Heterogeneous structure and carbon coating are important ways to enhance the reaction kinetics and cycling stability of metal phosphides as anode materials for sodium-ion batteries.Therefore,nitrogen-doped carbon-capp...Heterogeneous structure and carbon coating are important ways to enhance the reaction kinetics and cycling stability of metal phosphides as anode materials for sodium-ion batteries.Therefore,nitrogen-doped carbon-capped triphasic heterostructure Cu_(3)P/Co_(2)P/CoP@NC stands for nitrogen doped carbon nanorods were designed and synthesized through a combination of phosphide and carbonization.Kinetic analyses(cyclic voltammetry,electrochemical impedance spectroscopy,and galvanostatic intermittent titration technique)and density functional theory calculations show that the three-phase heterostructure and carbon layer effectively improve Na adsorption and migration as well as the electrochemical reactivity of the electrode.Based on this,Cu_(3)P/Co_(2)P/CoP@NC demonstrated excellent rate performance(305.9 mAh g^(-1)at 0.3 A g^(-1)and 202.8 mAh g^(-1)even at 10 A g^(-1))and cycling stability(the capacity decay rate is only 0.12%from the 5th to 300th cycle)when it is used for sodium-ion battery anodes.The in situ X-ray diffraction,ex situ X-ray photoelectron spectroscopy,and high-resolution transmission electron microscopy tests showed that Cu_(3)P/Co_(2)P/CoP@NC is based on a conversion reaction mechanism for sodium-ion storage.In addition,the NVP@reduced graphene oxide(rGO)//Cu_(3)P/Co_(2)P/CoP@NC full-cell delivers a high capacity of 210.2 mAh g^(-1)after 50 cycles at 0.3 A g^(-1).This work can provide a reference for the design of high-performance sodium electrode anode materials.展开更多
Lithium-sulfur(Li-S)batteries have attracted extensive attention along with the urgent increasing demand for energy storage owing to the high theoretical specific capacity and energy density,abundant reserves and low ...Lithium-sulfur(Li-S)batteries have attracted extensive attention along with the urgent increasing demand for energy storage owing to the high theoretical specific capacity and energy density,abundant reserves and low cost of sulfur.However,the practical application of Li-S batteries is still impeded due to the low utilization of sulfur and serious shuttle-effect of lithium polysulfides(LiPSs).Here,we fabricated the porous honeycomb-like C_(3)N_(4)(PHCN)through a hard template method.As a polar material,graphitic C_(3)N_(4)has abundant nitrogen content(-58%),which can provide enough active sites to mitigate shuttle-effect,and then conductive reduced graphene oxide(rGO)was introduced to combine with PHCN to form PHCN/rGO composite in order to improve the utilization efficiency of sulfur.After sulfur loading,the PHCN/rGO/S cathode exhibited an initial discharge capacity of 1,061.1 mA h g^-1 at 0.2 C and outstanding rate performance at high current density of 5 C(495.1 mA h g^(-1)),and also retained 519 mA h g^(-1),after 400 cycles at 1 C.Even at high sulfur loading(4.3 mg cm^(-2)),the capacity fade rate was only 0.16%per cycle at 0.5 C for 200 cycles.The above results demonstrate that the special design of PHCN/rGO composite as sulfur host has high potential application for Li-S rechargeable batteries.展开更多
Sulfur-host material with abundant pore structure and high catalysis plays an important role in development of high-energy-density lithium-sulfur(Li-S)batteries.Herein,we implanted NiCoP nanoparticles into the N,S co-...Sulfur-host material with abundant pore structure and high catalysis plays an important role in development of high-energy-density lithium-sulfur(Li-S)batteries.Herein,we implanted NiCoP nanoparticles into the N,S co-doped porous carbon derived from petroleum coke(PCPC)to fabricate the sulfur-host of PCPC/NiCoP composites.The high specific surface area of PCPC provides abundant adsorption sites for capturing LiPSs and the NiCoP nanoparticles to improve the polarity