Guangpeng Zhang

Lithium-gas batteries (LGBs) have garnered significant attention due to their impressive high-energy densities and unique gas conversion capability. Nevertheless, the practical application of LGBs faces substantial challenges, including sluggish gas conversion kinetics inducing in low-rate performance and high overpotential, along with limited electrochemical reversibility leading to poor cycle life. The imperative task is to develop gas electrodes with remarkable catalytic activity, abundant active sites, and exceptional electrochemical stability. Electrospinning, a versatile and well-established technique for fabricating fibrous nanomaterials, has been extensively explored in LGB applications. In this work, we emphasize the critical structure-property for ideal gas electrodes and summarize the advancement of employing electrospun nanofibers (NFs) for performance enhancement in LGBs. Beyond elucidating the fundamental principles of LGBs and the electrospinning technique, we focus on the systematic design of electrospun NF-based gas electrodes regarding optimal structural fabrication, catalyst handling and activation, and catalytic site optimization, as well as considerations for large-scale implementation. The demonstrated principles and regulations for electrode design are expected to inspire broad applications in catalyst-based energy applications. This review emphasizes the pivotal structure-property for ideal gas electrodes and highlights the great potential of employing electrospun nanofibers (NFs) for performance enhancement in lithium-gas batteries (LGBs). Our approach correlates the fundamental reaction mechanisms of various LGBs with foundational design principles for optimal gas electrodes. Beyond a succinct introduction to electrospinning technology, our focus extends to a comprehensive exploration of the systematic design of gas electrodes. image

Li–CO 2 batteries (LCBs) hold significant potential for meeting the energy transition requirements and mitigating global CO 2 emissions. However, the development of efficient LCBs is still in its early stages, necessitating the search for highly effective electrocatalysts and a deeper understanding of their mechanisms. To address these challenges, we have designed a versatile on-chip electrochemical testing platform, which enables simultaneous catalyst screening and in-situ analysis of the chemical composition and morphological evolution of reaction products. Six different metal nanoparticle catalysts were evaluated and it was found that Pt-based LCBs demonstrated a low overpotential (∼0.55 V). The reaction pathways and reversible nature of the LCBs were studied using in situ electrochemical Raman spectroscopy and atomic force microscopy, and were supported by ab initio calculations. As a result of the platform studies, LCB coin cells and pouch cells were fabricated which demonstrated high capacity, stability, and an energy efficiency of up to 90%. A multimodal lab-on-a-chip platform has a wide range of applications in other systems, such as metal–air batteries, electrocatalysts, fuel cells, and photoelectrochemical systems, thereby opening up new opportunities for rapid catalyst screening, mechanism investigation, and the development of practical applications.

A comprehensive discussion of the approaches for developing carbon-based sulfur hosts is presented, encompassing structural design and functional optimization. The recent implementation of effective machine learning methods in discovering carbon-based sulfur hosts has been systematically examined. The challenges and future directions of carbon-based sulfur hosts for practically application have been comprehensively discussed. A summary of the strengths and weaknesses, along with the outlook on carbon-based sulfur hosts for practical application has been incorporated. As the need for high-energy–density batteries continues to grow, lithium-sulfur (Li–S) batteries have become a highly promising next-generation energy solution due to their low cost and exceptional energy density compared to commercially available Li-ion batteries. Research into carbon-based sulfur hosts for Li–S batteries has been ongoing for over two decades, leading to a significant number of publications and patents. However, the commercialization of Li–S batteries has yet to be realized. This can be attributed, in part, to the instability of the Li metal anode. However, even when considering just the cathode side, there is still no consensus on whether carbon-based hosts will prove to be the best sulfur hosts for the industrialization of Li–S batteries. Recently, there has been controversy surrounding the use of carbon-based materials as the ideal sulfur hosts for practical applications of Li–S batteries under high sulfur loading and lean electrolyte conditions. To address this question, it is important to review the results of research into carbon-based hosts, assess their strengths and weaknesses, and provide a clear perspective. This review systematically evaluates the merits and mechanisms of various strategies for developing carbon-based host materials for high sulfur loading and lean electrolyte conditions. The review covers structural design and functional optimization strategies in detail, providing a comprehensive understanding of the development of sulfur hosts. The review also describes the use of efficient machine learning methods for investigating Li–S batteries. Finally, the outlook section lists and discusses current trends, challenges, and uncertainties surrounding carbon-based hosts, and concludes by presenting our standpoint and perspective on the subject.