ratios (HR) and 95 % confidence intervals (CI). Higher weekly AQ scores were associated with lower risks of CVD, cancer, and all-cause mortalities. Compared with inactive individuals, HRs (CI) for the association of AQ scores of ≤50, 50-99, 100-149, 150-199, and ≥ 200 were 0.93 (0.89-0.97), 0.91 (0.85-0.96), 0.84 (0.77-0.91), 0.84 (0.74-0.96), and 0.81 (0.73-0.90) with cancer mortality; and 0.88 (0.83-0.93), 0.86 (0.80-0.93), 0.81 (0.73-0.90), 0.71 (0.60-0.85), and 0.73 (0.64-0.84) with CVD mortality, respectively. Subgroup analyses showed that meeting 50 AQ a week was associated with lower risk of disease specific mortality risk across age groups and among individuals with known risk factors. Higher weekly AQ scores were also associated with longer life expectancy, with the highest gains observed among those achieving 150-199 weekly AQ. Our findings show that AQ may be an objective tool for assessing and tracking PA and predicting mortality risks. Encouraging individuals to achieve ≥50 AQ a week could have substantial public health benefits, including lower mortality from major chronic diseases as well as prolonged health- and life expectancy.

The potential impact of optimal blood pressure treatment intensity to reduce disparities in dementia between Black and White individuals.

Black adults have higher dementia risk than White adults. Whether tighter population-level blood pressure (BP) control reduces this disparity is unknown. Estimate the impact of optimal BP treatment intensity on racial disparities in dementia. A microsimulation study of US adults ≥18 across a life-time policy-planning horizon. BP treatment strategies were the Systolic Blood Pressure Intervention Trial (SPRINT) protocol, the Eighth Joint National Committee (JNC-8) recommendations, and usual care (non-intervention control). Outcomes were all-cause dementia, atherosclerotic cardiovascular disease (ASCVD), stroke, myocardial infarction, non-ASCVD death, global cognitive performance, and optimal brain health (being free of dementia, cognitive impairment, or stroke). Population-level and individual-level effects stratified by race were estimated. Optimal population-level implementation of a SPRINT-based BP treatment strategy, compared to usual care, would increase average annual dementia incidence in White, but not Black, adults (1% versus 0%), due to hypertensive individuals' greater survival, and reduce annual ASCVD events more in Black than White adults (13% versus 5%). Under a SPRINT-based strategy, individuals with hypertension gained more years lived without dementia, ASCVD, myocardial infarction, or stroke and more years lived in optimal brain health. A SPRINT-based strategy did not attenuate individual-level race disparities in outcomes, except stroke. Due to longer life expectancy, a SPRINT-based strategy did not substantially reduce lifetime dementia risk in either group. The JNC-8-based strategy had similar but smaller effects as the SPRINT-based strategy. Our results suggest that tighter population-level BP control would not reduce population-level disparities in dementia between US Black and White adults.

Enablers of and barriers to ART adherence among female sex workers in mid-western Uganda: a qualitative study

IntroductionFemale sex workers (FSWs) in Uganda experience numerous barriers to antiretroviral therapy (ART) adherence. We used the planned behavior theory to help explore the enablers and barriers to ART adherence among FSWs. Understanding the barriers to ART adherence may help contribute to the development of interventions to improve ART adherence among the FSWs.Materials and methodsA descriptive qualitative study was conducted in Fort portal City. We conducted 30 in-depth interviews among FSWs who had been taking ART for at least six months. Furthermore, six key informant interviews were conducted with healthcare workers and leaders of the FSWs initiative. Data collection lasted for two months. Thematic deductive analysis was applied to analyse the data through the lens of the theory of planned behavior.FindingsThe attitudes, subjective norms, and perceived behavioral control influenced adherence to ART. Positive attitudes including perceived benefits of ART, and experiencing positive outcomes from taking ART were seen to enable its adherence. Subjective norms such as social support, disclosure of HIV status, seeing others take ART, and aspirations of longer life enabled ART adherence. Taking ART in the morning, responsive and respectful healthcare workers, and availability of food/basic needs facilitated compliance with ART adherence. Negative attitudes such as misconceptions and fear of side effects hindered ART adherence. Social disapproval of sex work and or HIV, lack of social support, gender-based violence, non-disclosure, stigma, and abandonment hindered the use of ART among FSWs. Socio-economic constraints (e.g., food scarcity), and occupation-related factors (substance use, incarceration, busy and predictable schedules, and abrupt migrations) were the additional barriers to ART adherence.ConclusionART adherence among FSWs was influenced by attitudes, subjective norms, and perceived behavioral control. Addressing these barriers in ART adherence through targeted interventions could facilitate ART adherence and improve health outcomes among FSWs.

