轨道交通车辆直流继电器自主化设计

对进口继电器的防护系统、磁路系统、接触系统及灭弧方式等关键技术进行深入研究,针对其大电流分断能力、强制导向结构、耐特殊环境、长电寿命、高机械耐久性的特点,提出了自主化攻关设计。利用三维集成设计、电磁仿真和结构强度分析等技术,实现了轨道交通车辆继电器关键核心技术自主可控,提升了轨道交通产品的竞争力。

Crystalline and amorphous metal sulfide composite electrode materials with long cycle life:Preparation and performance of hybrid capacitors

Crystalline@amorphous NiCo_(2)S_(4)@MoS_(2)(v-NCS@MS)nanostructures were designed and constructed via an ethylene glycol-induced strategy with hydrothermal synthesis and solvothermal method,which simultaneously realized the defect regulation of crystal NiCo_(2)S_(4) in the core.Taking advantage of the flexible protection of an amor-phous shell and the high capacity of a conductive core with defects,the v-NCS@MS electrode exhibited high specif-ic capacity(1034 mAh·g^(-1) at 1 A·g^(-1))and outstanding rate capability.Moreover,a hybrid supercapacitor was assembled with v-NCS@MS as cathode and activated carbon(AC)as anode,which can achieve remarkably high specific energy of 111 Wh·kg^(-1) at a specific power of 219 W·kg^(-1) and outstanding capacity retention of 80.5%after 15000 cycling at different current densities.

Preparation of Ti/PTFE-F-PbO2 Electrode with a Long Life from the Sulfamic Acid Bath and Its Application in Organic Degradation

A polytetrafluoroethylene （PTFE）-doped PbO2 electrode on a Ti substrate was prepared by galvanostatic method from the sulfamic acid bath （Ti/PTFE-F-PbO2-I） or nitric acid bath （Ti/PTFE-F-PbO2-II）. Scanning Electron Microscopy revealed that the Ti/PTFE-PbO2-I electrode had a more regular morphology with smaller size crystals than the Ti/PTFE-F-PbO2-II electrode. On the basis of the results of both the accelerated electrolysis test and the empirical formula for estimating the service life of an electrode, the service life of the Ti/PTFE-PbO2-I electrode was predicted to be more than 7 years under conventional electrolysis conditions （0.1 A·cm^-2）. During the treatment of 4-chlorophenol-contaminated water, the Ti/PTFE-PbO2-I anode showed both a good electro-catalytic activity and high electrochemical stability, exhibiting an excellent potential application.

Power Uprate and Lifetime Extension

Overall purpose of a power uprate and lifetime extension project （PLEX） is to modernize the power station cost-efficiently resulting in fulfilling the following overall requirements. The primary target is to meet the requirements provided by the local regulations from the regulatory offices. The controlling, monitoring and power supply of safety functions have to comply with these regulations. Any deviations from the existing safety analysis report （SAR） have to be corrected. On top of the safety measures the general technical status should be raised to extend the lifetime to 60 years. A high availability during the modernization has to be assured.

SnSe2 nanocrystals coupled with hierarchical porous carbon microspheres for long-life sodium ion battery anode

Tin selenides have been attracting great attention as anode materials for the state-of-the-art rechargeable sodium-ion batteries(SIBs)due to their high theoretical capacity and low cost.However,they deliver unsatisfactory performance in practice,owing to their intrinsically low conductivity,sluggish kinetics and volume expansion during the charge-discharge process.Herein,we demonstrate the synthesis of SnSe2 nanocrystals coupled with hierarchical porous carbon(SnSe2 NCs/C)microspheres for boosting SIBs in terms of capacity,rate ability and durability.The unique structure of SnSe2 NCs/C possesses several advantages,including inhibiting the agglomeration of SnSe2 nanoparticles,relieving the volume expansion,accelerating the diffusion kinetics of electrons/ions,enhancing the contact area between the electrode and electrolyte and improving the structural stability of the composite.As a result,the as-obtained SnSe2 NCs/C microspheres show a high reversible capacity(565 mA h g^-1 after 100 cycles at 100 mA g^-1),excellent rate capability,and long cycling life stability(363 mA h g^-1 at1 A g^-1 after 1000 cycles),which represent the best performances among the reported SIBs based on SnSe2-based anode materials.

