Lithium-ion batteries(LIBs)have greatly facilitated our daily lives since 1990s[1,2].To meet the ever-increasing demand on energy density,Li metal is seen as the ultimate anode because of its ultra-high specific capac...Lithium-ion batteries(LIBs)have greatly facilitated our daily lives since 1990s[1,2].To meet the ever-increasing demand on energy density,Li metal is seen as the ultimate anode because of its ultra-high specific capacity(3860 m Ah/g)and the lowest electrochemical potential(-3.04 V vs.the standard hydrogen electrode)[3–6].However,issues of Li metal anode,such as Li dendrite formation and large volume change during plating/stripping。展开更多
The insurmountable charge transfer impedance at the Li metal/solid polymer electrolytes(SPEs)interface at room temperature as well as the ascending risk of short circuits at the operating temperature higher than the m...The insurmountable charge transfer impedance at the Li metal/solid polymer electrolytes(SPEs)interface at room temperature as well as the ascending risk of short circuits at the operating temperature higher than the melting point,dominantly limits their applications in solid-state batteries(SSBs).Although the inorganic filler such as CeO_(2)nanoparticle content of composite solid polymer electrolytes(CSPEs)can significantly reduce the enormous charge transfer impedance at the Li metal/SPEs interface,we found that the required content of CeO_(2)nanoparticles in SPEs varies for achieving a decent interfacial charge transfer impedance and the bulk ionic conductivity in CSPEs.In this regard,a sandwich-type composited solid polymer electrolyte with a 10%CeO_(2)CSPEs interlayer sandwiched between two 50%CeO_(2)CSPEs thin layers(sandwiched CSPEs)is constructed to simultaneously achieve low charge transfer impedance and superior ionic conductivity at 30℃.The sandwiched CSPEs allow for stable cycling of Li plating and stripping for 1000 h with 129 mV polarized voltage at 0.1 mA cm^(-2)and 30℃.In addition,the LiFePO_(4)/Sandwiched CSPEs/Li cell also exhibits exceptional cycle performance at 30℃and even elevated120℃without short circuits.Constructing multi-layered CSPEs with optimized contents of the inorganic fillers can be an efficient method for developing all solid-state PEO-based batteries with high performance at a wide range of temperatures.展开更多
Recent advances in utilizing ^(17)O isotopic labeling methods for solid-state nuclear magnetic resonance(NMR)investigations of metal oxides for lithium-ion batteries have yielded extensive insights into their structur...Recent advances in utilizing ^(17)O isotopic labeling methods for solid-state nuclear magnetic resonance(NMR)investigations of metal oxides for lithium-ion batteries have yielded extensive insights into their structural and dynamic details.Herein,we commence with a brief introduction to recent research on lithium-ion battery oxide materials studied using ^(17)O solid-state NMR spectroscopy.Then we delve into a review of ^(17)O isotopic labeling methods for tagging oxygen sites in both the bulk and surfaces of metal oxides.At last,the unresolved problems and the future research directions for advancing the ^(17)O labeling technique are discussed.展开更多
All-solid-state batteries(ASSBs)assembled with sulfide solid electrolytes(SSEs)and nickel(Ni)-rich oxide cathode materials are expected to achieve high energy density and safety,representing potential candidates for t...All-solid-state batteries(ASSBs)assembled with sulfide solid electrolytes(SSEs)and nickel(Ni)-rich oxide cathode materials are expected to achieve high energy density and safety,representing potential candidates for the next-generation energy storage systems.However,interfacial issues between SSEs and Nirich oxide cathode materials,attributed to space charge layer,interfacial side reactions,and mechanical contact failure,significantly restrict the performances of ASSBs.The interface degradation is closely related to the components of the composite cathode and the process of electrode fabrication.Focusing on the influencing factors of interface compatibility between SSEs and Ni-rich oxide cathode,this article systematically discusses how cathode active materials(CAMs),electrolytes,conductive additives,binders,and electrode fabrication impact the interface compatibility.In addition,the strategies for the compatibility modification are reviewed.Furthermore,the challenges and prospects of intensive research on the degradation and modification of the SSE/Ni-rich cathode material interface are discussed.This review is intended to inspire the development of high-energy-density and high-safety all-solid-state batteries.展开更多
Novel cost-effective fuel cells have become more attractive due to the demands for rare and expensive platinum-group metal(PGM)catalysts for mitigating the sluggish kinetics of the oxygen reduction reaction(ORR).The h...Novel cost-effective fuel cells have become more attractive due to the demands for rare and expensive platinum-group metal(PGM)catalysts for mitigating the sluggish kinetics of the oxygen reduction reaction(ORR).The high-cost PGM catalyst in fuel cells can be replaced by earth-abundant transition-metalbased catalysts,that is,an Fe-N-C catalyst,which is considered one of the most promising alternatives.However,the performance of the Fe-N-C catalyst is hindered by the low catalytic activity and poor stability,which is caused by insufficient active sites and the lack of optimization of the triple-phase interface for mass transportation.Herein,a novel Fe–N–C catalyst consisting of mono-dispersed hierarchically mesoporous carbon sphere cores and single Fe atom-dispersed functional shells are presented.The synergistic effect between highly dispersed Fe-active sites and well-organized porous structures yields the combination of high ORR activity and high mass transfer performance.The half-wave potential of the catalyst in 0.1M H_(2)SO_(4) is 0.82 V versus reversible hydrogen electrode,and the peak power density is 812 mW·cm^(−2) in H_(2)–O_(2) fuel cells.Furthermore,it shows superior methanol tolerance,which is almost immune to methanol poisoning and generates up to 162 mW·cm^(−2) power density in direct methanol fuel cells.展开更多
As a promising solid electrolyte for thin-film lithium batteries,the amorphous Li_(0.33)La_(0.56)TiO_(3)(LLTO)thin film has gained great interest.However,enhancing ionic conductivity remains challenging in the field.H...As a promising solid electrolyte for thin-film lithium batteries,the amorphous Li_(0.33)La_(0.56)TiO_(3)(LLTO)thin film has gained great interest.However,enhancing ionic conductivity remains challenging in the field.Here,a systematical study was performed to improve the ionic conductivity of sputter-deposited LLTO thin films via the optimization of processing atmosphere and temperature.By combining the optimized oxygen partial pressure(30%),annealing temperature(300℃),and annealing atmosphere(air),an amorphous LLTO thin film with an ionic conductivity of 5.32910^(-5)·S·cm^(-1) at room temperature and activation energy of 0.26 eV was achieved.The results showed that,first,the oxygen partial pressure should be high enough to compensate for the oxygen loss,but low enough to avoid the abusive oxygen scattering effect on lithium precursors that results in a lithium-poor composition.The oxygen partial pressure needs to achieve a balance between lithium loss and oxygen defects to improve the ionic conductivity.Second,a proper annealing temperature reduces the oxygen defects of LLTO thin films while maintaining its amorphous state,which improves the ionic conductivity.Third,the highest ionic conductivity for the LLTO thin films that were annealed in air(a static space without a gas stream)occurs because of the decreased lithium loss and oxygen defects during annealing.These findings show that the lithium-ion concentration and oxygen defects affect the ionic conductivity for amorphous LLTO thin films,which provides insight into the optimization of LLTO thin-film solid electrolytes,and generates new opportunities for their application in thinfilm lithium batteries.展开更多
