Heterostructured sulfur electrocatalysts have long been heralded as an effective approach to settle the issues of the shuttle effect and sluggish reaction kinetics of lithium polysulfides(LiPSs)in lithium-sulfur(Li-S)...Heterostructured sulfur electrocatalysts have long been heralded as an effective approach to settle the issues of the shuttle effect and sluggish reaction kinetics of lithium polysulfides(LiPSs)in lithium-sulfur(Li-S)batteries.However,the limited active sites on the interface of the heterostructure offer unsatisfactory LiPSs conversion capability,rendering sluggish reaction kinetics.Herein,we have designed abnormal step-scheme nano-heterointerfaces,containing P-N,N-semimetal,and P-semimetal heterostructures as sulfur electrocatalysts to regulate the LiPSs catalytic conversion behavior,which demonstrates efficient catalytic activity and robust structural stability.The excellent electron-confinement contributed by the step-scheme barrier endows the electron gathering at the nano-heterointerfaces,conferring high selectivity and durability of electrocatalyst for an accelerated sulfur reduction reaction.The unique robust structure design further bestows the sulfur composite with favored ion/mass transportation within the electrode.Attributed to these structural features,the Li-S cell delivers excellent performance under high areal capacity over 7 mAh cm^(−2) and lean electrolyte/sulfur ratio below 2.5μL mg^(−1),decent rate capability up to 8 C,remarkable cyclic stability over 500 cycles,and satisfactory energy density of 386.3 Wh kg^(−1) in a 7.5 Ah pouch cell.This nano-heterointerface structure design strategy endows a sulfur cathode with superior LiPSs catalytic activity,opening new insights into high-performance Li-S batteries.展开更多
基金supported by the Natural Science Foundation of China(grant no.22309179)Natural Science Foundation of Ningxia(grant no.2023AAC01003)Chinese Academy of Sciences,and the Foundation of State Key Laboratory of High Efficiency Utilization of Coal and Green Chemical Engineering(grant no.2022-K79)。
文摘Heterostructured sulfur electrocatalysts have long been heralded as an effective approach to settle the issues of the shuttle effect and sluggish reaction kinetics of lithium polysulfides(LiPSs)in lithium-sulfur(Li-S)batteries.However,the limited active sites on the interface of the heterostructure offer unsatisfactory LiPSs conversion capability,rendering sluggish reaction kinetics.Herein,we have designed abnormal step-scheme nano-heterointerfaces,containing P-N,N-semimetal,and P-semimetal heterostructures as sulfur electrocatalysts to regulate the LiPSs catalytic conversion behavior,which demonstrates efficient catalytic activity and robust structural stability.The excellent electron-confinement contributed by the step-scheme barrier endows the electron gathering at the nano-heterointerfaces,conferring high selectivity and durability of electrocatalyst for an accelerated sulfur reduction reaction.The unique robust structure design further bestows the sulfur composite with favored ion/mass transportation within the electrode.Attributed to these structural features,the Li-S cell delivers excellent performance under high areal capacity over 7 mAh cm^(−2) and lean electrolyte/sulfur ratio below 2.5μL mg^(−1),decent rate capability up to 8 C,remarkable cyclic stability over 500 cycles,and satisfactory energy density of 386.3 Wh kg^(−1) in a 7.5 Ah pouch cell.This nano-heterointerface structure design strategy endows a sulfur cathode with superior LiPSs catalytic activity,opening new insights into high-performance Li-S batteries.
