All-Day Thermogalvanic Cells for Environmental Thermal Energy Harvesting

Abstract

<jats:p>Direct conversion of the tremendous and ubiquitous low-grade thermal energy into electricity by thermogalvanic cells is a promising strategy for energy harvesting. The environment is one of the richest and renewable low-grade thermal source. However, critical challenges remain for all-day electricity generation from environmental thermal energy due to the low frequency and small amplitude of temperature fluctuations in the environment. In this work, we report a tandem device consisting of a polypyrrole (PPy) broadband absorber/radiator, thermogalvanic cell, and thermal storage material (Cu foam/PEG1000) that integrates multiple functions of heating, cooling, and recycling of thermal energy. The thermogalvanic cell enables continuous utilization of environmental thermal energy at both daytime and nighttime, yielding maximum outputs as high as 0.6 W m<jats:sup>-2</jats:sup> and 53 mW m<jats:sup>-2</jats:sup>, respectively. As demonstrated outdoors by a large-scale prototype module, this design offers a feasible and promising approach to all-day electricity generation from environmental thermal energy.</jats:p>

Janus Poly(Vinylidene Fluoride) Membranes with Penetrative Pores for Photothermal Desalination

“…First, a high-performance solar steam generation strongly relies on the photothermal materials to absorb sunlight as much as possible. Carbonbased materials (e.g., reduced graphene oxide [11,12], carbon nanotubes [13], carbon black [14,15]), plasmonic nanoparticles [16,17] (e.g., Al or Au), and super-black polymers (e.g., polypyrrole (PPy) [18,19], polydopamine (PDA) [20]) have been extensively adopted due to their remarkable solar-thermal conversion efficiency. Second, an elaborated thermal management is required, aiming to confine the absorbed heat on the water surface and then to ensure thermal insulation from the bulk water.…”

Redox-induced electricity for energy scavenging and self-powered sensors

“…3a) is composed of a thermogalvanic cell that has an absorber/radiator polypyrrole (PPy) and copper foam/PEG100 as a thermal storage element to harvest environmental thermal energy during both day and night. 53 To harvest industrial waste heat more cheaply, a gas electrode-based thermo-electrochemical cell has been designed for molten carbonate electrolytes, as shown in Fig. 3b.…”

“…3a), providing a daytime output power of 0.6 W m À2 with a nighttime power of 53 mW m À2 . 53 The performance of the thermogalvanic cell increased by using polypyrrole (PPy) as a phase-changing material (PPy-PCM) given that it is a good absorber and radiator. Fig.…”

“…52 Thus, currently, carbon-related materials, for instance, nanotubes, graphite, composites, and carbon bers have been studied intensely for electrodes due to their low cost and excellent conductive properties. 36,48,53,56,81 Multiwalled carbon nanotube-coated (MWCNTs) electrodes show excellent device output compared to other electrodes, as illustrated in Fig. 11a, for electrochemistry-based energy scavenging.…”

Nanogenerator-Based Self-Powered Sensors for Wearable and Implantable Electronics

“…Typically, NGs can be divided into three types based on electricity generation mode, namely, piezoelectric nanogenerator (PENG), triboelectric nanogenerator (TENG) [17], and pyroelectric nanogenerator (PYENG) [18]. They have been widely used as micro-nanoenergy or blue energy harvesters and self-powered sensors [19][20][21][22][23][24][25]. Considering that more and more implantable and wearable electronic sensors have been employed by humans, developing NG-based technology is extremely attractive [26,27].…”