• Energy Research

AbstractThermal energy storage technologies based on phase‐change materials (PCMs) have received tremendous attention in recent years. These materials are capable of reversibly storing large amounts of thermal energy during the isothermal phase transition and offer enormous potential in the development of state‐of‐the‐art renewable energy infrastructure. Thermal conductivity plays a vital role in regulating the thermal charging and discharging rate of PCMs and improving the heat‐utilization efficiency. The strategies for tuning the thermal conductivity of PCMs and their potential energy applications, such as thermal energy harvesting and storage, thermal management of batteries, thermal diodes, and other forms of energy utilization, are summarized systematically. Furthermore, a research perspective is given to highlight emerging research directions of engineering advanced functional PCMs for energy applications.

Organic phase change materials are usually insulating in nature, and they are unlikely to directly trigger latent heat storage through an electrical way. Here we report a multifunctional phase change composite in which the energy storage can be driven by small voltages (e.g., 1.5 V) or light illumination with high electro-to-heat or photo-to-thermal storage efficiencies (40% to 60%). The composite is composed of paraffin wax infiltrated into a porous, deformable carbon nanotube sponge; the latter not only acts as a flexible encapsulation scaffold for wax but also maintains a highly conductive network during the phase change process (for both solid and liquid states). Uniform interpenetration between the nanotube network and paraffin wax with high affinity results in enhanced phase change enthalpy and thermal conductivity compared to pure paraffin wax. Our phase change composite can store energy in practical ways such as by sunlight absorption or under voltages applied by conventional lithium-ion batteries.

This review highlights the broad and critical role of latent heat storage in sustainable energy systems including solar-thermal storage, electro-thermal storage, waste heat storage and thermal regulations.

A dual-channel superstructured Ni single-atom catalyst with a unique axial oxygen coordination configuration was controllably constructed and affords a preeminent performance for convergent paired electrosynthesis of dimethyl carbonate from CO2.

This review presents a summary of recent progress and strategies in fabricating MOF-based nanostructures for electrochemical applications.

This review presents a summary of recent progress and strategies in fabricating nanoencapsulated PCMs for thermal energy applications.

AbstractMetal‐organic frameworks (MOFs) and MOF‐derived materials have attracted great attention as alternatives to noble‐metal based electrocatalysts owing to their intriguing structure properties, especially for high efficiency and stable oxygen reduction reaction (ORR). Herein, we employed a one‐pot reaction to make a multimetal (Fe, Co, Cu, and Zn) mixed zeolitic imidazolate framework (MM‐ZIF) via adopting a simple in situ redox reaction. Further pyrolysis of the target MM‐ZIF, a highly porous carbon polyhedron (FC‐C@NC) grafted with abundant carbon nanotubes was obtained, in which ultrasmall Co nanoparticles with partial lattice sites substituted by Fe and Cu were embedded. The obtained FC‐C@NC possessed large surface area, highly porous structure, widely‐spread metal active sites, and conductive carbon frameworks, contributing to outstanding ORR activity and long‐term stability. It displayed superior tolerance to methanol crossover and exceeded the commercial Pt/C catalyst and most previously reported non‐noble‐metal catalysts. Impressively, the as‐produced FC‐C@NC‐based zinc‐air battery afforded an open‐circuit potential of 1.466 V, a large specific capacity of 659.5 mAh/g, and a high gravimetric energy density of 784.3 Wh/kgZn, significantly outperforming the Pt/C‐based cathode.

The recent progress in the synthesis and energy applications of the covalent organic frameworks has been elaborated in this review article.

AbstractRecently, two‐dimensional transition metal dichalcogenides (TMDs) demonstrated their great potential as cost‐effective catalysts in hydrogen evolution reaction. Herein, we systematically summarize the existing defect engineering strategies, including intrinsic defects (atomic vacancy and active edges) and extrinsic defects (metal doping, nonmetal doping, and hybrid doping), which have been utilized to obtain advanced TMD‐based electrocatalysts. Based on theoretical simulations and experimental results, the electronic structure, intermediate adsorption/desorption energies and possible catalytic mechanisms are thoroughly discussed. Particular emphasis is given to the intrinsic relationship between various types of defects and electrocatalytic properties. Furthermore, current opportunities and challenges for mechanical investigations and applications of defective TMD‐based catalysts are presented. The aim herein is to reveal the respective properties of various defective TMD catalysts and provide valuable insights for fabricating high‐efficiency TMD‐based electrocatalysts.