and boost the LiPSs conversion kinetics of PCPC.The Li-S cells fabricated with PCPC/NiCoP as sulfur-host deliver high discharge capacity of 1,462.7 mAh·g^(-1)under the current density of 0.1 C and exhibit ultralong lifespan over 800 cycles under the current density of 1,2,and even 5 C.Additionally,the prepared composites cathodes deliver an outstanding discharge capacity of 932.5 and 826.4 mAh·g^(-1)at 0.5 and 1 C with a high sulfur loading of over 3.90 mg·cm^(-2),and remain stable about 60 cycles.Furthermore,the promoted adsorption-conversion process of polysulfides by introducing NiCoP nanoparticles into PCPC was investigated by experimental and theoretical calculation studies.This work offers a new light for tacking the obstacles of porous carbon-based sulfur-host and propelling the development of petroleum coke-based porous carbon for high performance Li-S batteries.展开更多
Lithium metal is regarded as one of the most promising candidates for next-generation batteries.However,lithium dendrite formation and dead lithium accumulation are the critical problems which hinder its practical app...Lithium metal is regarded as one of the most promising candidates for next-generation batteries.However,lithium dendrite formation and dead lithium accumulation are the critical problems which hinder its practical application.Herein,we constructed a flexible coating membrane layer which could effectively uniform the lithium deposition by isolating lithium metal from electrolyte and regulating the ion flux distribution.After modification,both the Li||Li symmetric cells(more than 1,400 h at 1 mA·cm^(−2)and 1 mAh·cm^(−2))and Li||Cu cells(more than 500 cycles at 0.5 mA·cm^(−2)and 0.5 mAh·cm^(−2),coulombic efficiency over 98%)deliver excellent long-cycle performance with high coulombic efficiency.The high performance is also proved in LiFePO4(capacity retention increases from 79%to 93%at 2 C after 400 cycles)and NCM811 full cells(capacity retention from 28.5%to 78%at 2 C after 500 cycles).High electro-performance in batteries demonstrates that the multifunctional layer plays a crucial role in stabilizing lithium anode.Moreover,in order to verify the universality of the method,we have extended this facile way to fabricate other types of flexible membranes.This work offers an insight into solving the current obstacles in the application of lithium metal batteries.展开更多
Potassium-ion batteries(PIBs)are promising candidates for next-generation energy storage devices due to the earth abundance of potassium,low cost,and stable redox potentials.However,the lack of promising high-performa...Potassium-ion batteries(PIBs)are promising candidates for next-generation energy storage devices due to the earth abundance of potassium,low cost,and stable redox potentials.However,the lack of promising high-performance electrode materials for the intercalation/deintercalation of large potassium ions is a major challenge up to date.Herein,we report a novel uniform nickel selenide nanoparticles encapsulated in nitrogen-doped carbon(defined as“NiSe@NC”)as an anode for PIBs,which exhibits superior rate performance and cyclic stability.Benefiting from the unique hierarchical core-shell like nanostructure,the intrinsic properties of metal-selenium bonds,synergetic effect of different components,and a remarkable pseudocapacitance effect,the anode exhibits a very high reversible capacity of 438 mA·h·g^(-1)at 50 mA·g^(-1),an excellent rate capability,and remarkable cycling performance over 2,000 cycles.The electrochemical mechanism were investigated by the in-situ X-ray diffraction,ex-situ high-resolution transmission electron microscopy,selected area electron diffraction,and first principle calculations.In addition,NiSe@NC anode also shows high reversible capacity of 512 mA·h·g^(-1)at 100 mA·g^(-1)with 84%initial Coulombic efficiency,remarkable rate performance,and excellent cycling life for sodium ion batteries.We believe the proposed simple approach will pave a new way to synthesize suitable anode materials for secondary ion batteries.展开更多
