Quantitative description of the high-capacity channels in unconsolidated sandstone reservoirs, into which water was injected to improve oil recovery, is a hot topic in the field of reservoir development. This paper pr...Quantitative description of the high-capacity channels in unconsolidated sandstone reservoirs, into which water was injected to improve oil recovery, is a hot topic in the field of reservoir development. This paper presents a novel approach to describing quantitatively the characteristics of connected macropores in unconsolidated sandstone reservoirs using in situ production data. Based on physical simulation for formation mechanisms of high capacity channels and interwell tracer test data, a mathematical model was established to describe high-capacity channels by grey correlation theory, flow mechanism of fluid in porous media and reservoir engineering, and a program was developed to describe quantitatively the channel characteristics. The predicted results were consistent with field monitoring data (80%), so this model could be economically and effectively used to identify high-capacity channels.展开更多
This paper presents a scheme for high-capacity three-party quantum secret sharing with quantum superdense coding, following some ideas in the work by Liuet al (2002 Phys. Rev. A 65 022304) and the quantum secret sha...This paper presents a scheme for high-capacity three-party quantum secret sharing with quantum superdense coding, following some ideas in the work by Liuet al (2002 Phys. Rev. A 65 022304) and the quantum secret sharing scheme by Deng et al (2008 Phys. Lett. A 372 1957). Instead of using two sets of nonorthogonal states, the boss Alice needs only to prepare a sequence of Einstei^Podolsky-l^osen pairs in d-dimension. The two agents Bob and Charlie encode their information with dense coding unitary operations, and security is checked by inserting decoy photons. The scheme has a high capacity and intrinsic efficiency as each pair can carry 21bd bits of information, and almost all the pairs can be used for carrying useful information.展开更多
Flexible lithium-ion batteries(LIBs)are critical for the development of next-generation smart electronics.Conversion reaction-based electrodes have been considered promising to construct high energy-density flexible L...Flexible lithium-ion batteries(LIBs)are critical for the development of next-generation smart electronics.Conversion reaction-based electrodes have been considered promising to construct high energy-density flexible LIBs,which satisfy the ever-increasing demand for practical use.However,these electrodes suffer from inferior lithium-storage performance and structural instability during deformation and long-term lithiation/delithiation.These are caused by the sluggish reaction kinetics of active-materials and the superposition of responsive strains originating from the large lithiation-induced stress and applied stress.Here,we propose a stress-release strategy through elastic responses of nested wrinkle texturing of graphene,to achieve high deformability while maintaining structural integrity upon prolonged cycles within high-capacity electrodes.The wrinkles endow the electrode with a robust and flexible network for effective stress release.The resulting electrode shows large reversible stretchability,along with excellent electrochemical performance including high specific capacity,high-rate capability and long-term cycling stability.This strategy offers a new way to obtain high-performance flexible electrodes and can be extended to other energy-storage devices.展开更多
Electrification has great impacts on our modern society.To electrify future transportation,state-of-the-art lithium-ion batteries(LIBs)are still not sufficient in multiple aspects including cost,energy density,lifespa...Electrification has great impacts on our modern society.To electrify future transportation,state-of-the-art lithium-ion batteries(LIBs)are still not sufficient in multiple aspects including cost,energy density,lifespan,and safety.To this end,next-generation high-energy LIBs and beyond are highly regarded.In this regard,high-capacity anodes are undergoing intensive investigation,such as silicon,SnO_(2),and lithium metal.However,such anode materials are commonly experiencing large volume changes and related issues,which are reflected on mechanical degradation,capacity fading,low efficiency,and unsatisfactory lifetime.To address these challenges,many technical strategies have been investigated.In the past decade,atomic layer deposition(ALD)has emerged as a new promising technique enabling atomic-scale surface modification and nanoscale design of high-capacity anodes for high performance.In this review,recent ALD studies on developing high-capacity anodes for LIBs and beyond are thoroughly summarized.In addition,ALD strategies and their effectiveness in pursing high-energy LIBs and beyond are discussed.Particularly,we highlighted the latest advances of ALD for addressing the notorious issues associated with Li metal anodes.It is expected that this work will promote the applications of ALD in new battery systems.展开更多
A new protocol for quantum secure communication with authentication is proposed. The proposed protocol has a higher capacity as each EPR pair can carry four classical bits by the XOR operation and an auxiliary photon....A new protocol for quantum secure communication with authentication is proposed. The proposed protocol has a higher capacity as each EPR pair can carry four classical bits by the XOR operation and an auxiliary photon. Tile security and efficiency are analyzed in detail and the major advantage of this protocol is that it is more efficient without losing security.展开更多
