Chemo-mechanics of iron phosphate cathode in alkali metal-ion batteries

Utilization of renewable energy sources requires the use of grid-scale stationary energy storage that requires low-cost, safe, and nontoxic systems. For these applications, “beyond” lithium-ion battery chemistries, such as sodium and potassium-ion batteries, are possible alternatives due to their abundance and lower cost. However, their larger ionic radius and chemical reactivity can cause performance degradation in the long-term because of chemo-mechanical instabilities. The main goal of the work is to elucidate the relationship between chemo-mechanics of different alkali-metal ion intercalation and chemo-physical response of electrode materials. Investigation of this phenomena carried out by utilizing in-situ strain measurement coupled with in-situ XRD, HR-TEM, and mathematical model. First stage of the investigation focused on the effect of different alkali metals on the same host structure. Initial findings indicated that iron phosphate host structure experienced larger-than-expected expansion during first lithium and sodium intercalation, which became more reversible in subsequent cycles. During potassium intercalation, in-situ XRD and HR-TEM results showed the amorphization of iron phosphate structure. By employing DIC technique, reversible deformations in the amorphous phase was tracked during electrochemical redox reaction. Comparing the effect of these alkali metal on redox chemistry and mechanical deformation showed that strain rate, instead of absolute value of the strain, is critical factor in the amorphization of crystal structure. Second stage of the research focused on the effect of cycling rate on the mechanical deformation of electrode materials. In-situ strain measurements, coupled with GITT analysis and transport-mechanics model indicated that, lower diffusivity of sodium in the cathode results in the steep concentration gradient and misfit strain generation at faster scan rates. In the case of lithium intercalation, in situ strain measurements during pulsed current charge/discharge experiments indicated that at faster scan rates, phase transformation was delayed. In the last stage, DIC system was employed to investigate mechanical deformation of LAGP solid electrolyte for all-solid-state battery applications. During this study, increase strains at the metal/solid electrolyte interphase coincided with increase in the overpotential. This result experimentally showed the relationship between overpotential generation and strain evolution between metal/solid electrolyte interphase. These findings indicate that 1) strain rate is critical to the amorphization of crystal structure and 2) chemical reactivity of different alkali metals cause difference in mechanical response of electrode materials when batteries cycled at different scan rates. Understanding the similarities and differences between alkali metals on mechanical deformation will provide new insights into the selection of battery materials for beyond lithium-ion battery applications

How to make a battery

Background: The steady increase in the consumption of fossil fuels in modern society has caused several serious environmental and human health issues. The burning of fossil fuels not only produces carbon dioxide emissions, which are contributing to global warming and poisoning the world’s oceans but also releases toxic air-borne pollutants into the atmosphere4,5. Most commercial batteries are currently being mass-produced to power personal electronics, store renewable energy, and more recently, power electric automobiles. I believe we can utilize them for even more, but to do that we must understand, deeply, how a battery works.Research Objective: Learn the chemistry process of a battery, so I can test the concept of toxic diesel soot being recycled and used in a Na-ion battery to make more affordable batteries and create sustainable material sources by harvesting industrial waste as a valuable material for batteries.Research Plan: Through this research, I will learn to manufacture Na-ion batteries as well as test them using cyclic voltammetry and galvanostatic cycling. The learning process involves the fabrication of composite electrodes, usage of glove boxes, assembly of coin battery cells, and executing electrochemical measurements. I will closely work with the graduate students in the group. The performance of the diesel soot anode will be tested at various scan rates and an electrolyte environments.Expected Results: With the chemical knowledge behind the battery I can begin to see which technique provides the highest quality harvested ship soot carbon, there will be enormous opportunities to fabricate more affordable Na-ion batteries for grid-scale storage. Furthermore, with an established high-quality baseline the progress of sodium-ion battery research can only increase allowing earlier entrance into the commercial and industrial worlds. This ultimately results in a cheaper, more available energy source for the masses.Oklahoma Louis Stokes Alliance for Minority Participation ProgramNational Science Foundation (U.S.)Chemical Engineerin

The relationship between Chlamydophila pneumoniae IgG titer and coronary atherosclerosis

