Capacitive deionization(CDI)technology has been considered a promising desalination technique,especially for brackish water,because of its relatively low energy consumption,facile operation,and easy regeneration of el...Capacitive deionization(CDI)technology has been considered a promising desalination technique,especially for brackish water,because of its relatively low energy consumption,facile operation,and easy regeneration of electrodes.However,the desalination capacity,cost,fabrication method,electrochemical stability,and environmental unfriendliness of the electrodes have restricted the practical application of the CDI technique.Herein,we reported the one-step in situ preparation of nitrogen-doped and carbon-decorated MXene-derived TiO_(2)(termed N-TiO_(2−x)/C)through the confinement-growth strategy.The small particle size(∼25 nm)and uniform distribution of a peanut-like N-TiO_(2−x)/C material could be ascribed to the confined growth space created by the nanoporous structure of melamine foam.The defects produced by N doping provide an enhanced electrical conductivity and more adsorption sites,while wrapping with a carbon shell layer increases the conductivity and offers protection for N-TiO_(2−x) to achieve an excellent electrochemical stability.The prepared N-TiO_(2−x)/C electrode is hydrophilic due to the abundant oxygen-containing functional groups(e.g.,C-O,N-Ti-O,-NO_(x),and-OH)and exhibits a high salt removal capacity(33.4 mg·g^(−1)),desalination rate(1.5 mg·g^(−1)·min^(−1)),and remarkable cycling stability(without declining after 100 cycles),which might be ascribed to the synergistic effects of the short ion diffusion path,more active adsorption sites,enhanced conductivity,pseudocapacitive behavior,and protection of the carbon shell layer.This work provides a confined-growth strategy to develop MXene-derived oxide electrodes for electrochemical desalination.展开更多
To improve rate and cycling performance of manganese oxide anode material,a precipitation method was combined with thermal annealing to prepare the Mn O/Mn3O4/Se Ox(x=0,2)hybrid anode by controlling the reaction tempe...To improve rate and cycling performance of manganese oxide anode material,a precipitation method was combined with thermal annealing to prepare the Mn O/Mn3O4/Se Ox(x=0,2)hybrid anode by controlling the reaction temperature of Mn2O3 and Se powders.At 3 A/g,the synthesized Mn O/Mn3O4/Se Ox anode delivers a discharge capacity of 1007 m A·h/g after 560 cycles.A cyclic voltammetry quantitative analysis reveals that 89.5%pseudocapacitive contribution is gained at a scanning rate of 2.0 m V/s,and the test results show that there is a significant synergistic effect between Mn O and Mn3O4 phases.展开更多
Sodium-ion battery(SIB)is an ideal device that could replace lithium-ion battery(LIB)in grid-scale energy storage system for power because of the low cost and rich reserve of raw material.The key challenge lies in dev...Sodium-ion battery(SIB)is an ideal device that could replace lithium-ion battery(LIB)in grid-scale energy storage system for power because of the low cost and rich reserve of raw material.The key challenge lies in developing electrode materials enabling reversible Na+insertion/desertion and fast reaction kinetics.Herein,a core-shell structure,FeS2 nanoparticles encapsulated in biphase TiO2 shell(FeS2@TiO2),is developed towards the improvement of sodium storage.The diphase TiO2 coating supplies abundant anatase/rutile interface and oxygen vacancies which will enhance the charge transfer,and avoid severe volume variation of FeS2 caused by the Na+insertion.The FeS2 core will deliver high theoretical capacity through its conversion reaction mechanism.Consequently,the FeS2@TiO2 nanorods display notable performance as anode for SIBs including long-term cycling performance(637.8 m A·h·g^-1 at 0.2 A·g^-1 after 300 cycles,374.9 m A·h·g^-1 at 5.0 A·g^-1 after 600 cycles)and outstanding rate capability(222.2 m A·h·g^-1 at 10 A·g^-1).Furthermore,the synthesized FeS2@TiO2 demonstrates significant pseudocapacitive behavior which accounts for 90.7%of the Na+storage,and efficiently boosts the rate capability.This work provides a new pathway to fabricate anode material with an optimized structure and crystal phase for SIBs.展开更多
