Ultra-long cycle life of flexible Sn anode using DME electrolyte

Abstract Sodium-ion batteries (SIBs) are highly anticipated energy storage devices due to the low-cost, widely available resources, and similar electrochemical performances with lithium-ion batteries. Even though excellent performances are demonstrated for SIB cathodes, the SIB anodes still need improvement to meet the commercial standards. Tin (Sn) anode is a popular anode that has high prospects but the previous reports show unsatisfactory electrochemical results. Here we demonstrate the excellent electrochemical performance of a flexible Sn anode for SIBs in DME electrolyte for the first time. The spherical Sn particles are embedded on carbon fibers by the facile electrospinning method. The Sn anode delivered a capacity of 661 mAh g-1 at 0.5 C. Also, the Sn anode delivered exceptional cycling performance up to 30000 cycles with a negligible capacity degradation of 0.002% per cycle at 25 C. Moreover, a full cell with freestanding Sn anode was assembled for the first time by coupling with Na3V2(PO4)3 delivers a maximum energy density of 114 Wh kg-1 and a power density of 3256 W kg-1 based on the mass of total active materials demonstrating excellent prospects.