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[en] Highlights: • A new design for DCNB with sub-micrometer thickness radiation source, both-side emission and collection. • The energy conversion efficiency of DCNB with this design may reaches over 20% in theory. • This work will establish a theoretical foundation for application of DCNBs in the future. - Abstract: Direct charging nuclear batteries (DCNB) have the potential of being widely used to meet the special requirements in the area of aerospace and ocean. The current application of direct charging nuclear batteries is restricted by the low energy conversion efficiency, commonly less than 10%. This low efficiency is limited mainly by issues of low source efficiency and shunt factor among others, such as collection and geometry factors. Based on a numerical simulation and empirical calculations we here propose a design of DCNB by utilization of a sub-micrometer thickness radiation source to increase the source efficiency, both-side emission, and collection of decay particles to improve the collection and geometry factors, as well as impedance matching of batteries and load to improve the shunt factor, among other various optimizations. The energy conversion efficiency of DCNB with this design reaches over 20%. The successful deployment of the current design should vastly improve the energy conversion efficiency of DCNBs, and also establish a theoretical foundation for extending the scope of applications of DCNBs in the future.
[en] In this paper, we review the fuel cell innovative technologies announced at Fuel Cell Seminar & Energy Exposition 2017, where the whole process of hydrogen energy is discussed. Reviewing area is listed as follows: fuel pre-treatment, material processing, component production/connection, system design, and operation control. The main contents of reviewed innovative technologies are as follows. 1) Passive sorbent systems provide a simple solution for desulfurization. 2) High velocity forming through adiabatic softening cuts manufacturing cost of metal bipolar plates. 3) Coating using functional materials solves the durability issue of metals bipolar plates. 4) Using low sealing stress compression gasket enhances compatibility with high-temperature fuel cells. 5) Regenerative fuel cell system simplifies the configuration of fuel cell and electrolysis systems. 6) Periodic current interruption enables the sustainable operation of direct hydrocarbon-fueled low-temperature fuel cells.
[en] The wide-bandgap semiconductors, which have the advantages of radiation resistance and high carrier mobility, have gained increased research attention in recent years for the conversion nuclear battery. Nevertheless, when a wide-bandgap semiconductor is used, the collection efficiency and current are reduced, even though the open circuit voltage is increased. In this research, a heterojunction photovoltaic cell is used to increase collection efficiency and power in the betavoltaic battery. A theoretical investigation of the electrical performance has been carried out on Ni63/GaN and Ni63/GaN-Si betavoltaic cells. The effects of doping concentration and junction depth on the maximum power are examined. By optimizing the doping concentration and junction depth, a high-efficiency heterojunction betavoltaic microbattery can be achieved. The maximum power is calculated as 22.90 nW/cm2 using 1 mCi Ni63 beta source and GaN-Si heterojunction with junction depth of 0.1 μm and doping concentrations of Na = 4 × 1017 cm-3 and Nd = 4 × 1016 cm-3 in the emitter and the base region, respectively. (author)
[en] We demonstrate that it is technologically possible to obtain graphite-like films which can be used for the creation of a thermoelectric generator. The proposed technology ensures uniformity and rather small thickness of these films and allows them to be formed on a diamond-like film substrate with deposited contacts at acceptable interface. Measurements show that the electron-phonon drag effect in this system ensures thermo-emf values about 100 times as large as those provided by the diffusion process. Arrangement of the graphite-like material on a diamond-like film substrate also favors increase in the thermo-emf, which is a manifestation of the electron–ballistic phonon drag. It is established that conditions necessary for the creation of a thermoelectric generator can be achieved based on the proposed carbon nanostructures.
[en] Microbial fuel cells and biophotovoltaics represent promising technologies for green bioelectricity generation. However, these devices suffer from low durability and efficiency that stem from their reliance on living organisms to act as catalysts. Such limitations can be overcome with augmented capabilities enabled by nanotechnology. This review presents an overview of the different nanomaterials used to enhance bioelectricity generation through improved light harvesting, extracellular electron transfer, and anode performance. The implementation of nanomaterials in whole-cell energy devices holds promise in developing bioelectrical devices that are suitable for industry. .
[en] In this work, the optimal conditions for assembling a fuel cell containing membranes of different parameters and from different manufacturers were studied. Influence of membrane thickness, glass transition temperature and equivalent mass of ionomer used for membrane production was studied. Individual fuel cells were characterized in terms of their total ohmic resistance and maximum achieved power. (authors)
[en] Star-shaped small molecule has lots of fascinating advantages compare with the linear small molecule. In this paper, two star-shaped small-molecules (S-TT and S-TT-R) with vinyl trithiophene with or without alkyl substituents as core, N-ethylrhodanine as terminal and withdrawing groups, vinyl as bridge group were synthesized by different synthetic routes. Both of the two materials demonstrate high thermal stability and broad absorption. Both S-TT and S-TT-R exhibit narrow bandgap (1.72 and 1.82 eV), low LUMO energy levels (− 3.92 eV) for S-TT and high HOMO energy levels (− 5.37 eV) for S-TT-R which could be applied as acceptor or donor materials for photovoltaics, respectively. Both of the two compounds were used as donor materials with PC61BM acceptor and S-TT were used as acceptor material with P3HT donor.
[en] Self-powered wearable electronics have attracted extensive attention due to the limited power supply of traditional batteries. Small sized and flexible thermoelectric generators (TEGs) can harvest body heat and convert it into electricity, which is a promising approach to obtain a sustainable power source for wearable electronics. This paper develops a self-powered wearable ultraviolet index (UVI) detector, which is enabled by using a flexible TEG as the power supply. The design of the wearable UVI detector, including the driven circuit, voltage conversion and UVI detection modules are presented. The step-up chip is utilized in the voltage conversion module to boost the relatively low voltage, which is generated by the TEG. The output power is stored by the capacitors, which can wake up the UVI sensor for detection periodically. Then, the prototype UVI detector is fabricated and its detection performances are characterized. Wrist wearing experiments showed that the wearable UVI detector can be successfully self-powered by harvesting human body heat. Also, the proposed wearable UVI detector can measure the environmental UVI under different weathers and protections, which can provide a reference for the daily dressing and healthcare applications. (paper)
[en] An abundant source of energy is available in solar radiation which could be used for the generation of electrical energy. This research paper investigates a new method for the conversion of solar thermal energy into electrical energy. This method uses the Thermoelectric Generator (TEG) coordinated with the Phase Change Material (PCM). To enhance the performance of solar TEG, Solar radiation is focused on the Fresnel lens and solar concentrator. The output obtained from the solar concentrator is more than from the Fresnel lens. From the concentrator, 1.38 V is generated with a hot side TEG temperature of 195 °C and a cold side temperature of 62 °C in the day time and the off radiation maximum potential of 134 mv. The proposed system can harvest a maximum voltage of about 1.38 volts and 0.17Watts of power during day time. (paper)