Power density

About: Power density is a research topic. Over the lifetime, 9534 publications have been published within this topic receiving 197264 citations. The topic is also known as: volumic power & volume power density.

Efficiency and power density potential of combustion-driven thermophotovoltaic systems using GaSb photovoltaic cells

Abstract: The renewed interest in thermophotovoltaic (TPV) energy conversion, based on recent progress in materials and photovoltaic (PV) cell technology, requires a new evaluation of the TPV efficiency and power density potential. In this paper, we address some important points in TPV system design. We proceed in three steps, analyzing 1) the thermodynamic limit, 2) an idealized, and 3) a realistic model, based on an extrapolation of the current state of technology. In a TPV system, the radiation converted to electricity is adapted to the spectral response of the PV cell. This can be achieved by different means, which are examined in detail. Broadband and selective radiators, and optical filters are considered. We focus on combustion driven systems using low bandgap GaSb PV cells. For a system containing GaSb cells and a radiator at 1500 K, we find a thermodynamic limit efficiency of 60.5% and an output power density of 3 W/cm/sup 2/. For an idealized system model, an efficiency of 34% and a power density of 2.2 W/cm/sup 2/ are determined. For a realistic system with a broadband radiator and a filter, 9% and 1.2 W/cm/sup 2/ are estimated; using a selective radiator without filter, 16% and 1 W/cm/sup 2/ are expected. Performance values of this order should be achievable with a sufficient development effort.

A 3D walking palm-like core-shell CoMoO4@NiCo2S4@nickel foam composite for high-performance supercapacitors.

Abstract: Supercapacitors are one of the most promising renewable-energy storage systems. In this study, a three-dimensional walking palm-like core–shell CoMoO4@NiCo2S4@nickel foam (NF) nanostructure was synthesized using a two-step hydrothermal method for high electrochemical performance. The as-prepared composite exhibited a high areal capacitance of 17.0 F cm−2 (2433 F g−1) at a current density of 5 mA cm−2 in a three-electrode system. The results revealed outstanding cycling stability of 114% after 10 000 charge–discharge cycles. An aqueous asymmetric supercapacitor device assembled with CoMoO4@NiCo2S4@NF and activated carbon (AC)@NF as the positive and negative electrodes, respectively, showed a high capacitance of 4.19 F cm−2 (182 F g−1) and delivered a high energy density of 60.2 W h kg−1 at a power density of 188 W kg−1 and a high power density of 1.5 kW kg−1 at an energy density 29.2 W h kg−1, lighting 22 parallel-connected red light emitting diodes for over 60 s. The synergistic effects of the core–shell CoMoO4@NiCo2S4@NF electrode material highlight the potential of this composite as an effective active material for supercapacitor applications.