The high energy density of lithium-sulfur batteries (LSBs) is mainly based on the complex redox reactions and phase conversions.The sluggish redox kinetics and the large accumulation of soluble polysulfides in the ele...The high energy density of lithium-sulfur batteries (LSBs) is mainly based on the complex redox reactions and phase conversions.The sluggish redox kinetics and the large accumulation of soluble polysulfides in the electrolyte leads to low sulfur utilization and serious shuttle effect.Herein,an integrated sulfur cathode is constructed through a facile and large-scale method.It is composed of sulfur-N,S doped bamboo like CNTs@Co3S4 (NSC@Co3S4) composites on polypropylene separator.The immobilized polysulfides on the NSC@Co3S4 surface are further reduced/oxidized during the discharge/charge process via the efficient bi-functional catalytic effect of NSC@Co3S4,resulting in the rapid conversion of LiPSs.Consequently,the integrated sulfur cathode delivers a high initial reversible capacity of 1,473.6 mAh·g^-1 at 0.2 C and a high specific capacity of 979 mAh·g^-1 at 1 C after 500 cycles as well as excellent cycling stability for 1,000 cycles with a high specific capacity of 362.5 mAh·g^-1 at 5 C,which are superior to reported similar host materials.展开更多
基金the Postdoctoral Science Foundation of China (No. 2017M611171)the National Natural Science Foundation of China (Nos. 21571170, 2150116& and 51702236)Tianjin Municipal Science and Technology Commission (No. 17JCZDJC38000).
文摘The high energy density of lithium-sulfur batteries (LSBs) is mainly based on the complex redox reactions and phase conversions.The sluggish redox kinetics and the large accumulation of soluble polysulfides in the electrolyte leads to low sulfur utilization and serious shuttle effect.Herein,an integrated sulfur cathode is constructed through a facile and large-scale method.It is composed of sulfur-N,S doped bamboo like CNTs@Co3S4 (NSC@Co3S4) composites on polypropylene separator.The immobilized polysulfides on the NSC@Co3S4 surface are further reduced/oxidized during the discharge/charge process via the efficient bi-functional catalytic effect of NSC@Co3S4,resulting in the rapid conversion of LiPSs.Consequently,the integrated sulfur cathode delivers a high initial reversible capacity of 1,473.6 mAh·g^-1 at 0.2 C and a high specific capacity of 979 mAh·g^-1 at 1 C after 500 cycles as well as excellent cycling stability for 1,000 cycles with a high specific capacity of 362.5 mAh·g^-1 at 5 C,which are superior to reported similar host materials.
