汽车热交换器用铝合金复合板的开发现状及其材料选择

本文简述了国内外开发利用铝合金复合板的情况，并简述了作为汽车热交换器使用的铝合金复合板的芯材、包覆材、牺牲的阳极材的选择，以及各种材料所具有的性能，同时介绍了几种常用复合板的组合形式及其所用合金。

Synthesis of α-Fe_2O_3@SnO_2 core-shell nanoparticles via low-temperature molten salt reaction route

A cost-effective carbon-free nanocoating strategy was developed for the synthesis of ultra-fine SnO2 coatingα-Fe2O3 core-shell nanoparticles. This strategy only involves a two-step molten salt reaction at low temperature of 300 °C. The as-preparedα-Fe2O3@SnO2 core-shell nanocomposites show enhanced electrochemical performances than the bareα-Fe2O3 nanoparticles. This involved metal oxide nanocoating method is easy to be carried out, and the heat treatment temperature is much lower than that of other traditional solid-state annealing method and many carbon or metal oxide nanocoating methods. The molten salt method may also be used to produce other metal oxides coating nanostructures as the electrode materials for lithium-ion batteries.

Synthesis and characterization of LiFePO_4 coating with aluminum doped zinc oxide

Aluminum doped zinc oxide （AZO）, as an electrically conductive material, was applied to coating on the surface of olivine-type LiFePO4 synthesized by solid-state method. The charge-discharge test results show that the rate performance and low-temperature performance of LiFePO4 are greatly improved by the surface treatment. Even at 20C rate, the discharge specific capacity of 100.9 mA.h/g was obtained by the AZO-coated LiFePO4 at room temperature. At -20 ℃, the discharge specific capacity at 0.2C for un-coated LiFePO4 and the coated one are 50.3 mA.h/g and 119.4 mA.h/g, respectively. It should be attributed to the electrically conductive AZO-coating which increases the electronic conductivity of LiFePO4. Furthermore, the surface-coating increases the tap-density of LiFePO4. The results indicate that the AZO-coated LiFePO4 is a good candidate of cathode material for applying in lithium power batteries.

Fabrication,characterization and electrochemical properties of porous coral-structured Si/C composite anode for lithium ion battery

A porous coral-structured Si/C composite as an anode material was fabricated by coating Si nanoparticles with a carbon layer from polyvinyl alcohol（PVA）, erosion of hydrofluoric（HF） acid, and secondary coating with pitch. Three samples with different pitch contents of 30%, 40% and 50% were synthesized. The composition and morphology of the composites were characterized by X-ray diffractometry（XRD） and scanning electron microscopy（SEM）, respectively, and the properties were tested by electrochemical measurements. The results indicated that the composites showed obviously enhanced electrochemical performance compared with that without secondary carbon coating. The second discharge capacity of the composite was 773 m A·h/g at a current density of 100 m A/g, and still retained 669 m A·h/g after 60 cycles with a small capacity fade of less than 0.23%/cycle, while the content of secondary carbon source of pitch was set at 40%. Therefore, the cycle stability of the composite could be excellently improved by regulating carbon content of secondary coating.

Effect of hydro co-extrusion on microstructure of duo-cast Al3003/Al4004 clad materials

The effects of hydro co-extrusion on the microstructure changes of aluminum hybrid duo-cast Al 3003/Al 4004 clad materials were studied. The specimen of duo-cast Al 3003/Al 4004 clad materials was in circle shape, and was composed of Al 3003(outside) and Al 4004(inside) materials. The specimen was extruded by the hydro co-extrusion equipment. The manufacturing conditions of the specimen were 423 K in temperature and 5 in extrusion ratio. The dimensions of the specimen were 80 mm in diameter of the Al 4004 material and 35 mm in thickness of the Al 3003 material before the hydro co-extrusion process, and 30 mm in diameter and about 5 mm in thickness after the extrusion process, respectively. The microstructure and the hardness for two specimens were investigated. The hardness value of cross section in the duo-cast Al 3003/Al 4004 clad materials before the extrusion process was increased in form of the parabola toward the center. However, after the extrusion process, it was almost constant in the portion of Al 4004 material. Lots of big voids above 1 mm in diameter in the specimen existed in the interfacing region of Al 3003 and Al 4004 materials before the extrusion process. These big voids disappeared after the process of hydro co-extrusion.

