The disparity in the transfer of carriers(electrons/mass)during the reaction in zinc-air batteries(ZABs)results in sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),along with e...The disparity in the transfer of carriers(electrons/mass)during the reaction in zinc-air batteries(ZABs)results in sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),along with elevated overpotentials,thereby imposing additional constraints on its utilization.Therefore,the pre-design and target-development of inexpensive,high-performance,and long-term stable bifunctional catalysts are urgently needed.In this work,an apically guiding dual-functional electrocatalyst(Ag-FeN_(x)-N-C)was prepared,in which a hierarchical porous nitrogen-doped carbon with three-dimensional(3D)hollow star-shaped structure is used as a substrate and high-conductivity Ag nanoparticles are coupled with iron nitride(FeN_(x))nanoparticles.Theoretical calculations indicate that the Mott-Schottky heterojunction as an inherent electric field comes from the two-phase bound of Ag and FeN_(x),of which electron accumulation in the FeN_(x)phase region and electron depletion in the Ag phase region promote orientated-guiding charge migration.The effective modulation of local electronic structures felicitously reforms the d-band electron-group distribution,and intellectually tunes the masstransfer reaction energy barriers for both ORR/OER.Additionally,the hollow star-s haped hierarchical porous structure provides an apical region for fast mass transfer.Experimental results show that the halfwave potential for ORR is 0.914 V,and the overpotential for OER is only 327 mV at 10 mA cm^(-2).A rechargeable ZAB with Ag-FeN_(x)-N-C as the air cathode demonstrates long-term cycling performance exceeding 1500 cycles(500 h),with a power density of 180 mW cm^(-2).Moreover,when employing AgFeN_(x)-N-C as the air cathode,flexible ZABs demonstrate a notable open-circuit voltage of 1.42 V and achieve a maximum power density of 65.6 mW cm^(-2).Ag-FeN_(x)-N-C shows guiding electron/mass transfer route and apical reaction microenvironment for the electrocatalyst architecture in the exploration prospects of ZABs.展开更多
Lithium-sulfur(Li-S)batteries possess overwhelming energy density of 2654 Wh kg-1,and are considered as the next-generation battery technology for energy demanding applications.Flooded electrolytes are ubiquitously em...Lithium-sulfur(Li-S)batteries possess overwhelming energy density of 2654 Wh kg-1,and are considered as the next-generation battery technology for energy demanding applications.Flooded electrolytes are ubiquitously employed in cells to ensure sufficient redox kinetics and preclude the interference of the electrolyte depletion due to side reactions with the lithium metal anode.This strategy is capable of enabling long-lasting,high-capacity and excellent-rate battery performances,but it mask the requirements of practical Li-S batteries,where high-sulfur-loading/content and lean electrolyte are prerequisite to realize the energy-dense Li-S batteries.Sparingly and highly solvating electrolytes have emerged as effective yet simple approaches to decrease the electrolyte/sulfur ratio through altering sulfur species and exerting new reaction pathways.Sparingly solvating electrolytes are characterized by few free solvents to solvate lithium polysulfides,rendering a quasi-solid sulfur conversion and decoupling the reaction mechanisms from electrolyte quantity used in cells;while highly solvating electrolytes adopt highdonicity or high-permittivity solvents and take their advantages of strong solvation ability toward polysulfide intermediates,thereby favoring the polysulfide formation and stabilizing unique radicals,which subsequently accelerate redox kinetics.Both solvation chemistry approaches have their respective features to allow the operation of cells under electrolyte-starved conditions.This Review discusses their unique features and basic physicochemical properties in the working Li-S batteries,presents remaining technical and scientific issues and provides future directions for the electrolyte chemistry to attain highenergy Li-S batteries.展开更多
Lithium-ion batteries(LIBs)have become an indispensable part of our daily life,however,the energy and power capability that LIBs can deliver are lagging far behind the ever-increasing demands of portable electronics a...Lithium-ion batteries(LIBs)have become an indispensable part of our daily life,however,the energy and power capability that LIBs can deliver are lagging far behind the ever-increasing demands of portable electronics and electric vehicles.Metal-sulfur batteries as one of the most promising alternatives to LIBs are receiving rapidly growing research interests due to the extremely high energy density and abundant resources of sulfur.In this short review,we will discuss the state-of-art development of high energy density battery technologies based on sulfur cathode in combination with different metal anodes,with focus on sodium,magnesium and aluminum anodes.We leave lithium-sulfur batteries out of discussion since there are already a large number of nicely organized review papers available.The operation mechanism of various anode materials and the variety of electrolytes used in sulfur batteries will be reviewed.Some perspectives on improving the performances and overcoming the remaining issues in sulfur batteries will be discussed.It is expected that this review will draw more attention to sulfur batteries from both the academic and industrial communities.展开更多
