Embodiments of the present disclosure generally relate to flexible substrate fabrication. In particular, embodiments described herein relate to methods for flexible substrate fabrication which can be used to improve the life of lithium-ion batteries. In one or more embodiments, a method of fabricating alloy anodes includes forming an alloy anode using a planar flow melt spinning process including solidifying a molten material over a quenching surface of a rotating casting drum and performing a pre-lithiation surface treatment on the alloy anode.