Lithium-sulfur(Li-S)batteries have been considered as the next generation high energy storage devices.However,its commercialization has been hindered by several issues,especially the dissolution and shuttle of the sol...Lithium-sulfur(Li-S)batteries have been considered as the next generation high energy storage devices.However,its commercialization has been hindered by several issues,especially the dissolution and shuttle of the soluble lithium polysulfides(LiPSs)as well as the slow reaction kinetics of LiPSs which may make shuttling effect even worse.Herein,we report a strategy to address this issue by in-situ transformation of Co−N_(x) coordinations in cobalt polyphthalocyanine(CoPPc)into Co nanoparticles(Co NPs)embedded in carbon matrix and mono-dispersed on graphene flakes.The Co NPs can provide rich binding and catalytic sites,while graphene flakes act as ideally LiPSs transportation and electron conducting platform.With a remarkable enhanced reaction kinetics of LiPSs via these merits,the sulfur host with a sulfur content up to 70 wt%shows a high initial capacity of 1048 mA∙h/g at 0.2C,good rate capability up to 399 mA·h/g at 2C.展开更多
Owing to the unique structure,anode-free lithium metal batteries(AFLMBs)have higher energy density and lower production cost than traditional lithium metal batteries(LMBs)or lithium-ion batteries(LIBs),However,AFLMBs ...Owing to the unique structure,anode-free lithium metal batteries(AFLMBs)have higher energy density and lower production cost than traditional lithium metal batteries(LMBs)or lithium-ion batteries(LIBs),However,AFLMBs suffer from an inherently finite Li reservoir and exhibit poor cycle stability,low Coulombic efficiency(CE)and severe dendrite growth.In this work,polydiallyl lithium disulfide(PDS-Li)was successfully synthesized and coated on Cu current collector by electrochemical polymerization.The PDS-Li acts as an additional lithium resource to compensate for the irreversible loss of lithium during cycling.In addition,the special structure and lithiophilicity of PDS-Li contribute to lower nucleation overpotential and uniform lithium deposition.When coupled with Li-rich manganese-based(LRM)cathode of Li1.2Mn0.54Ni0.13Co0.13O2,the anode-free full cell exhibits significantly improved cycle stability over 100 cycles and capacity retention of 63.3%and 57%after 80 and 100 cycles,respectively.We believe that PDS-Li can be used to ensure stable cycling performance and high-energy-density in AFLMBs.展开更多
Preparing carbon nanosheets with precise control of open porous morphology via universal process and understanding the relationship between structure and capacitive performance are very urgent for achieving advanced s...Preparing carbon nanosheets with precise control of open porous morphology via universal process and understanding the relationship between structure and capacitive performance are very urgent for achieving advanced supercapacitors.Herein,we propose a simple yet effective additive-free method to transform a bulk layered potassium phthalimide salt to novel nitrogen-doped twodimensional carbon sheets by self-activation during calcination.The obtained samples showed large-sized and flat structure with lateral size around 10μm,uniform sub-nanometer micropore size distribution of about 0.65 nm dimension,large specific surface area up to 2276.7 m^(2)g^(-1),and suitable nitrogen doping.Benefited from these merits,the optimized sample delivers a high specific capacitance of 345 F g^(-1)at 1 A g^(-1)and retains 270 F g^(-1)even at 50 A g^(-1)in6.0 M KOH electrolyte.Remarkably,the symmetric supercapacitor shows maximum energy densities of 16.43 Wh kg^(-1)and 23.6 Wh kg^(-1)in 6.0 M KOH and 1.0 M Na_(2)SO_(4)electrolytes,respectively.Importantly,on account the universality and simplicity of this method,the undoped as-prepared carbon sheet with uniform sub-nanometer micropore distribution can be synthesized from different potassium-containing salts with layered structure,which can be employed as a model for a deep understanding the effect of sub-nanometer micropores on capacitive performances.We find the number of micropores centered at 0.65 nm can be applied as one indicator to clarify the correlation between capacitance and critical pore size below 1 nm.展开更多
Nucleophile oxidation reaction(NOR),represented by ethanol oxidation reaction(EOR),is a promising pathway to replace oxygen evolution reaction(OER).EOR can effectively reduce the driving voltage of hydrogen production...Nucleophile oxidation reaction(NOR),represented by ethanol oxidation reaction(EOR),is a promising pathway to replace oxygen evolution reaction(OER).EOR can effectively reduce the driving voltage of hydrogen production in direct water splitting.In this work,large current and high efficiency of EOR on a Ni,Fe layered double hydroxide(NiFe-LDH)catalyst were simultaneously achieved by a facile fluorination strategy.F in NiFe-LDH can reduce the activation energy of the dehydrogenation reaction,thus promoting the deprotonation process of NiFe-LDH to achieve a lower EOR onset potential.It also weakens the absorption of OH-and nucleophile electrooxidation products on the surface of NiFe-LDH at a higher potential,achieving a high current density and EOR selectivity,according to density functional theory calculations.Based on our experiment results,the optimized fluorinated NiFe-LDH catalyst achieves a low potential of 1.386 V to deliver a 10 mA cm^(-2)EOR.Moreover,the Faraday efficiency is greater than 95%,with a current density ranging from 10 to 250 mA cm^(-2).This work provides a promising pathway for an efficient and cost-effective NOR catalyst design for economic hydrogen production.展开更多
The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processe...The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processes.Two-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical stability.To resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle effect.Meanwhile,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass transfer.Impressively,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding cyclability.This work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries.展开更多
The search for a low-cost metal-free cathode material with excellent mass transfer structure and catalytic activity in oxygen reduction reaction(ORR)is one of the most challenging issues in fuel cells.In this work,nit...The search for a low-cost metal-free cathode material with excellent mass transfer structure and catalytic activity in oxygen reduction reaction(ORR)is one of the most challenging issues in fuel cells.In this work,nitrogen-rich mphenylenediamine is introduced into the synthesis of porous carbon spheres to tune the pore structure and nitrogen-doped active sites.As a result,more pyridinic N and pyrrolic N functional species were observed at the interior and surface of the carbon spheres.The introduction of m-phenylenediamine also regulated the nucleating of precursors,an urchin-like mesoporous surface structure ensures point contact and less agglomeration between each particle was obtained.With optimized proportion of micropores/mesopores and improved nitrogen-contained functional species,the ORR activity can be remarkably improved.The half-wave potential of this catalyst could achieve to 0.81 V(versus RHE)which is only 42 m V lower than commercial Pt/C catalyst.Furthermore,the optimized cathode catalyst achieved a 69 m W cm-2 maximum power density when operated in direct methanol fuel cells at room temperature.展开更多