Organic active units often transform into radical intermediates during the redox processes but exhibit poor cycling stability due to the uncontrollable redox of the radicals. Herein, we report a facile and efficient s...Organic active units often transform into radical intermediates during the redox processes but exhibit poor cycling stability due to the uncontrollable redox of the radicals. Herein, we report a facile and efficient strategy to modulate the molecular orbital energies, charge transport capacities, and spin electron densities of the active units in covalent organic frameworks(COFs) via regulating the conjugated unit size to optimize the redox activity and stability of the organic radicals. COFs based on different imide conjugated units exhibit tunable discharge voltages, rate performance and cycling stabilities. Detailed characterizations and theoretical calculation reveal that imide radicals are the important active intermediates during the redox processes of these COFs. Specifically, increasing the size of the imide conjugated units could effectively delocalize the radical electrons and improve the stability of the COFs electrodes. This study offers a very effective strategy to modulate the redox chemistry of organic materials for electrochemical energy storage.展开更多
Single crystals of a bismuth-based coordination polymer(CP)with carboxyl-thiol ligands,[Bi(C_(8)H_(2)O_(4)S_(2))(C2H8N)]n(Bi-DSBDC-DMA,DMBDC=2,5-disulfur-1,4-dicarboxylate,DMA=dimethylamine),have been successfully syn...Single crystals of a bismuth-based coordination polymer(CP)with carboxyl-thiol ligands,[Bi(C_(8)H_(2)O_(4)S_(2))(C2H8N)]n(Bi-DSBDC-DMA,DMBDC=2,5-disulfur-1,4-dicarboxylate,DMA=dimethylamine),have been successfully synthesized.X-ray diffraction analysis reveals that Bi-DSBDC-DMA possesses a layered structure,with two-dimensional(2D)Bi-DSBDC networks alternating with layers composed of dimethylamine ions.This material demonstrates semiconducting properties,featuring an optical bandgap of 2.2 eV and an electrical conductivity of 2×10^(-8) S/cm.Furthermore,electrodes based on this material exhibit a capacity of 250 mAh/g after 200 cycles for lithium-ion storage.展开更多
Nickel-rich layered oxides are attractive cathode for lithium-ion batteries(LIBs)because of the high energy density and low cost.The critical problem is capacity fading caused by the highly reactive metastable phases ...Nickel-rich layered oxides are attractive cathode for lithium-ion batteries(LIBs)because of the high energy density and low cost.The critical problem is capacity fading caused by the highly reactive metastable phases under voltages of higher than 4.15 V.Herein,we find that facile Ar/H2 plasma treating could produce oxygen vacancies that will readily transform into homogeneous spinel layer(~6 nm)on the LiNi_(0.8)CO_(0.1)Mn_(0.1)O_(2)(NCM811)surface after a few cycles of lithiation/delithiation procedure.Owing to the structural matching between spinel and layered structure,the diffusion of Li ions could remain fast upon cycling.Besides,the spinel layer is electrochemically inert,which guarantees surface stabilization and inhibits the detrimental phase transition from H2 to H3 at high voltages.Under the protection of the homogeneous spinel layer,the NCM_(811) electrode shows superior capacity retention of 91.2% after 200 cycles at the current density of 100 mA·g^(−1).This work proposes a novel strategy of surface reconstruction to stabilize nickel-rich layered oxide materials for LIBs.展开更多
本论文采用快速微波辅助低温回流策略制备了桑椹形Na_3V_2(PO_4)_2O_2F@C纳米复合材料.研究表明微乳液中的V(acac)_3反胶束体系对该自组装结构的形成起到了关键作用.制得的Na_3V_2(PO_4)_2O_2F晶粒沿着[002]方向生长并被原位包封在碳壳...本论文采用快速微波辅助低温回流策略制备了桑椹形Na_3V_2(PO_4)_2O_2F@C纳米复合材料.研究表明微乳液中的V(acac)_3反胶束体系对该自组装结构的形成起到了关键作用.制得的Na_3V_2(PO_4)_2O_2F晶粒沿着[002]方向生长并被原位包封在碳壳中,形成了高度稳定的自组装结构,这不仅有利于Na^+/e^-的快速迁移,而且能够有效改善电极材料的循环性能并抑制电压衰减.作为钠离子电池正极材料,在0.1 C条件下, Na_3V_2(PO_4)_2O_2F@C的初始放电容量约为127.9 mA h g^(-1).在高倍率(20 C)条件下,容量达88.1 mA h g^(-1), 2000次循环后容量保持率为82.1%.此外,利用非原位X射线衍射, X射线光电子能谱和恒电流间歇滴定技术,初步研究了Na_3V_2(PO4)_2O_2F@C在充放电过程中的反应机理和Na^+迁移机制.同时,在Li/Na离子混合电池当中, Na_3V_2(PO_4)_2O_2F@C也表现出了优异的倍率和循环性能.上述微波辅助低温回流合成策略为开发高性能电化学储能材料开辟了新的途径.展开更多
A novel lath-shaped CuO microassemble consisting of well-crystalized ultrafine nanocrystals was prepared by an ionothermal method with the assistance of ionic liquids (ILs, 1-butyl-3-methylimidazolium tetrafluorobor...A novel lath-shaped CuO microassemble consisting of well-crystalized ultrafine nanocrystals was prepared by an ionothermal method with the assistance of ionic liquids (ILs, 1-butyl-3-methylimidazolium tetrafluoroborate). As anode material of lithium ion batteries, the ILs-CuO exhibits high specific capacity, durability and good rate per- formance, superior to bare CuO. At a high current density of 1000 mA·g^-1, after 100 cycles, ILs-CuO still retains a discharge capacity of 483.2 mAh·g^-1. The improved electrochemical performances could be ascribed to the unique microscale lath-shape CuO assembles composed of ultrafine nanostructure.展开更多
制备具有大电流析氢性能的非贵金属电催化剂是一个巨大挑战.协同调控催化剂的电子结构和形貌能够增强其本征催化能力和增加活性位点,被认为是提高催化性能的有效方法.本文以具有协同电子结构和形貌调控功能的三元Co_(1-x)V_(x)P纳米针...制备具有大电流析氢性能的非贵金属电催化剂是一个巨大挑战.协同调控催化剂的电子结构和形貌能够增强其本征催化能力和增加活性位点,被认为是提高催化性能的有效方法.本文以具有协同电子结构和形貌调控功能的三元Co_(1-x)V_(x)P纳米针阵列作为碱性析氢的高效电催化剂.实验和理论计算结果表明,其优异的催化性能来源于物理化学性质的提高、活性表面积的增加及反应动力学的加速.此外,组装的(NF@Co_(1-x)V_(x)–HNNs(+)||NF@Co_(1-x)V_(x)P(-))电解池在1.58、1.75和1.92 V的电压下,能够分别得到10、100和300 mA cm^(-2)的电流密度.展开更多