Exploring Patient-Related Contextual Factors and Personal Reflections About the Managing Cancer and Living Meaningfully (CALM) Intervention for Adults With Advanced Cancer in Metropolitan and Non-Metropolitan Southern Alberta: A Mixed Methods Study.

The evidence-based Managing Cancer and Living Meaningfully (CALM) psychotherapeutic intervention was designed to address the complex needs of those with advanced cancer. Ample evidence supports the efficacy of CALM therapy; less is known about the patient-specific factors that influence initiation and continuation of CALM sessions. To gain understanding of patient-specific factors and referral routes that influence initiation and continuation of CALM. An Interpretive Description framework and concurrent triangulation mixed-methods design was used to analyse baseline patient-specific variables for prediction of engagement (number of sessions) in CALM following recruitment from cancer centres, palliative care services, and community cancer care organisations across Southern Alberta, Canada. Patient input (n=10) occurred through semi-structured interviews exploring experiences with advanced cancer, CALM referral and engagement. Among consented individuals (n=69), those directly referred by healthcare providers (HCPs) and self-referred (total n=32), engaged in more CALM sessions (M=4.97, SD=3.51) than those referred indirectly (M=3.19, SD=2.26, p<0.05), particularly younger participants (< 65years) and those with longer life expectancy (> 10months). Participants chose CALM based on experiences of distress, wanting to talk openly, and expecting benefit. Greater patient engagement in the CALM intervention following HCPs' direct referrals may be based on trust in the HCP-patient relationship, and accurately prognosticating sufficient physical well-being for participation and benefit. Future health systems research may evaluate systematic programing with offering CALM referrals following an advanced cancer diagnosis.

Performance Evaluation of Composite Materials for Wind Turbine Blade Design

Due to the growing consciousness to utilize renewable sources of energy, the improvement of wind turbine technologies which is especially focused on the blade design of the turbines. The advanced composite forms of glass fiber reinforced polymer (GFRP), carbon fiber reinforced polymer (CFRP) and hybrid composites have gained tremendous importance in wind turbine blades due to their increased mechanical strength, longer life, light weight characteristics. This work assesses the efficiency of different composite materials in relation to tensile strength, fatigue life, and vulnerability to environmental factors, including cost factors. Stress distribution and deformation patterns are modelled through finite element analysis (FEA) to compare them to those obtained experimentally. Some of the current concerns such as recyclability and disposal are presented with the prospects such as bio-composites and thermoplastic recyclates. Some suggestions are given for manufacturing of hybrid composites and some of the advanced manufacturing technologies to enhance the blade capabilities and its environmental impact resistant. These findings enrich the existing understandings of material selection, enhance new wind energy solutions.

The Impact of Population Aging on Economic Growth

Population ageing is a global phenomenon that is now affecting many countries. For China, the main cause of population ageing was the early baby boom, which, despite the Government's family planning policy, had had little effect. At the same time, advances in health care leading to longer life expectancy and declining birth rates have also exacerbated population ageing. Population aging also has economic implications, such as labor shortages, shifting consumption patterns, and increased government social welfare spending. This study examines the overall impact of population aging on economic growth with a focus on China. The introductory section explores the definition, status and development trends of China population aging and the world. The study then focuses on population aging in China, including the proportion of the elderly population, the rapid growth of population aging in China, and particular aspects of China's population aging pattern. The study highlights the significant economic impacts of aging, such as a declining labor force, rising social security costs, and changes in consumption behavior. By assessing these issues, the study attempts to make recommendations that are consistent with the current aging situation in China.

