Effect of doped Ni-Bi-B alloy on hydrogen generation performance of Al-InCl3

In this work,Ni-Bi-B alloy has been synthesized via chemical synthesis method.A new kind of Al-InCl3-(Ni-Bi-B)composite has been prepared by high energy mechanical ball grinding A1 powder with additives.Results show that the doped Ni-Bi-B alloy can significantly improve the hydrogen generation performance of Al-InCl3 and the catalytic activity is enhanced with the increasing content of Bi in Ni-Bi-B alloy.Under optimal conditions,the hydrogen generation yield and conversion yield of Al-InCl3-(Ni-Bi-B)reached1196.8 mL g^-1 and 100.0%at room temperature,respectively.Mechanism study shows five kinds of active sites,such as the fresh surface/defect of Al particle,Al-AlCl3,Al-In,Al-Bi/B and Al-Ni/B produced during the ball milling process.Their synergistic effect enhances the hydrogen generation performance of AlInCl3-(Ni-Bi-B)remarkably.In general,the proposed Al-InCl3-(Ni-Bi-B)composite is possible to serve as hydrogen generation material for fuel cells.

Rambutan-like hierarchically porous carbon microsphere as electrodematerial for high-performance supercapacitors

Used as high-performance electrodes,both structural and compositional alterations of carbon materials play very important roles in energy conversion/storage devices.Especially in supercapacitors,hierarchical pores and heteroatom doping in carbon materials are indispensable.Here the rambutan-like hierarchically porous carbon microspheres(PCMs)have been constructed via a hydrothermal treatment,followed by carbonization/activation.The hierarchically porous microstructure is composed of three-dimensional porous carbon networks,which give rise to a large surface area.Moreover,N and O functional groups are introduced in the as-prepared samples,which could generate the extra pseudocapacitance.Benefitting from the interconnected hierarchical and open structure,PCM exhibits outstanding capacitive performance,for example,superior specific capacitance and rate capability(397 and 288 F g^(−1) at 0.5 and 20A g^(−1),respectively),as well as long cycling stability(about 95%capacitance retention after 10,000 cycles).These encouraging results may pave an efficient way to fabricate advanced supercapacitors in the future.

Stabilized multifunctional phase change materials based on carbonized Cu-coated melamine foam/reduced graphene oxide framework for multiple energy conversion and storage

The leakage of organic phase change materials(OPCMs)at temperatures above their melting point severely limits their large-scale application.The introduction of porous supports has been identified as an efficient leakageproofing method.In this study,a novel carbonized Cu-coated melamine foam(MF)/reduced graphene oxide(rGO)framework(MF/rGO/Cu-C)is constructed as a support for fabricating stabilized multifunctional OPCMs.MF serves as the supporting material,while rGO and Cu act as functional reinforcements.As a thermal energy storage material,polyethylene glycol(PEG)is encapsulated into MF/rGO/Cu-C through a vacuum-assisted impregnation method to obtain PEG@MF/rGO/Cu-C composite with excellent comprehensive performance.PEG@MF/rGO/Cu-C exhibits high phase change enthalpies of 148.3 J g^(-1)(melting)and 143.9 J g^(-1)(crystallization),corresponding to a high energy storage capability of 92.7%.Simultaneously,MF/rGO/Cu-C endues the composite with an enhanced thermal conductivity of 0.4621Wm^(-1) K^(-1),which increases by 463%compared to that of PEG@MF.Furthermore,PEG@MF/rGO/Cu-C displays great light-to-thermal and electric-to-thermal conversion capabilities,thermal cycle stability,light-tothermal cycle stability,and shape stability,showing promising application prospects in different aspects.

Spacing graphene and Ni-Co layered double hydroxides with polypyrrole for high-performance supercapacitors

The urgent need of high-performance of energy storage devices triggers us to design newly class of materials.Generally,the materials feature with high conductivity,abundant pore s and excellent stability.Here,a sandwiched hybrid composite containing reduced graphene oxide,polypyrrole and Ni-Co layered double hydroxides(RGO/PPy/NiCo-LDH) was prepared in a facile way.The polypyrrole was incorporated in the two dimensional(2D) nanosheets,which not only serve as the spacer to increase the surface area,but also enhance the conductivity of the nanocomposite.The obtained architecture was employed as an advanced electrode in a supercapacitor.The electrode shows an ultrahigh specific capacitance(2534 F g^-1 at 1 A g^-1) and good cycling efficiency(78 % after 5000 cycles).Moreover,an asymmetric cell based RGO/PPy/NiCo-LDH composite demonstrates excellent electrochemical properties and good prospect of practical use.

