Prelithiation is a good method used to mitigate the loss of lithium caused by the formation of the solid electrolyte interface (SEI) layer and by the irreversible reactions at the first discharge cycle. The main goal of this work is to systematically study the effect of prelithiation and thermal treatment on the electrochemical performance of carbon fiber anodes for LIBs. We present results on the centrifugal spinning of Polyacrylonitrile (PAN) fibers and PAN/ceramic composite fibers subjected to thermal treatment under different temperature and environmental conditions. The carbon composite-fibers anodes treated under a nitrogen atmosphere showed better electrochemical performance than that treated under argon atmosphere. The pre-lithiation of carbon fiber anodes after the first cycle exhibited higher charge/discharge capacities and higher coulombic efficiency up to 98% than the pristine carbon fibers. The results show that the pre-lithiation and the creation of defects onto the carbon-fibers surface are the detrimental keys of achieving and designing anode materials with enhanced electrochemical performance.