Development of aqueous ion-intercalation battery systems for high power and bulk energy storage

Philosophiae Doctor - PhDAqueous ion-intercalation batteries (AIB’s) have the potential to provide both high power for hybrid-electric transport, and low cost bulk energy storage for electric grid supply. However, a major setback to AIB development is the instability of suitable ionintercalation anode material in aqueous electrolyte. To counter this problem, the use of activated carbon (AC) (a supercapacitor anode) paired against the low cost ionintercalation cathode spinel LiMn2O4 (LMO) provides a stable alternative. This thesis comprises two novel areas of investigation concerning: (1) the development of the AC/LMO cell for high power applications, and (2) the introduction of PbSO4 as a high capacity alternative anode material paired against LMO for low cost bulk energy storage. The study on AC/LMO explores the electrode combination’s practical specific energy and power capability at high P/E (power to energy ratio) of 50:1 suitable for hybrid electric vehicle batteries. To study the relationship between electrode material loading density, active material performance, and current collector mass contribution, a specially designed cell was constructed for galvanic cycling of different thicknesses of electrode. Between a loading density range of 25 – 100 mg, ~50 mg of total active material between two 1 cm2 current collectors produced the highest 50:1 P/E ratio values of 4 Wh/kg and 200 W/kg, constituting a 4-fold reduction of the active material values of thin films at 50:1 P/E. The cycling potentials of the individual electrodes revealed that doublings of electrode film loading density increased the LMO electrode’s polarization and voltage drop to similar levels as doublings in applied current density. However, by increasing the charging voltage from 1.8 V to 2.2 V, 6 Wh/kg and 300 W/kg was obtainable with minimal loss of energy efficiency. Finally a large-format cell of a calculated 3 Ah capacity at 50:1 P/E was constructed and tested. The cell produced ~60% of the anticipated capacity due to a suspected high level of resistance in the electrode contact points. The overall conclusion to the study was that AC/LMO holds promise for high power applications, and that future use of higher rate capability forms of LMO offers a promising avenue for further research. v The second part of this thesis presents the development of a novel cell chemistry, PbSO4/LMO, that has yet to be reported elsewhere in existing literature. The cell uses aqueous pH 7, 1 M, Li2SO4 electrolyte, and forms an electrode coupling where the PbSO4 anode charge/discharge is analogous to that in Pb-acid batteries. The average discharge voltage of the cell was 1.4 V and formed a flat charge/discharge plateau. The use of a low cost carbon coating method to encapsulate PbSO4 microparticles had a marked improvement on cell performance, and compared to uncoated PbSO4 improved both rate capability and specific capacity of the material. The active materials of the carbon-coated PbSO4/LMO cell produced a specific energy 51.1 Wh/kg, which, if a 65% yield is possible for a practical cell format, equals 38.4 Wh/kg, which is 15 Wh/kg higher than AC/LMO bulk storage cells at 23 Wh/kg, but lower than Pb-acid batteries at ~25-50 Wh/kg. Interestingly, the specific capacity of PbSO4 was 76 mAh/g compared to 100 mAh/g in Pb-acid cells. The predicted cost of the cell, providing a 65% value of the active material specific energy for a practical cell can be realized, is on par with Pb-acid battery technology and, importantly, uses 2.3 × less Pb/kWh. The cycling stability achieved thus far is promising, but will require testing over comparable cycle life periods to commercial batteries, which could be anywhere between 5 – 15 years

Development of a small-scale electro-chlorination system for rural water supplies