In this artide, highly [010]-oriented self-assembled LiCoPO4/C nanoflakes were prepared through simple and facile solution-phase strategies at low temperature and ambient pressure. The formation of 5-hydroxylmethylfur...In this artide, highly [010]-oriented self-assembled LiCoPO4/C nanoflakes were prepared through simple and facile solution-phase strategies at low temperature and ambient pressure. The formation of 5-hydroxylmethylfurfural and levoglucosan via the dehydration of glucose during the reaction played a key role in mediating the morphology and structure of the resulting products. LiCoPO4 highly oriented along the (010)-facets exposed Li^+ ion transport channels, facilitating ultrafast lithium ion transportation. In turn, the unique assembled mesoporous structure and the flake-like morphology of the prepared products benefit lithium ion batteries constructed using two-dimensional (2D) LiCoPO4/C nanoflakes self- assembles as cathodes and commercial Li4Ti5O12 as anodes. The tested batteries provide high capacities of 154.6 mA·h·g^-1 at 0.1 C (based on the LiCoPO4 weight of 1 C = 167 mA·h·g^-1) and stable cycling with 93.1% capacity retention after 100 cycles, which is outstanding compared to other recently developed LiCoPO4 cathodes.展开更多
Potassium-ion batteries(PIBs)are promising ne15t-generation energy storage candidates due to abundant resources and low cost.Sb-based materials with high theoretical capacity(660 mAh·g^(-1))and low working potent...Potassium-ion batteries(PIBs)are promising ne15t-generation energy storage candidates due to abundant resources and low cost.Sb-based materials with high theoretical capacity(660 mAh·g^(-1))and low working potential are considered as promising anode for PIBs.The remaining challenge is poor stability and slow kinetics.In this work,FeSb@N-doped carbon quantum dots anchored in three-dimensional(3D)porous N-doped carbon(FeSb@C/Nc3DC/N),a Sb-based material with a particular structure,is designed and constructed by a green salt-template method.As an anode for PIBs,it exhibits extraordinarily high-rate and long-cycle stability(a capacity of 245 mAh·g^(-1) at 3,080 mAh·g^(-1) after 1,000 cycles).The pseudocapacitance contribution(83%)is demonstrated as the origin of high-rate performance of the FeSb@C/NС3DC/N electrode.Furthermore,the potassium storage mechanism in the electrode is systematically investigated through ex-situ characterization techniques including ex-situ transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).Overall,this study could provide a useful guidance for future design of high-performance electrode materials for PIBs.展开更多
PX-phase PbTiO3 (PT) nanowires with open channels running along the length direction have been investigated as an anode material for lithium ion batteries. This material shows a stabilized reversible specific capaci...PX-phase PbTiO3 (PT) nanowires with open channels running along the length direction have been investigated as an anode material for lithium ion batteries. This material shows a stabilized reversible specific capacity of about 410 mAh·g^-1 up to 200 cycles with a charge/discharge voltage plateau of around 0.3-0.65 V. In addition, it exhibits superior high-rate performance, with 90% and 77% capacity retention observed at 1 and 2 A·g^-1, respectively. At a very high current rate of 10 A·g^-1, a specific capacity of over 170 mAh·g^-1 is retained up to 100 cycles, significantly outperforming the rate capability reported for Pb and Pb oxides. The results of X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analyses along with the cyclic voltammogram results reveal that the PX-phase PT nanowires undergo irreversible structural amorphization and reduction reactions during the initial cycle, which allow them to transform into a composite structure composed of 2-5 nm Pb nanoparticles uniformly dispersed in the 1D amorphous Li2O·TiO2·LiTiO2 matrix. In this composite structure, the presence of abundant amounts of Ti^3+ in both the charged and discharged states enhances the electrical conductance of the system, whereas the presence of ultrafine Pb nanoparticles imparts high reversible capacity. The structurally stable TiO2-based amorphous matrix can also considerably buffer the volume variation during the charge/discharge process, thereby facilitating extremely stable cycling performance. This compound combines the high specific capacity of Pb-based materials and the good rate capability of Ti^3+-based wiring. Our results might furnish a possible route for achieving superior cycling and rate performance and contribute towards the search for next-generation anode materials.展开更多
Herein,we prepared a bimetallic layered double hydroxide(FeCo LDH)featuring a dandelion-like structure.Anchoring of CeO_(2)onto FeCo LDH produced interfaces between the functionalizing CeO_(2)and the parent LDH.Compar...Herein,we prepared a bimetallic layered double hydroxide(FeCo LDH)featuring a dandelion-like structure.Anchoring of CeO_(2)onto FeCo LDH produced interfaces between the functionalizing CeO_(2)and the parent LDH.Comparative electrochemical studies were carried out.Onset potential,overpotential,and Tafel slope point to the superior oxygen-evolving performance of CeO_(2)-FeCo LDH with respect to FeCo LDH,therefore,demonstrating the merits of CeO_(2)functionalization.The electronic structures of Fe,Co,and Ce were analyzed by X-ray photoelectron spectroscopy(XPS)and electron energy loss spectroscopy(EELS)from which the increase of Co^(3+)and the concurrent lowering of Ce^(4+)were established.With the use of CeO_(2)-FeCo LDH,accelerated formation at a sizably reduced potential of Co-OOH,one of the key intermediates preceding the release of O_(2)was observed by in situ Raman spectroscopy.We now have the atomic-level and location-specific evidence,the increase of the active Co^(3+)across the interface to correlate the enhanced catalytic performance with CeO_(2)functionalization.展开更多
