A Redox-Robust Ceramic Anode-Supported Low-Temperature Solid Oxide Fuel Cell.

A critical factor hampering the deployment of fuel-flexible, low-temperature solid oxide fuel cells (LT-SOFCs) is the long-term stability of the electrode in different gas environments. Specifically, for state-of-the-art Ni-cermet anodes, reduction/oxidation (redox) cycles during fuel-rich and fuel-starved conditions cause a huge volume change, eventually leading to cell failure. Here, we report a robust redox-stable SrFe0.2Co0.4Mo0.4O3 (SFCM)/Ce0.9Gd0.1O2 ceramic anode-supported LT-SOFC with high performance and remarkable redox stability. The anode-supported configuration tackles the high ohmic loss associated with conventional ceramic anodes, achieving a high open circuit voltage of ∼0.9 V and a peak power density of 500 mW/cm2 at 600 °C in hydrogen. In addition, ceramic anode-supported SOFCs are stable over tens of redox cycles under harsh operating conditions. Our study reveals that oxygen nonstoichiometry of SFCM compensates for the dimensional changes that occur during redox cycles. Our results demonstrate the potential of all ceramic cells for the next generation of LT-SOFCs.

Highly Performing Chromate-Based Ceramic Anodes (Y0.7Ca0.3Cr1- xCu xO3-δ) for Low-Temperature Solid Oxide Fuel Cells.

Exploitation of alternative anode materials for low-temperature solid oxide fuel cells (LT-SOFCs, 350-650 °C) is technologically important but remains a major challenge. Here we report a potential ceramic anode Y0.7Ca0.3Cr1- xCu xO3-δ ( x = 0, 0.05, 0.12, and 0.20) (YCC) exhibiting relatively high conductivity at low temperatures (≤650 °C) in both fuel and oxidant gas conditions. Additionally, the newly developed composition (YCC12) is structurally stable in reducing and oxidizing gas conditions, indicating its suitability for SOFC anodes. The I- V characteristics and performance of the ceramic anode infiltrated with Ni-(Ce0.9Gd0.1O2-δ)(GDC) were determined using GDC/(La0.6Sr0.4CoO3-δ)(LSC)-based cathode supported SOFCs. High peak power densities of ∼1.2 W/cm2 (2.2A/cm2), 1 W/cm2 (2.0A/cm2), and 0.6 W/cm2 (1.3 A/cm2) were obtained at 600, 550, and 500 °C, respectively, in H2/3% H2O as fuel and air as oxidant. SOFCs showed excellent stability with a low degradation rate of 0.015 V kh-1 under 0.2 A/cm2. YCC-based ceramic anodes are therefore critical for the advancement of LT-SOFC technology.

Nanointegrated, High-Performing Cobalt-Free Bismuth-Based Composite Cathode for Low-Temperature Solid Oxide Fuel Cells.

Cost-effective cathodes that actively catalyze the oxygen reduction reaction (ORR) are one of the major challenges for the technological advancement of low-temperature solid oxide fuel cells (LT-SOFCs). In particular, cobalt has been an essential element in electrocatalysts for efficiently catalyzing the ORR; nevertheless, the cost, safety, and stability issues of cobalt in cathode materials remain a severe drawback for SOFC development. Here, we demonstrated that by appropriate nanoengineering, we can overcome the inherent electrocatalytic advantages of cobalt-based cathodes to achieve comparable performance with a cobalt-free electrocatalyst on a bismuth-based fast oxygen ion-conducting scaffold that simultaneously enhances the performance and stability of LT-SOFCs. Consequently, the peak power density of the SOFCs reaches 1.2 W/cm2 at 600 °C, highest performance of a cobalt-free-based cathode that has been ever reported. In addition, by the surface-protecting effect of covered nanoelectrocatalysts, the evaporation of highly volatile bismuth is greatly suppressed, resulting in an 80% improvement in performance durability, the best among all reported bismuth-based fuel cells.

The watt or Kibble balance: a technique for implementing the new SI definition of the unit of mass.

The redefinition of the SI unit of mass in terms of a fixed value of the Planck constant has been made possible by the Kibble balance, previously known as the watt balance. Once the new definition has been adopted, the Kibble balance technique will permit the realisation of the mass unit over a range from milligrams to kilograms. We describe the theory underlying the Kibble balance and practical techniques required to construct such an instrument to relate a macroscopic physical mass to the Planck constant with an uncertainty, which is achievable at present, in the region of 2 parts in 108. A number of Kibble balances have either been built or are under construction and we compare the principal features of these balances.

Is psychological distress in people living with cancer related to the fact of diagnosis, current treatment or level of disability? Findings from a large Australian study.

OBJECTIVE: To investigate whether the observed elevated levels of psychological distress in cancer survivors relate specifically to aspects of cancer diagnosis, to treatment or to disability. DESIGN, PARTICIPANTS AND SETTING: Self-reported questionnaire data on demographic, health and lifestyle factors and mental health from 89574 Australian men and women aged 45 years or older, sampled from the Medicare database for the 45 and Up Study from 1 February 2006 to 30 April 2008. Logistic regression was used to examine the risk of high levels of psychological distress in relation to cancer diagnosis and disability, adjusting for age, sex, income and education. MAIN OUTCOME MEASURE: High psychological distress (Kessler Psychological Distress Scale score > or = 22). RESULTS: Overall, 7.5% of participants had high levels of psychological distress. Among cancer survivors, the median time since diagnosis was 7.3 years. Compared with people without cancer, the odds ratios (95% CIs) for psychological distress were: 1.17 (1.09-1.26) in people reporting having had any cancer apart from non-melanoma skin cancer; 1.34 (1.08-1.67) in those with cancer diagnosed in the previous year; 1.53 (1.33-1.76) for those reporting treatment for cancer in the previous month and 1.11 (1.03-1.19) for those with cancer but without recent treatment. Using individuals with neither cancer nor disability as the reference group, the adjusted odds ratio (95% CI) for psychological distress was 6.51 (5.95-7.12) in those reporting significant disability but no cancer, 1.14(1.04-1.24) in those without disability but with cancer and 5.81(4.88-6.91) in those with both cancer and disability. CONCLUSION: The risk of psychological distress in individuals with cancer relates much more strongly to their level of disability than it does to the cancer diagnosis itself.