UPS－1－3C型防止蓄电池过量放电保护装置

ＵＰＳ－１－３Ｃ型防止蓄电池过量放电保护装置张平，鲍少君１概述ＵＰＳ（不间断电源）八块蓄电池充满电后，电压为１１５Ｈ，并在限流浮充状态。ＵＰＳ向负载输出的是经交流一直流一交流变换后的稳压２２０Ｖ交流电源。当市电停电时，蓄电池的直流电供给逆变器，输出２...

阀控密封铅酸蓄电池的应用及维护

本文对阀控密封铅酸蓄电池的组成、工作原理、安装使用和可能出现的问题做了详细的介绍和了解,在此基础上又较详细地说明了蓄电池在日常维护中所注意的维护事项。

犬内脏性癫痫的诊断与防治原则

癫痫性发作是一种临床征候群,是由于脑部兴奋性过高的神经元的过量放电而引起的阵发性大脑功能紊乱,其表现可能是抽搐性的,也可以无抽搐而以感觉、意识、行为等障碍的方式表现,具体症状根据所牵涉的神经元的部位范围,及其功能而定。神经元的过量放电,可能是由于大脑的器质性或功能性疾病,也可以是由于全身性的代谢障碍。面以反复的痫性发作作为特征的急慢性病态,称癫痫。癫痫类型多样,本文就犬内脏疾病导致癫痫的发作及发病原因,临床表现,诊断与防治原则作一表浅的论述供大家参考。

Carbon-coated Fe2O3 hollow sea urchin nanostructures as high-performance anode materials for lithium-ion battery

Fe2O3 has become a promising anode material in lithium-ion batteries (LIBs) in light of its low cost, high theoretical capacity (1007 mA h g^−1) and abundant reserves on the earth. Nevertheless, the practical application of Fe2O3 as the anode material in LIBs is greatly hindered by several severe issues, such as drastic capacity falloff, short cyclic life and huge volume change during the charge/discharge process. To tackle these limitations, carbon-coated Fe2O3 (Fe2O3@MOFC) composites with a hollow sea urchin nanostructure were prepared by an effective and controllable morphology-inherited strategy. Metal-organic framework (MOF)-coated FeOOH (FeOOH@-MIL-100(Fe)) was applied as the precursor and self-sacrificial template. During annealing, the outer MOF layer protected the structure of inner Fe2O3 from collapsing and converted to a carbon coating layer in situ. When applied as anode materials in LIBs, Fe2O3@MOFC composites showed an initial discharge capacity of 1366.9 mA h g^−1 and a capacity preservation of 1551.3 mA h g^−1 after 200 cycles at a current density of 0.1 A g^−1. When increasing the current density to 1 A g^−1, a reversible and high capacity of 1208.6 mA h g^−1 was obtained. The enhanced electrochemical performance was attributed to the MOF-derived carbon coating layers and the unique hollow sea urchin nanostructures. They mitigated the effects of volume expansion, increased the lithium-ion mobility of electrode, and stabilized the as-formed solid electrolyte interphase films.

Confining ultrafine SnS nanoparticles in hollow multichannel carbon nanofibers for boosting potassium storage properties

SnS has been extensively investigated as a potential anode material in potassium-ion batteries (PIBs) for its high theoretical capacity.Nonetheless,it suffers a limited cyclic lifespan owing to its poor electronic conductivity and huge volume expansion.This work proposed a facile approach where SnS nanocrystals are confined in the walls of hollow multichannel carbon nanofibers (denoted SnS@HMCFs) to tackle the issues above.In contrast to previous studies,impregnated ultrafine SnS nanocrystals in HMCFs compactly can increase the SnS loading number per unit area of the carbon matrix.Furthermore,the unique hollow multichannel carbon nanofibers are used as a robust carrier to uniformly distribute the SnS nanocrystals.This can significantly accelerate K;/electron transport,resulting in large specific capacity,outstanding rate performance,and steady cycling property for PIBs.High reversible capacities of 415.5 mAh g^(-1)at0.1 A g^(-1)after 300 cycles and 245.5 mAh g^(-1)at 1 A g^(-1)after 1000 cycles are retained,suggesting great potential of SnS@HMCFs as a negative electrode material for PIBs.Additionally,when the SnS@HMCF anode is assembled with the KVPO_(4)F cathode,the obtained full cell shows a large discharge capacity of165.3 m Ah g^(-1)after 200 cycles at 0.1 A g^(-1).

