Correlation between the morphology of carbon nanofibers and the transport characteristics of Li-ions in a battery anode under fast charging conditions

Abstract

Energy storage materials for electric vehicles and energy storage systems must be able to supply high capacity quickly, which requires efficient Li-ion transport within the anode active material. The transport of Li ions through a battery system can lead to concentration polarization and subsequent overpotential, which can limit the electrochemical performance, especially under fast charging conditions. To overcome these limitations, it is important to control solvated Li-ion transport and design an anode material with a rational approach. One way to achieve this is by controlling the morphology of carbon nanofibers (CNFs) to create ion transport channels. A facile method for this was investigated using an immiscible polymer blend electrospinning system and interpreting a ternary phase diagram. The effects of the morphology and space characteristics of each CNF on the electrochemical performance were studied, particularly the rate capability and cycle stability under fast charging conditions. These characteristics were analyzed in terms of the transport properties of the electrochemical species in different types of ion channels.