The preparation process and properties of the thermally prepared Ti anodes coated with IrO2+Ta2O5 was studied. The structure and morphologies of the IrO2+Ta2O5 coatings were determined by XRD and SEM. Their electroche...The preparation process and properties of the thermally prepared Ti anodes coated with IrO2+Ta2O5 was studied. The structure and morphologies of the IrO2+Ta2O5 coatings were determined by XRD and SEM. Their electrochemical properties were studied by polarization curve and cyclic voltammetry. Trivalent chromium electroplating using Ti/IrO2+Ta2O5 anodes is carried out and the results were analyzed. Results show that this anode exhibits excellent electrochemical activity and stability in sulfate electrolysis. The electrocatalytic activity is determined not only by the content of IrO2 but also the structure and morphology of the anode coatings. The electroplating results indicats that Ti/IrO2+Ta2O5 anodes have excellent capabilities and merits in improving the stability of trivalent chromium electroplating in sulfate system.展开更多
Lithium (Li) metal batteries have attracted much attention owing to its ultra-high energy density.However,as important part of Li metal batteries,Li anodes still face many challenges,mainly including uncontrolled dend...Lithium (Li) metal batteries have attracted much attention owing to its ultra-high energy density.However,as important part of Li metal batteries,Li anodes still face many challenges,mainly including uncontrolled dendritic Li formation,dramatical volume variation and serious pulverization.Herein,manganese dioxide (MnO_(2)) nanosheet modified nitrogen (N),phosphorus (P) co-doping carbon nanofibers(NPC) on carbon cloth (CC)(MnO_(2)@NPC-CC) is successfully fabricated through electrodeposition approach and further treated with Li by the molten-infusion method to prepare Li based Mn@NPC-CC(Li-Mn@NPC-CC) electrode.The synergy of MnO_(2) and NPC obviously increases the reaction rate between MnO_(2)@NPC-CC and Li and guides even Li distribution over infusion process.Additionally,theoretical calculation,simulation and experimental results further indicate that N,P,Mn multi-doping effectively improves the superior lithiophilicity of Li-Mn@NPC-CC,which induces uniform Li deposition/dissolution to suppress dendrite growth over cycles.Moreover,conductive and porous NPC matrix not only effectively improves the stability of Li-Mn@NPC-CC,but also provides abundant spaces to accelerate the transfer of ion/electron and buffer electrode dimension variation during cycling.Hence,Li-Mn@NPC-CC-based symmetric cells exhibit extra-long cycling life (over 2200 h) with small hysteresis of 20 mV.When the LiMn@NPC-CC anode couples with air,Li iron phosphate (LiFePO_(4)),or hard carbon (C) cathode,the assembled full cells exhibit outstanding performance with low hysteresis and stable cycling properties.Especially,the corresponding pouch-typed Li–air cells also exhibit good performance at different bending angles and even power a series of electronic devices.展开更多
P-doping is an effective way to modulate the electronic structure and improve the Na+diffusion kinetics of TiO_(2), enabling enhanced electrochemical performance. However, it is a challenge to prepare TiO;with a high ...P-doping is an effective way to modulate the electronic structure and improve the Na+diffusion kinetics of TiO_(2), enabling enhanced electrochemical performance. However, it is a challenge to prepare TiO;with a high P-doping concentration starting from TiO_(2)in a crystalline state. In this work, we design a novel two-step route for constructing a carbon-coated anatase P-doping TiO_(2)nanospheres(denote as(PAn TSS)@NC) with high P-doping concentration, by utilizing amorphous TiO;nanospheres with the ultrahigh specific area as P-doping precursor firstly, and followed by carbon coating treatment. Experimental results demonstrate that P is successfully doped into the crystal lattice and carbon layer is well coated on the surface of TiO_(2), with P-doping and carbon-coating contents of ~13.5 wt% and 10.4 wt%, respectively,which results in the enhanced pseudocapacitive behavior as well as favorable Na+and electron transferring kinetics. The(P-AnTSS)@NC sample shows excellent rate and cycle performance, exhibiting specific capacities of 177 and 115 m Ah/g at 0.1 and 1.0 A/g after 150 and 2000 cycles, respectively.展开更多