Rechargeable aluminum ion battery(AIB) with high theoretical specific capacity, abundant elements and low cost engages considerable attention as a promising next generation energy storage and conversion system. Nevert...Rechargeable aluminum ion battery(AIB) with high theoretical specific capacity, abundant elements and low cost engages considerable attention as a promising next generation energy storage and conversion system. Nevertheless, to date, one of the major barriers to pursuit better AIB is the limited applicable cathode materials with the ability to store aluminum highly reversibly. Herein, a highly reversible AIB is proposed using mesoporous TiO2 microparticles(M-TiO2) as the cathode material. The improved performance of Ti O2/Al battery is ascribed to the high ionic conductivity and material stability, which is caused by the stable architecture with a mesoporous microstructure and no random aggregation of secondary particles. In addition, we conducted detailed characterization to gain deeper understanding of the Al^(3+) storage mechanism in anatase Ti O2 for AIB. Our findings demonstrate clearly that Al^(3+)can be reversibly stored in anatase TiO2 by intercalation reactions based on ionic liquid electrolyte. Especially, DFT calculations were used to investigate the accurate insertion sites of aluminum ions in M-Ti O2 and the volume changes of M-TiO2 cells during discharging. As for the controversial side reactions in AIBs, in this work, by normalized calculation, we confirm that M-Ti O2 alone participate in the redox reaction. Moreover, cyclic voltammetry(CV) test was performed to investigate the pseudocapacitive behavior.展开更多
A series of bimetallic nickel cobalt sulfides with hierarchical micro/nano architectures were fabricated via a facile synthesis strategy of bimetallic micro/nano structure precursor construction-anion exchange via sol...A series of bimetallic nickel cobalt sulfides with hierarchical micro/nano architectures were fabricated via a facile synthesis strategy of bimetallic micro/nano structure precursor construction-anion exchange via solvothermal method. Among the nickel cobalt sulfides with different Ni/Co contents, the coral-like Ni1.01Co1.99S4 (Ni/Co, 1/2) delivers ultrafast and stable Na-ion storage performance (350 mAh·g−1 after 1,000 cycles at 1 A·g−1 and 355 mAh·g−1 at 5 A·g−1). The remarkable electrochemical properties can be attributed to the enhanced conductivity by co-existence of bimetallic components, the unique coral-like micro/nanostructure, which could prevent structural collapse and self-aggregation of nanoparticles, and the easily accessibility of electrolyte, and fast Na+ diffusion upon cycling. Detailed kinetics studies by a galvanostatic intermittent titration technique (GITT) reveal the dynamic change of Na+ diffusion upon cycling, and quantitative kinetic analysis indicates the high contribution of pseudocapacitive behavior during charge-discharge processes. Moreover, the ex-situ characterization analysis results further verify the Na-ion storage mechanism based on conversion reaction. This study is expected to provide a feasible design strategy for the bimetallic sulfides materials toward high performance sodium-ion batteries.展开更多
Lithium-ion capacitors(LICs)have attracted wide attention due to their potential of achieving merits of high-power output as well as high energy density.How-ever,the key issue of kinetics mismatch between anode and ca...Lithium-ion capacitors(LICs)have attracted wide attention due to their potential of achieving merits of high-power output as well as high energy density.How-ever,the key issue of kinetics mismatch between anode and cathode hinders the electrochemical performance of LICs.Therefore,a vanadium nitride composite with nanoparti-cles embedded in carbon matrix(VN-C)was prepared as an efficiently pseudocapacitive anode material with high electronic conductivity and fast Li-ion diffusion rate.The VN-C composites were synthesized through one-step ammonia heating treatment at different temperatures among which the sample annealed at 600℃exhibits high specific capacity(513 mAh·g^(-1)at 0.1 A·g^(-1)),outstanding rate performance(~300 mAh·g^(-1)at 10 A·g^(-1)),and excellent cyclic steadiness(negligible capacity decay over 2000 cycles)in half-cell devices.A high-performance lithium-ion capacitor device was also fabricated by using VN-C-600 as the anode and activated carbon as the cath-ode,delivering a maximum energy density of 112.6 Wh·kg^(-1)and an extreme power density of 10 kW·kg^(-1).展开更多