Our IP Base Station Controller offers the highest capacity in industry, supporting 15,000 Eri. For you, it means lower implementation cost and higher availability. We also offer the lightest BTS in industry (2kg) and ...Our IP Base Station Controller offers the highest capacity in industry, supporting 15,000 Eri. For you, it means lower implementation cost and higher availability. We also offer the lightest BTS in industry (2kg) and the most energy efficient equipment, reducing your power bills with 40-60 percent. Furthermore, ZTE is the only one to this day offering both modular BTS and split BBU/RRU base station solutions. The result for you is better signal quality and lower cost of networking. So far, we have installed over 15 million lines for 60 operators in 50 countries.展开更多
High-capacity anode materials are highly desirable for sodium ion batteries. Here, a porous Sb/Sb2O3 nanocomposite is successfully synthesized by the mild oxidization of Sb nanocrystals in air. In the composite, Sb co...High-capacity anode materials are highly desirable for sodium ion batteries. Here, a porous Sb/Sb2O3 nanocomposite is successfully synthesized by the mild oxidization of Sb nanocrystals in air. In the composite, Sb contributes good conductivity and Sb2O3 improves cycling stability, particularly within the voltage window of 0.02-1.5 V. It remains at a reversible capacity of 540 mAh-g-1 after 180 cycles at 0.66 A-g-1. Even at 10 A-g-1, the reversible capacity is still preserved at 412 mAh·g-1, equivalent to 71.6% of that at 0.066 A.g-L These results are much better than Sb nanocrystals with a similar size and structure. Expanding the voltage window to 0.02-2.5 V includes the conversion reaction between Sb203 and Sb into the discharge/charge profiles. This would induce a large volume change and high structure strain、stress, deteriorating the cycling stability. The identification of a proper voltage window for Sb/Sb2O3 paves the way for its development in sodium ion batteries.展开更多
Organic lithium-ion batteries(OLIBs) represent a new generation of power storage approach for their environmental benignity and high theoretical specific capacities.However, it has the disadvantage with regard to th...Organic lithium-ion batteries(OLIBs) represent a new generation of power storage approach for their environmental benignity and high theoretical specific capacities.However, it has the disadvantage with regard to the dissolution of active materials in organic electrolyte. In this study, we encapsulated high capacity material calix[4]quinone(C4Q) in the nanochannels of ordered mesoporous carbon(OMC)CMK-3 with various mass ratios ranging from 1:3 to 3:1, and then systematically investigated their morphology and electrochemical properties. The nanocomposites characterizations confirmed that C4Q is almost entirely capsulated in the nanosized pores of the CMK-3 while the mass ratio is less than2:1. As cathodes in lithium-ion batteries, the C4Q/CMK-3(1:2) nanocomposite exhibits optimal initial discharge capacity of 427 mA h g^(-1) with 58.7% cycling retention after 100 cycles. Meanwhile, the rate performance is also optimized with a capacity of 170.4 mA h g^(-1) at 1 C. This method paves a new way to apply organic cathodes for lithium-ion batteries.展开更多
Lithium-ion batteries(LIBs) as energy storage devices play an important role in all aspects of our life. The increasing energy demand of the society requires LIBs with higher energy density and better performance. We ...Lithium-ion batteries(LIBs) as energy storage devices play an important role in all aspects of our life. The increasing energy demand of the society requires LIBs with higher energy density and better performance. We here develop a new and easy-to-scaleup sol-gel method to coat a surface protection layer on commercial LiCoO2cathode. We demonstrate that a proper thickness can improve the cycling life with a higher cut-off potential(4.5 V), larger energy capacity(180 mAh/g at 0.5 C) and better energy density(35% more compared to non-coated LiCoO2). The mechanism of the protection layer is also revealed by a combination of electron microscopy and synchrotron X-ray spectroscopy.展开更多
Development of aqueous rechargeable zinc ion battery is an important direction towards grid energy storage sought in various applications.At present,the efficient utilization of aqueous rechargeable zinc ion batteries...Development of aqueous rechargeable zinc ion battery is an important direction towards grid energy storage sought in various applications.At present,the efficient utilization of aqueous rechargeable zinc ion batteries has been seriously affected due to the defects nature of the cathode materials,such as poor capacity,limited rate performance,and limited cycle stability.Therefore,the search for high-performance cathode materials is a main challenge in this field.Herein,we in-situ prepared graphdiyne-wrapped K_(0.25)·MnO_(2)(K_(0.25)·MnO_(2)@GDY)hybrid nanowall arrays as the cathode of aqueous rechargeable zinc ion battery.The hybridnanowall arrays have obviously alleviated the pulverization and sluggish kinetic process of MnO_(2) cathode materials and shown high specific capacity(520 mA·h/g at a current density of 55 mA/g),which is near-full two-electron capacity.The high specific capacity was resulted from more than one Zn^(2+)(de)intercalation process occurring per formula unit,in which we observed a structural evolution that partially stemmed from ion exchange between the intercalated K^(+) and Zn^(2+) ions during the discharge process.The present investigation not only provides a new material for the aqueous rechargeable Zn ion batteries,also contributes a novel route for the development of next generation aqueous rechargeable Zn ion batteries with high capacity.展开更多
Dual ion batteries(DIBs) exhibit broad application prospects in the field of electrical energy storage(EES)devices with excellent properties,such as high voltage,high energy density,and low cost.In the graphitebased D...Dual ion batteries(DIBs) exhibit broad application prospects in the field of electrical energy storage(EES)devices with excellent properties,such as high voltage,high energy density,and low cost.In the graphitebased DIBs,high voltage is needed to store enough anions with the formation of anion intercalation compound XCn(X=AlCl4-,PF6-,TFSI-,etc.).Hence,it is difficult for graphite-based DIBs to match proper anodes and electrolytes.Here,an Se/graphene composite is prepared via a convenient method,and assembled into a dual-ion full battery(DIFB) as anode with graphite cathode and 1 mol/L NaPF6 in EC:EMC(1:1,v:v).This DIFB has achieved a high discharge capacity of 75.9 mAh/g and high medium output voltage of 3.5 V at 0.1 A/g.Actually,the suitable anode materials,such as the present Se/graphene composite,are extremely important for the development and application of graphite-based DIBs.This study is enlightening for the design of future low-cost EES devices including graphite-based DIBs.展开更多