Na_(2)Li_(2)Ti_(6)O_(14) as a reliable anode material is becoming a hopeful candidate for Li-ion battery.Nevertheless,the pristine Na_(2)Li_(2)Ti_(6)O_(14) usually suffer from bad rate performance and poor cycling sta...Na_(2)Li_(2)Ti_(6)O_(14) as a reliable anode material is becoming a hopeful candidate for Li-ion battery.Nevertheless,the pristine Na_(2)Li_(2)Ti_(6)O_(14) usually suffer from bad rate performance and poor cycling stability under high current due to limited diffusion kinetics and poor electrical conductivity.Here,the PPy-coated Na_(2)Li_(2)Ti_(6)O_(14) composites are successfully obtained via the solid-state method and followed by chemical oxidation process in the first time.The results of tests prove that the Na_(2)Li_(2)Ti_(6)O_(14)@PPy composites have better electrochemical performance than the bare Na_(2)Li_(2)Ti_(6)O_(14) because of the excellent electrical conductivity and the special macromolecular architecture of PPy.In particular,the Na_(2) Li_(2) Ti_(6) O_(14) @PPy(4 wt%)exhibits excellent charge capacities of about 223.2,218.0,200.8,184.3 and 172.6 mAh g^(-1) at 50,100,200,300 and500 mA g^(-1),respectively,revealing the best rate capability of all electrode materials.The Na_(2)Li_(2)Ti_(6)O_(14)@PPy(4 wt%)not only has the highest charge capacity under 0.5 mA g^(-1),but also has the highest capacity retention of 85.12%among all samples after 100 loops.Hence,the PPy coating is known as a promising way to improve the electrochemical property of Na_(2)Li_(2)Ti_(6)O_(14).The PPy-coated Na_(2)Li_(2)Ti_(6)O_(14) demonstrates the great prospect as promising negative materials for Li-ion batteries.展开更多
SrLi_(2)Ti_(6)O_(14)(SLTO)coated with different amount of ZrO_(2)was successfully prepared.The as-obtained composites are stacked by a series of particles with a pure phase structure and a good crystallinity.Furthermo...SrLi_(2)Ti_(6)O_(14)(SLTO)coated with different amount of ZrO_(2)was successfully prepared.The as-obtained composites are stacked by a series of particles with a pure phase structure and a good crystallinity.Furthermore,ZrO_(2)coating not only enhances the structural stability of the materials but also facilitates the diffusion of lithium through the SEI film.As a result,the redox polarization was reduced,and the reversibility of the electrochemical reaction was enhanced.Particularly,SLTO-ZrO_(2)-2 sample delivers a high initial lithiation capacity of 283.6 mA h g^(-1),and the values maintain at 251.7,228.0,207.4,175.3,and 147.7 mA h g^(-1)at the current densities of 0.13,0.26,0.54,1.31,and 2.62 A g^(-1),respectively.Our experiment also confirmed that SLTO materials coated with ZrO_(2)are suitable for high power density applications,and the lithiation specific energy efficiency of SLTO-ZrO_(2)-2 is 200%as high as that of pure SLTO at a power density of 1257 W kg^(-1).展开更多
Bismuth sulfide(Bi_(2)S_(3))has attracted particular interest as a potential anode material for sodium-ion batteries(SIBs).However,the low electrical conductivity and dramatic volumetric change greatly restrict its pr...Bismuth sulfide(Bi_(2)S_(3))has attracted particular interest as a potential anode material for sodium-ion batteries(SIBs).However,the low electrical conductivity and dramatic volumetric change greatly restrict its practical applications.In view of the apparent structural and compositional advantages of metal-organic frameworks(MOFs)derived carbon-based composite,herein,as a proof of concept,Bi_(2)S_(3) spheres coated with the MOF-derived Co_(9)S_(8) and N-doped carbon composite layer(Bi_(2)S_(3)@Co_(9)S_(8)/NC composite spheres)have been rational designed and synthesized.As expected,the core-shell Bi_(2)S_(3)@Co_(9)S_(8)/NC composite spheres exhibit remarkable electrochemical performance in terms of high reversible capacity(597 m Ah g^(-1) after 100 cycles at 0.1 A g^(-1)),good rate capability(341 m Ah g^(-1) at 8 A g^(-1))and long-term cycling stability(458 m Ah g^(-1) after 1000 cycles at 1 A g^(-1))when investigated as anode materials for SIBs.Electrochemical analyses further reveal the favorable reaction kinetics in the Bi_(2)S_(3)@Co_(9)S_(8)/NC composite spheres.In addition,the possible sodium storage mechanism has been studied by ex-situ X-ray diffraction technique.More importantly,a sodium-ion full cell based on Na_(3) V_(2)(PO_(4))_(3)/r GO as cathode and Bi_(2)S_(3)@Co_(9)S_(8)/NC as anode is also fabricated,suggesting their potential for practical applications.It is anticipated that the present work could be extended to construct other advanced electrode materials using MOFs-derived carbon-based composites as surface coating materials for various energy storagerelated applications.展开更多
文摘The preparation process and properties of the thermally prepared Ti anodes coated with IrO2+Ta2O5 was studied. The structure and morphologies of the IrO2+Ta2O5 coatings were determined by XRD and SEM. Their electrochemical properties were studied by polarization curve and cyclic voltammetry. Trivalent chromium electroplating using Ti/IrO2+Ta2O5 anodes is carried out and the results were analyzed. Results show that this anode exhibits excellent electrochemical activity and stability in sulfate electrolysis. The electrocatalytic activity is determined not only by the content of IrO2 but also the structure and morphology of the anode coatings. The electroplating results indicats that Ti/IrO2+Ta2O5 anodes have excellent capabilities and merits in improving the stability of trivalent chromium electroplating in sulfate system.
