Encapsulating segment-like antimony nanorod in hollow carbon tube as long-lifespan, high-rate anodes for rechargeable K-ion batteries

摘要: K-ion battery (KIB) is a new-type energy storage device that possesses potential advantages of low-cost and abundant resource potassium. To develop advanced electrode materials for accommodating the large size high activity potassium ion great interests. Herein, segment-like antimony (Sb) nanorod encapsulated in hollow carbon tube material (Sb@HCT) was prepared. Beneficial from virtue nitrogen doping tube, one-dimensional structure advantages, Sb@HCT exhibits excellent properties: case bis(fluorosulfonyl)imide (KFSI) electrolyte, displays reversible capacity up to 453.4 mAh·g−1 at current density 0.5 A·g−1 good rate performance (a 211.5 could be achieved an ultrahigh 5 A·g−1). Additionally, demonstrates long-cycle stability 2 over 120 cycles. Meanwhile, electrolyte optimization effective strategy greatly improving electrochemical performance. Through ex-situ characterizations, we disclosed potassiation Sb anode quite undergoes multistep processes, combining solid solution reaction two-phase reaction.