It is a big challenge to well control the porous structure of carbon materials for supercapacitor application.Herein,a simple in-situ self-templating strategy is developed to prepare three-dimensional(3D)hierarchical ...It is a big challenge to well control the porous structure of carbon materials for supercapacitor application.Herein,a simple in-situ self-templating strategy is developed to prepare three-dimensional(3D)hierarchical porous carbons with good combination of micro and meso-porous architecture derived from a new oxygen-bridged porous organic polymer(OPOP).The OPOP is produced by the condensation polymerization of cyanuric chloride and hydroquinone in NaOH ethanol solution and NaCl is in-situ formed as by-product that will serve as template to construct an interconnected 3D hierarchical porous architecture upon carbonization.The large interface pore architecture,and rich doping of N and O heteroatoms effectively promote the electrolyte accessibility and electronic conductivity,and provide abundant active sites for energy storage.Consequently,the supercapacitors based on the optimized OPOP-800 sample display an energy density of 8.44 and 27.28 Wh·kg^(−1)in 6.0 M KOH and 1.0 M Na2SO4 electrolytes,respectively.The capacitance retention is more than 94%after 10,000 cycles.Furthermore,density functional theory(DFT)calculations have been employed to unveil the charge storage mechanism in the OPOP-800.The results presented in this job are inspiring in finely tuning the porous structure to optimize the supercapacitive performance of carbon materials.展开更多
Electrocatalysts for the oxygen reduction reaction(ORR)are critically important in the development of fuel cells and metal-air batteries.Intensive research interests have been devoted to improving the electrocatalytic...Electrocatalysts for the oxygen reduction reaction(ORR)are critically important in the development of fuel cells and metal-air batteries.Intensive research interests have been devoted to improving the electrocatalytic performance by tuning the morphology and defect-active sites.Herein,we demonstrate that the oxidation state can also serve as an effective strategy for designingORR electrocatalysts.Valencemodels of silver with gradient chemical valence from zero valence to trivalence were successfully built.Their oxidation states were evaluated by cryo-X-ray photoelectron spectroscopy,X-ray absorptionfinestructure,and electron paramagnetic resonance spectroscopy.For the first time,our results demonstrated that the electrocatalytic activities of silver species can be improved by increasing their valence,conforming the orderofAg<Ag_(2)O<Ag_(2)O_(2)<Ag_(3)O_(4)<Ag_(2)O_(3).Computational studies reveal that higher valence Ag species possess a higher proportion of d band holes andmore electrons closer to the Fermi level.Therefore,the oxygen adsorption and activation energy on the Ag sites can be regulated to a near-optimal level and the ORR catalytic efficiency increases.This work clearly presents that oxidation state is another degree of freedom in designing efficient ORR electrocatalysts.展开更多
基金the financial support of the National Natural Science Foundation of China(52002079,22378074,22179025 and U20A20340)the Guangdong Basic and Applied Basic Research Foundation(2022A1515140085)+2 种基金the Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology(FC202209)the Guangzhou Hongmian Project(HMJH-20200012)the Foshan Introducing Innovative and Entrepreneurial Teams(1920001000108)。
文摘The disparity in the transfer of carriers(electrons/mass)during the reaction in zinc-air batteries(ZABs)results in sluggish kinetics of the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),along with elevated overpotentials,thereby imposing additional constraints on its utilization.Therefore,the pre-design and target-development of inexpensive,high-performance,and long-term stable bifunctional catalysts are urgently needed.In this work,an apically guiding dual-functional electrocatalyst(Ag-FeN_(x)-N-C)was prepared,in which a hierarchical porous nitrogen-doped carbon with three-dimensional(3D)hollow star-shaped structure is used as a substrate and high-conductivity Ag nanoparticles are coupled with iron nitride(FeN_(x))nanoparticles.Theoretical calculations indicate that the Mott-Schottky heterojunction as an inherent electric field comes from the two-phase bound of Ag and FeN_(x),of which electron accumulation in the FeN_(x)phase region and electron depletion in the Ag phase region promote orientated-guiding charge migration.The effective modulation of local electronic structures felicitously reforms the d-band electron-group distribution,and intellectually tunes the masstransfer reaction energy barriers for both ORR/OER.Additionally,the hollow star-s haped hierarchical porous structure provides an apical region for fast mass transfer.Experimental results show that the halfwave potential for ORR is 0.914 V,and the overpotential for OER is only 327 mV at 10 mA cm^(-2).A rechargeable ZAB with Ag-FeN_(x)-N-C as the air cathode demonstrates long-term cycling performance exceeding 1500 cycles(500 h),with a power density of 180 mW cm^(-2).Moreover,when employing AgFeN_(x)-N-C as the air cathode,flexible ZABs demonstrate a notable open-circuit voltage of 1.42 V and achieve a maximum power density of 65.6 mW cm^(-2).Ag-FeN_(x)-N-C shows guiding electron/mass transfer route and apical reaction microenvironment for the electrocatalyst architecture in the exploration prospects of ZABs.