The rapid development of flexible electronic technologies has promoted flexible electronic markets,such as wearable electronics,intelligent clothing,electronic skin,flexible displays,implantable medical devices,etc.,w...The rapid development of flexible electronic technologies has promoted flexible electronic markets,such as wearable electronics,intelligent clothing,electronic skin,flexible displays,implantable medical devices,etc.,which reflects the direction of future flexible energy storage systems[1-3].Lithium-ion batteries(LIBs)have become the most important energy storage device relying on strong upstream-downstream supply chains and high-tech-maturity manufacturing technologies.To drive flexible electronics,LIBs need to maintain their electrochemical functions while having at least the same deformability as these devices.展开更多
With a 10%reversible compressive strain in more than 10 deformation cycles,the shape memory polymer composites(SMPCs)could be used for deployable structure and releasing mechanism.In this paper,without traditional ele...With a 10%reversible compressive strain in more than 10 deformation cycles,the shape memory polymer composites(SMPCs)could be used for deployable structure and releasing mechanism.In this paper,without traditional electro-explosive devices or motors/controllers,the deployable SMPC flexible solar array system(SMPC-FSAS)is studied,developed,ground-based tested,and finally on-orbit validated.The epoxy-based SMPC is used for the rolling-out variable-stiffness beams as a structural frame as well as an actuator for the flexible blanket solar array.The releasing mechanism is primarily made of the cyanate-based SMPC,which has a high locking stiffness to withstand 50 g gravitational acceleration and a large unlocking displacement of 10 mm.The systematical mechanical and thermal qualification tests of the SMPC-FSAS flight hardware were performed,including sinusoidal sweeping vibration,shocking,acceleration,thermal equilibrium,thermal vacuum cycling,and thermal cycling test.The locking function of the SMPC releasing mechanisms was in normal when launching aboard the SJ20 Geostationary Satellite on 27 Dec.,2019.The SMPC-FSAS flight hardware successfully unlocked and deployed on 5 Jan.,2020 on geostationary orbit.The triggering signal of limit switches returned to ground at the 139 s upon heating,which indicated the successful unlocking function of SMPC releasing mechanisms.A pair of epoxy-based SMPC rolled variable-stiffness tubes,which clapped the flexible blanket solar array,slowly deployed and finally approached an approximate 100%shape recovery ratio within 60 s upon heating.The study and on-orbit successful validation of the SMPC-FSAS flight hardware could accelerate the related study and associated productions to be used for the next-generation releasing mechanisms as well as space deployable structures,such as new releasing mechanisms with low-shocking,testability and reusability,and ultra-large space deployable solar arrays.展开更多
Garnet-type solid-state electrolytes(SSEs)are particularly attractive in the construction of all-solid-state lithium(Li)batteries due to their high ionic conductivity,wide electrochemical window and remarkable(electro...Garnet-type solid-state electrolytes(SSEs)are particularly attractive in the construction of all-solid-state lithium(Li)batteries due to their high ionic conductivity,wide electrochemical window and remarkable(electro)chemical stability.However,the intractable issues of poor cathode/garnet interface and general low cathode loading hinder their practical application.Herein,we demonstrate the construction of a reinforced cathode/garnet interface by spark plasma sintering,via co-sintering Li_(6.5)La_(3)Zr_(1.5)Ta_(0.5)O_(12)(LLZTO)electrolyte powder and LiCoO_(2)/LLZTO composite cathode powder directly into a dense dual-layer with 5 wt%Li_(3)BO_(3)as sintering additive.The bulk composite cathode with LiCoO_(2)/LLZTO cross-linked structure is firmly welded to the LLZTO layer,which optimizes both Li-ion and electron transport.Therefore,the one-step integrated sintering process implements an ultra-low cathode/garnet interfacial resistance of 3.9Ωcm^(2)(100◦C)and a high cathode loading up to 2.02 mAh cm^(−2).Moreover,the Li_(3)BO_(3)reinforced LiCoO_(2)/LLZTO interface also effectively mitigates the strain/stress of LiCoO_(2),which facilitates the achieving of superior cycling stability.The bulk-type Li|LLZTO|LiCoO_(2)-LLZTO full cell with areal capacity of 0.73 mAh cm^(−2)delivers capacity retention of 81.7%after 50 cycles at 100μA cm^(−2).Furthermore,we reveal that non-uniform Li plating/stripping leads to the formation of gaps and finally results in the separation of Li and LLZTO electrolyte during long-term cycling,which becomes the dominant capacity decay mechanism in high-capacity full cells.This work provides insight into the degradation of Li/SSE interface and a strategy to radically improve the electrochemical performance of garnet-based all-solid-state Li batteries.展开更多
Solid-state thermoelectric energy conversion devices attract broad research interests because of their great promises in waste heat recycling,space power generation,deep water power generation,and temperature control,...Solid-state thermoelectric energy conversion devices attract broad research interests because of their great promises in waste heat recycling,space power generation,deep water power generation,and temperature control,but the search for essential thermoelectric materials with high performance still remains a great challenge.As an emerging low cost,solution-processed thermoelectric material,inorganic metal halide perovskites CsPb(I_(1–x)Br_(x))_(3) under mechanical deformation is systematically investigated using the first-principle calculations and the Boltzmann transport theory.It is demonstrated that halogen mixing and mechanical deformation are efficient methods to tailor electronic structures and charge transport properties in CsPb(I_(1–x)Br_(x))_(3) synergistically.Halogen mixing leads to band splitting and anisotropic charge transport due to symmetry-breakinginduced intrinsic strains.Such band splitting reconstructs the band edge and can decrease the charge carrier effective mass,leading to excellent charge transport properties.Mechanical deformation can further push the orbital energies apart from each other in a more controllable manner,surpassing the impact from intrinsic strains.Both anisotropic charge transport properties and ZT values are sensitive to the direction and magnitude of strain,showing a wide range of variation from 20%to 400%(with a ZT value of up to 1.85)compared with unstrained cases.The power generation efficiency of the thermoelectric device can reach as high as approximately 12%using mixed halide perovskites under tailored mechanical deformation when the heat-source is at 500 K and the cold side is maintained at 300 K,surpassing the performance of many existing bulk thermoelectric materials.展开更多