Metal-organic frameworks(MOFs)with porous crystal structures have attracted extensive attention in application of energy storage and conversion,owing to their regularity,porosity,large specific surface area,etc.In thi...Metal-organic frameworks(MOFs)with porous crystal structures have attracted extensive attention in application of energy storage and conversion,owing to their regularity,porosity,large specific surface area,etc.In this work,Co-MOF-74 microflower has been successfully prepared via a controllable solvent regulation strategy.Through modulating the polarity of the solvent,crystals grow in certain preferred orientation and Co-MOF-74 with various morphologies were obtained.Thereinto,the energy storage performance of Co-MOF-74 microflower was measured in both three-electrode system and asymmetric supercapacitor device(specific capacitance of 164.2 F/g at 0.5 A/g in the three-electrode system and 62.5 F/g at 1 A/g in the asymmetric supercapacitor device).This can be attributed to the preferred crystal orientation resulting in a regular and uniform microflower,which is of great significance to electronic interfacial exchange and ion transfer during electrochemical reactions.展开更多
The practical applications of carbon anode for lithium-ion batteries(LIBs)are largely obstructed by their moderate rate capability and cyclic stability.Herein,we report a N,S-codoped porous carbon nanosheet(NSC)decora...The practical applications of carbon anode for lithium-ion batteries(LIBs)are largely obstructed by their moderate rate capability and cyclic stability.Herein,we report a N,S-codoped porous carbon nanosheet(NSC)decorated with Fe_(3)C nanoparticles(Fe_(3)C/NSC)by a one-pot pyrolysis process.The high surface area and abundant defects of NSC can not only promote electrons and ions transfer,but also induce high pseudocapacitive contribution.More importantly,the synergistic catalysis effect of Fe-Nx and Fe_(3)C can catalyze the reversible conversion of some solid electrolyte interface(SEI)components to offer excess capacity during cycling.As expected,the Fe_(3)C-NSC anode delivers a discharge capacity of750 mAh·g^(-1)under a current density of 0.5 A·g^(-1)through 500 cycles and retains a dis-charge capacity of 366 mAh·g^(-1)at 4 A·g^(-1)after 1600 cycles,respectively.Most importantly,the lithium-ion capacitors based on Fe_(3)C/NSC anode demonstrate a high energy density of 249.5 Wh·kg^(-1)at 560 W·kg^(-1).展开更多
Sodium-ion capacitors(SICs)have received increasing interest for grid stationary energy storage application due to their affordability,high power,and energy densities.The major challenge for SICs is to overcome the ki...Sodium-ion capacitors(SICs)have received increasing interest for grid stationary energy storage application due to their affordability,high power,and energy densities.The major challenge for SICs is to overcome the kinetics imbalance between faradaic anode and nonfaradaic cathode.To boost the Na+reaction kinetics,the present work demonstrated a high-rate MnS-based anode by embedding the MnS nanocrystals into the N,S-co-doped carbon matrix(MnS@NSC).Benefiting from the fast pseudocapacitive Na+storage behavior,the resulting composite exhibits extraordinary rate capability(205.6 mAh g−1 at 10 A g−1)and outstanding cycling stability without notable degradation after 2000 cycles.A prototype SIC was demonstrated using MnS@NSC anode and N-doped porous carbon(NC)cathode;the obtained hybrid SIC device can display a high energy density of 139.8 Wh kg−1 and high power density of 11,500 W kg−1,as well as excellent cyclability with 84.5%capacitance retention after 3000 cycles.The superior electrochemical performance is contributed to downsizing of MnS and encapsulation of conductive N,S-co-doped carbon matrix,which not only promote the Na+and electrons transport,but also buffer the volume variations and maintain the structure integrity during Na+insertion/extraction,enabling its comparable fast reaction kinetics and cyclability with NC cathode.展开更多
Transition metal phosphides(TMPs)/carbonaceous matrices have gradually attracted attention in the field of energy storage.In this study,we presented nickel phosphide(Ni2P)nanoparticles anchored to nitrogen-doped carbo...Transition metal phosphides(TMPs)/carbonaceous matrices have gradually attracted attention in the field of energy storage.In this study,we presented nickel phosphide(Ni2P)nanoparticles anchored to nitrogen-doped carbon porous spheres(Ni2P/NC)by using metal-organic framework-Ni as the template.The comprehensive encapsulation architecture provides closer contact among the Ni2P nanoparticles and greatly improves the structural integrity as well as the electronic conductivity,resulting in excellent lithium storage performance.The reversible specific capacity of 286.4 mA hg^-1 has been obtained even at a high current density of 3.0 Ag^-1 and 450.4 mA hg^-1 is obtained after 800 cycles at 0.5 Ag^-1.Furthermore,full batteries based on LiNi1/3Co1/3Mn1/3O2||Ni2P/NC exhibit both good rate capability and cycling life.This study provides a powerful and indepth insight on new advanced electrodes in high-performance energy storage devices.展开更多
