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.

A Shape‐Adaptive Thin‐Film‐Based Approach for 50% High‐Efficiency Energy Generation Through Micro‐Grating Sliding Electrification

Abstract: Effectively harvesting ambient mechanical energy is the key for realizing self-powered and autonomous electronics, which addresses limitations of batteries and thus has tremendous applications in sensor networks, wireless devices, and wearable/implantable electronics, etc. Here, a thin-film-based micro-grating triboelectric nanogenerator (MG-TENG) is developed for high-efficiency power generation through conversion of mechanical energy. The shape-adaptive MG-TENG relies on sliding electrification between complementary micro-sized arrays of linear grating, which offers a unique and straightforward solution in harnessing energy from relative sliding motion between surfaces. Operating at a sliding velocity of 10 m/s, a MG-TENG of 60 cm(2) in overall area, 0.2 cm(3) in volume and 0.6 g in weight can deliver an average output power of 3 W (power density of 50 mW cm(-2) and 15 W cm(-3)) at an overall conversion efficiency of ∼ 50%, making it a sufficient power supply to regular electronics, such as light bulbs. The scalable and cost-effective MG-TENG is practically applicable in not only harvesting various mechanical motions but also possibly power generation at a large scale.

Carbon‐Coated Porous Aluminum Foil Anode for High‐Rate, Long‐Term Cycling Stability, and High Energy Density Dual‐Ion Batteries

Abstract: A 3D porous Al foil coated with a uniform carbon layer (pAl/C) is prepared and used as the anode and current collector in a dual-ion battery (DIB). The pAl/C-graphite DIB demonstrates superior cycling stability and high rate performance, achieving a highly reversible capacity of 93 mAh g-1 after 1000 cycles at 2 C over the voltage range of 3.0-4.95 V. In addition, the DIB could achieve an energy density of ≈204 Wh kg-1 at a high power density of 3084 W kg-1 .

Novel BaTiO3-based lead-free ceramic capacitors featuring high energy storage density, high power density, and excellent stability

Abstract: The development of energy storage devices with a high energy storage density, high power density, and excellent stability has always been a long-cherished goal for many researchers as they tackle issues concerning energy conservation and environmental protection. In this work, we report a novel BaTiO3-based lead-free composition (0.85BaTiO3–0.15Bi(Zn1/2Sn1/2)O3) with an ultrahigh energy storage density (2.41 J cm−3) and a high energy storage efficiency of 91.6%, which is superior to other lead-free systems reported recently. The energy storage properties of 0.85BT–0.15BZS ceramic manifest excellent frequency stability (5–1000 Hz) and fatigue endurance (cycle number: 105). The pulsed charging–discharging process is measured to elucidate the actual operation performance in the 0.85BT–0.15BZS ceramic. Delightfully, the 0.85BT–0.15BZS ceramic also possesses an ultrahigh current density of 551 A cm−2 and a giant power density of 30.3 MW cm−3, and the stored energy is released in sub-microseconds. Moreover, the 0.85BT–0.15BZS ceramic exhibits outstanding temperature stability of its dielectric properties, energy storage properties, and charging–discharging performance over a broad temperature range (20–160 °C) due to the weakly-coupled relaxor behavior. These results not only indicate the superior potential of environment-friendly BaTiO3-based relaxor ferroelectric ceramics for the design of ceramic capacitors of both high energy storage and power applications, but they also show the merit of the weakly-coupled relaxor behavior to improve the thermal stability of energy storage properties.

Mesoporous LiFePO4/C Nanocomposite Cathode Materials for High Power Lithium Ion Batteries with Superior Performance.

Abstract: Hexagonally ordered mesoporous LiFePO4/C nanocomposites can be synthesized with LiFePO4 nanoparticles embedded in an interconnected carbon framework. Mesoporous LiFePO4/C nanocomposites exhibit superior electrochemical performance and ultra-high specific power density, which makes this architecture suitable for high power applications such as hybrid electric vehicles (HEVs) and stationary energy storage for smart grids.

Nanotubular metal–insulator–metal capacitor arrays for energy storage

Abstract: Nanostructured devices have the potential to serve as the basis for next-generation energy systems that make use of densely packed interfaces and thin films 1 . One approach to making such devices is to build multilayer structures of large area inside the open volume of a nanostructured template. Here, we report the use of atomic layer deposition to fabricate arrays of metal–insulator–metal nanocapacitors in anodic aluminium oxide nanopores. These highly regular arrays have a capacitance per unit planar area of 10 m Fc m 22 for 1-mm-thick anodic aluminium oxide and 100 m Fc m 22 for 10-mm-thick anodic aluminium oxide, significantly exceeding previously reported values for metal–insulator–metal capacitors in porous templates 2–6 . It should be possible to scale devices fabricated with this approach to make viable energy storage systems that provide both high energy density and high power density. The nanocapacitor structures in this Letter are formed of metal electrodes separated by a dielectric film; therefore they behave in the same manner as conventional electrostatic capacitors, in which charge is stored on opposing electrode surfaces. A characteristic feature of electrostatic capacitors is high power. This is because charge can be moved rapidly, with speeds limited only by external circuit RCs. However, energy storage is limited because only surface charge is used. In contrast, conventional electrochemical supercapacitors store charge in electric double layers or in faradic reactions, permitting larger energy density storage on the electrode surfaces. Power density is limited in these devices because of the requirement for mass transport of ions and/or redox reactions 7 . The use of highly regular nanostructures promises both high energy and high power density. For the nanocapacitors described in this Letter, the nanostructure significantly enhances capacitance density. The nanocapacitors demonstrate the high power (up to � 1 � 10 6 Wk g 21 ) typical of electrostatic capacitors while achieving the much higher energy density (� 0.7 Wh kg 21 ) characteristic of electrochemical supercapacitors. As a result, electrostatic nanocapacitors are attractive for high-burst-power applications requiring the energy density of supercapacitors. To obtain energy devices that achieve dense packing of active interfaces and thin films, nanoporous structures are required that have internal surfaces on which highly uniform films can be reproducibly formed. We make use of the self-assembly of regular nanopore arrays available from anodic aluminium oxide (AAO) formation together with multilayer atomic layer deposition (ALD) to form highly controlled, self-aligned nanocapacitors. ALD has become the leading process used to achieve such coatings, yielding a high degree of thickness control and conformality in the most demanding nanostructures, with features that are either highly ordered 8–10 or are random porous networks 11–13 . Nanostructures fabricated with AAO and ALD show a high degree of uniformity across massive arrays, imparting the regularity that is a key factor in the viability of any technology 8 . Our fabrication strategy makes use of AAO nanopore templates in combination with metal–insulator–metal (MIM) structures deposited in the nanopores by ALD. The anodization process produces an ultrahigh density (� 1 � 10 10 cm 22 ) of hexagonally arranged, uniform, self-assembled nanopores in AAO film on Al tens of micrometres deep, which provides a good template for