Using polyacrylonitrile (PAN) as a template, a composite of tin salt/PAN nanofiber is facilely produced by an electrospinning technique. Under high-temperature heat treatment, the carbonization of PAN and the crystal growth of tin oxide proceed simultaneously to form a composite structure of tin nanoparticles wrapped in carbon nanofibers (tin@CNF). The composite structure of tin@CNF is controllable by the precursor ratio of PAN with tin salt and the carbonization temperature. The sample Sn1Pan1_700, synthesized from the precursor with weight ratio of SnCl2:PAN51:1 and carbonized at 700 degrees C, delivers the initial capacity of 1329.8 mAh g(-1) and remains at 741.1 mAh g(-1) at the 40th cycle. The proper morphology of tin nanoparticles wrapped in carbon nanofibers plays an important role in specific capacity and cyclic performance, because the proper structure of carbon fiber hinders the aggregation of tin nanoparticles during the lithiation and delithiation processes. (C) 2016 Wiley Periodicals, Inc.