Argyrodites,Li_(6)PS_(5)X(X=Cl,Br,I),have piqued the interest of researchers by offering promising lithium ionic conductivity for their application in all-solid-state batteries(ASSBs).However,other than Li_(6)PS_(5)Cl...Argyrodites,Li_(6)PS_(5)X(X=Cl,Br,I),have piqued the interest of researchers by offering promising lithium ionic conductivity for their application in all-solid-state batteries(ASSBs).However,other than Li_(6)PS_(5)Cl(651Cl)and Li_(6)PS_(5)Br(651Br),Li_(6)PS_(5)I(651I)shows poor ionic conductivity(10^(-7)S cm^(-1)at 298 K).Herein,we present Al-doped 651I with I^(-)/S^(2-)site disordering to lower activation energy(Ea)and improve ionic conductivity.They formed argyrodite-type solid solutions with a composition of(Li_(6–3x)Al_(x))PS_(5)I in 0≤x≤0.10,and structural analysis revealed that Al^(3+)is located at Li sites.Also,the Al-doped samples contained anion I^(-)/S^(2-)site disorders in the crystal structures and smaller lattice parameters than the non-doped samples.Impedance spectroscopy measurements indicated that Al-doping reduced the ionic diffusion barrier,Ea,and increased the ionic conductivity to 10^(-5)S cm^(-1);the(Li5.7Al0.1)PS5I had the highest ionic conductivity in the studied system,at 2.6×10^(-5)S cm^(-1).In a lab-scale ASSB,with(Li_(5.7)Al_(0.1))PS_(5)I functioned as a solid electrolyte,demonstrating the characteristics of a pure ionic conductor with negligible electronic conductivity.The evaluated ionic conduction is due to decreased Li+content and I^(-)/S^(2-)disorder formation.Li-site cation doping enables an in-depth understanding of the structure and provides an additional approach to designing betterperforming SEs in the argyrodite system.展开更多
SiO_(x)is commonly used in lithium-ion batteries because of its capacity and affordability,but it has issues with volume expansion and conductivity.Synthetic methods are crucial for achieving the desired microstructur...SiO_(x)is commonly used in lithium-ion batteries because of its capacity and affordability,but it has issues with volume expansion and conductivity.Synthetic methods are crucial for achieving the desired microstructure and material properties.This study introduces a new technique,fluidized bed granulation,to produce SiO_(x)@GNs composites.These composites have a core-shell structure with SiO_(x)particles coated in graphene sheets,and high-energy vibration is used to create a SiO_(x)-Fe structure on the surface.The graphene coating prevents volume expansion and enhances electron transfer.Real-time confocal imaging shows the charging and discharging process.Experiment results show that the SiO_(x)@GNs electrode has a lower expansion rate of 53.60%compared to 73.04%for the SiO electrode,indicating improved electrochemical properties with the graphene coating.After 100 cycles at 2 C,SiO_(x)@GNs demonstrate a reversible capacity of 1265.8 mA,h·g^(-1)and discharge capability at 7 C with a capacity of 1050 mA,h·g^(-1).The battery retains 90.21%of its capacity after 500 cycles at 0.5 C,showing potential as a LIB anode alternative with a unique structure for different energy storage materials.Fluidized bed granulation can aid in scaling up the use of SiO_(x)anodes in lithium-ion batteries.展开更多
The increasing demand for versatile and high-quality near-field radiative heat transfer(NFRHT) has created a critical need for a design approach that can handle numerous candidate structures. In this work, we employ a...The increasing demand for versatile and high-quality near-field radiative heat transfer(NFRHT) has created a critical need for a design approach that can handle numerous candidate structures. In this work, we employ and develop an adaptive hybrid Bayesian optimization(AHBO) algorithm to design the high-quality quasi-monochromatic NFRHT. The candidate materials include hexagonal boron nitride, silicon carbide, and doped silicon. The high-quality quasi-monochromatic NFRHT is optimized over 1.0 × 10^(8) candidate structures to maximize the evaluation factor. It is worth noting that only 2.6% of the candidate structures needed to be calculated to identify the optimal structure. The optimal structure of quasi-monochromatic NFRHT is an aperiodic multilayer metamaterial that differs from conventional periodic multilayer structures. Moreover, we investigate the robustness and mechanisms of the optimal quasi-monochromatic NFRHT with respect to the vacuum gap distance and the temperature difference between the emitter and receiver. In addition, the high-quality multi-peak NFRHT is designed using the AHBO algorithm by improving the definition of the evaluation factor. The results demonstrate that the AHBO algorithm is efficient in designing high-quality quasi-monochromatic and multi-peak NFRHT, and it can be further expanded to other structural designs in the field of energy conversion.展开更多
Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially ad...Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially adsorbed CO species(COad))formed during the EOR process can easily adsorb and block the active sites on Pd electrodes,which in turn limits the catalytic efficiency.Hence,we present a series of Pd-based composites with a strong coupling interface consisting of Pd nanosheets and amorphous Bi(OH)_(3)species.The incorporation of Bi(OH)3 can induce an electron-rich state adjacent to the Pd sites and effectively separate the Pd ensemble,leading to excellent CO tolerance.The optimal Pd-Bi(OH)_(3)NSs catalyst manifests a mass activity of 2.2 A·mgPd^(-1),which is 5.7 and 2.0 times higher than that of Pd NSs and commercial Pd/C catalyst,respectively.Further CO-stripping experiments and CO-DRIFTS tests confirm the excellent CO tolerance on Pd-Bi(OH)3 NSs electrode,leading to the enhanced EOR durability.展开更多
基金financial support by the National Natural Science Foundation of China(No.51802224)“Shanghai Rising-Star Program”(19QA1409300)Shanghai Aerospace Science and Technology Innovation Fundation(SISP2018)。
文摘Lithium-ion batteries(LIBs)have greatly facilitated our daily lives since 1990s[1,2].To meet the ever-increasing demand on energy density,Li metal is seen as the ultimate anode because of its ultra-high specific capacity(3860 m Ah/g)and the lowest electrochemical potential(-3.04 V vs.the standard hydrogen electrode)[3–6].However,issues of Li metal anode,such as Li dendrite formation and large volume change during plating/stripping。
基金supported by the National Key R&D Program of China(2021YFB2400400)the National Natural Science Foundation of China(Grant No.22379120,22179085)+5 种基金the Key Research and Development Plan of Shanxi Province(China,Grant No.2018ZDXM-GY-135,2021JLM-36)the National Natural Science Foundation of China(Grant No.22108218)the“Young Talent Support Plan”of Xi’an Jiaotong University(71211201010723)the Qinchuangyuan Innovative Talent Project(QCYRCXM-2022-137)the“Young Talent Support Plan”of Xi’an Jiaotong University(HG6J003)the“1000-Plan program”of Shaanxi Province。
文摘The insurmountable charge transfer impedance at the Li metal/solid polymer electrolytes(SPEs)interface at room temperature as well as the ascending risk of short circuits at the operating temperature higher than the melting point,dominantly limits their applications in solid-state batteries(SSBs).Although the inorganic filler such as CeO_(2)nanoparticle content of composite solid polymer electrolytes(CSPEs)can significantly reduce the enormous charge transfer impedance at the Li metal/SPEs interface,we found that the required content of CeO_(2)nanoparticles in SPEs varies for achieving a decent interfacial charge transfer impedance and the bulk ionic conductivity in CSPEs.In this regard,a sandwich-type composited solid polymer electrolyte with a 10%CeO_(2)CSPEs interlayer sandwiched between two 50%CeO_(2)CSPEs thin layers(sandwiched CSPEs)is constructed to simultaneously achieve low charge transfer impedance and superior ionic conductivity at 30℃.The sandwiched CSPEs allow for stable cycling of Li plating and stripping for 1000 h with 129 mV polarized voltage at 0.1 mA cm^(-2)and 30℃.In addition,the LiFePO_(4)/Sandwiched CSPEs/Li cell also exhibits exceptional cycle performance at 30℃and even elevated120℃without short circuits.Constructing multi-layered CSPEs with optimized contents of the inorganic fillers can be an efficient method for developing all solid-state PEO-based batteries with high performance at a wide range of temperatures.