The sluggish intercalation kinetics of potassium ions in various anode materials severely hinders the practical application of potassium ion batteries(PIBs) in the field of new energy storage. To overcome this difficu...The sluggish intercalation kinetics of potassium ions in various anode materials severely hinders the practical application of potassium ion batteries(PIBs) in the field of new energy storage. To overcome this difficulty, we developed a green and recyclable molten-salt(MS) strategy using natural tremella as raw material to construct self-N-doped two-dimensional(2D)tremella-derived carbon nanosheets(TCNs), which possesses large specific surface area(SSA), expanded interlayer spacing and rich defects/active sites. Thanks to the unique 2D nanosheet structure and self-N doping, TCNs800 electrode exhibits superior K+storage capacity(386.3 mA h g^(-1) at 0.1 A g^(-1)), ultrafast rate performance(119.7 mA h g^(-1) at 2.0 A g^(-1)) and long-term cycling stability(122.9 mA h g^(-1) with the Coulombic efficiency of near 100% after 1000 cycles). Moreover, detailed electrochemical kinetic analysis shows that the potassium-ion storage mechanism of TCNs800 electrode has enhanced by the pseudocapacitancecontrolled behavior. This work proves an effective green and environmentally friendly MS strategy to prepare 2D biomass nanosheet materials, and provides a reference for exploring excellent electrode materials with pseudocapacitance-controlled behavior.展开更多
基金This research was supported by the National Natural Science Foundation of China(No.21777118).
文摘Capacitive deionization(CDI)technology has been considered a promising desalination technique,especially for brackish water,because of its relatively low energy consumption,facile operation,and easy regeneration of electrodes.However,the desalination capacity,cost,fabrication method,electrochemical stability,and environmental unfriendliness of the electrodes have restricted the practical application of the CDI technique.Herein,we reported the one-step in situ preparation of nitrogen-doped and carbon-decorated MXene-derived TiO_(2)(termed N-TiO_(2−x)/C)through the confinement-growth strategy.The small particle size(∼25 nm)and uniform distribution of a peanut-like N-TiO_(2−x)/C material could be ascribed to the confined growth space created by the nanoporous structure of melamine foam.The defects produced by N doping provide an enhanced electrical conductivity and more adsorption sites,while wrapping with a carbon shell layer increases the conductivity and offers protection for N-TiO_(2−x) to achieve an excellent electrochemical stability.The prepared N-TiO_(2−x)/C electrode is hydrophilic due to the abundant oxygen-containing functional groups(e.g.,C-O,N-Ti-O,-NO_(x),and-OH)and exhibits a high salt removal capacity(33.4 mg·g^(−1)),desalination rate(1.5 mg·g^(−1)·min^(−1)),and remarkable cycling stability(without declining after 100 cycles),which might be ascribed to the synergistic effects of the short ion diffusion path,more active adsorption sites,enhanced conductivity,pseudocapacitive behavior,and protection of the carbon shell layer.This work provides a confined-growth strategy to develop MXene-derived oxide electrodes for electrochemical desalination.
基金Project(2018JJ2513)supported by the Natural Science Foundation of Hunan Province,ChinaProject(18A378)supported by the Education Bureau Research Foundation of Hunan Province,ChinaProject(2019GK4012)supported by the Emerging Strategic Industrial Science and Technology Project of Hunan Province,China。
文摘To improve rate and cycling performance of manganese oxide anode material,a precipitation method was combined with thermal annealing to prepare the Mn O/Mn3O4/Se Ox(x=0,2)hybrid anode by controlling the reaction temperature of Mn2O3 and Se powders.At 3 A/g,the synthesized Mn O/Mn3O4/Se Ox anode delivers a discharge capacity of 1007 m A·h/g after 560 cycles.A cyclic voltammetry quantitative analysis reveals that 89.5%pseudocapacitive contribution is gained at a scanning rate of 2.0 m V/s,and the test results show that there is a significant synergistic effect between Mn O and Mn3O4 phases.
