FeS_(2)is a promising anode material for potassium-ion batteries(PIBs),with the advantages of low cost and high capacity.However,it still faces challenges of capacity fading and poor rate performance in potassium stor...FeS_(2)is a promising anode material for potassium-ion batteries(PIBs),with the advantages of low cost and high capacity.However,it still faces challenges of capacity fading and poor rate performance in potassium storage.Rational structural design is one way to overcome these drawbacks.In this work,MIL-88B-Fe-derived FeS_(2)nanoparticles/N-doped carbon nanofibers(M-FeS_(2)@CNFs)with expansion buffer capability are designed and synthesized for high-performance PIB anodes via electrospinning and subsequent sulfurization.The uniformly distributed cavity-type porous structure effectively mitigates the severe aggregation problem of FeS_(2)nanoparticles during cycling and buffers the volume change,further enhancing the potassium storage capacity.Meanwhile,the robust KF-rich solid electrolyte interphase induced by methyl trifluoroethylene carbonate(FEMC)additive improves the cycling stability of the M-FeS_(2)@CNF anode.In the electrolyte with 3 wt%FEMC,the M-FeS_(2)@CNF anode shows a reversible specific capacity of 592.7 mA h g^(-1)at 0.1 A g^(-1),an excellent rate capability of 327.1 mA h g^(-1)at 5 A g^(-1),and a retention rate 80.7%over 1000 cycles at 1 A g^(-1).More importantly,when assembled with a K_(1.84)Ni[Fe(CN)_(6)]_(0.88)·0.49H_(2)O cathode,the full battery manifests excellent cycle stability and high rate performance.This study demonstrates the significant importance of the synergistic effect of structural regulation and electrolyte optimization in achieving high cycling stability of PIBs.展开更多
基金supported by the National Natural Science Foundation of China(22179063,22479078,and 22409093)the Natural Science Foundation of Jiangsu Province of China(BK20240579)。
文摘FeS_(2)is a promising anode material for potassium-ion batteries(PIBs),with the advantages of low cost and high capacity.However,it still faces challenges of capacity fading and poor rate performance in potassium storage.Rational structural design is one way to overcome these drawbacks.In this work,MIL-88B-Fe-derived FeS_(2)nanoparticles/N-doped carbon nanofibers(M-FeS_(2)@CNFs)with expansion buffer capability are designed and synthesized for high-performance PIB anodes via electrospinning and subsequent sulfurization.The uniformly distributed cavity-type porous structure effectively mitigates the severe aggregation problem of FeS_(2)nanoparticles during cycling and buffers the volume change,further enhancing the potassium storage capacity.Meanwhile,the robust KF-rich solid electrolyte interphase induced by methyl trifluoroethylene carbonate(FEMC)additive improves the cycling stability of the M-FeS_(2)@CNF anode.In the electrolyte with 3 wt%FEMC,the M-FeS_(2)@CNF anode shows a reversible specific capacity of 592.7 mA h g^(-1)at 0.1 A g^(-1),an excellent rate capability of 327.1 mA h g^(-1)at 5 A g^(-1),and a retention rate 80.7%over 1000 cycles at 1 A g^(-1).More importantly,when assembled with a K_(1.84)Ni[Fe(CN)_(6)]_(0.88)·0.49H_(2)O cathode,the full battery manifests excellent cycle stability and high rate performance.This study demonstrates the significant importance of the synergistic effect of structural regulation and electrolyte optimization in achieving high cycling stability of PIBs.