Life expectancy and health care spending in South Asia: An econometric analysis

Affordable health care is often a result of increased government spending on the health sector. Out-of-pocket expenses remain the primary health care funding source in many South Asian nations. Lack of adequate public funding for health services, difficulty in obtaining health insurance, and high out-of-pocket costs can result in indebtedness, reductions in actual consumption, and decreased access to health care services. The study examines life expectancy and health care spending in South Asian countries. The life expectancy of South Asian countries is studied as a health outcome in relation to health care spending, gross national income per capita, and expected years of schooling. This study is based on secondary data from World Bank statistics that covers eight South Asian countries from 2000 to 2021, for a total of 176 pooled time series and cross-sectional observations. The data were analysed using econometric models, including the cross sectional dependency test, panel unit root test, panel co-integration test, vector error correction model, pair-wise Granger causality test, and Wald test statistics. The vector error correction model results indicate that health care spending, anticipated years of schooling, and gross national income per capita have a long-run association with health outcomes. Health care spending, per capita gross national income, and expected years of education have all greatly enhanced life expectancy in South Asian countries. An effective health strategy is necessary to increase people’s healthy life expectancy and well-being. To accomplish this, government may need to promote school enrolment to help people become more health literate and aware of their health outcomes. As a result, persons with more years of schooling have better health, higher levels of well-being, healthier habits, and ultimately, a longer life expectancy. This study will provide an important insight to policymakers in improving health outcomes through targeted and sustained health care spending in South Asia.

Energy choices to health outcomes: A multidimensional analysis of risk in BRICS via PMG-ARDL approach.

This article employs a Panel Mean Group Autoregressive Distributed Lag (PMG-ARDL) approach to investigate the interaction between carbon dioxide (CO2) emissions, Gross Domestic Product (GDP), fossil fuel, renewable energy consumption, trade, and their collective impact on life expectancy within the BRICS nations. The research reveals compelling findings. Notably, CO2 emissions and trade openness exhibit negative and statistically significant impact on life expectancy. In contrast, GDP per capita and renewable energy consumption are positive and significant determinants of longer life expectancy. The nuanced outcomes underscore the complex interplay of economic, environmental, and social factors within the BRICS nations. The effects found by PMG-ARDL and FMOLS are very comparable, except for the trade openness' coefficients, which is the inverse. These findings hold significant implications for policy interpretation and sustainable development strategies. As nations struggle to balance economic growth and environmental improvement with public health, tailored interventions targeting CO2 reduction, trade openness, renewable energy, and GDP growth can collectively contribute to longer life expectancy. In a broader context, this research contributes to the global discourse on sustainability, economic improvement, and health issue.

Solid-State Battery Developments: A Cross-Sectional Patent Analysis

Solid-state batteries (SSBs) hold the potential to revolutionize energy storage systems by offering enhanced safety, higher energy density, and longer life cycles compared with conventional lithium-ion batteries. However, the widespread adoption of SSBs faces significant challenges, including low charge mobility, high internal resistance, mechanical degradation, and the use of unsustainable materials. These technical and manufacturing hurdles have hindered the large-scale commercialization of SSBs, which are crucial for applications such as electric vehicles, portable electronics, and renewable energy storage. This study systematically reviews the global SSB patent landscape using a cross-sectional bibliometric and thematic analysis to identify innovations addressing key technical challenges. The study classifies innovations into key problem and solution areas by meticulously examining 244 patents across multiple dimensions, including year, geographic distribution, inventor engagement, award latency, and technological focus. The analysis reveals significant advancements in electrolyte materials, electrode designs, and manufacturability. This research contributes a comprehensive analysis of the technological landscape, offering valuable insights into ongoing advancements and providing a roadmap for future research and development. This work will benefit researchers, industry professionals, and policymakers by highlighting the most promising areas for innovation, thereby accelerating the commercialization of SSBs, and supporting the transition toward more sustainable and efficient energy storage solutions.