基金supported by the National Nature Science Foundation of China(No.51775366)。
文摘Sodium-ion battery(SIB)is an ideal device that could replace lithium-ion battery(LIB)in grid-scale energy storage system for power because of the low cost and rich reserve of raw material.The key challenge lies in developing electrode materials enabling reversible Na+insertion/desertion and fast reaction kinetics.Herein,a core-shell structure,FeS2 nanoparticles encapsulated in biphase TiO2 shell(FeS2@TiO2),is developed towards the improvement of sodium storage.The diphase TiO2 coating supplies abundant anatase/rutile interface and oxygen vacancies which will enhance the charge transfer,and avoid severe volume variation of FeS2 caused by the Na+insertion.The FeS2 core will deliver high theoretical capacity through its conversion reaction mechanism.Consequently,the FeS2@TiO2 nanorods display notable performance as anode for SIBs including long-term cycling performance(637.8 m A·h·g^-1 at 0.2 A·g^-1 after 300 cycles,374.9 m A·h·g^-1 at 5.0 A·g^-1 after 600 cycles)and outstanding rate capability(222.2 m A·h·g^-1 at 10 A·g^-1).Furthermore,the synthesized FeS2@TiO2 demonstrates significant pseudocapacitive behavior which accounts for 90.7%of the Na+storage,and efficiently boosts the rate capability.This work provides a new pathway to fabricate anode material with an optimized structure and crystal phase for SIBs.
基金supported by the National Basic Research Program of China (Grant No. 2015CB251100)the Shell Global Solutions International B.V. (Agreement No. PT76419)。
文摘Rechargeable aluminum ion battery(AIB) with high theoretical specific capacity, abundant elements and low cost engages considerable attention as a promising next generation energy storage and conversion system. Nevertheless, to date, one of the major barriers to pursuit better AIB is the limited applicable cathode materials with the ability to store aluminum highly reversibly. Herein, a highly reversible AIB is proposed using mesoporous TiO2 microparticles(M-TiO2) as the cathode material. The improved performance of Ti O2/Al battery is ascribed to the high ionic conductivity and material stability, which is caused by the stable architecture with a mesoporous microstructure and no random aggregation of secondary particles. In addition, we conducted detailed characterization to gain deeper understanding of the Al^(3+) storage mechanism in anatase Ti O2 for AIB. Our findings demonstrate clearly that Al^(3+)can be reversibly stored in anatase TiO2 by intercalation reactions based on ionic liquid electrolyte. Especially, DFT calculations were used to investigate the accurate insertion sites of aluminum ions in M-Ti O2 and the volume changes of M-TiO2 cells during discharging. As for the controversial side reactions in AIBs, in this work, by normalized calculation, we confirm that M-Ti O2 alone participate in the redox reaction. Moreover, cyclic voltammetry(CV) test was performed to investigate the pseudocapacitive behavior.
基金This work was supported by the Shandong Provincial Natural Science Foundation (Nos. ZR2020QB123, ZR2020QB108, and ZR2019MEM030)the National Natural Science Foundation of China (Nos. 51972180, 22071135, and 51572134)+2 种基金Academy of Sciences large apparatus United Fund of China (No. U1832187)Key Research & Development Project of Shandong Province (No. 2019GGX102070)the Program for Scientific Research Innovation Team in Colleges and Universities of Jinan (No. 2018GXRC006).
文摘A series of bimetallic nickel cobalt sulfides with hierarchical micro/nano architectures were fabricated via a facile synthesis strategy of bimetallic micro/nano structure precursor construction-anion exchange via solvothermal method. Among the nickel cobalt sulfides with different Ni/Co contents, the coral-like Ni1.01Co1.99S4 (Ni/Co, 1/2) delivers ultrafast and stable Na-ion storage performance (350 mAh·g−1 after 1,000 cycles at 1 A·g−1 and 355 mAh·g−1 at 5 A·g−1). The remarkable electrochemical properties can be attributed to the enhanced conductivity by co-existence of bimetallic components, the unique coral-like micro/nanostructure, which could prevent structural collapse and self-aggregation of nanoparticles, and the easily accessibility of electrolyte, and fast Na+ diffusion upon cycling. Detailed kinetics studies by a galvanostatic intermittent titration technique (GITT) reveal the dynamic change of Na+ diffusion upon cycling, and quantitative kinetic analysis indicates the high contribution of pseudocapacitive behavior during charge-discharge processes. Moreover, the ex-situ characterization analysis results further verify the Na-ion storage mechanism based on conversion reaction. This study is expected to provide a feasible design strategy for the bimetallic sulfides materials toward high performance sodium-ion batteries.
