scispace - formally typeset
Search or ask a question
Topic

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.


Papers
More filters
Journal ArticleDOI
TL;DR: Rechargeable zinc-air battery based on Ni-doped CoO NSs affords an unprecedented small charge-discharge voltage of 0.63 V, outperforming state-of-the-art Pt/C catalyst-based device and it is shown that Ni- doped Coo NSs assembled into all-solid-state coin cells can power 17 light-emitting diodes and charge an iPhone 7 mobile phone.
Abstract: Zinc-air batteries offer a possible solution for large-scale energy storage due to their superhigh theoretical energy density, reliable safety, low cost, and long durability. However, their widespread application is hindered by low power density. Herein, a multiscale structural engineering of Ni-doped CoO nanosheets (NSs) for zinc-air batteries with superior high power density/energy density and durability is reported for the first time. In micro- and nanoscale, robust 2D architecture together with numerous nanopores inside the nanosheets provides an advantageous micro/nanostructured surface for O2 diffusion and a high electrocatalytic active surface area. In atomic scale, Ni doping significantly enhances the intrinsic oxygen reduction reaction activity per active site. As a result of controlled multiscale structure, the primary zinc-air battery with engineered Ni-doped CoO NSs electrode shows excellent performance with a record-high discharge peak power density of 377 mW cm-2 , and works stable for >400 h at 5 mA cm-2 . Rechargeable zinc-air battery based on Ni-doped CoO NSs affords an unprecedented small charge-discharge voltage of 0.63 V, outperforming state-of-the-art Pt/C catalyst-based device. Moreover, it is shown that Ni-doped CoO NSs assembled into all-solid-state coin cells can power 17 light-emitting diodes and charge an iPhone 7 mobile phone.

121 citations

Journal ArticleDOI
Yanchao Li1, Xiaofeng Lyu1, Dong Cao1, Shuai Jiang2, Chenhao Nan2 
TL;DR: Through the proposed design methodology in this paper, power loss on switching devices and planar inductors can be minimized and detailed power loss analysis and breakdown provide hints for further efficiency improvement.
Abstract: Achieving high efficiency and high power density features of intermediate bus converter (IBC) in data center application is very critical. This paper proposes a nonisolated switched-tank dc–dc converter (STC) to meet the high requirement of IBC. The proposed STC has fixed voltage conversion ratio. Theoretical analysis provides the guideline for designing resonant tank and nonresonant tank as well as selecting proper deadtime for the proposed circuit. With resonant operation feature of the proposed circuit, zero current switching is realized on all switching devices to help the high-efficiency operation of the proposed converter. Through the proposed design methodology in this paper, power loss on switching devices and planar inductors can be minimized. In addition, detailed power loss analysis and breakdown provide hints for further efficiency improvement. Simulation has been performed to validate the operating principle of the proposed STC. A designed 6x STC (450 W nominal/600 W maximum) based on eGaNFETs is demonstrated. With 54 V typical input voltage, the output of the 6x STC is 9 V. The GaN-based prototype achieves a peak efficiency of 98.55%. Also, it achieves 97.18% efficiency and 750 W/in3 power density at 450 W.

120 citations

Journal ArticleDOI
TL;DR: In this article, a thin-film composite (TFC) membrane consisting of a polyamide thin film layer via interfacial polymerization (IP) and a macro void-free polyimide support was fabricated to harvest osmotic energy from salinity gradients from pressure retarded osmosis (PRO) processes.

120 citations

Journal ArticleDOI
TL;DR: In this paper, the authors evaluate the ability of gallium nitride transistors to improve efficiency and output power density in high frequency resonant and soft-switching applications, and experimentally verify the benefits of replacing Si MOSFETs with enhancement mode GaN transistors (eGaNFETs).
Abstract: The emergence of gallium nitride (GaN)-based power devices offers the potential to achieve higher efficiencies and higher switching frequencies than possible with mature silicon (Si) power MOSFETs. In this paper, we will evaluate the ability of gallium nitride transistors to improve efficiency and output power density in high frequency resonant and soft-switching applications. To experimentally verify the benefits of replacing Si MOSFETs with enhancement mode GaN transistors (eGaNFETs) in a high frequency resonant converter, 48–12 V unregulated isolated bus converter prototypes operating at a switching frequency of 1.2 MHz and an output power of up to 400 W are compared using Si and GaN power devices.

120 citations

Journal ArticleDOI
TL;DR: In this article, a new kind of power analysis is conducted on a reversible Joule-Brayton cycle, where the effects of the engine sizes were included in the analysis.
Abstract: A new kind of power analysis is conducted on a reversible Joule-Brayton cycle. Although many performance analyses have been carried out resulting in famous efficiencies (Carnot, Curzon-Ahlborn), most do not consider the sizes of the engines. In the studies of Curzon and Ahlborn and others, researchers utilized the thermal efficiency at maximum power as an efficiency standard for practical heat engines. In this paper, instead of just maximizing power for certain cycle parameters, the power density defined as the ratio of power to the maximum specific volume in the cycle, is maximised. Therefore the effects of the engine sizes were included in the analysis. The result showed a new type of efficiency at the maximum power density which is always greater than that at the maximum power (Curzon-Ahlborn efficiency). Evaluations show that design parameters at the maximum power density lead to smaller and more efficient Joule-Brayton engines.

120 citations


Network Information
Related Topics (5)
Oxide
213.4K papers, 3.6M citations
85% related
Thin film
275.5K papers, 4.5M citations
84% related
Carbon nanotube
109K papers, 3.6M citations
84% related
Graphene
144.5K papers, 4.9M citations
83% related
Silicon
196K papers, 3M citations
83% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023652
20221,294
2021519
2020594
2019595
2018600