基金funding support from the National Natural Science Foundation of China (21905151 and 51772162)the Youth Innovation and Technology Foundation of Shandong Higher Education Institutions, China (2019KJC004)+1 种基金the Outstanding Youth Foundation of Shandong Province, China (ZR2019JQ14)the Taishan Scholar Young Talent Program, Major Scientific and Technological Innovation Project (2019JZZY020405)。
文摘Lithium (Li) metal batteries have attracted much attention owing to its ultra-high energy density.However,as important part of Li metal batteries,Li anodes still face many challenges,mainly including uncontrolled dendritic Li formation,dramatical volume variation and serious pulverization.Herein,manganese dioxide (MnO_(2)) nanosheet modified nitrogen (N),phosphorus (P) co-doping carbon nanofibers(NPC) on carbon cloth (CC)(MnO_(2)@NPC-CC) is successfully fabricated through electrodeposition approach and further treated with Li by the molten-infusion method to prepare Li based Mn@NPC-CC(Li-Mn@NPC-CC) electrode.The synergy of MnO_(2) and NPC obviously increases the reaction rate between MnO_(2)@NPC-CC and Li and guides even Li distribution over infusion process.Additionally,theoretical calculation,simulation and experimental results further indicate that N,P,Mn multi-doping effectively improves the superior lithiophilicity of Li-Mn@NPC-CC,which induces uniform Li deposition/dissolution to suppress dendrite growth over cycles.Moreover,conductive and porous NPC matrix not only effectively improves the stability of Li-Mn@NPC-CC,but also provides abundant spaces to accelerate the transfer of ion/electron and buffer electrode dimension variation during cycling.Hence,Li-Mn@NPC-CC-based symmetric cells exhibit extra-long cycling life (over 2200 h) with small hysteresis of 20 mV.When the LiMn@NPC-CC anode couples with air,Li iron phosphate (LiFePO_(4)),or hard carbon (C) cathode,the assembled full cells exhibit outstanding performance with low hysteresis and stable cycling properties.Especially,the corresponding pouch-typed Li–air cells also exhibit good performance at different bending angles and even power a series of electronic devices.
基金supported by the National Natural Science Foundation of China (No. 21875071)the Guangdong key R&D Program of China (No. 2019B090908001)。
文摘P-doping is an effective way to modulate the electronic structure and improve the Na+diffusion kinetics of TiO_(2), enabling enhanced electrochemical performance. However, it is a challenge to prepare TiO;with a high P-doping concentration starting from TiO_(2)in a crystalline state. In this work, we design a novel two-step route for constructing a carbon-coated anatase P-doping TiO_(2)nanospheres(denote as(PAn TSS)@NC) with high P-doping concentration, by utilizing amorphous TiO;nanospheres with the ultrahigh specific area as P-doping precursor firstly, and followed by carbon coating treatment. Experimental results demonstrate that P is successfully doped into the crystal lattice and carbon layer is well coated on the surface of TiO_(2), with P-doping and carbon-coating contents of ~13.5 wt% and 10.4 wt%, respectively,which results in the enhanced pseudocapacitive behavior as well as favorable Na+and electron transferring kinetics. The(P-AnTSS)@NC sample shows excellent rate and cycle performance, exhibiting specific capacities of 177 and 115 m Ah/g at 0.1 and 1.0 A/g after 150 and 2000 cycles, respectively.