基金financially supported by the National Natural Science Foundation of China (Nos. 52072173 and U1802256)Jiangsu Specially-Appointed Professors Program+2 种基金Jiangsu Province Outstanding Youth Fund (No. BK20200016)the Leading-Edge Technology of Jiangsu Province (No. BK20202008)the Fundamental Research Funds for the Central Universities (No. NE2016005)
文摘Lithium-ion capacitors(LICs)have attracted wide attention due to their potential of achieving merits of high-power output as well as high energy density.How-ever,the key issue of kinetics mismatch between anode and cathode hinders the electrochemical performance of LICs.Therefore,a vanadium nitride composite with nanoparti-cles embedded in carbon matrix(VN-C)was prepared as an efficiently pseudocapacitive anode material with high electronic conductivity and fast Li-ion diffusion rate.The VN-C composites were synthesized through one-step ammonia heating treatment at different temperatures among which the sample annealed at 600℃exhibits high specific capacity(513 mAh·g^(-1)at 0.1 A·g^(-1)),outstanding rate performance(~300 mAh·g^(-1)at 10 A·g^(-1)),and excellent cyclic steadiness(negligible capacity decay over 2000 cycles)in half-cell devices.A high-performance lithium-ion capacitor device was also fabricated by using VN-C-600 as the anode and activated carbon as the cath-ode,delivering a maximum energy density of 112.6 Wh·kg^(-1)and an extreme power density of 10 kW·kg^(-1).
基金supported by the National Natural Science Foundation of China(Nos.U1904215,21671170,21673203)the Topnotch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP)+2 种基金Changjiang scholars program of the Ministry of Education(No.Q2018270)Excellent doctoral dissertation of Yangzhou universityUndergraduate scientific research innovation projects in Jiangsu province(No.201911117036Z)。
文摘Metal-organic frameworks(MOFs)with porous crystal structures have attracted extensive attention in application of energy storage and conversion,owing to their regularity,porosity,large specific surface area,etc.In this work,Co-MOF-74 microflower has been successfully prepared via a controllable solvent regulation strategy.Through modulating the polarity of the solvent,crystals grow in certain preferred orientation and Co-MOF-74 with various morphologies were obtained.Thereinto,the energy storage performance of Co-MOF-74 microflower was measured in both three-electrode system and asymmetric supercapacitor device(specific capacitance of 164.2 F/g at 0.5 A/g in the three-electrode system and 62.5 F/g at 1 A/g in the asymmetric supercapacitor device).This can be attributed to the preferred crystal orientation resulting in a regular and uniform microflower,which is of great significance to electronic interfacial exchange and ion transfer during electrochemical reactions.
基金financially supported by the National Science Foundation of China (Nos. 51772169, 52072217 and 51802261)the National Key R&D Program of China (No. 2018YFB0905400)+2 种基金the Major Technological Innovation Project of Hubei Science and Technology Department (No. 2019AAA164)the Natural Science Foundation of Hubei Province of China (No. 2019CFB337)the Natural Science Foundation of Hubei Provincial Department of Education (No. Q20191204)
文摘The practical applications of carbon anode for lithium-ion batteries(LIBs)are largely obstructed by their moderate rate capability and cyclic stability.Herein,we report a N,S-codoped porous carbon nanosheet(NSC)decorated with Fe_(3)C nanoparticles(Fe_(3)C/NSC)by a one-pot pyrolysis process.The high surface area and abundant defects of NSC can not only promote electrons and ions transfer,but also induce high pseudocapacitive contribution.More importantly,the synergistic catalysis effect of Fe-Nx and Fe_(3)C can catalyze the reversible conversion of some solid electrolyte interface(SEI)components to offer excess capacity during cycling.As expected,the Fe_(3)C-NSC anode delivers a discharge capacity of750 mAh·g^(-1)under a current density of 0.5 A·g^(-1)through 500 cycles and retains a dis-charge capacity of 366 mAh·g^(-1)at 4 A·g^(-1)after 1600 cycles,respectively.Most importantly,the lithium-ion capacitors based on Fe_(3)C/NSC anode demonstrate a high energy density of 249.5 Wh·kg^(-1)at 560 W·kg^(-1).
