A review on new methods of recycling waste carbon fiber and its application in construction and industry

•The advantages of degradable resins in the recycling process of CFCs are highlighted.•The application of WCFs in cement-based materials, lithium-ion battery materials, and other functional fields is analyzed.•The possible problems of carbon fiber recycling methods are added, and future directions for improvement are proposed. Carbon fiber composites (CFCs) are widely used in modern industry with their excellent properties. However, a large amount of CFCs waste has been produced because of the limitations of the processing technology and service life. And in the next 20 years, the amount of waste will increase dramatically, resulting in environmental pollution and waste of resources. How to efficiently recycle and reuse CFCs is a common problem faced by mankind. Facing the shortages of traditional recycling technology, this paper focuses on the recycling of CFCs by various new degradable resins, including degradation conditions, degradation mechanism and degradation effect. Meanwhile, the application of waste carbon fibers (WCFs) in cement-based materials (Mechanical and electrical conductivity, etc.), lithium-ion battery materials, thermoelectric materials, and other functional fields (Fillers, electromagnetic shielding, and parts manufacturing, etc.) are described in detail. The recycling of WCFs is imperative, but the traditional resin is not easily degradable, which is the biggest obstacle to the recycling of WCFs. Degradable resin-based CFCs has huge application prospects in the future. With appropriate recycling techniques, the strength of WCFs will be lost by 5 % to 50 %, but it still meets the requirements for use in construction materials and some industrial fields.