The Impact of Monetary Policy on Healthcare Affordability: A Case Study of China's Urban and Rural Basic Medical Insurance

Longer life expectancy and improved health are key indicators of economic growth. As such, strategies to bolster the medical security system are priorities in government budgeting. The government is dedicating all available resources to better healthcare in rural and underdeveloped areas, narrowing the urban-rural healthcare gap, and achieving equitable healthcare resource distribution. This study examines the effect of monetary policy on healthcare affordability, focusing on China's Urban and Rural Basic Medical Insurance (URRBMI). It investigates how macroeconomic policies, such as interest rates and inflation control, affect healthcare costs and shape URRBMI's financial protection. Using an integrated methodology, including a literature review, theoretical framework, and econometric analysis, the research uncovers how monetary policy impacts healthcare costs and URRBMI's effectiveness. The findings highlight the importance of monetary policy in healthcare affordability. The study recommends collaboration between monetary authorities and healthcare policymakers to improve China's healthcare system's sustainability and effectiveness. Furthermore, these insights are crucial for refining URRBMI and provide new understandings of optimizing macroeconomic policy interactions with social welfare programs.

Women's Empowerment and Health: A Narrative Review.

Empowerment, the process by which a person is enabled to increase control over decisions concerning their life, is a multidimensional construct that has been extensively discussed by various disciplines for more than four decades. Several empowerment models have been presented, based on different approaches. This paper proposes a four-step model, based on individual and contextual awareness and advancement. Disparate factors may positively or negatively affect empowerment, including gender, race, culture, education, financial autonomy, socioeconomic status, family, neighborhood, religion, social cohesion, civic society, and political context. Empowerment has been extensively discussed in parallel with health promotion, since it is expected to positively affect health, both on the level of the individual and community, as well as in the context of the patient-healthcare professional relationship. Considering the position of women in patriarchal societies, where women may experience feelings of powerlessness, their social position and more importantly health may be adversely affected. Gender biases that were developed due to the marginalized position of women in different societies, coupled with paternalistic approaches of healthcare professionals, may significantly contribute to higher comorbidity, albeit longer life expectancy for women. Empowerment can therefore be a powerful tool for achieving equity in health and improving women's well-being.

Ischemic Stroke in Women: Understanding Sex-Specific Risk Factors, Treatment Considerations, and Outcomes.

Ischemic stroke is a major cause of mortality and disability and has become a significant public health concern among women. Overall, women have more ischemic stroke events than men, in part due to their longer life span, and also suffer from more severe stroke-related disabilities compared to men. Women are also more likely than men to present with atypical non-focal neurological symptoms, potentially leading to delayed diagnosis and treatment. Female-specific risk factors, especially those related to pregnancy, are often under-recognized. A woman's risk for ischemic stroke evolves throughout her lifespan, influenced by various factors including the age of menarche, pregnancy and its complications (such as parity, pre-eclampsia/eclampsia, and preterm delivery), postpartum challenges, oral contraceptive use, and menopause. Additionally, vascular risk factors like hypertension, diabetes, and atrial fibrillation are more prevalent among older women. Despite comparable treatment efficacies, women generally experience poorer outcomes after stroke. They also face higher rates of post-stroke depression, further complicating recovery. Although significant strides have been made in reducing the incidence of ischemic stroke, our understanding of the unique risks, underlying causes, and long-term consequences for women remains limited. While sex hormones may explain some differences, a lack of awareness regarding sex-related disparities can result in suboptimal care. This review aims to illuminate the unique risks and burdens of ischemic stroke faced by women, advocating for a more nuanced understanding to enhance prevention and treatment strategies.

A Taxonomy and Archetypes of AI-Based Health Care Services: Qualitative Study.