基金supported by the National Natural Science Foundation of China(21805162 and 21671096)National Key Research and Development Program(2018YFB0104300)+3 种基金Key Program of the Natural Science Foundation of China(51732005)Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(2018B030322001)Shenzhen Key Laboratory of Solid State Batteries(No.ZDSYS201802081843465)Research Support for Postdoctoral Scholars coming to Shenzhen(K19407556)。
文摘Lithium-sulfur(Li-S)batteries possess overwhelming energy density of 2654 Wh kg-1,and are considered as the next-generation battery technology for energy demanding applications.Flooded electrolytes are ubiquitously employed in cells to ensure sufficient redox kinetics and preclude the interference of the electrolyte depletion due to side reactions with the lithium metal anode.This strategy is capable of enabling long-lasting,high-capacity and excellent-rate battery performances,but it mask the requirements of practical Li-S batteries,where high-sulfur-loading/content and lean electrolyte are prerequisite to realize the energy-dense Li-S batteries.Sparingly and highly solvating electrolytes have emerged as effective yet simple approaches to decrease the electrolyte/sulfur ratio through altering sulfur species and exerting new reaction pathways.Sparingly solvating electrolytes are characterized by few free solvents to solvate lithium polysulfides,rendering a quasi-solid sulfur conversion and decoupling the reaction mechanisms from electrolyte quantity used in cells;while highly solvating electrolytes adopt highdonicity or high-permittivity solvents and take their advantages of strong solvation ability toward polysulfide intermediates,thereby favoring the polysulfide formation and stabilizing unique radicals,which subsequently accelerate redox kinetics.Both solvation chemistry approaches have their respective features to allow the operation of cells under electrolyte-starved conditions.This Review discusses their unique features and basic physicochemical properties in the working Li-S batteries,presents remaining technical and scientific issues and provides future directions for the electrolyte chemistry to attain highenergy Li-S batteries.
基金supported by the National Natural Science Foundation of China (No. 21671096, and No. 21603094)the Natural Science Foundation of Shenzhen (No. JCYJ20170412153139454 and, No. JCYJ20170817110251498)the Guangdong Special Support for the Science and Technology Leading Young Scientist (No. 2016TQ03C919)
文摘Lithium-ion batteries(LIBs)have become an indispensable part of our daily life,however,the energy and power capability that LIBs can deliver are lagging far behind the ever-increasing demands of portable electronics and electric vehicles.Metal-sulfur batteries as one of the most promising alternatives to LIBs are receiving rapidly growing research interests due to the extremely high energy density and abundant resources of sulfur.In this short review,we will discuss the state-of-art development of high energy density battery technologies based on sulfur cathode in combination with different metal anodes,with focus on sodium,magnesium and aluminum anodes.We leave lithium-sulfur batteries out of discussion since there are already a large number of nicely organized review papers available.The operation mechanism of various anode materials and the variety of electrolytes used in sulfur batteries will be reviewed.Some perspectives on improving the performances and overcoming the remaining issues in sulfur batteries will be discussed.It is expected that this review will draw more attention to sulfur batteries from both the academic and industrial communities.
基金supports from the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen (No. JCYJ20200109141640095)the Shenzhen Key Laboratory of Interfacial Science and Engineering of Materials (No. ZDSYS20200421111401738)+3 种基金the Leading Talents of Guangdong Province Program (No. 2016LJ06C536)the GuangdongHong Kong-Macao Joint Laboratory (No. 2019B121205001)the National Natural Science Foundation of China (No. 21875097)the support from the Hong Kong Research Grants Council (Project number CityU 11218420)。
文摘Organic active units often transform into radical intermediates during the redox processes but exhibit poor cycling stability due to the uncontrollable redox of the radicals. Herein, we report a facile and efficient strategy to modulate the molecular orbital energies, charge transport capacities, and spin electron densities of the active units in covalent organic frameworks(COFs) via regulating the conjugated unit size to optimize the redox activity and stability of the organic radicals. COFs based on different imide conjugated units exhibit tunable discharge voltages, rate performance and cycling stabilities. Detailed characterizations and theoretical calculation reveal that imide radicals are the important active intermediates during the redox processes of these COFs. Specifically, increasing the size of the imide conjugated units could effectively delocalize the radical electrons and improve the stability of the COFs electrodes. This study offers a very effective strategy to modulate the redox chemistry of organic materials for electrochemical energy storage.
基金supported by the Research Projects of Department of Education of Guangdong Province(No.2023KTSCX319)the National Natural Science Foundation of China(No.92372114).
文摘Single crystals of a bismuth-based coordination polymer(CP)with carboxyl-thiol ligands,[Bi(C_(8)H_(2)O_(4)S_(2))(C2H8N)]n(Bi-DSBDC-DMA,DMBDC=2,5-disulfur-1,4-dicarboxylate,DMA=dimethylamine),have been successfully synthesized.X-ray diffraction analysis reveals that Bi-DSBDC-DMA possesses a layered structure,with two-dimensional(2D)Bi-DSBDC networks alternating with layers composed of dimethylamine ions.This material demonstrates semiconducting properties,featuring an optical bandgap of 2.2 eV and an electrical conductivity of 2×10^(-8) S/cm.Furthermore,electrodes based on this material exhibit a capacity of 250 mAh/g after 200 cycles for lithium-ion storage.