基金supported by National Key R&D Program of China(2021YFA1502803)the National Natural Science Foundation of China(NSFC)(21972066,91745202)+3 种基金NSFC-Royal Society Joint Program(21661130149)L.P.thanks the Royal Society and Newton Fund for a Royal Society-Newton Advanced Fellowshipsupported by the Research Funds for the Frontiers Science Centre for Critical Earth Material Cycling,Nanjing Universitya Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Recent advances in utilizing ^(17)O isotopic labeling methods for solid-state nuclear magnetic resonance(NMR)investigations of metal oxides for lithium-ion batteries have yielded extensive insights into their structural and dynamic details.Herein,we commence with a brief introduction to recent research on lithium-ion battery oxide materials studied using ^(17)O solid-state NMR spectroscopy.Then we delve into a review of ^(17)O isotopic labeling methods for tagging oxygen sites in both the bulk and surfaces of metal oxides.At last,the unresolved problems and the future research directions for advancing the ^(17)O labeling technique are discussed.
基金financially supported by the National Natural Science Foundation of China(52072036,52272187)the China Petroleum&Chemical Corporation(SINOPEC)project(223128).
文摘All-solid-state batteries(ASSBs)assembled with sulfide solid electrolytes(SSEs)and nickel(Ni)-rich oxide cathode materials are expected to achieve high energy density and safety,representing potential candidates for the next-generation energy storage systems.However,interfacial issues between SSEs and Nirich oxide cathode materials,attributed to space charge layer,interfacial side reactions,and mechanical contact failure,significantly restrict the performances of ASSBs.The interface degradation is closely related to the components of the composite cathode and the process of electrode fabrication.Focusing on the influencing factors of interface compatibility between SSEs and Ni-rich oxide cathode,this article systematically discusses how cathode active materials(CAMs),electrolytes,conductive additives,binders,and electrode fabrication impact the interface compatibility.In addition,the strategies for the compatibility modification are reviewed.Furthermore,the challenges and prospects of intensive research on the degradation and modification of the SSE/Ni-rich cathode material interface are discussed.This review is intended to inspire the development of high-energy-density and high-safety all-solid-state batteries.
基金We gratefully acknowledge support from the National Natural Science Foundation of China(Grant Nos.21905220,51772240,21503158,51425301,U1601214,21703184)the China Postdoctoral Science Foundation(2020M673408)+5 种基金the Key Research and Development Plan of Shaanxi Province,China(Grant No.2018ZDXM-GY-135)the Fundamental Research Funds for“Young Talent Support Plan”of Xi'an Jiaotong University(HG6J003)the“1000‐Plan program”of Shaanxi Province,the Promotion Program for Young and Middle-Aged Teacher in Science and Technology Research of Huaqiao University(ZQN-PY506)the Scientific Research Funds of Huaqiao University(17BS405)the State Key Laboratory for Mechanical Behavior of Materials(20192101)the Natural Science Foundation Committee of Jiangsu Province(BK20201190).
文摘Novel cost-effective fuel cells have become more attractive due to the demands for rare and expensive platinum-group metal(PGM)catalysts for mitigating the sluggish kinetics of the oxygen reduction reaction(ORR).The high-cost PGM catalyst in fuel cells can be replaced by earth-abundant transition-metalbased catalysts,that is,an Fe-N-C catalyst,which is considered one of the most promising alternatives.However,the performance of the Fe-N-C catalyst is hindered by the low catalytic activity and poor stability,which is caused by insufficient active sites and the lack of optimization of the triple-phase interface for mass transportation.Herein,a novel Fe–N–C catalyst consisting of mono-dispersed hierarchically mesoporous carbon sphere cores and single Fe atom-dispersed functional shells are presented.The synergistic effect between highly dispersed Fe-active sites and well-organized porous structures yields the combination of high ORR activity and high mass transfer performance.The half-wave potential of the catalyst in 0.1M H_(2)SO_(4) is 0.82 V versus reversible hydrogen electrode,and the peak power density is 812 mW·cm^(−2) in H_(2)–O_(2) fuel cells.Furthermore,it shows superior methanol tolerance,which is almost immune to methanol poisoning and generates up to 162 mW·cm^(−2) power density in direct methanol fuel cells.
基金This study was financially supported by the National Natural Science Funds of China(No.21905040)the Startup Funds from the University of Electronic Science and Technology of China,the National Key Research and Development Program of China(Nos.2017YFB0702802 and 2018YFB0905400)Shanghai Venus Project(No.18QB1402600).
文摘As a promising solid electrolyte for thin-film lithium batteries,the amorphous Li_(0.33)La_(0.56)TiO_(3)(LLTO)thin film has gained great interest.However,enhancing ionic conductivity remains challenging in the field.Here,a systematical study was performed to improve the ionic conductivity of sputter-deposited LLTO thin films via the optimization of processing atmosphere and temperature.By combining the optimized oxygen partial pressure(30%),annealing temperature(300℃),and annealing atmosphere(air),an amorphous LLTO thin film with an ionic conductivity of 5.32910^(-5)·S·cm^(-1) at room temperature and activation energy of 0.26 eV was achieved.The results showed that,first,the oxygen partial pressure should be high enough to compensate for the oxygen loss,but low enough to avoid the abusive oxygen scattering effect on lithium precursors that results in a lithium-poor composition.The oxygen partial pressure needs to achieve a balance between lithium loss and oxygen defects to improve the ionic conductivity.Second,a proper annealing temperature reduces the oxygen defects of LLTO thin films while maintaining its amorphous state,which improves the ionic conductivity.Third,the highest ionic conductivity for the LLTO thin films that were annealed in air(a static space without a gas stream)occurs because of the decreased lithium loss and oxygen defects during annealing.These findings show that the lithium-ion concentration and oxygen defects affect the ionic conductivity for amorphous LLTO thin films,which provides insight into the optimization of LLTO thin-film solid electrolytes,and generates new opportunities for their application in thinfilm lithium batteries.
