Recent developments in centrifugally spun composite fibers and their performance as anode materials for lithium-ion and sodium-ion batteries

Highlights: • Recent developments & challenges of fiber processing methods/techniques are reviewed. • The centrifugal spinning (CF) effect on fiber formation & morphology is discussed. • Results on centrifugally spun composite-fiber anodes for LIBs & SIBs are reported. • Procedures employed to produce beneficial fiber morphologies in CF are discussed. • Outlook and prospective on the use of CF in battery applications are given. Nanofibers (NFs) and composite NFs have been widely used as electrode and separator materials in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) due to their high surface-area-to-volume ratio and versatility of their morphologies. The majority of carbon-fibers (CFs) anodes have been prepared by electrospinning and subsequent thermal treatment. Nevertheless, the low fiber yield and safety hazards associated with this method have raised concerns and limited the commercialization of composite CF anodes. Fiber and nanofiber processing methods such as centrifugal spinning can overcome low productivity and eliminate the use of a high voltage to produce fibers. In the present work, centrifugally spun fibers with alloying, transition metal oxides, and transition metal sulfite-based materials are presented and discussed for potential use as anode materials in LIBs and SIBs. Emphasis is given on the centrifugal spinning process and its effects on fiber formation, morphology, and structure of these nanocomposite anodes.