Introduction to hollow structures for energy applications

Dan Wang

Dan Wang is a professor at the Institute of Process Engineering, Chinese Academy of Sciences. His research interest is focused on synthesis chemistry of multifunctional structure systems, including the controllable synthesis of hollow multishelled structures, doping and complexing of 2D materials and their applications for multicomponent efficient electrodes.

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The use of hollow structures has been a great success in the process of human development. For example, the appearance of the house, which is a typical hollow structure, has enabled human beings to step into modern civilization away from perils of the wild. As a typical hollow structure, the appearance of the house has enabled human beings to step into modern architecture, and with the development of science and technology, hollow structures have demonstrated their great advantages in applications from biomedicine to aerospace.

In the past decades, the fascinating properties of hollow structures – including low density, high surface-to-volume ratio, short mass and charge transport path, and high volumetric loading capacity – have made them promising candidates for various energy related applications. For example, with sufficient inner void to buffer the destructive volume expansion and alleviate stress during lithiation, hollow structured electrodes can achieve excellent cycling stability. As lithium is the host for lithium-metal anodes, hollow structures could inhibit lithium dendrite growth, thus achieving better safety and stability. When applied to electrocatalysis, hollow structures can provide abundant catalytic centers due to their large specific surface area, and facilitate mass transport due to the porous nanoshell. Given the above advantages, great effort has been devoted to the design and synthesis of hollow structures for energy conversion and storage applications.

This themed issue collects 11 articles, which includes 3 review articles, 7 research articles and 1 chemistry frontiers. These articles nicely illustrate the significant progress in designing hollow structures to effectively solve the problems of energy related technologies, which will guide the better design of hollow structures to fulfil the requirements of specific applications, such as lithium-ion batteries, lithium–sulfur batteries, sodium-ion batteries, water splitting and heterogeneous catalysis. As several contributions show, hollow structures have evolved considerably in recent years. Hollow multishell structures (HoMS) which feature multiple shells that are separated by internal voids, provide new possibilities for improving the performance of energy devices. Superior to their single-shelled counterparts, HoMS materials possess a larger volumetric capacity and better structural and electrochemical stability when used as electrode materials. Particularly, the realization of a novel concept “temporal-spatial ordering” in HoMS has paved the way for more promising applications in energy conversion, storage and catalysis.

We hope the outstanding contributions in this themed issue may give researchers the opportunity to tackle the key challenges in this exciting research area, and get some inspiration to further boost this area. Finally, I want to give my deep acknowledgements to all the authors who accepted my invitations and contributed to this themed issue. I also extend my gratitude to all the reviewers and the editorial staff at Materials Chemistry Frontiers, for their great efforts dedicated to this themed issue.

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