基金Project(21905220) supported by the National Natural Science Foundation of ChinaProject(BK20201190) supported by the Jiangsu Provincial Department of Science and Technology,China+2 种基金Projects(2018ZDXM-GY-135,2021JLM-36) supported by the Key Research and Development Plan of Shaanxi Province,ChinaProject(HG6J003) supported by the Fundamental Research Funds for “Young Talent Support Plan” of Xi’ an Jiaotong University,ChinaProject supported by the “1000-Plan program” of Shaanxi Province,China。
文摘Lithium-sulfur(Li-S)batteries have been considered as the next generation high energy storage devices.However,its commercialization has been hindered by several issues,especially the dissolution and shuttle of the soluble lithium polysulfides(LiPSs)as well as the slow reaction kinetics of LiPSs which may make shuttling effect even worse.Herein,we report a strategy to address this issue by in-situ transformation of Co−N_(x) coordinations in cobalt polyphthalocyanine(CoPPc)into Co nanoparticles(Co NPs)embedded in carbon matrix and mono-dispersed on graphene flakes.The Co NPs can provide rich binding and catalytic sites,while graphene flakes act as ideally LiPSs transportation and electron conducting platform.With a remarkable enhanced reaction kinetics of LiPSs via these merits,the sulfur host with a sulfur content up to 70 wt%shows a high initial capacity of 1048 mA∙h/g at 0.2C,good rate capability up to 399 mA·h/g at 2C.
基金financially supported by the National Natural Science Foundations of China(Nos.52071226,51872193 and U21A20332)the Natural Science Foundations of Jiangsu Province(Nos.BK20181168,BK20201171 and BK20220061)+2 种基金the Key R&D Project funded by Department of Science and Technology of Jiangsu Province(No.BE2020003-3)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(No.19KJA210004)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Owing to the unique structure,anode-free lithium metal batteries(AFLMBs)have higher energy density and lower production cost than traditional lithium metal batteries(LMBs)or lithium-ion batteries(LIBs),However,AFLMBs suffer from an inherently finite Li reservoir and exhibit poor cycle stability,low Coulombic efficiency(CE)and severe dendrite growth.In this work,polydiallyl lithium disulfide(PDS-Li)was successfully synthesized and coated on Cu current collector by electrochemical polymerization.The PDS-Li acts as an additional lithium resource to compensate for the irreversible loss of lithium during cycling.In addition,the special structure and lithiophilicity of PDS-Li contribute to lower nucleation overpotential and uniform lithium deposition.When coupled with Li-rich manganese-based(LRM)cathode of Li1.2Mn0.54Ni0.13Co0.13O2,the anode-free full cell exhibits significantly improved cycle stability over 100 cycles and capacity retention of 63.3%and 57%after 80 and 100 cycles,respectively.We believe that PDS-Li can be used to ensure stable cycling performance and high-energy-density in AFLMBs.
基金support from the National Natural Science Foundation of China(Grant No.21905220,51772240,21503158 and Distinguished Youth Scientist Program of 51425301)the Key Research and Development Plan of Shanxi Province(China,Grant No.2018ZDXM-GY-135)+3 种基金the Fundamental Research Funds for“Young Talent Support Plan”of Xi’an Jiaotong University(HG6J003)“1000-Plan program”of Shanxi ProvinceSanyo Chem.Co.Ltdthe grant from Shaanxi Joint Laboratory of Graphene(NPU)
文摘Preparing carbon nanosheets with precise control of open porous morphology via universal process and understanding the relationship between structure and capacitive performance are very urgent for achieving advanced supercapacitors.Herein,we propose a simple yet effective additive-free method to transform a bulk layered potassium phthalimide salt to novel nitrogen-doped twodimensional carbon sheets by self-activation during calcination.The obtained samples showed large-sized and flat structure with lateral size around 10μm,uniform sub-nanometer micropore size distribution of about 0.65 nm dimension,large specific surface area up to 2276.7 m^(2)g^(-1),and suitable nitrogen doping.Benefited from these merits,the optimized sample delivers a high specific capacitance of 345 F g^(-1)at 1 A g^(-1)and retains 270 F g^(-1)even at 50 A g^(-1)in6.0 M KOH electrolyte.Remarkably,the symmetric supercapacitor shows maximum energy densities of 16.43 Wh kg^(-1)and 23.6 Wh kg^(-1)in 6.0 M KOH and 1.0 M Na_(2)SO_(4)electrolytes,respectively.Importantly,on account the universality and simplicity of this method,the undoped as-prepared carbon sheet with uniform sub-nanometer micropore distribution can be synthesized from different potassium-containing salts with layered structure,which can be employed as a model for a deep understanding the effect of sub-nanometer micropores on capacitive performances.We find the number of micropores centered at 0.65 nm can be applied as one indicator to clarify the correlation between capacitance and critical pore size below 1 nm.
基金the financial support from the National Natural Science Foundation of China(22197121)Knowledge Innovation Program of Wuhan-Basic Research(2022010801010202)Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology(FC202201)。
文摘Nucleophile oxidation reaction(NOR),represented by ethanol oxidation reaction(EOR),is a promising pathway to replace oxygen evolution reaction(OER).EOR can effectively reduce the driving voltage of hydrogen production in direct water splitting.In this work,large current and high efficiency of EOR on a Ni,Fe layered double hydroxide(NiFe-LDH)catalyst were simultaneously achieved by a facile fluorination strategy.F in NiFe-LDH can reduce the activation energy of the dehydrogenation reaction,thus promoting the deprotonation process of NiFe-LDH to achieve a lower EOR onset potential.It also weakens the absorption of OH-and nucleophile electrooxidation products on the surface of NiFe-LDH at a higher potential,achieving a high current density and EOR selectivity,according to density functional theory calculations.Based on our experiment results,the optimized fluorinated NiFe-LDH catalyst achieves a low potential of 1.386 V to deliver a 10 mA cm^(-2)EOR.Moreover,the Faraday efficiency is greater than 95%,with a current density ranging from 10 to 250 mA cm^(-2).This work provides a promising pathway for an efficient and cost-effective NOR catalyst design for economic hydrogen production.
基金Jiangsu Provincial Department of Science and Technology,Grant/Award Number:BK20201190Fundamental Research Funds for“Young Talent Support Plan”of Xi'an Jiaotong University,Grant/Award Number:HG6J003+1 种基金“1000-Plan program”of Shaanxi Province and the Velux Foundations through the research center V-Sustain,Grant/Award Number:9455National Key R&D Program of China,。
文摘The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processes.Two-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical stability.To resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle effect.Meanwhile,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass transfer.Impressively,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding cyclability.This work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries.