基金financially supported by the NRF Investigatorship (NRFI), Award No. NRF-NRFI2016-05the Campus for Research Excellent and Technological Enterprise (CREATE),National Research Foundation, Prime Minister’s Office, Singapore
文摘Sodium-ion capacitors(SICs)have received increasing interest for grid stationary energy storage application due to their affordability,high power,and energy densities.The major challenge for SICs is to overcome the kinetics imbalance between faradaic anode and nonfaradaic cathode.To boost the Na+reaction kinetics,the present work demonstrated a high-rate MnS-based anode by embedding the MnS nanocrystals into the N,S-co-doped carbon matrix(MnS@NSC).Benefiting from the fast pseudocapacitive Na+storage behavior,the resulting composite exhibits extraordinary rate capability(205.6 mAh g−1 at 10 A g−1)and outstanding cycling stability without notable degradation after 2000 cycles.A prototype SIC was demonstrated using MnS@NSC anode and N-doped porous carbon(NC)cathode;the obtained hybrid SIC device can display a high energy density of 139.8 Wh kg−1 and high power density of 11,500 W kg−1,as well as excellent cyclability with 84.5%capacitance retention after 3000 cycles.The superior electrochemical performance is contributed to downsizing of MnS and encapsulation of conductive N,S-co-doped carbon matrix,which not only promote the Na+and electrons transport,but also buffer the volume variations and maintain the structure integrity during Na+insertion/extraction,enabling its comparable fast reaction kinetics and cyclability with NC cathode.
基金partly supported by the National Natural Science Foundation of China(11705015 and U1832147)the Foundation of Jiangsu Science and Technology Department(BA2016041)the Science and Technology Plan Project of Suzhou(SYG201738 and SZS201710)。
文摘Transition metal phosphides(TMPs)/carbonaceous matrices have gradually attracted attention in the field of energy storage.In this study,we presented nickel phosphide(Ni2P)nanoparticles anchored to nitrogen-doped carbon porous spheres(Ni2P/NC)by using metal-organic framework-Ni as the template.The comprehensive encapsulation architecture provides closer contact among the Ni2P nanoparticles and greatly improves the structural integrity as well as the electronic conductivity,resulting in excellent lithium storage performance.The reversible specific capacity of 286.4 mA hg^-1 has been obtained even at a high current density of 3.0 Ag^-1 and 450.4 mA hg^-1 is obtained after 800 cycles at 0.5 Ag^-1.Furthermore,full batteries based on LiNi1/3Co1/3Mn1/3O2||Ni2P/NC exhibit both good rate capability and cycling life.This study provides a powerful and indepth insight on new advanced electrodes in high-performance energy storage devices.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.21863006,51662029,21365013 and 51704134)the Natural Science Foundation of Jiangxi Province(Grant Nos.20192ACB21010 and 20202ACB202004)。
文摘The sluggish intercalation kinetics of potassium ions in various anode materials severely hinders the practical application of potassium ion batteries(PIBs) in the field of new energy storage. To overcome this difficulty, we developed a green and recyclable molten-salt(MS) strategy using natural tremella as raw material to construct self-N-doped two-dimensional(2D)tremella-derived carbon nanosheets(TCNs), which possesses large specific surface area(SSA), expanded interlayer spacing and rich defects/active sites. Thanks to the unique 2D nanosheet structure and self-N doping, TCNs800 electrode exhibits superior K+storage capacity(386.3 mA h g^(-1) at 0.1 A g^(-1)), ultrafast rate performance(119.7 mA h g^(-1) at 2.0 A g^(-1)) and long-term cycling stability(122.9 mA h g^(-1) with the Coulombic efficiency of near 100% after 1000 cycles). Moreover, detailed electrochemical kinetic analysis shows that the potassium-ion storage mechanism of TCNs800 electrode has enhanced by the pseudocapacitancecontrolled behavior. This work proves an effective green and environmentally friendly MS strategy to prepare 2D biomass nanosheet materials, and provides a reference for exploring excellent electrode materials with pseudocapacitance-controlled behavior.