From density functional theory (DFT) calculations, we predicted that the sandwich-type dinuclear organometallic compounds Cpffi2 and Cp2Sc2 can adsorb up to eight hydrogen molecules respectively, corresponding to a ...From density functional theory (DFT) calculations, we predicted that the sandwich-type dinuclear organometallic compounds Cpffi2 and Cp2Sc2 can adsorb up to eight hydrogen molecules respectively, corresponding to a high gravimetric storage capacity of 6.7% and 6.8% (w), respectively. These sandwich-type organometallocenes proposed in this work are favorable for reversible adsorption and desorption of hydrogen at ambient conditions.展开更多
It is of great significance to develop clean and new energy sources with high-efficient energy storage technologies,due to the excessive use of fossil energy that has caused severe environmental damage.There is great ...It is of great significance to develop clean and new energy sources with high-efficient energy storage technologies,due to the excessive use of fossil energy that has caused severe environmental damage.There is great interest in exploring advanced rechargeable lithium batteries with desirable energy and power capabilities for applications in portable electronics,smart grids,and electric vehicles.In practice,high-capacity and low-cost electrode materials play an important role in sustaining the progresses in lithium-ion batteries.This review aims at giving an account of recent advances on the emerging high-capacity electrode materials and summarizing key barriers and corresponding strategies for the practical viability of these electrode materials.Effective approaches to enhance energy density of lithium-ion batteries are to increase the capacity of electrode materials and the output operation voltage.On account of major bottlenecks of the power lithium-ion battery,authors come up with the concept of integrated battery systems,which will be a promising future for high-energy lithium-ion batteries to improve energy density and alleviate anxiety of electric vehicles.展开更多
Carbonyl polymers as booming electrode materials for lithium-organic batteries are currently limited by low practical capacities and poor rate performance due to their inherent electronic insulation and microscopic ag...Carbonyl polymers as booming electrode materials for lithium-organic batteries are currently limited by low practical capacities and poor rate performance due to their inherent electronic insulation and microscopic agglomeration morphologies.Herein graphene/carbonyl-enriched polyquinoneimine(PQI@Gr)composites were readily prepared by in situ hydrothermal polycondensation of dianhydride and anthraquinone co-monomer salts in the presence of graphene oxide(GO).Conductive graphene sheets derived from hydrothermal reduction of GO are fully sandwiched between densely interlaced quinone-containing polyimide nanosheets.Remarkably,the as-fabricated PQI@Gr cathodes exhibit much larger specific capacity(205 mAh g^(-1)at 0.1 A g^(-1)),higher carbonyl utilization(up to 89.9%),and better rate capability(179.4 mAh g^(-1)at 5.0 A g^(-1))due to a surface-dominated capacitive process via fast kinetics compared to bare PQI electrode(162.5 mAh g^(-1)at 0.1 A g^(-1);67.5%;96.9 mAh g^(-1)at 5 A g^(-1)).The capacity retention as high as 73%for PQI@Gr is also achieved over ultra-long 10000 cycles at 5.0 A g^(-1).Such outstanding electrochemical performances are attributable to the combined merits of polyimides and polyquinones,and robust 3D hierarchical heterostructures with efficient conductive networks,abundant porous channels for electrolyte infiltration and ion accessibility,and highly exposed carbonyl groups.This work offers new insights into the development of high-performance polymer electrodes for sustainable batteries.展开更多
Aqueous Zn//MnO2 batteries are emerging as promising large-scale energy storage devices owing to their cost-effectiveness,high safety,high output voltage,and energy density.However,the MnO2 cathode suffers from intrin...Aqueous Zn//MnO2 batteries are emerging as promising large-scale energy storage devices owing to their cost-effectiveness,high safety,high output voltage,and energy density.However,the MnO2 cathode suffers from intrinsically poor rate performance and rapid capacity deterioration.Here,we remove the roadblock by compositing MnO2 nanorods with highly conductive graphene,which remarkably enhances the electrochemical properties of the MnO2 cathode.Benefiting from the boosted electric conductivity and ion diffusion rate as well as the structural protection of graphene,the Zn//MnO2-graphene battery presents an admirable capacity of 301 mAh g^-1 at 0.5 A g^-1,corresponding to a high energy density of 411.6 Wh kg^-1.Even at a high current density of 10 A g^-1,a decent capacity of 95.8 mAh g^-1 is still obtained,manifesting its excellent rate property.Furthermore,an impressive power density of 15 kW kg^-1 is achieved by the Zn//MnO2-graphene battery.展开更多