基金This work was financially supported by the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen(No.JCYJ20200109141640095)Shenzhen Key Laboratory of Interfacial Science and Engineering of Materials(No.ZDSYS20200421111401738)+2 种基金the Leading Talents of Guangdong Province Program(No.2016LJ06C536)the Guangdong-Hong Kong-Macao Joint Laboratory(No.2019B121205001)the National Natural Science Foundation of China(No.21875097).
文摘Nickel-rich layered oxides are attractive cathode for lithium-ion batteries(LIBs)because of the high energy density and low cost.The critical problem is capacity fading caused by the highly reactive metastable phases under voltages of higher than 4.15 V.Herein,we find that facile Ar/H2 plasma treating could produce oxygen vacancies that will readily transform into homogeneous spinel layer(~6 nm)on the LiNi_(0.8)CO_(0.1)Mn_(0.1)O_(2)(NCM811)surface after a few cycles of lithiation/delithiation procedure.Owing to the structural matching between spinel and layered structure,the diffusion of Li ions could remain fast upon cycling.Besides,the spinel layer is electrochemically inert,which guarantees surface stabilization and inhibits the detrimental phase transition from H2 to H3 at high voltages.Under the protection of the homogeneous spinel layer,the NCM_(811) electrode shows superior capacity retention of 91.2% after 200 cycles at the current density of 100 mA·g^(−1).This work proposes a novel strategy of surface reconstruction to stabilize nickel-rich layered oxide materials for LIBs.
基金This work was supported by the National Natural Science Foundation of China (No. 21001117), the Shenzhen Peacock Plan (No. KQCX20140522150815065), and the Starting-Up Funds of South University of Science and Technology of China (SUSTC) through the Talent Plan of the Shenzhen Government. H. T. L. acknowledges the support from a Key Project of the Hunan Provincial Science and Technology Plan (No. 2014FJ2007).
文摘小说三维(3D ) 集中坡度 Ni 公司氢氧化物 nanostructures (3DCGNC ) 被一个灵巧的逐步的电气化学的免职方法直接在镍泡沫上种了并且强烈地为 supercapacitors 调查同样没有文件夹、没有售票员的电极。基于一种三电极的电气化学的描述技术,获得的 3DCGNC 电极表明了 1,760 F 的一个高特定的电容 ????
基金supported by the National Natural Science Foundation of China (21303042, 21875097, 21671096 and 21603094)Guangdong Special Support for the Science and Technology Leading Young Scientist (2016TQ03C919)the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen (JCYJ20170412153139454 and JCYJ20170817110251498)
文摘本论文采用快速微波辅助低温回流策略制备了桑椹形Na_3V_2(PO_4)_2O_2F@C纳米复合材料.研究表明微乳液中的V(acac)_3反胶束体系对该自组装结构的形成起到了关键作用.制得的Na_3V_2(PO_4)_2O_2F晶粒沿着[002]方向生长并被原位包封在碳壳中,形成了高度稳定的自组装结构,这不仅有利于Na^+/e^-的快速迁移,而且能够有效改善电极材料的循环性能并抑制电压衰减.作为钠离子电池正极材料,在0.1 C条件下, Na_3V_2(PO_4)_2O_2F@C的初始放电容量约为127.9 mA h g^(-1).在高倍率(20 C)条件下,容量达88.1 mA h g^(-1), 2000次循环后容量保持率为82.1%.此外,利用非原位X射线衍射, X射线光电子能谱和恒电流间歇滴定技术,初步研究了Na_3V_2(PO4)_2O_2F@C在充放电过程中的反应机理和Na^+迁移机制.同时,在Li/Na离子混合电池当中, Na_3V_2(PO_4)_2O_2F@C也表现出了优异的倍率和循环性能.上述微波辅助低温回流合成策略为开发高性能电化学储能材料开辟了新的途径.
基金Acknowledgement This work was supported by the National Natural Science Foundation of China (Nos. 21671096, 21603094), the Shenzhen Peacock Plan (Nos. KQCX20140522150- 815065), and the Natural Science Foundation of Shenzhen (Nos. JCYJ20150630145302231, and JCYJ20150331101823677). We also thanks to the support by Foundation of SRG7004276 and SRG7004545.
文摘A novel lath-shaped CuO microassemble consisting of well-crystalized ultrafine nanocrystals was prepared by an ionothermal method with the assistance of ionic liquids (ILs, 1-butyl-3-methylimidazolium tetrafluoroborate). As anode material of lithium ion batteries, the ILs-CuO exhibits high specific capacity, durability and good rate per- formance, superior to bare CuO. At a high current density of 1000 mA·g^-1, after 100 cycles, ILs-CuO still retains a discharge capacity of 483.2 mAh·g^-1. The improved electrochemical performances could be ascribed to the unique microscale lath-shape CuO assembles composed of ultrafine nanostructure.