Background: The role of Chlamydophila pneumoniae (CP) in the progression of atherosclerosis is controversial. Also no sufficient angiographic study is available about the impact of CP infection on severity and intensity of coronary atherosclerosis. We investigated the relation between CP IgG antibody titers and severity and intensity of coronary atherosclerosis Methods: The study population consisted of 516 consecutive patients who underwent a coronary angiography. The group included 353 patients who had coronary artery disease; a control group included 163 subjects with angiographically proven normal coronary arteries. Chlamydophila pneumoniae IgG antibody titers were measured by an enzyme immunoassay method in all patients. Gensini scores and extent scores were used to evaluate the angiographic extent and severity of atherosclerosis. Results: The mean value of IgG antibody titer was 44.3 &#177; 28.8 IU/mL in the patients and 39.8 &#177; 27.4 IU/mL in the control group (p = 0.14). There was no statistically significant correlation between the Gensini scores, extent scores and CP IgG titers (Gensini score: r = +0.103, p = 0.07, extent score: r = +0.110, p = 0.31). When we grouped the patients as high (> 50 IU/mL) and low (< 50 IU/mL) IgG antibody titers, the number of diseased coronary arteries was higher in patients with high IgG antibody titers (respectively: 2.6 &#177; 1.1 vs. 2.2 &#177; 0.8, p = 0.01). While the Gensini score was significantly higher in patients with high IgG antibody titers (7.5 &#177; 4.0 vs. 6.17 &#177; 4.0, p = 0.01), the extent score did not change with IgG titers (29.8 &#177; 15.9 vs. 25.8 &#177; 15.4, p = 0.08). Conclusions: In our study, we investigated the relation between CP infection and coronary atherosclerosis and found that CP IgG antibody titers are associated with the severity of coronary stenosis at higher antibody levels. However, there is no association between CP antibody titers and clinical presentation of coronary artery disease. We suggest that CP has limited effect on coronary atherosclerosis. (Cardiol J 2008; 15: 245-251

Improved arterial stiffness in mitral stenosis after successful percutaneous balloon valvuloplasty

Background: Rheumatic mitral stenosis (MS) is still a common disease in developing countries with high morbidity and mortality rates. The purpose of the study was to evaluate arterial stiffness in severe MS before and after percutaneous mitral balloon valvuloplasty (PMBV). Methods: Thirty patients with MS in sinus rhythm requiring PMBV and 20 age-gender matched healthy volunteers. The analyze of pulse wave velocities (PWV) were performed using of the carotid artery at the femoral by PWV technique on patients at baseline and a week after PMBV. Results: The values of PWV were significantly decreased after successful PMBW in MS patients. Mitral mean gradients and systolic pulmonary artery pressures (sPAP) both on echocardiography and catheterization also had a significant decrease after PMBW. The mitral valve areas were significantly increased after PMBW. There was a highly significant negative correlation between mitral valve areas and PWV values. A highly significant positive correlation was seen between mitral mean gradient on catheterization and PWV (r = 0.830, p < 0.001). There was also a significant correlation between sPAP on catheterization and PWV values (r = 0.639, p < 0.001). Echocardiographic mitral mean gradients and PWV were highly positive correlated with each other (r = 0.841, p < 0.001). The sPAP on echocardiography had also a highly positive correlation with PWV (r = 0.681, p < 0.001). Conclusions: Mitral stenosis is a cause of impaired arterial stiffness and after the enlargened mitral valve area arterial stiffness improved in patients with MS

Thrombus in Transit within a Patent Foramen Ovale: Gone with the Cough!

Pulmonary embolism and concomitant right atrial thrombus entrapped in a patent foramen ovale (PFO) is a rare, unusual finding in echocardiography. The diagnosis of paradoxical embolism is usually presumptive when PFO is detected by echocardiography. We herein reported a case of a 53-year-old patient presenting with pulmonary embolism in which a thrombusin-transit through a PFO was found and disappeared during transesophageal echocardiography

Recycling diesel combustion byproducts as conductive additives in lithium-ion battery cathodes

Lithium-ion batteries (LIBs) are the most widely industrialized form of portable, rechargeable energy storage in over three decades. LIBs commonly use Super P carbon as a conductive additive. Super P is chemically similar to industrial waste produced via diesel combustion, and therefore shares chemical properties with diesel soot. Here we show how diesel soot particulate matter obtained postcombustion can be used as a conductive additive in LIBs.Lew Wentz FoundationChemical Engineerin

Multilab Direct Replication of Flavell, Beach, and Chinsky (1966): Spontaneous Verbal Rehearsal in a Memory Task as a Function of Age

Work by Flavell, Beach, and Chinsky indicated a change in the spontaneous production of overt verbalization behaviors when comparing young children (age 5) with older children (age 10). Despite the critical role that this evidence of a change in verbalization behaviors plays in modern theories of cognitive development and working memory, there has been only one other published near replication of this work. In this Registered Replication Report, we relied on researchers from 17 labs who contributed their results to a larger and more comprehensive sample of children. We assessed memory performance and the presence or absence of verbalization behaviors of young children at different ages and determined that the original pattern of findings was largely upheld: Older children were more likely to verbalize, and their memory spans improved. We confirmed that 5- and 6-year-old children who verbalized recalled more than children who did not verbalize. However, unlike Flavell et al., substantial proportions of our 5- and 6-year-old samples overtly verbalized at least sometimes during the picture memory task. In addition, continuous increase in overt verbalization from 7 to 10 years old was not consistently evident in our samples. These robust findings should be weighed when considering theories of cognitive development, particularly theories concerning when verbal rehearsal emerges and relations between speech and memory

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)