>Magister Scientiae - MScTo address the urgent need for safe potable water in South Africa’s rural areas, sustainable systems for water disinfection at the village-scale of operation are required.In this thesis, the development of a small-scale water chlorination system that runs on salt and solar panels is described. The system combines a membrane-based hypochlorite generator, or “membrane electrolyser”, with an automated hypochlorite dosing system.The system was designed to (i) coordinate hypochlorite production and dosing automatically in a flow-through system, and (ii) fit inline with low pressure pipelines from overhead storage tanks or raised water sources. Low cost materials were used for construction, and water-powered mechanisms were devised to control both brine supply to the electrolyser and regulation of water flow. The capacity of the system was based on the maximum daily output of the electrolyser at ~20 g of sodium hypochlorite. This was sufficient chlorinate up to 10 kL of water per day using less than 80 g of salt and less than 0.1 kW.h of electricity. The cost of the system was estimated at ~R10 000 and therefore potentially affordable for communities up to 100 people, e.g. small farms and villages.Testing of the system was carried out at a farm site in Worcester (Western Cape) using remote monitoring of current levels in the electrolyser. Operation of the system over a two month test period, dosing at ~4 mg/L, produced consistent chlorination measured as(FAC). Community participation in maintenance of the brine supply was managed and chlorinated water was made available to the community after a brief social survey was conducted. Community awareness of chlorination was minimal. No significant history of diarrhoea was reported. However, the community regularly boiled their tap water in response to turbidity increase in summer.The system was affected by turbidity increase in the local water, which caused a drop in electrolyser current and chlorine production due to particle blockage of the membrane in the electrolyser. However, turbidity at acceptable levels for chlorination was found to have no detrimental effect on the system’s performance. The system showed promise for rural implementation providing low turbidity was maintained. Therefore,groundwater sites, and surface waters with appropriate clarification systems are recommended for the system’s installation. Further testing of the system will be required to establish its long term viability in the hands of a rural community

An Fe@Fe3C-inserted carbon nanotube/graphite composite supportproviding highly dispersed Pt nanoparticles for ethanol oxidation

Iron/iron carbide-inserted carbon nanotube/graphite composite (Fe-C) was prepared by pyrolyzing amixture of melamine and iron (III) chloride to form a support for high loading of Pt nanoparticles as adirect ethanol fuel cell anode catalyst. The obtained Fe-C was characterized by Raman spectroscopy, X-raydiffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The Fe-C surfacecharacteristics supported a high (40 wt%) loading of Pt nanoparticles with uniform dispersion and smallparticle size. Compared to Vulcan carbon-supported Pt (40 wt%), Fe-C-supported Pt exhibited enhancedcatalytic activity for CO and ethanol oxidation, and high stability due to the effect of the Fe-C supportmaterial

Palygorskite hybridized carbon nanocomposite as a high-performance electrocatalyst support for formic acid oxidation

A nanocomposite, in which acid-treated palygorskite was hybridized with carbon, was prepared and designed as an efficient support for electrocatatlysts. Pd nanoparticles were deposited on the hybrid support as an electrocatalyst for formic acid oxidation. The hybrid supports and electrocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS).TEMandXRDresults showed that acid treatment had an effective impact on the morphology of palygorskite, but did not destroy its architecture. XPS results indicated that the introduction of palygorskite resulted in a negative shift of binding energy of Pd deposited on it. The electrochemical results showed that the addition of palygorskite into the carbon facilitated the formation ofOHads orOads on the surface of Pd/C-PLS, and further improved the formic acid electrooxidation activity. Therefore, considerable improvements in electrocatalytic activity toward formic acid oxidation was achieved by using this hybrid support when compared with conventional carbon support, suggesting that the introduction of SiO2-based porous palygoriskite was an excellent and cost-efficient way to improve the electrocatalytic performance of carbon support.Web of Scienc

The effect of PtRuIr nanoparticle crystallinity in electrocatalytic methanol oxidation

Two structural forms of a ternary alloy PtRuIr/C catalyst, one amorphous and one highly crystalline, were synthesized and compared to determine the effect of their respective structures on their activity and stability as anodic catalysts in methanol oxidation. Characterization techniques included TEM, XRD, and EDX. Electrochemical analysis using a glassy carbon disk electrode for cyclic voltammogram and chronoamperometry were tested in a solution of 0.5 mol L−1 CH3OH and 0.5 mol L−1 H2SO4. Amorphous PtRuIr/C catalyst was found to have a larger electrochemical surface area, while the crystalline PtRuIr/C catalyst had both a higher activity in methanol oxidation and increased CO poisoning rate. Crystallinity of the active alloy nanoparticles has a big impact on both methanol oxidation activity and in the CO poisoning rate