To cope with the enormous burdens placed on health care systems around the world, from the strains and stresses caused by longer life expectancy to the large-scale emergency relief actions required by pandemics like COVID-19, many health care companies have been using artificial intelligence (AI) to adapt their services. Nevertheless, conceptual insights into how AI has been transforming the health care sector are still few and far between. This study aims to provide an overarching structure with which to classify the various real-world phenomena. A clear and comprehensive taxonomy will provide consensus on AI-based health care service offerings and sharpen the view of their adoption in the health care sector. The goal of this study is to identify the design characteristics of AI-based health care services. We propose a multilayered taxonomy created in accordance with an established method of taxonomy development. In doing so, we applied 268 AI-based health care services, conducted a structured literature review, and then evaluated the resulting taxonomy. Finally, we performed a cluster analysis to identify the archetypes of AI-based health care services. We identified 4 critical perspectives: agents, data, AI, and health impact. Furthermore, a cluster analysis yielded 13 archetypes that demonstrate our taxonomy's applicability. This contribution to conceptual knowledge of AI-based health care services enables researchers as well as practitioners to analyze such services and improve their theory-led design.

Mortality Risks of US Healthcare Workers

Introduction: Physicians and nurses have lower annual mortality rates than the general population. One explanation for the low mortality rates of these healthcare workers emphasizes their specialized medical knowledge and greater access to healthcare while a second emphasizes their generally higher level of education. We evaluated the extent to which general educational level accounts for the lower all-cause mortality rates of US healthcare than non-healthcare workers. We also compared cause-specific mortality risks of healthcare and non-healthcare workers. MethodsA nationally representative sample of healthcare workers (n=176,000) and non-healthcare workers (n=1,662,000) from the 2008 American Community Survey (n=3,310,000) was followed through 2019 for mortality. Cox models estimated hazard ratios of all-cause and cause-specific mortality for six healthcare worker groups. Analyses were performed in 2024. ResultsAge- and sex-standardized all-cause death rates per 100,000 were lower for healthcare (370.7, 95%CI=361.5-379.9) than non-healthcare (442.2, 95%CI=439.2-445.2) workers (p<0.001). However, this difference was not evident after additionally adjusting for level of education (aHR=1.00, 0.97-1.02). In fully adjusted models, hazards of mortality were lower for healthcare than non-healthcare workers for cardiovascular disease (aHR=0.94, 0.89-0.99) and lung cancer (aHR=0.89, 95%=0.81-0.98), but higher for pancreatic cancer (aHR=1.21, 1.05-1.39) and external causes of death (aHR=1.20, 1.10-1.30). ConclusionsHigher educational attainment accounted for the longer life expectancy of US healthcare workers than other workers. Nevertheless, healthcare work relative to non-healthcare work was associated with lower hazards of deaths due to cardiovascular diseases and lung cancer, but higher hazards of deaths due to external causes.

Impact of population ageing on fiscal balance in the European Union

In the past two decades, the EU has experienced low fertility rates and declining mortality rates leading to population ageing. Although increasing immigration and longer life expectancy reinforced population growth, these trends could not counterbalance the negative impact of low birth rates on labour supply. Demographic transition towards an aging society is characterised by increase of public health and pension expenditures, as well as decrease of tax revenues that are triggers for fiscal imbalance. The paper aims to analyse the effects of population ageing on government fiscal balance in the EU-27 by applying modern methods of panel data analysis in the period 2001-2021. The dependent variable is general government fiscal balance, while the explanatory variables are related to demographic transition indicators (population aged over 64 in total population, old-age dependency ratio, and health expenditures) and macroeconomic control variables. The results of research show that population ageing has created a significant negative impact on fiscal balance of the EU countries, which was confirmed by all the analysed models. The fixed-effects panel threshold model did not identify a statistically significant threshold of any demographic transition indicator, concluding that population ageing has equally negatively affected fiscal balance, independent of the values of demographic transition indicators.