基金financially supported by the National Natural Science Foundation of China(No.U1960107)the“333”Talent Project of Hebei Province(No.A202005018)the Fundamental Research Funds for the Central Universities(No.N2123001)。
文摘Na_(2)Li_(2)Ti_(6)O_(14) as a reliable anode material is becoming a hopeful candidate for Li-ion battery.Nevertheless,the pristine Na_(2)Li_(2)Ti_(6)O_(14) usually suffer from bad rate performance and poor cycling stability under high current due to limited diffusion kinetics and poor electrical conductivity.Here,the PPy-coated Na_(2)Li_(2)Ti_(6)O_(14) composites are successfully obtained via the solid-state method and followed by chemical oxidation process in the first time.The results of tests prove that the Na_(2)Li_(2)Ti_(6)O_(14)@PPy composites have better electrochemical performance than the bare Na_(2)Li_(2)Ti_(6)O_(14) because of the excellent electrical conductivity and the special macromolecular architecture of PPy.In particular,the Na_(2) Li_(2) Ti_(6) O_(14) @PPy(4 wt%)exhibits excellent charge capacities of about 223.2,218.0,200.8,184.3 and 172.6 mAh g^(-1) at 50,100,200,300 and500 mA g^(-1),respectively,revealing the best rate capability of all electrode materials.The Na_(2)Li_(2)Ti_(6)O_(14)@PPy(4 wt%)not only has the highest charge capacity under 0.5 mA g^(-1),but also has the highest capacity retention of 85.12%among all samples after 100 loops.Hence,the PPy coating is known as a promising way to improve the electrochemical property of Na_(2)Li_(2)Ti_(6)O_(14).The PPy-coated Na_(2)Li_(2)Ti_(6)O_(14) demonstrates the great prospect as promising negative materials for Li-ion batteries.
基金financially supported by the National Natural Science Foundation of China(nos.21773060,51774002,and 21601054)Fundamental Research Funds for the Central Universities(no.N182304014)+1 种基金Youth Innovation Team Project of Science and technology of Heilongjiang University(2018-KYYWF-1593)Young Scholar Project of the Long Jiang Scholars Program(Q201818)
文摘SrLi_(2)Ti_(6)O_(14)(SLTO)coated with different amount of ZrO_(2)was successfully prepared.The as-obtained composites are stacked by a series of particles with a pure phase structure and a good crystallinity.Furthermore,ZrO_(2)coating not only enhances the structural stability of the materials but also facilitates the diffusion of lithium through the SEI film.As a result,the redox polarization was reduced,and the reversibility of the electrochemical reaction was enhanced.Particularly,SLTO-ZrO_(2)-2 sample delivers a high initial lithiation capacity of 283.6 mA h g^(-1),and the values maintain at 251.7,228.0,207.4,175.3,and 147.7 mA h g^(-1)at the current densities of 0.13,0.26,0.54,1.31,and 2.62 A g^(-1),respectively.Our experiment also confirmed that SLTO materials coated with ZrO_(2)are suitable for high power density applications,and the lithiation specific energy efficiency of SLTO-ZrO_(2)-2 is 200%as high as that of pure SLTO at a power density of 1257 W kg^(-1).
基金the financial support from the Central Government Research Programs to Guide the Local Scientific and Technological Development(Grant no.2018L3001)the National Natural Science Foundation of China(Grant nos.51872048 and U1732155)the Natural Science Foundation of Fujian Province,China(Grant no.2018J01677)。
文摘Bismuth sulfide(Bi_(2)S_(3))has attracted particular interest as a potential anode material for sodium-ion batteries(SIBs).However,the low electrical conductivity and dramatic volumetric change greatly restrict its practical applications.In view of the apparent structural and compositional advantages of metal-organic frameworks(MOFs)derived carbon-based composite,herein,as a proof of concept,Bi_(2)S_(3) spheres coated with the MOF-derived Co_(9)S_(8) and N-doped carbon composite layer(Bi_(2)S_(3)@Co_(9)S_(8)/NC composite spheres)have been rational designed and synthesized.As expected,the core-shell Bi_(2)S_(3)@Co_(9)S_(8)/NC composite spheres exhibit remarkable electrochemical performance in terms of high reversible capacity(597 m Ah g^(-1) after 100 cycles at 0.1 A g^(-1)),good rate capability(341 m Ah g^(-1) at 8 A g^(-1))and long-term cycling stability(458 m Ah g^(-1) after 1000 cycles at 1 A g^(-1))when investigated as anode materials for SIBs.Electrochemical analyses further reveal the favorable reaction kinetics in the Bi_(2)S_(3)@Co_(9)S_(8)/NC composite spheres.In addition,the possible sodium storage mechanism has been studied by ex-situ X-ray diffraction technique.More importantly,a sodium-ion full cell based on Na_(3) V_(2)(PO_(4))_(3)/r GO as cathode and Bi_(2)S_(3)@Co_(9)S_(8)/NC as anode is also fabricated,suggesting their potential for practical applications.It is anticipated that the present work could be extended to construct other advanced electrode materials using MOFs-derived carbon-based composites as surface coating materials for various energy storagerelated applications.