基金support from the National Natural Science Foundation of China(Grant No.51772240,21503158,21905220)the Key Research and Development Plan of Shaanxi Province(China,Grant No.2018ZDXM-GY-135)+1 种基金the Fundamental Research Funds for“Young Talent Support Plan”of Xi’an Jiaotong University(HG6J003)“1000-Plan program”of Shaanxi Province
文摘The search for a low-cost metal-free cathode material with excellent mass transfer structure and catalytic activity in oxygen reduction reaction(ORR)is one of the most challenging issues in fuel cells.In this work,nitrogen-rich mphenylenediamine is introduced into the synthesis of porous carbon spheres to tune the pore structure and nitrogen-doped active sites.As a result,more pyridinic N and pyrrolic N functional species were observed at the interior and surface of the carbon spheres.The introduction of m-phenylenediamine also regulated the nucleating of precursors,an urchin-like mesoporous surface structure ensures point contact and less agglomeration between each particle was obtained.With optimized proportion of micropores/mesopores and improved nitrogen-contained functional species,the ORR activity can be remarkably improved.The half-wave potential of this catalyst could achieve to 0.81 V(versus RHE)which is only 42 m V lower than commercial Pt/C catalyst.Furthermore,the optimized cathode catalyst achieved a 69 m W cm-2 maximum power density when operated in direct methanol fuel cells at room temperature.
基金supported by the National Key Research and Development Program of China(2022YFE0138900)the National Natural Science Foundation of China(22279026)the Startup Fund for Introducing Talents of Southwest University of Science and Technology(23zx7171).
文摘The rapid development of flexible electronic technologies has promoted flexible electronic markets,such as wearable electronics,intelligent clothing,electronic skin,flexible displays,implantable medical devices,etc.,which reflects the direction of future flexible energy storage systems[1-3].Lithium-ion batteries(LIBs)have become the most important energy storage device relying on strong upstream-downstream supply chains and high-tech-maturity manufacturing technologies.To drive flexible electronics,LIBs need to maintain their electrochemical functions while having at least the same deformability as these devices.
基金supported by the National Natural Science Foundation of China(Grant No.11632005)。
文摘With a 10%reversible compressive strain in more than 10 deformation cycles,the shape memory polymer composites(SMPCs)could be used for deployable structure and releasing mechanism.In this paper,without traditional electro-explosive devices or motors/controllers,the deployable SMPC flexible solar array system(SMPC-FSAS)is studied,developed,ground-based tested,and finally on-orbit validated.The epoxy-based SMPC is used for the rolling-out variable-stiffness beams as a structural frame as well as an actuator for the flexible blanket solar array.The releasing mechanism is primarily made of the cyanate-based SMPC,which has a high locking stiffness to withstand 50 g gravitational acceleration and a large unlocking displacement of 10 mm.The systematical mechanical and thermal qualification tests of the SMPC-FSAS flight hardware were performed,including sinusoidal sweeping vibration,shocking,acceleration,thermal equilibrium,thermal vacuum cycling,and thermal cycling test.The locking function of the SMPC releasing mechanisms was in normal when launching aboard the SJ20 Geostationary Satellite on 27 Dec.,2019.The SMPC-FSAS flight hardware successfully unlocked and deployed on 5 Jan.,2020 on geostationary orbit.The triggering signal of limit switches returned to ground at the 139 s upon heating,which indicated the successful unlocking function of SMPC releasing mechanisms.A pair of epoxy-based SMPC rolled variable-stiffness tubes,which clapped the flexible blanket solar array,slowly deployed and finally approached an approximate 100%shape recovery ratio within 60 s upon heating.The study and on-orbit successful validation of the SMPC-FSAS flight hardware could accelerate the related study and associated productions to be used for the next-generation releasing mechanisms as well as space deployable structures,such as new releasing mechanisms with low-shocking,testability and reusability,and ultra-large space deployable solar arrays.
基金This work was supported by the National Key R&D Program of China(Grant No.2021YFB2401800)the National Natural Science Foundation of China(Grants Nos.21875196,22279108,21935009 and 22021001)the Fundamental Research Funds for Xiamen University(No.20720202019).
文摘Garnet-type solid-state electrolytes(SSEs)are particularly attractive in the construction of all-solid-state lithium(Li)batteries due to their high ionic conductivity,wide electrochemical window and remarkable(electro)chemical stability.However,the intractable issues of poor cathode/garnet interface and general low cathode loading hinder their practical application.Herein,we demonstrate the construction of a reinforced cathode/garnet interface by spark plasma sintering,via co-sintering Li_(6.5)La_(3)Zr_(1.5)Ta_(0.5)O_(12)(LLZTO)electrolyte powder and LiCoO_(2)/LLZTO composite cathode powder directly into a dense dual-layer with 5 wt%Li_(3)BO_(3)as sintering additive.The bulk composite cathode with LiCoO_(2)/LLZTO cross-linked structure is firmly welded to the LLZTO layer,which optimizes both Li-ion and electron transport.Therefore,the one-step integrated sintering process implements an ultra-low cathode/garnet interfacial resistance of 3.9Ωcm^(2)(100◦C)and a high cathode loading up to 2.02 mAh cm^(−2).Moreover,the Li_(3)BO_(3)reinforced LiCoO_(2)/LLZTO interface also effectively mitigates the strain/stress of LiCoO_(2),which facilitates the achieving of superior cycling stability.The bulk-type Li|LLZTO|LiCoO_(2)-LLZTO full cell with areal capacity of 0.73 mAh cm^(−2)delivers capacity retention of 81.7%after 50 cycles at 100μA cm^(−2).Furthermore,we reveal that non-uniform Li plating/stripping leads to the formation of gaps and finally results in the separation of Li and LLZTO electrolyte during long-term cycling,which becomes the dominant capacity decay mechanism in high-capacity full cells.This work provides insight into the degradation of Li/SSE interface and a strategy to radically improve the electrochemical performance of garnet-based all-solid-state Li batteries.
基金supported by the Thousand Talent Young Scholar Program(BE0200006)Shanghai Aerospace Science and Technology Innovation Fund(USCAST2020-13)+1 种基金the Oceanic Interdisciplinary Program from Shanghai Jiao Tong University(SL2020MS008)the National Natural Science Foundation of China(Grant No.51776041).
文摘Solid-state thermoelectric energy conversion devices attract broad research interests because of their great promises in waste heat recycling,space power generation,deep water power generation,and temperature control,but the search for essential thermoelectric materials with high performance still remains a great challenge.As an emerging low cost,solution-processed thermoelectric material,inorganic metal halide perovskites CsPb(I_(1–x)Br_(x))_(3) under mechanical deformation is systematically investigated using the first-principle calculations and the Boltzmann transport theory.It is demonstrated that halogen mixing and mechanical deformation are efficient methods to tailor electronic structures and charge transport properties in CsPb(I_(1–x)Br_(x))_(3) synergistically.Halogen mixing leads to band splitting and anisotropic charge transport due to symmetry-breakinginduced intrinsic strains.Such band splitting reconstructs the band edge and can decrease the charge carrier effective mass,leading to excellent charge transport properties.Mechanical deformation can further push the orbital energies apart from each other in a more controllable manner,surpassing the impact from intrinsic strains.Both anisotropic charge transport properties and ZT values are sensitive to the direction and magnitude of strain,showing a wide range of variation from 20%to 400%(with a ZT value of up to 1.85)compared with unstrained cases.The power generation efficiency of the thermoelectric device can reach as high as approximately 12%using mixed halide perovskites under tailored mechanical deformation when the heat-source is at 500 K and the cold side is maintained at 300 K,surpassing the performance of many existing bulk thermoelectric materials.