Use of metallic Li anode raises serious concerns on the safety and operational performance of Li-S batteries due to uncontrolled hazard of Li dendrite formation, which is difficultly eliminated as long as the metallic...Use of metallic Li anode raises serious concerns on the safety and operational performance of Li-S batteries due to uncontrolled hazard of Li dendrite formation, which is difficultly eliminated as long as the metallic Li exists in the cells. Pairing lithium sulfide (Li2S) cathode with currently available metallic Lifree high-capacity anodes offers an alternative solution to this challenge. However, the performance of Li2S cathode is primarily restricted by high activation barrier upon initial charge, low active mass utilization and sluggish redox kinetics. Herein, a MXene-induced multifunctional collaborative interface is proposed to afford superb activity towards redox solid-liquid/liquid-liquid phase transformation, strong chemisorption, high conductivity and fast ionic/charge transport in high Li2S loading cathode. Applying collaborative interface effectively reduces initial voltage barrier of Li2S activation and regulates the kinetic behavior of redox polysulfide conversion. Therefore, stable operation of additive-free Li2S cathode with high areal capacities at high Li2S loading up to 9 mg cm^-2 can be achieved with less sacrifice of high capacity and rate capability in Li-S batteries. Rechargeable metallic Li-free batteries are successfully constructed by pairing this high-performance Li2S cathode with high-capacity metal oxide anodes, which delivers superior energy density to current Li-ion batteries.展开更多
Parallel multi-thread processing in advanced intelligent processors is the core to realize high-speed and high-capacity signal processing systems.Optical neural network(ONN)has the native advantages of high paralleliz...Parallel multi-thread processing in advanced intelligent processors is the core to realize high-speed and high-capacity signal processing systems.Optical neural network(ONN)has the native advantages of high parallelization,large bandwidth,and low power consumption to meet the demand of big data.Here,we demonstrate the dual-layer ONN with Mach-Zehnder interferometer(MZI)network and nonlinear layer,while the nonlinear activation function is achieved by optical-electronic signal conversion.Two frequency components from the microcomb source carrying digit datasets are simultaneously imposed and intelligently recognized through the ONN.We successfully achieve the digit classification of different frequency components by demultiplexing the output signal and testing power distribution.Efficient parallelization feasibility with wavelength division multiplexing is demonstrated in our high-dimensional ONN.This work provides a high-performance architecture for future parallel high-capacity optical analog computing.展开更多
Fast interfacial kinetics derived from bicontinuous three-dimensional(3D)architecture is a strategic feature for achieving fast-charging lithium-ion batteries(LIBs).One of the main reasons is its large active surface ...Fast interfacial kinetics derived from bicontinuous three-dimensional(3D)architecture is a strategic feature for achieving fast-charging lithium-ion batteries(LIBs).One of the main reasons is its large active surface and short diffusion path.Yet,understanding of unusual electrochemical properties still remain great challenge due to its complexity.In this study,we proposed a nickel–tin compound(Ni_(3)Sn_(4))supported by 3D Nickel scaffolds as main frame because the Ni_(3)Sn_(4) clearly offers a higher reversible capacity and stable cycling performance than bare tin(Sn).In order to verify the role of Ni,atomic-scale simulation based on density functional theory systematically addressed to the reaction mechanism and structural evolution of Ni_(3)Sn_(4) during the lithiation process.Our findings are that Ni enables Ni_(3)Sn_(4) to possess higher mechanical stability in terms of reactive flow stress,subsequently lead to improve Li storage capability.This study elucidates an understanding of the lithiation mechanism of Ni_(3)Sn_(4) and provides a new perspective for the design of high-capacity and high-power 3D anodes for fast-charging LIBs.展开更多
Ternary and quadruple lithium silicon nitride anode materials for lithium ion batteries with different precursors were prepared by the simple process of high-energy ball milling. High capacity and excellent cyclabilit...Ternary and quadruple lithium silicon nitride anode materials for lithium ion batteries with different precursors were prepared by the simple process of high-energy ball milling. High capacity and excellent cyclability were obtained. The influence of precursor introduction on the electrochemical performance of products was investigated. This research reveals that the electrochemical performance of lithium silicon hitilde can be enhanced significantly by doping O. The cyclability of quadruple lithium silicon nitfide can be optimized remarkably by controlling the introduction quantity of the precursors. It is possible for the composite to be used as a capacity compensator within a wide voltage cut-off window.展开更多
We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division mul...We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division multiplexing,and polarization multiplexing for signal transmission.Through the multiple-input-multiple-output(MIMO)equalization algorithms,we achieve the total line transmission rate of 4.096 Tbit/s.The results prove that the bit error rates(BERs)for the16QAM signals after 1000 km FMF transmission are below the soft-decision forward-error-correction(SD-FEC)threshold of2.4×10^(-2),and the net rate reaches 3.413 Tbit/s.Our proposed system provides a reference for the future development of high-capacity communication.展开更多
文摘Quantitative description of the high-capacity channels in unconsolidated sandstone reservoirs, into which water was injected to improve oil recovery, is a hot topic in the field of reservoir development. This paper presents a novel approach to describing quantitatively the characteristics of connected macropores in unconsolidated sandstone reservoirs using in situ production data. Based on physical simulation for formation mechanisms of high capacity channels and interwell tracer test data, a mathematical model was established to describe high-capacity channels by grey correlation theory, flow mechanism of fluid in porous media and reservoir engineering, and a program was developed to describe quantitatively the channel characteristics. The predicted results were consistent with field monitoring data (80%), so this model could be economically and effectively used to identify high-capacity channels.