Nb2O5 nanotubes on carbon cloth for high performance sodium-ion capacitors

Hybrid sodium-ion capacitors(SICs)bridge the gap between the supercapacitors(SCs)and batteries and have huge potential applications in large-scale energy storage.However,designing appropriate anode materials with fast kinetics behavior as well as long cycle life to match with the cathode electrodes remains a crucial challenge.Herein,Nb2O5 nanotubes and nanowire-to-nanotube homo-junctions were directly grown on the carbon cloth(CC)via a simple hydrothermal process through regulating the pH value of solution.The as-prepared Nb2O5@CC nanotubes displayed a high reversible capacity of 175 mA hg-1 at the current density of 1Ag-1 with the coulombic efficiency of 97%after 1500 cycles.Besides,the SICs fabricated with Nb2O5@CC and activated carbon(AC)electrode materials showed a high energy density of 195 W h kg-1 at 120 W kg-1,a power density of 7328 W kg-1 at 28 W hkg-1and 80%of the capacitance retention after 5000 cycles.Additionally,the flexible SIC devices can operate normally at various bendable conditions.The Nb2O5@CC nanotubes in this work can be promising electrode materials in flexible and wearable energy storage devices.

Three-dimensional porous V2O5 hierarchical octahedrons with adjustable pore architectures for long-life lithium batteries

Three-dimensional （3D） porous V2O5 octahedrons have been successfully fabricated via a solid-state conversion process of freshly prepared ammonium vanadium oxide （AVO） octahedrons. The formation of AVO octahedrons is a result of the selective adsorption of capping reagents and the favourable supersaturation of growth species. Subsequently, 3D porous V2O5 octahedrons were obtained by simple thermolysis of the AVO octahedrons via a calcination treatment. As cathode material for lithium batteries, the porous V2O5 octahedron cathode exhibits a capacity of 96 mAh·g^-1 at high rate up to 2 A·g^-1 in the rang of 2.4 4 V and excellent cyclability with little capacity loss after 500 cycles, which can be ascribed to its high specific surface area and tunable pore architecture. Importantly, this facile solid-state thermal conversion strategy can be easily extended to controllably fabricate other porous metal oxide micro/nano materials with specific surface textures and morphologies.

Thiourea-based polyimide/RGO composite cathode:A comprehensive study of storage mechanism with alkali metal ions

Although organic electrode materials have merits of abundant resources,diverse structures and environmental friendliness,their performance for electrochemical energy storage is far insufficient.In this work,a thiourea-based polyimide/reduced graphene oxide(PNTCSA/RGO)composite was synthesized via a condensation polymerization method.As a cathode material in lithium-ion batteries,excellent performance is demonstrated with high reversible capacity(144.2 mA h g^−1),high discharge voltage(∼2.5 V),and long cycling life(over 2000 cycles at 500 mA g^−1),which are comparable to those of other well documented in organic electrodes.Encouraging electrochemical performance is also demonstrated for sodium ion batteries(a cycling life of 800 cycles at 500 mA g^−1),while poor performance is delivered in potassium ion batteries.Theoretical studies reveal that the active sites are carbonyl groups for all alkali ions but one inserted alkali metal ion is shared by two carbonyl groups from the two neighbor units.More importantly,K ions have stronger interaction with S atoms than Li/Na ions,which may lead to poor structure reversibility and account for the poor cycling performance.Our findings provide a fundamental understanding of polyimide based polymer electrodes and help to design and develop high performance organic electrode materials for alkali metal ion batteries.