基金the National Natural Science Foundation of China(21671096,21603094 and21905180)the Natural Science Foundation of Guangdong Province(2018B030322001 and 2018A030310225)+4 种基金Shenzhen Peacock Plan(KQTD2016022620054656)Shenzhen Key Laboratory Project(ZDSYS201603311013489)the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen(JCYJ20190809115413414)the Science and Technology Development Fund from Macao SAR(FDCT–0102/2019/A2,FDCT–0035/2019/AGJ and FDCT–0154/2019/A3)the Multi-Year Research Grants(MYRG2017–00027–FST and MYRG2018–00003–IAPME)from the University of Macao。
文摘制备具有大电流析氢性能的非贵金属电催化剂是一个巨大挑战.协同调控催化剂的电子结构和形貌能够增强其本征催化能力和增加活性位点,被认为是提高催化性能的有效方法.本文以具有协同电子结构和形貌调控功能的三元Co_(1-x)V_(x)P纳米针阵列作为碱性析氢的高效电催化剂.实验和理论计算结果表明,其优异的催化性能来源于物理化学性质的提高、活性表面积的增加及反应动力学的加速.此外,组装的(NF@Co_(1-x)V_(x)–HNNs(+)||NF@Co_(1-x)V_(x)P(-))电解池在1.58、1.75和1.92 V的电压下,能够分别得到10、100和300 mA cm^(-2)的电流密度.
基金This work is financially supported by the National Natural Science Foundation of China (Nos. 51671072, 21303042, and 21671096), the Natural Science Foundation of Shenzhen (Nos. JCYJ20170412153139454 and JCYJ20150331101823677), and the Shenzhen Key Laboratory Project (No. ZDSYS201603311013489).
文摘In this artide, highly [010]-oriented self-assembled LiCoPO4/C nanoflakes were prepared through simple and facile solution-phase strategies at low temperature and ambient pressure. The formation of 5-hydroxylmethylfurfural and levoglucosan via the dehydration of glucose during the reaction played a key role in mediating the morphology and structure of the resulting products. LiCoPO4 highly oriented along the (010)-facets exposed Li^+ ion transport channels, facilitating ultrafast lithium ion transportation. In turn, the unique assembled mesoporous structure and the flake-like morphology of the prepared products benefit lithium ion batteries constructed using two-dimensional (2D) LiCoPO4/C nanoflakes self- assembles as cathodes and commercial Li4Ti5O12 as anodes. The tested batteries provide high capacities of 154.6 mA·h·g^-1 at 0.1 C (based on the LiCoPO4 weight of 1 C = 167 mA·h·g^-1) and stable cycling with 93.1% capacity retention after 100 cycles, which is outstanding compared to other recently developed LiCoPO4 cathodes.
基金the National Natural Science Foundation of China(Nos.51661009 and 21875097)the Natural Science Foundation of Guangxi Province(No.2019GXNSFDA245014)+1 种基金the Science and Technology Base and Talent Special Project of Guangxi Province(No.AD 19245162)the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen(No.JCYJ20200109141640095).
文摘Potassium-ion batteries(PIBs)are promising ne15t-generation energy storage candidates due to abundant resources and low cost.Sb-based materials with high theoretical capacity(660 mAh·g^(-1))and low working potential are considered as promising anode for PIBs.The remaining challenge is poor stability and slow kinetics.In this work,FeSb@N-doped carbon quantum dots anchored in three-dimensional(3D)porous N-doped carbon(FeSb@C/Nc3DC/N),a Sb-based material with a particular structure,is designed and constructed by a green salt-template method.As an anode for PIBs,it exhibits extraordinarily high-rate and long-cycle stability(a capacity of 245 mAh·g^(-1) at 3,080 mAh·g^(-1) after 1,000 cycles).The pseudocapacitance contribution(83%)is demonstrated as the origin of high-rate performance of the FeSb@C/NС3DC/N electrode.Furthermore,the potassium storage mechanism in the electrode is systematically investigated through ex-situ characterization techniques including ex-situ transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).Overall,this study could provide a useful guidance for future design of high-performance electrode materials for PIBs.
基金This work is supported by National Natural Science Foundation of China (No. 51302143), Shenzhen Special Fund for the Development of Emerging Industries (No. JCYJ20140417115840233), and Shenzhen Peacock Plan (No. KQCX20140521161756228).
文摘PX-phase PbTiO3 (PT) nanowires with open channels running along the length direction have been investigated as an anode material for lithium ion batteries. This material shows a stabilized reversible specific capacity of about 410 mAh·g^-1 up to 200 cycles with a charge/discharge voltage plateau of around 0.3-0.65 V. In addition, it exhibits superior high-rate performance, with 90% and 77% capacity retention observed at 1 and 2 A·g^-1, respectively. At a very high current rate of 10 A·g^-1, a specific capacity of over 170 mAh·g^-1 is retained up to 100 cycles, significantly outperforming the rate capability reported for Pb and Pb oxides. The results of X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analyses along with the cyclic voltammogram results reveal that the PX-phase PT nanowires undergo irreversible structural amorphization and reduction reactions during the initial cycle, which allow them to transform into a composite structure composed of 2-5 nm Pb nanoparticles uniformly dispersed in the 1D amorphous Li2O·TiO2·LiTiO2 matrix. In this composite structure, the presence of abundant amounts of Ti^3+ in both the charged and discharged states enhances the electrical conductance of the system, whereas the presence of ultrafine Pb nanoparticles imparts high reversible capacity. The structurally stable TiO2-based amorphous matrix can also considerably buffer the volume variation during the charge/discharge process, thereby facilitating extremely stable cycling performance. This compound combines the high specific capacity of Pb-based materials and the good rate capability of Ti^3+-based wiring. Our results might furnish a possible route for achieving superior cycling and rate performance and contribute towards the search for next-generation anode materials.
