Multi-protection from nanochannels and graphene of SnSb-graphene‑carbon composites ensuring high properties for potassium-ion batteries

Potassium-ion batteries (KIBs) are drawing great attention as the substitutions of commercial lithium-ion batteries (LIBs), due to the abundance of potassium and close redox potential to lithium. However, the lack of suitable electrodes to host large K+ for rapid as well as reversible insertion/extraction hinders the developments of KIBs. In this work, SnSb-graphene‑carbon (SnSb-G-C) nanofibers with porous multichannel structure are synthesized via an electrospinning method and applied as potential KIB anodes. The SnSb-G-C anodes exhibit a great cycling stability of 275.14 mAh g−1 over 100 cycles at the current density of 100 mA g−1, as well as the high rate capacity of 207.27 mAh g−1 at 1 A g−1, which are much better than those of SnSb‑carbon (SnSb-C) and graphene‑carbon (G-C) counterparts. The enhanced electrochemical performances of SnSb-G-C nanofibers can be ascribed to the nanochannels and the dispersive graphene inside the carbon matrix, effectively buffering the structural changes and protecting the SnSb particles from destruction. Meanwhile, the dispersed graphene facilitates the electrons transportation, leading to the good rate capability. The results may pave the way to more future studies on KIBs.