Surface modification of calcium carbonate:A review of theories,methods and applications

Calcium carbonate,which is widely employed as a filler added into the polymer matrix,has large numbers of applications owing to the excellent properties such as low cost,non-toxicity,high natural reserves and biocompatibility.Nevertheless,in order to obtain the good filling effect,calcium carbonate needs to be surface modified by organic molecules so as to enhance the dispersion and compatibility within the composites.This review paper systematically introduces the theory,methods,and applications progress of calcium carbonate with surface modification.Additionally,the key factors that affect the properties of the composites as well as the current difficulties and challenges are highlighted.The current research progress and potential application prospects of calcium carbonate in the fields of plastics,rubber,paper,medicine and environmental protection are discussed as well.Generally,this review can provide valuable reference for the modification and comprehensive utilization of calcium carbonate.

Li_(1.4)Al_(0.4)Ti_(1.6)(PO_(4))_(3) coated Li_(1.2)Ni_(0.13)Co_(0.13)Mn_(0.54)O_(2) for enhancing electrochemical performance of lithium-ion batteries

Lithium(Li)-rich manganese(Mn)-based cathode Li_(1.2)Ni_(0.13)Co_(0.13)Mn_(0.54)O_(2)(LRNCM)has attracted considerable attention owing to its high specific discharge capacity and low cost.However,unsatisfactory cycle performance and poor rate property hinder its large-scale application.The fast ionic conductor has been widely used as the cathode coating material because of its superior stability and excellent lithium-ion conductivity rate.In this study,Li_(1.2)Ni_(0.13)Co_(0.13)Mn_(0.54)O_(2) is modified by using Li_(1.4)Al_(0.4)Ti_(1.6)(PO_(4))_(3)(LATP)ionic conductor.The electrochemical test results show that the discharge capacity of the resulting LRNCM@LATP1 sample is 198 mA·h/g after 100 cycles at 0.2C,with a capacity retention of 81%.Compared with the uncoated pristine LRNCM(188.4 m A·h/g and 76%),LRNCM after the LATP modification shows superior cycle performance.Moreover,the lithium-ion diffusion coefficient D_(Li+)is a crucial factor affecting the rate performance,and the D_(Li+)of the LRNCM material is improved from 4.94×10^(-13) to 5.68×10^(-12)cm^(2)/s after modification.The specific capacity of LRNCM@LATP1 reaches 102.5 mA·h/g at 5C,with an improved rate performance.Thus,the modification layer can considerably enhance the electrochemical performance of LRNCM.

Characterization and adsorption behaviors of a novel synthesized mesoporous silica coated carbon composite

A novel mesoporous silica coated carbon composite(denoted SEG) with hierarchical pore structure has been successfully prepared in an aqueous solution that contains triblock copolymer template, aluminum chloride, siliceous source and expanded graphite. Textural property and morphology of the SEG composite were characterized by the combination of X-ray diffraction, N_2 adsorption–desorption, scanning electron microscopy,transmission electron microscopy and Fourier transform infrared measurements. Results show that mesoporous silica is steadily and uniformly grown on the surface of the graphite slices and the thickness of the silica layer can be finely tuned according to the silica/C molar ratio in the initial reaction solution. This newly synthesized SEG composite shows greatly increased adsorption capacity to methylene blue than the pristine expanded graphite in the batch tests. Both Langmuir and Frendlich models were further used to evaluate the adsorption isotherms of methylene blue over expanded graphite and SEG samples with different silica contents. Finally, pseudosecond-order model was used to describe the kinetics of methylene blue over expanded graphite and the silica-carbon composites.