基金Project supported by the National Natural Science Foundation (NSF) of China (Grant No 10847147)the NSF of Jiangsu Province, China (Grant No BK2008437)+1 种基金Jiangsu Provincial Universities (Grant No 07KJB510066)the Science Foundation of NUIST, China
文摘This paper presents a scheme for high-capacity three-party quantum secret sharing with quantum superdense coding, following some ideas in the work by Liuet al (2002 Phys. Rev. A 65 022304) and the quantum secret sharing scheme by Deng et al (2008 Phys. Lett. A 372 1957). Instead of using two sets of nonorthogonal states, the boss Alice needs only to prepare a sequence of Einstei^Podolsky-l^osen pairs in d-dimension. The two agents Bob and Charlie encode their information with dense coding unitary operations, and security is checked by inserting decoy photons. The scheme has a high capacity and intrinsic efficiency as each pair can carry 21bd bits of information, and almost all the pairs can be used for carrying useful information.
基金financial support from the National Natural Science Foundation of China(Nos.52020105010,51927803,51525206)the National Key R&D Program of China(2016YFA0200102 and 2016YFB0100100)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010602)the LiaoNing Revitalization Talents Program(No.XLYC1908015)。
文摘Flexible lithium-ion batteries(LIBs)are critical for the development of next-generation smart electronics.Conversion reaction-based electrodes have been considered promising to construct high energy-density flexible LIBs,which satisfy the ever-increasing demand for practical use.However,these electrodes suffer from inferior lithium-storage performance and structural instability during deformation and long-term lithiation/delithiation.These are caused by the sluggish reaction kinetics of active-materials and the superposition of responsive strains originating from the large lithiation-induced stress and applied stress.Here,we propose a stress-release strategy through elastic responses of nested wrinkle texturing of graphene,to achieve high deformability while maintaining structural integrity upon prolonged cycles within high-capacity electrodes.The wrinkles endow the electrode with a robust and flexible network for effective stress release.The resulting electrode shows large reversible stretchability,along with excellent electrochemical performance including high specific capacity,high-rate capability and long-term cycling stability.This strategy offers a new way to obtain high-performance flexible electrodes and can be extended to other energy-storage devices.
基金supported in part by the Natural Science Foundation of China(51802150,51571111,and 51721001)Jiangsu Province(BK20170645,BK20201087)
文摘Electrification has great impacts on our modern society.To electrify future transportation,state-of-the-art lithium-ion batteries(LIBs)are still not sufficient in multiple aspects including cost,energy density,lifespan,and safety.To this end,next-generation high-energy LIBs and beyond are highly regarded.In this regard,high-capacity anodes are undergoing intensive investigation,such as silicon,SnO_(2),and lithium metal.However,such anode materials are commonly experiencing large volume changes and related issues,which are reflected on mechanical degradation,capacity fading,low efficiency,and unsatisfactory lifetime.To address these challenges,many technical strategies have been investigated.In the past decade,atomic layer deposition(ALD)has emerged as a new promising technique enabling atomic-scale surface modification and nanoscale design of high-capacity anodes for high performance.In this review,recent ALD studies on developing high-capacity anodes for LIBs and beyond are thoroughly summarized.In addition,ALD strategies and their effectiveness in pursing high-energy LIBs and beyond are discussed.Particularly,we highlighted the latest advances of ALD for addressing the notorious issues associated with Li metal anodes.It is expected that this work will promote the applications of ALD in new battery systems.
基金Supported by the Chongqing Research Program of Application Foundation and Advanced Technology under Grant No cstc2014jcyjA40028
文摘A new protocol for quantum secure communication with authentication is proposed. The proposed protocol has a higher capacity as each EPR pair can carry four classical bits by the XOR operation and an auxiliary photon. Tile security and efficiency are analyzed in detail and the major advantage of this protocol is that it is more efficient without losing security.
文摘Our IP Base Station Controller offers the highest capacity in industry, supporting 15,000 Eri. For you, it means lower implementation cost and higher availability. We also offer the lightest BTS in industry (2kg) and the most energy efficient equipment, reducing your power bills with 40-60 percent. Furthermore, ZTE is the only one to this day offering both modular BTS and split BBU/RRU base station solutions. The result for you is better signal quality and lower cost of networking. So far, we have installed over 15 million lines for 60 operators in 50 countries.
