Hierarchically Structured Components: Design, Additive Manufacture, and Their Energy Applications

Abstract

term solutions are urgently needed before adequate supply of the renewable energy. [1,2] Improvement of efficiency in the energy production and consumption processes is a key factor to address these problems. Meanwhile, the large reaction rate is a key factor to meet the industrial energy requirements. [1][2][3][4][5] Mass transport intensification is an effective method to improve the efficiency and reaction rate in the adsorptions, chemical reactions, and electrochemical reactions, which plays crucial roles in the gas (H 2 , CH 4 , CO 2 , etc.) storage, [6,7] energy conversion, [8] and energy storage. [3,9,10] Recently, novel batteries [2,3,[11][12][13] and microreactors [8,[14][15][16][17][18] for the gas (H 2 , CH 4 , CO 2 , etc.) storage [6,7] and energy conversion [8] have been developed to meet the requirements of high efficiency and rates. In these devices, the mass transport intensification is particularly important to acquire the high selectivity, large reaction rate, great conversion efficiency. [2,8,19,20] The mass transfer steps in the monolithic adsorbents, structured catalysts, and shaped electrodes are similar. Therefore, it is possible to use an identical term to describe the monolithic adsorbents, structured catalysts, and shaped electrodes for convenience to discuss the mass transfer processes. Herein, we use the hierarchically structured components (HSCs) to describe the structures which are comprised of designed channels and matrix between channels, where the matrix is made from functional materials (ceramics, carbon, metals, etc.) with pores in the size from nanometer to sub-millimeters, as illustrated in Figure 1a. In the flow batteries and fuel cells, the assembly of bipolar plate and electrode is regarded as HSC.Generally, the reactants undergo four steps (distribution, adsorption, acceleration, and reaction) in the HSC, as shown in Figure 1b-e. The distribution starts as soon as the reactant flows into the inlet. In this step, the reactant is distributed across the HSC through the designed channels, as shown in Figure 1b. [21,22] Subsequently the fluid is adsorbed by the macropores (>50 nm) which act as buffers for the reactants in the matrix, shown in Figure 1c. [23] As shown in Figure 1d,e, the reactants are accelerated by the mesopores (2-50 nm) and transferred to the micropores (<2 nm) which provide high surface area for the active sites. [23][24][25] After reaction at the active sites, the products are transferred by the mesopores and macropores to the outlet, successively. [26,27] Therefore, the Pursuing high energy efficiency and reaction rate is an effective direction in mitigating the energy and climate crisis. Mass transfer intensification is a powerful approach to enhance the energy efficiency and reaction rate in the energy conversion and storage processes. The nature-inspired channels are outstanding tools to uniformly distribute the reactants, fast remove products, and reduce the diffusion distance for mass transfer intensification in monolithic adsorbents, structured catal...

A review of hierarchical porous carbon derived from various 3D printing techniques

“…This correlation is ascribed to the fact that an ideal porous carbon electrode must allow for fast mass diffusion routes for the ions as well as providing rapid electron transfer pathways. 80 Since SLA 3D printing not only produces porous carbon but does so in a controllable way for architectured electrode design with a high resolution, this makes it highly applicable in electrochemical energy storage and conversion applications, particularly when a complex electrode structure is required.…”

“…9 Schematic of the SLA print process and SEM/TEM imaging of macroarchitectures, macropores, mesopores, and micropores with scale bars of 1 mm, 20 µm, 100 nm, and 5 nm, respectively. 80 Fig. 10 Schematic of the process for the preparation of a 3D-printed hierarchical porous carbon lattice with MnO 2 deposition.…”

Light and Mass Transport Computations Guide the Fabrication of 3D-Structured TiO2 and Au/TiO2 Aerogel Photocatalysts for Efficient Hydrogen Production in the Gas Phase

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Enhanced Cooling Performance of Three‐Dimensional Printed Heat Sink via Solution‐Processed Layer‐by‐Layer CNT Coatings

“…[27][28][29] However, in the 3D-printing process, filler incorporation inside the resin and precursors essentially modifies their properties that are directly related to curing, absorption, and rheological characteristics, thereby necessitating major changes to the processing conditions. [30] Therefore, a rational strategy for compensating the thermal conductivity in an alternative way is significant to develop practically feasible 3D-printed components such as heat sinks for thermal energy dissipation.…”