cGMP Recombinant FIX for IV and Oral Hemophilia B Therapy

Three specific aims are proposed: Specific Aim # 1. Process engineer and scale-up the recovery and purification of transgenic recombinant human Factor IX. The University of Nebraska-Lincoln Biological Process Development Facility will complete process development and scale-up, and produce clinical grade materials for preclinical studies. The endpoint is a proposed final product specification to help facilitate transfer to current Good Manufacturing Practices compliant production of clinical grade material to support an Investigational New Drug filing with the United States Food and Drug Administration (FDA) leading to clinical trials. Specific Aim #2. Characterize and formulate transgenic recombinant human Factor IX for intravenous dosage, and evaluate in a hemophilia B dog model. These activities are directed toward characterization of the product important to assure the provision of safe and reproducibly effective hemostasis. The results of these investigations will help support an IND filing with the FDA. Specific Aim # 3. Develop an oral dosage form of transgenic recombinant human Factor IX, and evaluate in hemophilia B mice and dog models. Oral administration of coagulation therapy will obviate the invasiveness, discomfort, potential for opportunistic infection, and complications of storage and supplies that accompany intravenous administration. Oral dosage forms of Factor IX will thus greatly increase the proportion of the patient population that can be treated. There is also published evidence suggesting that oral administration may reduce the potential for complicating immune responses to replacement therapy, especially in patients with severe hemophilia

Urinary tract reconstruction: Applied urodynamics

Sixty-four patients underwent urinary reconstruction guided by urodynamic investigation. Twenty-eight patients had myelodysplasia (MM) and 26 had spinal cord injuries (SCI). Operative outcomes were assessed by repetitive urodynamic testing. Bladder reservoir function and detrusor contractile activity were correctly assessed in all 64 patients. Operative creation of a more adequate reservoir was required in 58 patients. Assessment of urethral continence function was inaccurate in six instances wherein we judged urethral sphincter function adequate when, in fact, it was not. Ureteral function was judged radiographically or by furosimide renography, or Whitaker perfusion testing. In the two instances where ureteral function was in doubt, it made no difference in outcome. There was a striking resolution of ureteral radiographic abnormalities after reconstruction which we attribute to the low-pressure reservoir.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38471/1/1930090507_ftp.pd

Graphite-anchored lithium vanadium oxide as anode of lithium ion battery

Graphite-anchored lithium vanadium oxide (Li1.1V0.9O2) has been synthesized via a “one-pot” in situ method. The effects of the synthesis conditions, such as the ratio of reaction components and calcination temperature, on the electrochemical performance are systematically investigated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), galvanostatic discharge/charge tests and differential scanning calorimetry (DSC). Compared with the simple mixture of graphite and lithium vanadium oxide, the graphite-anchored lithium vanadium oxide delivers an enhanced reversible capacity, rate capability and cyclic stability. It also shows better thermal stability.Web of Scienc

Nitrogen-doped carbon coated ZeO2 as a support to Pt nanoparticles in the oxygen reduction reaction

A new nitrogen-doped carbon (CNx) support for Pt electrocatalysts was prepared by carbonizing polypyrrole on the surface of ZrO2 (ZrO2@CNx) at high temperature. Well-dispersed Pt nanoparticles were easily formed on the ZrO2@CNx. The electrocatalyst was characterized by FT-IR, XRD, TEM, XPS. The electrochemical performances indicate that the presence of ZrO2 modified the electro-structure of Pt on the catalyst surface and that ZrO2@CNx had superior oxygen reduction activity compared to a nitrogen-doped carbon coated carbon (C@CNx).Web of Scienc

Reasons to Be Skeptical about Sentience and Pain in Fishes and Aquatic Invertebrates

The welfare of fishes and aquatic invertebrates is important, and several jurisdictions have included these taxa under welfare regulation in recent years. Regulation of welfare requires use of scientifically validated welfare criteria. This is why applying Mertonian skepticism toward claims for sentience and pain in fishes and aquatic invertebrates is scientifically sound and prudent, particularly when those claims are used to justify legislation regulating the welfare of these taxa. Enacting welfare legislation for these taxa without strong scientific evidence is a societal and political choice that risks creating scientific and interpretational problems as well as major policy challenges, including the potential to generate significant unintended consequences. In contrast, a more rigorous science-based approach to the welfare of aquatic organisms that is based on verified, validated and measurable endpoints is more likely to result in “win-win” scenarios that minimize the risk of unintended negative impacts for all stakeholders, including fish and aquatic invertebrates. The authors identify as supporters of animal welfare, and emphasize that this issue is not about choosing between welfare and no welfare for fish and aquatic invertebrates, but rather to ensure that important decisions about their welfare are based on scientifically robust evidence. These ten reasons are delivered in the spirit of organized skepticism to orient legislators, decision makers and the scientific community, and alert them to the need to maintain a high scientific evidential bar for any operational welfare indicators used for aquatic animals, particularly those mandated by legislation. Moving forward, maintaining the highest scientific standards is vitally important, in order to protect not only aquatic animal welfare, but also global food security and the welfare of humans