文摘High-capacity anode materials are highly desirable for sodium ion batteries. Here, a porous Sb/Sb2O3 nanocomposite is successfully synthesized by the mild oxidization of Sb nanocrystals in air. In the composite, Sb contributes good conductivity and Sb2O3 improves cycling stability, particularly within the voltage window of 0.02-1.5 V. It remains at a reversible capacity of 540 mAh-g-1 after 180 cycles at 0.66 A-g-1. Even at 10 A-g-1, the reversible capacity is still preserved at 412 mAh·g-1, equivalent to 71.6% of that at 0.066 A.g-L These results are much better than Sb nanocrystals with a similar size and structure. Expanding the voltage window to 0.02-2.5 V includes the conversion reaction between Sb203 and Sb into the discharge/charge profiles. This would induce a large volume change and high structure strain、stress, deteriorating the cycling stability. The identification of a proper voltage window for Sb/Sb2O3 paves the way for its development in sodium ion batteries.
基金supported by the National Natural Science Foundation of China (21403187)the Natural Science Foundation of Hebei Province of China (B2015203124)the Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University
文摘Organic lithium-ion batteries(OLIBs) represent a new generation of power storage approach for their environmental benignity and high theoretical specific capacities.However, it has the disadvantage with regard to the dissolution of active materials in organic electrolyte. In this study, we encapsulated high capacity material calix[4]quinone(C4Q) in the nanochannels of ordered mesoporous carbon(OMC)CMK-3 with various mass ratios ranging from 1:3 to 3:1, and then systematically investigated their morphology and electrochemical properties. The nanocomposites characterizations confirmed that C4Q is almost entirely capsulated in the nanosized pores of the CMK-3 while the mass ratio is less than2:1. As cathodes in lithium-ion batteries, the C4Q/CMK-3(1:2) nanocomposite exhibits optimal initial discharge capacity of 427 mA h g^(-1) with 58.7% cycling retention after 100 cycles. Meanwhile, the rate performance is also optimized with a capacity of 170.4 mA h g^(-1) at 1 C. This method paves a new way to apply organic cathodes for lithium-ion batteries.
基金supported by Callahan Faculty Scholar Endowment Fund from Oregon State University,USA
文摘Lithium-ion batteries(LIBs) as energy storage devices play an important role in all aspects of our life. The increasing energy demand of the society requires LIBs with higher energy density and better performance. We here develop a new and easy-to-scaleup sol-gel method to coat a surface protection layer on commercial LiCoO2cathode. We demonstrate that a proper thickness can improve the cycling life with a higher cut-off potential(4.5 V), larger energy capacity(180 mAh/g at 0.5 C) and better energy density(35% more compared to non-coated LiCoO2). The mechanism of the protection layer is also revealed by a combination of electron microscopy and synchrotron X-ray spectroscopy.
基金This work was supported by the National Key Research and Development Project of China(No.2016YFA0200104)the National Natural Science Foundation of China(Nos.21875258,21790050,21790053)the Key Program of the Chinese Academy of Sciences(No.QYZDY-SSWSLH015).
文摘Development of aqueous rechargeable zinc ion battery is an important direction towards grid energy storage sought in various applications.At present,the efficient utilization of aqueous rechargeable zinc ion batteries has been seriously affected due to the defects nature of the cathode materials,such as poor capacity,limited rate performance,and limited cycle stability.Therefore,the search for high-performance cathode materials is a main challenge in this field.Herein,we in-situ prepared graphdiyne-wrapped K_(0.25)·MnO_(2)(K_(0.25)·MnO_(2)@GDY)hybrid nanowall arrays as the cathode of aqueous rechargeable zinc ion battery.The hybridnanowall arrays have obviously alleviated the pulverization and sluggish kinetic process of MnO_(2) cathode materials and shown high specific capacity(520 mA·h/g at a current density of 55 mA/g),which is near-full two-electron capacity.The high specific capacity was resulted from more than one Zn^(2+)(de)intercalation process occurring per formula unit,in which we observed a structural evolution that partially stemmed from ion exchange between the intercalated K^(+) and Zn^(2+) ions during the discharge process.The present investigation not only provides a new material for the aqueous rechargeable Zn ion batteries,also contributes a novel route for the development of next generation aqueous rechargeable Zn ion batteries with high capacity.
基金financial support by the National Natural Science Foundation of China(No.91963118)Fundamental Research Funds for the Central Universities(No.2412019ZD010)。
文摘Dual ion batteries(DIBs) exhibit broad application prospects in the field of electrical energy storage(EES)devices with excellent properties,such as high voltage,high energy density,and low cost.In the graphitebased DIBs,high voltage is needed to store enough anions with the formation of anion intercalation compound XCn(X=AlCl4-,PF6-,TFSI-,etc.).Hence,it is difficult for graphite-based DIBs to match proper anodes and electrolytes.Here,an Se/graphene composite is prepared via a convenient method,and assembled into a dual-ion full battery(DIFB) as anode with graphite cathode and 1 mol/L NaPF6 in EC:EMC(1:1,v:v).This DIFB has achieved a high discharge capacity of 75.9 mAh/g and high medium output voltage of 3.5 V at 0.1 A/g.Actually,the suitable anode materials,such as the present Se/graphene composite,are extremely important for the development and application of graphite-based DIBs.This study is enlightening for the design of future low-cost EES devices including graphite-based DIBs.