Effect of esterification reaction of citric acid and ethylene glycol on the formation of multi-shelled cobalt oxide powders with superior electrochemical properties

In this study, for the first time, polymeric precursors have been used in the preparation of yolk-shell powders using a large-scale spray drying process. An esterification reaction between the carboxyl group of citric acid and the hydroxyl group of ethylene glycol inside the droplet produced organic polymers during the drying process of the droplet. During the spray drying process, the polymeric precursors enabled the formation of multi-shell cobalt oxide yolk- shell powders with superior electrochemical properties. The maximum number of shells of the particles in the yolk-shell powders post-treated at 300, 400, and 500 ℃ were six, five, and four, respectively. The initial discharge capacities of the cobalt oxide yolk-shell powders post-treated at 300, 400, and 500 ℃ were 1,188, 1,331, and 1,110 mAh·g^-1, and their initial charge capacities were 868, 1,005, and 798 mAh·g^-1, respectively. The discharge capacities of the powders post- treated at 300, 400, and 500 ℃ after 100 cycles were 815, 958, and 670 mAh·g^-1, respectively and their corresponding capacity retentions measured after the first cycles were 92%, 93%, and 82%, respectively. The pure phase Co3O4 yolk-shell powders post-treated at 400 ℃ had low charge transfer resistance and high lithium-ion diffusion rate.

Interconnected CoS/NC-CNTs network as highperformance anode materials for lithium-ion batteries

Cobalt disulfide(CoS_(2))has been considered a promising anode material for lithium-ion batteries(LIBs)due to its high theoretical capacity of 870 mA h g^(-1).However,its practical applications have been hampered by undesirable cycle life and rate performance due to the volume change and deterioration of electronic conductivity during the dischargecharge process.In this study,an interconnected CoS_(2)/N-doped carbon/carbon nanotube(CoS_(2)/NC-CNTs-700)network was successfully prepared to boost its lithium storage performance,in which small-size CoS_(2)nanoparticles were confined by N-doped carbon and uniformly decorated on the surface of CNTs.N-doped carbon can effectively accommodate the large volume expansion of CoS_(2)nanoparticles.Additionally,the 3D conductive nanostructure design offers adequate electrical/mass transport spacing.Benefiting from this,the CoS_(2)/NCCNTs-700 electrode demonstrates a long cycle life(a residual capacity of 719 mA h g^(-1)after 100 cycles at 0.2 A g^(-1))and outstanding rate performance(335 mA hg^(-1)at 5.0 A g^(-1)).This study broadens the design and application of CoS_(2)and fosters the advances in battery anode research.

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.

Grafting polysulfides into a functional N-halo compound for high-performance lithium—sulfur battery

Due to its high energy density,lithium-sulfur(Li-S)battery is considered as the most promising candidate for the energy storage systems,but its practical application is hindered by the dissolution of lithium polysulfides in the electrolyte.In this work,N-bromophthalimide(C8H4NO2Br,NBP),an aromatic molecule with carbophilic,sulfiphilic,lithiophilic,and solvophilic nature,is introduced into active graphene(AG)to fabricate the sulfur composite cathode.The carbophilic NBP is anchored readily on the AG surface viaπ−πstacking interaction.During discharging,the dissolved lithium polysulfide anion(LiS−n)is grafted into the sulfiphilic NBP spontaneously via SN2 substitution reaction to form C8H4NO2SnLi,which brings the dissolved LiS−n back to the AG surface in the composite cathode.Moreover,the lithiophilic and solvophilic nature of NBP improve the wettability of the porous composite cathode,and the electrolyte molecule is easily penetrated into the micro-mesopores of AG to facilitate the diffusion of the electrolyte.Thus,NBP,as a multi-functional compound in Li-S battery,can immobilize LiS−n and enhance the diffusion of the electrolyte.The above features of NBP endow the sulfur composite cathode with improved electrochemical performance in the cycling stability.