With the increasing emphasis on environmental protection, the development of flame retardants for epoxy resin (EP) has tended to be non-toxic, efficient, multifunctional and systematic. Currently reported flame retardants have been capable of providing flame retardancy, heat resistance and thermal stability to EP. However, many aspects still need to be further improved. This paper reviews the development of EPs in halogen-free flame retardants, focusing on phosphorus flame retardants, carbon-based materials, silicon flame retardants, inorganic nanofillers, and metal-containing compounds. These flame retardants can be used on their own or in combination to achieve the desired results. The effects of these flame retardants on the thermal stability and flame retardancy of EPs were discussed. Despite the great progress on flame retardants for EP in recent years, further improvement of EP is needed to obtain numerous eco-friendly high-performance materials.

A facile dissolution–regeneration strategy is proposed to construct large-scale flexible SnS₂/sulfur-doped graphene composites as anodes for LIBs and SIBs.

The flame retardant mechanism of main group metals and transition metal flame retardant polymers were analyzed and outlined systematically.

The lithium-ion battery has the advantages of high energy density, long cycle life, small occupied volume, and high discharge voltage, which significantly promotes the development of portable electronic devices and electric vehicles. However, the accompanying safety issues have also aroused great concern. Solid-state lithium-ion batteries using solid-state electrolytes are considered next-generation advanced energy devices which are expected to fundamentally solve the safety problems of conventional lithium-ion batteries. At present, lithium metal is mainly used as the anode material in the research of solid-state lithium-ion batteries. However, during battery cycling, the lithium dendrites produced on the surface of lithium metal will also penetrate the solid electrolyte, threatening the battery's safety. Therefore, it is necessary to develop non-lithium metal anodes for solid-state batteries. This review focuses on the research progress of lithium-free anode materials in solid-state batteries, including C, Si, Sn, Bi, Sb, metal hydrides, and lithium titanate (Li₄Ti₅O₁₂). The effects of the size and structure of active materials, the use of a binder, the selection of solid electrolytes, and the manufacturing process on the electrochemical performance of the electrode are discussed in detail. The lithium storage mechanism, existing problems, improvement strategies, and application prospects of anode materials are summarized. By discussing the use of these active materials and their existing problems, this review provides a comprehensive insight into the application of non-lithium metal anode materials.

Proton exchange membrane fuel cells (PEMFCs) have received considerable interest due to their low operating temperature and high energy conversion rate. However, their practical implement suffers from significant performance challenge. In particular, proton exchange membrane (PEM) as the core component of PEMFCs, have shown a strong correlation between its properties (e.g., proton conductivity, dimensional stability) and the performance of fuel cells. Metal-organic frameworks (MOFs) as porous inorganic-organic hybrid materials have attracted extensive attention in gas storage, gas separation and reaction catalysis. Recently, the MOFs-modified PEMs have shown outstanding performance, which have great merit in commercial application. This manuscript presents an overview of the recent progress in the modification of PEMs with MOFs, with a special focus on the modification mechanism of MOFs on the properties of composite membranes. The characteristics of different types of MOFs in modified application were summarized.