Binary Co–Ni oxide nanoparticle-loaded hierarchical graphitic porous carbon for high-performance supercapacitors

Heteroatom doped graphitic porous carbon is highly desirable for electrochemical applications because of its excellent conductivity and high surface area.In this study,highly uniform Co-Ni oxide nanoparticleloaded B,N-doped hierarchical graphitic porous carbon was prepared through a dual pyrolysis process.Graphene dispersed chitosan hydrogel was first used as a precursor to fabricate the porous carbon(GCS–C)at 700℃.Co and Ni oxide nanoparticles were further anchored on the porous carbon through chemical reduction and calcined at high temperature.The structure of the porous carbon was optimized by the introduction of graphene to the chitosan hydrogel.The graphitic degree of the porous carbon was significantly improved by the Co and Ni species.The heteroatom B and N were found to be well doped in the composite.These features enable the composite to be an excellent candidate for supercapacitor electrodes.The composite demonstrates a high capacitance(1266.7 F g-1 at 1 A g-1)and excellent stability.

Low-temperature synthesis of sea urchin-like Co-Ni oxide on graphene oxide for supercapacitor electrodes

Transition metal oxides are ideal electrode materials used for supercapacitors.However,the synthesis of transition metal oxides suffers from drawbacks such as high reaction temperature and energy consumption.Herein,we report the synthesis of sea urchin-like Co3 O4-NiO composites supported on graphene oxide(GO) using a hydrothermal method followed by calcination with a low temperature(250℃).The obtained Co3O4-NiO/GO composite demonstrates a high specific capacitance of 883 F g^-1 at 1 A g^-1.Furthermore,upon coupling with an activated carbon(AC) positive electrode,an asymmetric cell of Co3 O4-NiO/GO//AC exhibits outstanding stability reflected by the high capacitance retention of 82% at a high current density of 10 A g^-1.The excellent electrochemical properties of the composite may be attributed to the good synergistic effect of Co3O4 and NiO,as well as the assembly of Co3 O4 and NiO into a sea urchin structure,which results in increased electron conductivity and more exposed electroactive sites leading to the promotion of the Faradaic redox process.

Encapsulation of hollow Cu_(2)O nanocubes with Co_(3)O_(4)on porous carbon for energy-storage devices

Co3 O4 is one of the most studied transition-metal oxides for use in energy-storage devices.However,its poor conductivity and stability limit its application.In this study,a facile method for anchoring Co3 O4-encapsulated Cu2 O nanocubes on porous carbon(PC) to form Cu2 O@Co3 O4/PC was developed.The Cu2 O@Co3 O4/PC composite exhibited superior electrochemical performance as a supercapacitor electrode material.The resultant supercapacitor delivered high specific capacitance(1096 F g^-1 at 1 A g^-1),high rate capability(83 % retention at 10 A g^-1),and excellent cycling stability(95 % retention of initial capacitance after 3000 cycles).Moreover,an asymmetric supercapacitor fabricated by coupling a Cu2 O@Co3 O4/PC positive electrode with a reduced graphene oxide negative electrode exhibited high energy density(32.1 W h kg^-1 at 700 W kg^-1).Thus,our results demonstrate that Cu2 O@Co3 O4/PC is a promising electrode material for energy-storage devices.

Superior performance for lithium storage from an integrated composite anode consisting of SiO-based active material and current collector

Silicon-based material is considered to be one of the most promising anodes for the next-generation lithium-ion batteries(LIBs)due to its rich sources,nontoxicity,low cost and high theoretical specific capacity.However,it cannot maintain a stable electrode structure during repeated charge/discharge cycles,and therefore long cycling life is difficult to be achieved.To address this problem,herein a simple and efficient method is developed for the fabrication of an integrated composite anode consisting of SiO-based active material and current collector,which exhibits a core-shell structure with nitrogen-doped carbon coating on SiO/P micro-particles.Without binder and conductive agent,the volume expansion of SiO active material in the integrated composite anode is suppressed to prevent its pulverization.At a current density of 500 mA·g−1,this integrated composite anode exhibits a reversible specific capacity of 458 mA·h·g−1 after 200 cycles.Furthermore,superior rate performance and cycling stability are also achieved.This work illustrates a potential method for the fabrication of integrated composite anodes with superior electrochemical properties for high-performance LIBs.