基金This work was supported by the Special Fund of Shaanxi Province Education Bureau (No. 10JK548) and the Shaanxi Natural Science Foundation Reasearch Programs (No. 2011JM6005).
文摘From density functional theory (DFT) calculations, we predicted that the sandwich-type dinuclear organometallic compounds Cpffi2 and Cp2Sc2 can adsorb up to eight hydrogen molecules respectively, corresponding to a high gravimetric storage capacity of 6.7% and 6.8% (w), respectively. These sandwich-type organometallocenes proposed in this work are favorable for reversible adsorption and desorption of hydrogen at ambient conditions.
基金supported by National Natural Science Foundation of China(No.51902340)Chongqing Natural Science Foundation,and Chongqing Postdoctoral Science Foundation(No.2021000051).
文摘It is of great significance to develop clean and new energy sources with high-efficient energy storage technologies,due to the excessive use of fossil energy that has caused severe environmental damage.There is great interest in exploring advanced rechargeable lithium batteries with desirable energy and power capabilities for applications in portable electronics,smart grids,and electric vehicles.In practice,high-capacity and low-cost electrode materials play an important role in sustaining the progresses in lithium-ion batteries.This review aims at giving an account of recent advances on the emerging high-capacity electrode materials and summarizing key barriers and corresponding strategies for the practical viability of these electrode materials.Effective approaches to enhance energy density of lithium-ion batteries are to increase the capacity of electrode materials and the output operation voltage.On account of major bottlenecks of the power lithium-ion battery,authors come up with the concept of integrated battery systems,which will be a promising future for high-energy lithium-ion batteries to improve energy density and alleviate anxiety of electric vehicles.
基金supported by the National Natural Science Foundation of China(52173091,and 51973235)Program for Leading Talents of National Ethnic Affairs Commission of China(MZR21001)+2 种基金Hubei Provincial Natural Science Foundation of China(2021CFA022)Wuhan Science and Technology Bureau(2020010601012198)Fundamental Research Funds for Central Universities(CZP19001).
文摘Carbonyl polymers as booming electrode materials for lithium-organic batteries are currently limited by low practical capacities and poor rate performance due to their inherent electronic insulation and microscopic agglomeration morphologies.Herein graphene/carbonyl-enriched polyquinoneimine(PQI@Gr)composites were readily prepared by in situ hydrothermal polycondensation of dianhydride and anthraquinone co-monomer salts in the presence of graphene oxide(GO).Conductive graphene sheets derived from hydrothermal reduction of GO are fully sandwiched between densely interlaced quinone-containing polyimide nanosheets.Remarkably,the as-fabricated PQI@Gr cathodes exhibit much larger specific capacity(205 mAh g^(-1)at 0.1 A g^(-1)),higher carbonyl utilization(up to 89.9%),and better rate capability(179.4 mAh g^(-1)at 5.0 A g^(-1))due to a surface-dominated capacitive process via fast kinetics compared to bare PQI electrode(162.5 mAh g^(-1)at 0.1 A g^(-1);67.5%;96.9 mAh g^(-1)at 5 A g^(-1)).The capacity retention as high as 73%for PQI@Gr is also achieved over ultra-long 10000 cycles at 5.0 A g^(-1).Such outstanding electrochemical performances are attributable to the combined merits of polyimides and polyquinones,and robust 3D hierarchical heterostructures with efficient conductive networks,abundant porous channels for electrolyte infiltration and ion accessibility,and highly exposed carbonyl groups.This work offers new insights into the development of high-performance polymer electrodes for sustainable batteries.
基金financially supported by the Guangdong Power Grid Co.,Ltd.(Grant No.GDKJXM20160000)。
文摘Aqueous Zn//MnO2 batteries are emerging as promising large-scale energy storage devices owing to their cost-effectiveness,high safety,high output voltage,and energy density.However,the MnO2 cathode suffers from intrinsically poor rate performance and rapid capacity deterioration.Here,we remove the roadblock by compositing MnO2 nanorods with highly conductive graphene,which remarkably enhances the electrochemical properties of the MnO2 cathode.Benefiting from the boosted electric conductivity and ion diffusion rate as well as the structural protection of graphene,the Zn//MnO2-graphene battery presents an admirable capacity of 301 mAh g^-1 at 0.5 A g^-1,corresponding to a high energy density of 411.6 Wh kg^-1.Even at a high current density of 10 A g^-1,a decent capacity of 95.8 mAh g^-1 is still obtained,manifesting its excellent rate property.Furthermore,an impressive power density of 15 kW kg^-1 is achieved by the Zn//MnO2-graphene battery.