基金supported by the National Natural Science Foundation of China (No. 22305210, 52371238 to C. D.)the Shandong Provincial Natural Science Foundation (No. ZR2020QB108)+1 种基金the Graduate Innovation Foundation of Yantai University (GIFYTU)the Shandong Laboratory of Advanced Materials and Green Manufacturing (Yantai, AMGM2024A01)
文摘Heterogeneous structure and carbon coating are important ways to enhance the reaction kinetics and cycling stability of metal phosphides as anode materials for sodium-ion batteries.Therefore,nitrogen-doped carbon-capped triphasic heterostructure Cu_(3)P/Co_(2)P/CoP@NC stands for nitrogen doped carbon nanorods were designed and synthesized through a combination of phosphide and carbonization.Kinetic analyses(cyclic voltammetry,electrochemical impedance spectroscopy,and galvanostatic intermittent titration technique)and density functional theory calculations show that the three-phase heterostructure and carbon layer effectively improve Na adsorption and migration as well as the electrochemical reactivity of the electrode.Based on this,Cu_(3)P/Co_(2)P/CoP@NC demonstrated excellent rate performance(305.9 mAh g^(-1)at 0.3 A g^(-1)and 202.8 mAh g^(-1)even at 10 A g^(-1))and cycling stability(the capacity decay rate is only 0.12%from the 5th to 300th cycle)when it is used for sodium-ion battery anodes.The in situ X-ray diffraction,ex situ X-ray photoelectron spectroscopy,and high-resolution transmission electron microscopy tests showed that Cu_(3)P/Co_(2)P/CoP@NC is based on a conversion reaction mechanism for sodium-ion storage.In addition,the NVP@reduced graphene oxide(rGO)//Cu_(3)P/Co_(2)P/CoP@NC full-cell delivers a high capacity of 210.2 mAh g^(-1)after 50 cycles at 0.3 A g^(-1).This work can provide a reference for the design of high-performance sodium electrode anode materials.
基金supported by the Chinese Academy of Sciences Large Apparatus United Fund(U1832187)the National Natural Science Foundation of China(21471091)+3 种基金the Natural Science Foundation of Shandong Province(ZR2019MEM030)Guangdong Province Science and Technology Plan Project for Public Welfare Fund and Ability Construction Project(2017A010104003)the Fundamental Research Funds of Shandong University(2018JC022)Taishan Scholar Project of Shandong Province(ts201511004)
文摘Lithium-sulfur(Li-S)batteries have attracted extensive attention along with the urgent increasing demand for energy storage owing to the high theoretical specific capacity and energy density,abundant reserves and low cost of sulfur.However,the practical application of Li-S batteries is still impeded due to the low utilization of sulfur and serious shuttle-effect of lithium polysulfides(LiPSs).Here,we fabricated the porous honeycomb-like C_(3)N_(4)(PHCN)through a hard template method.As a polar material,graphitic C_(3)N_(4)has abundant nitrogen content(-58%),which can provide enough active sites to mitigate shuttle-effect,and then conductive reduced graphene oxide(rGO)was introduced to combine with PHCN to form PHCN/rGO composite in order to improve the utilization efficiency of sulfur.After sulfur loading,the PHCN/rGO/S cathode exhibited an initial discharge capacity of 1,061.1 mA h g^-1 at 0.2 C and outstanding rate performance at high current density of 5 C(495.1 mA h g^(-1)),and also retained 519 mA h g^(-1),after 400 cycles at 1 C.Even at high sulfur loading(4.3 mg cm^(-2)),the capacity fade rate was only 0.16%per cycle at 0.5 C for 200 cycles.The above results demonstrate that the special design of PHCN/rGO composite as sulfur host has high potential application for Li-S rechargeable batteries.
基金This work was supported by the National Natural Science Foundation of China(No.22071135)Academy of Sciences Large Apparatus United Fund of China(No.U1832187)Natural Science Foundation of Shandong Province(Nos.ZR2019MEM030 and ZR2021ZD05).
