Bismuth-constructed high-speed channeled for Bi/Sb2SnO5@PCFs composite as high-rate and long-life anode for sodium-ion batteries

Abstract

To cope with the charging-time and driving-range issues of the power batteries, a composite and phase modification tactics is manifested to increase the cycling stability and rate capability of the Sb2SnO5 (SSO) anode for sodium-ion batteries (SIBs). The as-fabricated Bi/SSO@PCFs composite with Bi nanocrystals homogeneously dispersed on and around the SSO surface is prepared by an electrospinning method. The excellently dispersed Bi nanocrystals realize an effective contact with SSO, which effectively lowers the electron conduction barriers and promotes the sodium ion release as well as the transport upon the desodiation/sodiation process, increasing the rate capacity and cycle stability of the SSO anode. Importantly, a high-speed ion channel is constructed through the special layered Bi, and SbBi phase. The prepared Bi/SSO@PCFs anodes deliver a high rate capacity up to 25 A g−1 and long cycle life of 5000 cycles with 83 % capacity retention rate, sustaining an average capacity loss of 0.0034 % for each cycle. Particularly, the intercalation of Na+ between layer-structure Bi and SbBi galleries provides a good basis for excellent cycle performance due to small volume change and unobstructed ion channels. This finding provides an effective strategy to establish ion transport highways, which essentially increase the rate-capacity and cycle-life of the SSO-based anodes for SIBs.