基金supported by the National Natural Science Foundation of China (NSFC, No. 51522203, 51772040)Fok Ying Tung Education Foundation (No. 151047)+2 种基金the Recruitment Program of Global Youth ExpertsXinghai Scholarship of Dalian University of Technologythe Fundamental Research Funds for the Central Universities (No. DUT18LAB19)
文摘Use of metallic Li anode raises serious concerns on the safety and operational performance of Li-S batteries due to uncontrolled hazard of Li dendrite formation, which is difficultly eliminated as long as the metallic Li exists in the cells. Pairing lithium sulfide (Li2S) cathode with currently available metallic Lifree high-capacity anodes offers an alternative solution to this challenge. However, the performance of Li2S cathode is primarily restricted by high activation barrier upon initial charge, low active mass utilization and sluggish redox kinetics. Herein, a MXene-induced multifunctional collaborative interface is proposed to afford superb activity towards redox solid-liquid/liquid-liquid phase transformation, strong chemisorption, high conductivity and fast ionic/charge transport in high Li2S loading cathode. Applying collaborative interface effectively reduces initial voltage barrier of Li2S activation and regulates the kinetic behavior of redox polysulfide conversion. Therefore, stable operation of additive-free Li2S cathode with high areal capacities at high Li2S loading up to 9 mg cm^-2 can be achieved with less sacrifice of high capacity and rate capability in Li-S batteries. Rechargeable metallic Li-free batteries are successfully constructed by pairing this high-performance Li2S cathode with high-capacity metal oxide anodes, which delivers superior energy density to current Li-ion batteries.
基金Peng Xie acknowledges the support from the China Scholarship Council(Grant no.201804910829).
文摘Parallel multi-thread processing in advanced intelligent processors is the core to realize high-speed and high-capacity signal processing systems.Optical neural network(ONN)has the native advantages of high parallelization,large bandwidth,and low power consumption to meet the demand of big data.Here,we demonstrate the dual-layer ONN with Mach-Zehnder interferometer(MZI)network and nonlinear layer,while the nonlinear activation function is achieved by optical-electronic signal conversion.Two frequency components from the microcomb source carrying digit datasets are simultaneously imposed and intelligently recognized through the ONN.We successfully achieve the digit classification of different frequency components by demultiplexing the output signal and testing power distribution.Efficient parallelization feasibility with wavelength division multiplexing is demonstrated in our high-dimensional ONN.This work provides a high-performance architecture for future parallel high-capacity optical analog computing.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(NRF-2021M3H4A1A02045967)(NRF-2021M3H4A1A02048137)supported by the Chung-Ang University Research Scholarship Grants in 2021。
文摘Fast interfacial kinetics derived from bicontinuous three-dimensional(3D)architecture is a strategic feature for achieving fast-charging lithium-ion batteries(LIBs).One of the main reasons is its large active surface and short diffusion path.Yet,understanding of unusual electrochemical properties still remain great challenge due to its complexity.In this study,we proposed a nickel–tin compound(Ni_(3)Sn_(4))supported by 3D Nickel scaffolds as main frame because the Ni_(3)Sn_(4) clearly offers a higher reversible capacity and stable cycling performance than bare tin(Sn).In order to verify the role of Ni,atomic-scale simulation based on density functional theory systematically addressed to the reaction mechanism and structural evolution of Ni_(3)Sn_(4) during the lithiation process.Our findings are that Ni enables Ni_(3)Sn_(4) to possess higher mechanical stability in terms of reactive flow stress,subsequently lead to improve Li storage capability.This study elucidates an understanding of the lithiation mechanism of Ni_(3)Sn_(4) and provides a new perspective for the design of high-capacity and high-power 3D anodes for fast-charging LIBs.
基金This study is f'mancially supported by the National Natural Science Foundation of China (No.50502009)the Natural Science Foundation of Liaoning Province of China (No.20072146).
文摘Ternary and quadruple lithium silicon nitride anode materials for lithium ion batteries with different precursors were prepared by the simple process of high-energy ball milling. High capacity and excellent cyclability were obtained. The influence of precursor introduction on the electrochemical performance of products was investigated. This research reveals that the electrochemical performance of lithium silicon hitilde can be enhanced significantly by doping O. The cyclability of quadruple lithium silicon nitfide can be optimized remarkably by controlling the introduction quantity of the precursors. It is possible for the composite to be used as a capacity compensator within a wide voltage cut-off window.
基金supported by the National Key R&D Program of China(No.2018YFB1800905)the National Natural Science Foundation of China(Nos.61935005,61720106015,61835002,and 62127802)。
文摘We experimentally transmit eight wavelength-division-multiplexing(WDM)channels,16 quadratic-amplitude-modulation(QAM)signals at 32-GBaud,over 1000 km few mode fiber(FMF).In this experiment,we use WDM,mode division multiplexing,and polarization multiplexing for signal transmission.Through the multiple-input-multiple-output(MIMO)equalization algorithms,we achieve the total line transmission rate of 4.096 Tbit/s.The results prove that the bit error rates(BERs)for the16QAM signals after 1000 km FMF transmission are below the soft-decision forward-error-correction(SD-FEC)threshold of2.4×10^(-2),and the net rate reaches 3.413 Tbit/s.Our proposed system provides a reference for the future development of high-capacity communication.