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.

Low‐Temperature Micro‐Solid Oxide Fuel Cells with Partially Amorphous La0.6Sr0.4CoO3‐δ Cathodes

Abstract: Partially amorphous La0.6Sr0.4CoO3-δ (LSC) thin-film cathodes are fabricated using pulsed laser deposition and are integrated in free-standing micro-solid oxide fuel cells (micro-SOFC) with a 3YSZ electrolyte and a Pt anode. A low degree of crystallinity of the LSC layers is achieved by taking advantage of the miniaturization of the cells, which permits low-temperature operation (300–450 °C). Thermomechanically stable micro-SOFC are obtained with strongly buckled electrolyte membranes. The nanoporous columnar microstructure of the LSC layers provides a large surface area for oxygen incorporation and is also believed to reduce the amount of stress at the cathode/electrolyte interface. With a high rate of failure-free micro-SOFC membranes, it is possible to avoid gas cross-over and open-circuit voltages of 1.06 V are attained. First power densities as high as 200–262 mW cm−2 at 400–450 °C are achieved. The area-specific resistance of the oxygen reduction reaction is lower than 0.3 Ω cm2 at 400 °C around the peak power density. These outstanding findings demonstrate that partially amorphous oxides are promising electrode candidates for the next-generation of solid oxide fuel cells working at low-temperatures.

Hierarchical CoMoO4@Co3O4 nanocomposites on an ordered macro-porous electrode plate as a multi-dimensional electrode in high-performance supercapacitors

Abstract: Nanoscale core–shell CoMoO4@Co3O4 composite materials are fabricated by a multi-step hydrothermal process on the surface and side wall of an ordered macro-porous electrode plate (OMEP) as the active electrode in a high power density storage device. The morphology, formation mechanism of the CoMoO4@Co3O4 nanostructure, and capacitor performance are systematically studied. The CoMoO4@Co3O4/OMEP electrode has a capacity of 7.13 F cm−2 (1168.0 F g−1) at a constant current density of 0.6 A g−1 and a retention ratio of 81.4% after 5000 cycles. The large specific capacitance and excellent rate capability can be attributed to the unique 3D ordered porous architecture which facilitates electron and ion transport, enlarges the liquid–solid interfacial area, prevents agglomeration of nanomaterials, and boosts the utilization efficiency of the active materials. Reconstruction on the surface of the porous structured substrate enhances the power density and cycling performance at large current densities. Using the CoMoO4@Co3O4/OMEP electrode as the positive electrode and active carbon/nickel foam (AC/NF) as the negative electrode, the electrochemical electrode packaged in a CR2025 battery cell as a miniature hybrid device exhibits stable power characteristics (10 000 cycles with 91.7% retention at a current of 0.1 A). The device produces large instantaneous power that charging it for 10 s and using three devices in series can power four parallel LED arrays at a current of 0.152 A.

Performance of a Porous Electrolyte in Single-Chamber SOFCs

Abstract: A cell which consists of a porous 18 μm thick Y-doped ZrO 2 (YSZ) electrolyte (23 ′ 3 vol % open porosity) on a NiO-YSZ anode substrate and a cathode using (La, Sr)(Co, Fe)O 3 has been investigated in the single-chamber configuration. The cell performance and catalytic activity of the anode was measured in a flowing air-methane gas mixture with various flow rates. The results showed that the open-circuit voltage and the power density increased as the gas flow rate increased. The cell generated an open-circuit voltage of about 0.78 V, which was only about 0.1 V lower than that observed with dense electrolyte specimens. A maximum power density of 660 mW cm - 2 (0.44 V) was obtained at set temperature = 606°C (cell temperature = 744°C) in the flow rate of 900 cm 3 min - 1 , where the current efficiency was about 5% determined from fuel consumption.