文摘Sulfur-host material with abundant pore structure and high catalysis plays an important role in development of high-energy-density lithium-sulfur(Li-S)batteries.Herein,we implanted NiCoP nanoparticles into the N,S co-doped porous carbon derived from petroleum coke(PCPC)to fabricate the sulfur-host of PCPC/NiCoP composites.The high specific surface area of PCPC provides abundant adsorption sites for capturing LiPSs and the NiCoP nanoparticles to improve the polarity and boost the LiPSs conversion kinetics of PCPC.The Li-S cells fabricated with PCPC/NiCoP as sulfur-host deliver high discharge capacity of 1,462.7 mAh·g^(-1)under the current density of 0.1 C and exhibit ultralong lifespan over 800 cycles under the current density of 1,2,and even 5 C.Additionally,the prepared composites cathodes deliver an outstanding discharge capacity of 932.5 and 826.4 mAh·g^(-1)at 0.5 and 1 C with a high sulfur loading of over 3.90 mg·cm^(-2),and remain stable about 60 cycles.Furthermore,the promoted adsorption-conversion process of polysulfides by introducing NiCoP nanoparticles into PCPC was investigated by experimental and theoretical calculation studies.This work offers a new light for tacking the obstacles of porous carbon-based sulfur-host and propelling the development of petroleum coke-based porous carbon for high performance Li-S batteries.
基金the National Nature Science Foundation of China(No.22071135)the Academy of Sciences large apparatus United Fund(No.U1832187)the Nature Science Foundation of Shandong Province(No.ZR2019MEM030).
文摘Lithium metal is regarded as one of the most promising candidates for next-generation batteries.However,lithium dendrite formation and dead lithium accumulation are the critical problems which hinder its practical application.Herein,we constructed a flexible coating membrane layer which could effectively uniform the lithium deposition by isolating lithium metal from electrolyte and regulating the ion flux distribution.After modification,both the Li||Li symmetric cells(more than 1,400 h at 1 mA·cm^(−2)and 1 mAh·cm^(−2))and Li||Cu cells(more than 500 cycles at 0.5 mA·cm^(−2)and 0.5 mAh·cm^(−2),coulombic efficiency over 98%)deliver excellent long-cycle performance with high coulombic efficiency.The high performance is also proved in LiFePO4(capacity retention increases from 79%to 93%at 2 C after 400 cycles)and NCM811 full cells(capacity retention from 28.5%to 78%at 2 C after 500 cycles).High electro-performance in batteries demonstrates that the multifunctional layer plays a crucial role in stabilizing lithium anode.Moreover,in order to verify the universality of the method,we have extended this facile way to fabricate other types of flexible membranes.This work offers an insight into solving the current obstacles in the application of lithium metal batteries.
基金This work was supported by Academy of Sciences large apparatus United Fund(No.U1832187)the National Nature Science Foundation of China(No.22071135)the Nature Science Foundation of Shandong Province(No.ZR2019MEM030).
文摘Potassium-ion batteries(PIBs)are promising candidates for next-generation energy storage devices due to the earth abundance of potassium,low cost,and stable redox potentials.However,the lack of promising high-performance electrode materials for the intercalation/deintercalation of large potassium ions is a major challenge up to date.Herein,we report a novel uniform nickel selenide nanoparticles encapsulated in nitrogen-doped carbon(defined as“NiSe@NC”)as an anode for PIBs,which exhibits superior rate performance and cyclic stability.Benefiting from the unique hierarchical core-shell like nanostructure,the intrinsic properties of metal-selenium bonds,synergetic effect of different components,and a remarkable pseudocapacitance effect,the anode exhibits a very high reversible capacity of 438 mA·h·g^(-1)at 50 mA·g^(-1),an excellent rate capability,and remarkable cycling performance over 2,000 cycles.The electrochemical mechanism were investigated by the in-situ X-ray diffraction,ex-situ high-resolution transmission electron microscopy,selected area electron diffraction,and first principle calculations.In addition,NiSe@NC anode also shows high reversible capacity of 512 mA·h·g^(-1)at 100 mA·g^(-1)with 84%initial Coulombic efficiency,remarkable rate performance,and excellent cycling life for sodium ion batteries.We believe the proposed simple approach will pave a new way to synthesize suitable anode materials for secondary ion batteries.