基金This work was financially supported by Shenzhen Nobel Prize Scientists Laboratory Project(No.C17213101)Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)+6 种基金Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(No.2018B030322001)China Postdoctoral Science Foundation(No.2018M642133,X.Y.Z.)Post-doctorate Scientific Research Fund for staying(coming to)Shenzhen(No.K21217502,X.Y.Z.)the National Natural Science Foundation of China(No.21671096,Z.G.L.)Shenzhen Key Laboratory of Interfacial Science and Engineering of Materials(No.ZDSYS20200421111401738,Z.G.L.)The authors also acknowledge the assistance of Southern University of Science and Technology Core Research Facilities(SUSTech CRF)Key Laboratory of Energy Conversion and Storage Technologies(Southern University of Science and Technology).
文摘Herein,we prepared a bimetallic layered double hydroxide(FeCo LDH)featuring a dandelion-like structure.Anchoring of CeO_(2)onto FeCo LDH produced interfaces between the functionalizing CeO_(2)and the parent LDH.Comparative electrochemical studies were carried out.Onset potential,overpotential,and Tafel slope point to the superior oxygen-evolving performance of CeO_(2)-FeCo LDH with respect to FeCo LDH,therefore,demonstrating the merits of CeO_(2)functionalization.The electronic structures of Fe,Co,and Ce were analyzed by X-ray photoelectron spectroscopy(XPS)and electron energy loss spectroscopy(EELS)from which the increase of Co^(3+)and the concurrent lowering of Ce^(4+)were established.With the use of CeO_(2)-FeCo LDH,accelerated formation at a sizably reduced potential of Co-OOH,one of the key intermediates preceding the release of O_(2)was observed by in situ Raman spectroscopy.We now have the atomic-level and location-specific evidence,the increase of the active Co^(3+)across the interface to correlate the enhanced catalytic performance with CeO_(2)functionalization.
基金the National Natural Science Foundation of China(No.21805235)China Postdoctoral Science Foundation(No.2017M610502)+2 种基金the Opening Foundation of Creative Platform of the Key Laboratory of the Education Department of Hunan Province(No.20K131)the Construct Program of the Key Discipline in Hunan Province is greatly acknowledged.H.C.and Z.G.L.thank the support from the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen(No.JCYJ20170817110251498)Shenzhen Key Laboratory of Interfacial Science and Engineering of Materials(No.ZDSYS20200421111401738).
文摘It is a big challenge to well control the porous structure of carbon materials for supercapacitor application.Herein,a simple in-situ self-templating strategy is developed to prepare three-dimensional(3D)hierarchical porous carbons with good combination of micro and meso-porous architecture derived from a new oxygen-bridged porous organic polymer(OPOP).The OPOP is produced by the condensation polymerization of cyanuric chloride and hydroquinone in NaOH ethanol solution and NaCl is in-situ formed as by-product that will serve as template to construct an interconnected 3D hierarchical porous architecture upon carbonization.The large interface pore architecture,and rich doping of N and O heteroatoms effectively promote the electrolyte accessibility and electronic conductivity,and provide abundant active sites for energy storage.Consequently,the supercapacitors based on the optimized OPOP-800 sample display an energy density of 8.44 and 27.28 Wh·kg^(−1)in 6.0 M KOH and 1.0 M Na2SO4 electrolytes,respectively.The capacitance retention is more than 94%after 10,000 cycles.Furthermore,density functional theory(DFT)calculations have been employed to unveil the charge storage mechanism in the OPOP-800.The results presented in this job are inspiring in finely tuning the porous structure to optimize the supercapacitive performance of carbon materials.
基金This work was financially supported by the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen(no.JCYJ20200109141640095)the Shenzhen Key Laboratory of Interfacial Science and Engineering of Materials(no.ZDSYS20200421111401738)+3 种基金the Leading Talents of Guangdong Province Program(no.2016LJ06C536)the National Natural Science Foundation of China(no.21875097)Z.J.and G.L.were supported by the Introduced Innovative R&D Team of Guangdong(no.2017ZT07C062)the fund of the Guangdong Provincial Key Laboratory of Computational Science and Material Design(no.2019B030301001).
文摘Electrocatalysts for the oxygen reduction reaction(ORR)are critically important in the development of fuel cells and metal-air batteries.Intensive research interests have been devoted to improving the electrocatalytic performance by tuning the morphology and defect-active sites.Herein,we demonstrate that the oxidation state can also serve as an effective strategy for designingORR electrocatalysts.Valencemodels of silver with gradient chemical valence from zero valence to trivalence were successfully built.Their oxidation states were evaluated by cryo-X-ray photoelectron spectroscopy,X-ray absorptionfinestructure,and electron paramagnetic resonance spectroscopy.For the first time,our results demonstrated that the electrocatalytic activities of silver species can be improved by increasing their valence,conforming the orderofAg<Ag_(2)O<Ag_(2)O_(2)<Ag_(3)O_(4)<Ag_(2)O_(3).Computational studies reveal that higher valence Ag species possess a higher proportion of d band holes andmore electrons closer to the Fermi level.Therefore,the oxygen adsorption and activation energy on the Ag sites can be regulated to a near-optimal level and the ORR catalytic efficiency increases.This work clearly presents that oxidation state is another degree of freedom in designing efficient ORR electrocatalysts.