Preparation of Amorphous SiO2 Coated Li4Ti5O12 Anode and Their High Cycleability

In recent years, lithium-ion batteries (LIBs) have been commonly used in batteries for electric vehicles and smartphones because of their higher capacity, higher energy density, and longer life than other rechargeable batteries. The viewpoint of longer life in LIBs, Li4Ti5O12 (LTO) oxide anode is one of the possible alternative materials. LTO possesses less than 1% volume change property during charging and discharging, which prevents poor contact with active materials due to less cracking. Furthermore, LTO is operated at a high voltage of 1.55 V vs Li/Li+, so metallic Li dendrites do not grow. However, it is well known that side reactions such as SEI formation and gas generation are caused at the interface between the electrolyte and LTO. Therefore, in this study, in order to reduce side reactions at the interface, the LTO surface was coated with amorphous SiO2, which is electrochemically stable and inexpensive, to improve the rate and cycle characteristics. An amorphous SiO2-coated LTO (coated-LTO) was prepared by a sol-gel method using TEOS as the starting material. 5wt% and 10wt% of TEOS vs LTO were used to prepare coated LTO with different coating thicknesses. The obtained powders were analyzed by XRD, SEM/EDS, XPS, and AES for crystal structure and surface conditions. A 2032-type coin cell was fabricated for battery characterization. Li foil was used as the counter electrode and LiPF6 EC:DEC (3:7 vol%) as the liquid electrolyte. Charge-discharge measurements were carried out using CC-mode under a measured voltage range of 1.0 V to 3.0 V and a theoretical capacity of 175 mAh/g. To evaluate the C-rate performance of LIBs using coated-LTO, the C-rate was varied from 0.1C to 40C. In the cycle test, 1000 charge-discharge cycles were conducted at 3C, with 1 hour of OCV after charge and discharge in all cycles. EIS measurements were taken before and after charging and discharging to evaluate interfaces caused by side reactions. The results of the XRD analysis showed that the crystal structure was not disturbed by the coating, meaning that the coating did not destroy the LTO through the coating process. The average thickness of the SiO2 layer was 1-3 nm and 2-4 nm for the sample coated with TEOS at a concentration of 5wt% and 10wt% vs LTO, respectively. The C-rate performance of the charge-discharge test shows that the discharge capacity slightly decreased at low C-rate operation due to the coating, meaning that SiO2 should be a resistance of Li-ion migration at the interface. On the other hand, at high rates exceeding 2.0C, the discharge capacity of coated-LTO was higher than that of pure LTO. At 40C, the discharge capacity was approximately 80 mAh/g, suppressing energy loss at high C-rate operation. In the cycling test at 3C, only the sample coated with 10wt% coated-LTO achieved 1000 reversible cycles, and the capacity retention after 1000 cycles was 93.3%.(show in figure) The electrochemical impedance spectroscopy results should suggest that part of the improvement in battery properties was due to the prevention of SEI formation.

New 3D Current Collectors for Lithium-Ion Batteries

Lithium-ion batteries are among the most modern energy sources for consumer electronic devices. Each reversible lithium cell consists of components responsible for delivering charge and electrochemically inactive materials. The active components of a lithium-ion cell include electrode materials (such as graphite and lithiated cobalt oxide) and electrolyte. These compounds participate directly in the electrode reactions, generating the voltage and energy supplied by the battery. In addition to electrochemically active materials, lithium-ion cells contain several components that are not electrochemically active but perform important functions in the battery. Such components include the outer casing, internal and external leads, the separator, and the copper (for the negative electrode) and aluminium (for the positive electrode) current collectors. Current collectors are essential components connecting lithium-ion batteries to external circuits. They serve as a matrix that holds the active material in a mechanically stable form and are also involved in dissipating the charge generated by electrode processes. Thus, current collectors largely determine the capacity, performance, and long-term stability of lithium-ion batteries. Conventional current collectors, aluminium and copper foils, have been used since the first commercial lithium-ion battery. They account for about 15 percent by weight of the total cell, and because they are inactive components of the battery, there is a continuing need to reduce their mass share without losing functionality. Over the past two decades, in order to increase the energy density of lithium cells, the thickness of current collectors has decreased significantly. However, to further improve performance, alternative materials and structures are being explored, as well as specific collector treatments such as etching or carbon coating. These treatments aim to enhance the electrochemical stability and electrical conductivity of current collectors for the next generation of lithium-ion batteries with higher capacity and longer life. The presentation will review various types of current collector materials in terms of their electrochemical stability, electrical conductivity, mechanical properties, and durability. It will also include alternatives to traditional structures, such as 3D current collectors. Two types of three-dimensional current collectors will be presented: a 3D structure on a copper film collector and conductive porous carbon. The electrochemical properties of lithium-ion batteries utilizing these collectors will be demonstrated.