An ultralong-life SnS-based anode through phosphate-induced structural regulation for high-performance sodium ion batteries

As a star representative of transition metal sulfides, Sn S is viewed as a promising anode-material candidate for sodium ion batteries due to its high theoretical capacity and unique layered structure. However,the extremely poor electrical conductivity and severe volume expansion strongly hinder its practical application while achieving a high reversible capacity with long-cyclic stability still remains a grand challenge. Herein, different from the conventional enhancement method of elemental doping, we report a rational strategy to introduce PO_(4)^(3-)into the Sn S layers using phytic acid as the special phosphorus source.Intriguingly, the presence of PO_(4)^(3-)in the form of Sn–O–P covalent bonds can act as a conductive pillar to buffer the volume expansion of Sn S while expanding its interlay spacing to allow more Na+storage, supported by both experimental and theoretical evidences. Profiting from this effect combined with microstructural metrics by loading on high pyridine N-doped reduced graphene oxide, the as-prepared material presented an unprecedented ultra-long cyclic stability even after 10,000 cycles along with high reversible capacity and excellent full-cell performances. The findings herein open up new opportunities for elevating electrochemical performances of metal sulfides and provide inspirations for the fabrication of advanced electrode materials for broad energy use.

Long life rechargeable Li-O_2 batteries enabled by enhanced charge transfer in nanocable-like Fe@N-doped carbon nanotube catalyst

Rechargeable Li-O2 batteries have attracted considerable interests because of their exceptional energy density. However, the short lifetime still remained as one of the bottle-neck obstacles for the practical application of rechargeable Li-O2 batteries. The development of efficient cathode catalyst is highly desirable to reduce the energy barrier of Li-O2 reaction and electrode failure. In this work, we report a facile strategy for the fabrication of a high-per- formance cathode catalyst for rechargeable Li-O2 batteries by the encapsulation of high content of active Fe nanorods into N-doped carbon nanotubes with high stability （denoted as Fe@NCNTs）. First-principles calculations reveal that the synergistic charge transfer and redistribution between the interface of Fe nanorods, the CNT walls and the active N dopants greatly facilitate the chemisorption and subsequent dissociation of O2 molecules into the epoxy intermediates on the carbon surface, which benefits the uniform growth of nanosized discharge products on CNT surface and thus boosts the reversibility of Li-O2 reactions. As a result, the cathode with Fe@NCNT catalyst exhibRs long cycling sta- bility with high capacities （1000 mA h g-1 for 160 cycles and 600 mA h g-t for 270 cycles）. Based on the total mass of Fe@NCNTs ＋ Li2O2, high gravimetric energy densities of 2120-2600 W h kg-~ can be achieved at the power densities of 50-795 W kg-1.

Amorphous cobalt hydroxysulfide nanosheets with regulated electronic structure for high-performance electrochemical energy storage

Pseudocapacitors with high power density,longterm durability,as well as reliable safety,play a key role in energy conversion and storage.Designing electrode materials combing the features of high specific capacitance,excellent rate performance,and outstanding mechanical stability is still a challenge.Herein,a facile partial sulfurization strategy has been developed to modulate the electronic structure and crystalline texture of cobalt hydroxide nanosheets(denoted as Co(OH)2)at room temperature.The resultant cobalt hydroxysulfide nanosheet(denoted as Co SOH)electrode with abundant low-valence cobalt species and amorphous structure,exhibits a high specific capacitance of 2110 F g^-1at1 A g^-1with an excellent capability retention rate of 92.1%at10 A g^-1,which is much larger than that of Co(OH)2 precursor(916 F g^-1at 1 A g^-1 and 80%retention at 10 A g^-1).Furthermore,the fabricated asymmetric supercapacitor device constructed with Co SOH and active carbon displays a considerable high energy density of 44.9 W h kg^-1at a power density of 400 W kg^-1,and exceptional stability after 8000cycles.