基金supported by the Hundred-Talent Project of Hubei Province,China(Grant No.2021HG01)the Huanggang Young Talent+2 种基金China(Grant No.HRZF2022-5)the Pearl Scholars Research Programs(Grant Nos.P20190218,P20190219)Young Scholars Start-up Research Programs of Huanggang Normal University,China(Grant Nos.Y20190218,Y20190219)。
文摘Argyrodites,Li_(6)PS_(5)X(X=Cl,Br,I),have piqued the interest of researchers by offering promising lithium ionic conductivity for their application in all-solid-state batteries(ASSBs).However,other than Li_(6)PS_(5)Cl(651Cl)and Li_(6)PS_(5)Br(651Br),Li_(6)PS_(5)I(651I)shows poor ionic conductivity(10^(-7)S cm^(-1)at 298 K).Herein,we present Al-doped 651I with I^(-)/S^(2-)site disordering to lower activation energy(Ea)and improve ionic conductivity.They formed argyrodite-type solid solutions with a composition of(Li_(6–3x)Al_(x))PS_(5)I in 0≤x≤0.10,and structural analysis revealed that Al^(3+)is located at Li sites.Also,the Al-doped samples contained anion I^(-)/S^(2-)site disorders in the crystal structures and smaller lattice parameters than the non-doped samples.Impedance spectroscopy measurements indicated that Al-doping reduced the ionic diffusion barrier,Ea,and increased the ionic conductivity to 10^(-5)S cm^(-1);the(Li5.7Al0.1)PS5I had the highest ionic conductivity in the studied system,at 2.6×10^(-5)S cm^(-1).In a lab-scale ASSB,with(Li_(5.7)Al_(0.1))PS_(5)I functioned as a solid electrolyte,demonstrating the characteristics of a pure ionic conductor with negligible electronic conductivity.The evaluated ionic conduction is due to decreased Li+content and I^(-)/S^(2-)disorder formation.Li-site cation doping enables an in-depth understanding of the structure and provides an additional approach to designing betterperforming SEs in the argyrodite system.
基金supported by Guangdong Key R&D Program of China(2019B090908001)National Natural Science Foundation of China(U22B2069)+2 种基金Shanghai Rising Star Program(No.22QA1406400)National Key R&D Program of China(2022YFB3305400)Science and Technology lnnovation Action Plan of the Science and Technology Commission of Shanghai Municipality(No.23DZ1200800)。
文摘SiO_(x)is commonly used in lithium-ion batteries because of its capacity and affordability,but it has issues with volume expansion and conductivity.Synthetic methods are crucial for achieving the desired microstructure and material properties.This study introduces a new technique,fluidized bed granulation,to produce SiO_(x)@GNs composites.These composites have a core-shell structure with SiO_(x)particles coated in graphene sheets,and high-energy vibration is used to create a SiO_(x)-Fe structure on the surface.The graphene coating prevents volume expansion and enhances electron transfer.Real-time confocal imaging shows the charging and discharging process.Experiment results show that the SiO_(x)@GNs electrode has a lower expansion rate of 53.60%compared to 73.04%for the SiO electrode,indicating improved electrochemical properties with the graphene coating.After 100 cycles at 2 C,SiO_(x)@GNs demonstrate a reversible capacity of 1265.8 mA,h·g^(-1)and discharge capability at 7 C with a capacity of 1050 mA,h·g^(-1).The battery retains 90.21%of its capacity after 500 cycles at 0.5 C,showing potential as a LIB anode alternative with a unique structure for different energy storage materials.Fluidized bed granulation can aid in scaling up the use of SiO_(x)anodes in lithium-ion batteries.
基金supported by the National Natural Science Foundation of China (Grant Nos. 52120105009 and 51906144)the Science and Technology Commission of Shanghai Municipality (Grant Nos. 20JC1414800 and 22ZR1432900)the Open Fund of Key Laboratory of Thermal Management and Energy Utilization of Aircraft of Ministry of Industry and Information Technology (Grant No. CEPE2020015)。
文摘The increasing demand for versatile and high-quality near-field radiative heat transfer(NFRHT) has created a critical need for a design approach that can handle numerous candidate structures. In this work, we employ and develop an adaptive hybrid Bayesian optimization(AHBO) algorithm to design the high-quality quasi-monochromatic NFRHT. The candidate materials include hexagonal boron nitride, silicon carbide, and doped silicon. The high-quality quasi-monochromatic NFRHT is optimized over 1.0 × 10^(8) candidate structures to maximize the evaluation factor. It is worth noting that only 2.6% of the candidate structures needed to be calculated to identify the optimal structure. The optimal structure of quasi-monochromatic NFRHT is an aperiodic multilayer metamaterial that differs from conventional periodic multilayer structures. Moreover, we investigate the robustness and mechanisms of the optimal quasi-monochromatic NFRHT with respect to the vacuum gap distance and the temperature difference between the emitter and receiver. In addition, the high-quality multi-peak NFRHT is designed using the AHBO algorithm by improving the definition of the evaluation factor. The results demonstrate that the AHBO algorithm is efficient in designing high-quality quasi-monochromatic and multi-peak NFRHT, and it can be further expanded to other structural designs in the field of energy conversion.
基金This work was supported by the National Natural Science Foundation of China(Nos.51922073 and 21902109)the Natural Science Foundation of Jiangsu Province(Nos.BK20200960 and BK20180097)+1 种基金the Natural Science Foundation of Higher Education in Jiangsu Province(No.20KJB150041)the Natural Science Foundation of Nantong University for High-Level Talent(No.03083033).
文摘Highly active and durable Pd-based electrocatalysts for ethanol oxidation reaction(EOR)play a crucial role in the commercialization of direct ethanol fuel cells(DEFCs).However,the poisonous intermediates(especially adsorbed CO species(COad))formed during the EOR process can easily adsorb and block the active sites on Pd electrodes,which in turn limits the catalytic efficiency.Hence,we present a series of Pd-based composites with a strong coupling interface consisting of Pd nanosheets and amorphous Bi(OH)_(3)species.The incorporation of Bi(OH)3 can induce an electron-rich state adjacent to the Pd sites and effectively separate the Pd ensemble,leading to excellent CO tolerance.The optimal Pd-Bi(OH)_(3)NSs catalyst manifests a mass activity of 2.2 A·mgPd^(-1),which is 5.7 and 2.0 times higher than that of Pd NSs and commercial Pd/C catalyst,respectively.Further CO-stripping experiments and CO-DRIFTS tests confirm the excellent CO tolerance on Pd-Bi(OH)3 NSs electrode,leading to the enhanced EOR durability.
