Intricate Hollow Structures: Controlled Synthesis and Applications in Energy Storage and Conversion

Abstract

Intricate hollow structures garner tremendous interest due to their aesthetic beauty, unique structural features, fascinating physicochemical properties, and widespread applications. Here, the recent advances in the controlled synthesis are discussed, as well as applications of intricate hollow structures with regard to energy storage and conversion. The synthetic strategies toward complex multishelled hollow structures are classified into six categories, including well-established hard- and soft-templating methods, as well as newly emerging approaches based on selective etching of "soft@hard" particles, Ostwald ripening, ion exchange, and thermally induced mass relocation. Strategies for constructing structures beyond multishelled hollow structures, such as bubble-within-bubble, tube-in-tube, and wire-in-tube structures, are also covered. Niche applications of intricate hollow structures in lithium-ion batteries, Li-S batteries, supercapacitors, Li-O batteries, dye-sensitized solar cells, photocatalysis, and fuel cells are discussed in detail. Some perspectives on the future research and development of intricate hollow structures are also provided.

Hollow Structures Based on Prussian Blue and Its Analogs for Electrochemical Energy Storage and Conversion

“…One universal and important finding is that the properties of materials can be tailored by downscaling substances to the micro-and nanometer when maintaining their elemental compositions. Many review papers have provided insights into this field from diverse perspectives: synthetic strategies, [10][11][12][13][14][15][16][17] structural diversity, [18][19][20][21][22][23] product compositions, [24][25][26][27] and potential applications. [2][3][4][5][6][7][8][9] Motivated by the discovery of carbon nanotubes and fullerenes, scientists have devoted many efforts in exploiting nanomaterials with a hollow interior, for example hollow polyhedra and spheres, tubes, open cages, and frames, which has become an intriguing research topic over the past two decades.…”

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the supply and demand issues of energy have become one of the greatest challenges we now faces. [10,17,[22][23][24][25][26]28,30] Particularly, the large surface area endows the hollow structures with rich electrochemically active sites and large contact area between electrode and electrolyte for efficient mass diffusion and reactions. [33,34] Compared to their solid counterparts, hollow nanostructures have lower density, larger surface area, and higher loading capacity that derived from their extra void spaces, serving as promising candidates for energy-involved applications, such as lithium-ion batteries (LIBs), hybrid supercapacitors (HSCs), water splitting, and fuel cells.

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Flexible, Stretchable, and Transparent Planar Microsupercapacitors Based on 3D Porous Laser‐Induced Graphene

“…[1][2][3][4][5][6] Some of the most effective and practical technologies for electrochemical energy conversion and storage are batteries, fuel cells, and supercapacitors. [7][8][9][10][11][12][13][14][15] Among them, supercapacitors (SCs) have attracted intensive attentions due to their high power density and long lifecycle. [9,13,[16][17][18] The energy storage is performed by ion adsorption or fast surface redox reaction at the interface between electrodes and electrolyte.…”

Tailoring Iron Oxide Nanostructures for High-Capacity Lithium Storage

“…[61] Among the various 3D architectures, hollow structures attracted the most attention due to their unique merits of hollow cavity for volume change accommodation, reduced lengths for Li + diffusion, and abundant lithium storage sites. [62][63][64][65][66] In 2007, the lithium storage properties of α-Fe2O3 hollow spindles and microspheres were reported by Tang and co-workers. [67] Later, Xie's group reported the anode performance of α-Fe2O3 hollow spheres with a mesoporous shell.…”