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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.


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Journal ArticleDOI
TL;DR: In this paper, surface modified Fe2 O3 quantum dots anchored on graphene nanosheets are developed and exhibit greatly enhanced pseudocapacitance via fast dual-ion-involved redox reactions with both large specific capacity and fast charge/discharge capability.
Abstract: The insertion/deinsertion mechanism enables plenty of charge-storage sites in the bulk phase to be accessible to intercalated ions, giving rise to at least one more order of magnitude higher energy density than the adsorption/desorption mechanism. However, the sluggish ion diffusion in the bulk phase leads to several orders of magnitude slower charge-transport kinetics. An ideal energy-storage device should possess high power density and large energy density simultaneously. Herein, surface-modified Fe2 O3 quantum dots anchored on graphene nanosheets are developed and exhibit greatly enhanced pseudocapacitance via fast dual-ion-involved redox reactions with both large specific capacity and fast charge/discharge capability. By using an aqueous Na2 SO3 electrolyte, the oxygen-vacancy-tuned Fe2 O3 surface greatly enhances the absorption of SO32- anions that majorly increase the surface pseudocapacitance. Significantly, the Fe2 O3 -based electrode delivers a high specific capacity of 749 C g-1 at 5 mV s-1 and retains 290 C g-1 at an ultrahigh scan rate of 3.2 V s-1 . With a novel dual-electrolyte design, a 2 V Fe2 O3 /Na2 SO3 //MnO2 /Na2 SO4 asymmetric supercapacitor is constructed, delivering a high energy density of 75 W h kg-1 at a power density of 3125 W kg-1 .

184 citations

Journal ArticleDOI
TL;DR: A membrane-less hydrogen bromine laminar flow battery is reported on as a potential high-power density solution that will translate into smaller, inexpensive systems that could revolutionize the fields of large-scale energy storage and portable power systems.
Abstract: In order for the widely discussed benefits of flow batteries for electrochemical energy storage to be applied at large scale, the cost of the electrochemical stack must come down substantially. One promising avenue for reducing stack cost is to increase the system power density while maintaining efficiency, enabling smaller stacks. Here we report on a membrane-less hydrogen bromine laminar flow battery as a potential high-power density solution. The membrane-less design enables power densities of 0.795 W cm(-2) at room temperature and atmospheric pressure, with a round-trip voltage efficiency of 92% at 25% of peak power. Theoretical solutions are also presented to guide the design of future laminar flow batteries. The high-power density achieved by the hydrogen bromine laminar flow battery, along with the potential for rechargeable operation, will translate into smaller, inexpensive systems that could revolutionize the fields of large-scale energy storage and portable power systems.

184 citations

Journal ArticleDOI
TL;DR: In this paper, the authors analyzed the source of voltage losses and tailor the design of the battery to simultaneously minimize the ohmic resistance, maximize the transport of electrolytes, and boost the surface area and activity of electrodes.

183 citations

Journal ArticleDOI
TL;DR: In this article, a cost-effective, environmental-friendly aqueous asymmetric supercapacitor by using CuCo2O4/CuO nanowire arrays as the positive electrode and RGO/Fe2O3 composites as the negative electrode is presented.
Abstract: The applications of traditional asymmetric supercapacitors are restricted due to the low specific capacitance of carbon negative materials. The rational design of positive and negative electrodes that afford high-performance asymmetric devices is particularly important. In this paper, we fabricate a cost-effective, environmental-friendly aqueous asymmetric supercapacitor by using CuCo2O4/CuO nanowire arrays as the positive electrode and RGO/Fe2O3 composites as the negative electrode. The assembled device exhibits a high energy density of 33.0 W h kg−1 at a power density of 200 W kg−1, and it still operates at a high power density of 8.0 kW kg−1 with an energy density of 9.1 W h kg−1. The current strategy will provide a fresh route for the design and fabrication of novel asymmetric supercapacitors with high energy density and high power density.

183 citations

Journal ArticleDOI
TL;DR: In this paper, a comparison of power generation is conducted using various nanocarbon electrodes, including purified singlewalled and multi-walled carbon nanotubes (P-SWNTs and P-MWNTs), unpurified SWNTs, reduced graphene oxide (RGO), and P -SWNT/RGO composite.
Abstract: Nanocarbon-based thermocells involving aqueous potassium ferro/ferricyanide electrolyte are investigated as an alternative to conventional thermoelectrics for thermal energy harvesting. The dependencies of power output on thermocell parameters, such as cell orientation, electrode size, electrode spacing, electrolyte concentration and temperature, are examined to provide practical design elements and principles. Observation of thermocell discharge behavior provides an understanding of the three primary internal resistances (i.e., activation, ohmic and mass transport overpotentials). The power output from nanocarbon thermocells is found to be mainly limited by the ohmic resistance of the electrolyte and restrictions on mass transport in the porous nanocarbon electrode due to pore tortuosity. Based on these fundamental studies, a comparison of power generation is conducted using various nanocarbon electrodes, including purified single-walled and multi-walled carbon nanotubes (P-SWNTs and P-MWNTs, respectively), unpurified SWNTs, reduced graphene oxide (RGO) and P-SWNT/RGO composite. The P-SWNT thermocell has the highest specific power generation per electrode weight (6.8 W/kg for a temperature difference of 20 °C), which is comparable to that for the P-MWNT electrode. The RGO thermocell electrode provides a substantially lower specific power generation (3.9 W/kg).

183 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023652
20221,294
2021519
2020594
2019595
2018600