Lithium-sulfur(Li-S)batteries have been regarded as promising energy-storage systems,due to their high theoretical capacity and energy density.However,the carbonaceous sulfur hosts suffer from weak binding force betwe...Lithium-sulfur(Li-S)batteries have been regarded as promising energy-storage systems,due to their high theoretical capacity and energy density.However,the carbonaceous sulfur hosts suffer from weak binding force between the hosts and polysulfides,restricting the cyclic stability of sulfur electrode.Meantime,the presence of binder and conductive agent in the traditional electrode reduces its energy density.This study demonstrates that titanium nitride(TiN)nanorod array on carbon cloth(CC)is employed as a flexible host for highly stable Li-S batteries via solvothermal synthesis-nitridation strategy.On the one hand,the flexible integrated network composed of three-dimensional TiN nanorod array and CC significantly improves the conductivity,increases the electron transport and electrolyte penetration of cathode.On the other hand,the 3D structure of TiN/CC and the enhanced polarity of TiN effectively strengthen the physical and chemical double adsorption for polysulfides.As a result,the combination of TiN nanorod array and CC synergistic ally promotes sulfur utilization and electrochemical performances of S@TiN/CC cathode.A discharge capacity of1015.2 mAh·g^(-1)at 0.5C after 250 cycles and 604.1mAh·g^(-1)at 3C after 250 cycles is realized.Under a larger current density of 5C,the resulting S@TiN/CC cathode maintains a high discharge capacity of 666.6 mAh·g^(-1)and the Coulombic efficiency of about 100%.展开更多
Durability, rate capability, capacity and tap density are paramount performance metrics for promising anode materials, especially for sodium ion batteries. Herein, a carbon free mesoporous CoTiO3 micro-prism with a hi...Durability, rate capability, capacity and tap density are paramount performance metrics for promising anode materials, especially for sodium ion batteries. Herein, a carbon free mesoporous CoTiO3 micro-prism with a high tap density （1.8 gcm^-3） is newly developed by using a novel Co-Ti- bimetal organic framework （BMOF） as precursor. It is also interesting to find that the Co-Ti-BMOF derived carbon-free mesoporous CoTiO3 micro-prisms deliver a superior stable and more powerful Na^＋ storage than other similar reported titania, titanate and their carbon composites. Its achieved ca- pacity retention ratio for 2,000 cycles is up to 90.1% at 5 A g^-1.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos.22179064,91963119,21805140,51772157,21905141,22203046 and62174087)China Postdoctoral Science Foundation (No.2018M642287)+2 种基金Jiangsu Province Postdoctoral Research Grant Program (No.2018K156C)Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM)the Synergetic Innovation Center for Organic Electronics and Information Displays。
文摘Lithium-sulfur(Li-S)batteries have been regarded as promising energy-storage systems,due to their high theoretical capacity and energy density.However,the carbonaceous sulfur hosts suffer from weak binding force between the hosts and polysulfides,restricting the cyclic stability of sulfur electrode.Meantime,the presence of binder and conductive agent in the traditional electrode reduces its energy density.This study demonstrates that titanium nitride(TiN)nanorod array on carbon cloth(CC)is employed as a flexible host for highly stable Li-S batteries via solvothermal synthesis-nitridation strategy.On the one hand,the flexible integrated network composed of three-dimensional TiN nanorod array and CC significantly improves the conductivity,increases the electron transport and electrolyte penetration of cathode.On the other hand,the 3D structure of TiN/CC and the enhanced polarity of TiN effectively strengthen the physical and chemical double adsorption for polysulfides.As a result,the combination of TiN nanorod array and CC synergistic ally promotes sulfur utilization and electrochemical performances of S@TiN/CC cathode.A discharge capacity of1015.2 mAh·g^(-1)at 0.5C after 250 cycles and 604.1mAh·g^(-1)at 3C after 250 cycles is realized.Under a larger current density of 5C,the resulting S@TiN/CC cathode maintains a high discharge capacity of 666.6 mAh·g^(-1)and the Coulombic efficiency of about 100%.
基金supported by the National Natural Science Foundation of China(51402155 and 21373107)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)(YX03002)+2 种基金Jiangsu National Synergistic Innovation Center for Advanced Materials(SICAM)Foundation of NJUPT(NY217077)PolyU Start-up Fund for New Recruits(No.1-ZE8R)
文摘Durability, rate capability, capacity and tap density are paramount performance metrics for promising anode materials, especially for sodium ion batteries. Herein, a carbon free mesoporous CoTiO3 micro-prism with a high tap density （1.8 gcm^-3） is newly developed by using a novel Co-Ti- bimetal organic framework （BMOF） as precursor. It is also interesting to find that the Co-Ti-BMOF derived carbon-free mesoporous CoTiO3 micro-prisms deliver a superior stable and more powerful Na^＋ storage than other similar reported titania, titanate and their carbon composites. Its achieved ca- pacity retention ratio for 2,000 cycles is up to 90.1% at 5 A g^-1.