Encapsulated MnO in N-doping carbon nanofibers as efficient ORR electrocatalysts

Development of cheap,abundant and noblemetal-free materials as high efficient oxygen reduction electrocatalysts is crucial for future energy storage system. Here,one-dimensional（1D） MnO N-doped carbon nanofibers（MnO-NCNFs） were successfully developed by electrospinning combined with high temperature pyrolysis. The MnO-NCNFs exhibit promising electrochemical performance,methanol tolerance,and durability in alkaline medium. The outstanding electrocatalytic activity is mainly attributed to several issues.First of all,the uniform 1D fiber structure and the conductive network could facilitate the electron transport. Besides,the introduction of Mn into the precursor can catalyze the transformation of amorphous carbon to graphite carbon,while the improved graphitization means better conductivity,beneficial for the enhancement of catalytic activity for oxygen reduction reaction（ORR）. Furthermore,the porous structure and high surface area can effectively decrease the mass transport resistance and increase the exposed ORR active sites,thus improve utilization efficiency and raise the quantity of exposed ORR active sites. The synergistic effect of MnO and NCNFs matrix,which enhances charge transfer,adsorbent transport,and delivers efficiency in the electrolyte solution,ensures the high ORR performance of MnO-NCNFs.

Rationally designed carbon-coated Fe304 coaxial nanotubes with hierarchical porosity as high-rate anodes for lithium ion batteries

Fe3O4 is a promising high-capacity anode material for lithium ion batteries, but challenges including short cycle life and low rate capability hinder its widespread implementation. In this work, a well-defined tubular structure constructed by carbon-coated Fe3O4 has been successfully fabricated with hierarchically porous structure, high surface area, and suitable thickness of carbon layer. Such purposely designed hybrid nanostructures have an enhanced electronic/ionic conductivity, stable electrode/electrolyte interface, and physical buffering effect arising from the nanoscale combination of carbon with Fe3O4, as well as the hollow, aligned and hierarchically porous architectures. When used as an anode material for a lithium-ion half cell, the carbon-coated hierarchical Fe3O4 nanotubes showed excellent cycling performance with a specific capacity of 1,020 mAh.g^-1 at 200 mA.g^-1 after 150 cycles, a capacity retention of ca. 103%. Even at a higher current density of 1,000 mA·g^-1, a capacity of 840 mAh·g^-1 is retained after 300 cycles with no capacity loss. In particular, a superior rate capability can be obtained with a stable capacity of 355 mAh.g^-1 at 8,000 mA·g^-1. The encouraging results indicate that hierarchically tubular hybrid nanostructures can have important implications for the development of high-rate electrodes for future rechargeable lithium ion batteries （LIBs）.

One-pot facile fabrication of carbon-coated Bi2S3 nanomeshes with efficient Li-storage capability

Layered bismuth sulfide （Bi2S3） has emerged as an important type of Li-storage material due to its high theoretical capacity and intriguing reaction mechanism. The engineering and fabrication of Bi2S3 materials with large capacity and stable cyclability via a facile approach is essential, but still remains a great challenge. Herein, we employ a one-pot hydrothermal route to fabricate carbon-coated Bi2S3 nanomeshes （Bi2S3/C） as an efficient Li-storage material. The nanomeshes serve as a highly conducting and porous scaffold facilitating electron and ion transport, while the carbon coating layer provides flexible space for efficient reduction of mechanical strain upon electrochemical cycling. Consequently, the fabricated Bi2S3/C exhibits a high and stable capacity delivery in the 0.01-2.5 V region, notably outperforming previously reported Bi2S3 materials. It is able to discharge 472 mA·h·g^-1 at 120 mA.g^-1 over 50 full cycles, and to retain 301 mA·h·g^-1 in the 40th cycle at 600 mA.g^-l, demonstrating the potential of Bi2S3 as electrode materials for rechargeable batteries.

Soft template PEG-assisted synthesis of Fe_3O_4@C nanocomposite as superior anode materials for lithium-ion batteries

Carbon-encapsulated Fe3O4 composites were successfully fabricated via hydrothermal method and ex- amined by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The Fe3O4@C nanocomposite as an anode material with novel structure demonstrated excellent electrochemical performance, with enhanced specific reversible current density of 50 mA/g capacity （950 mAh/g at the after 50 cycles）, remarkable rate capability （more than 650 mAh/g even at the current density of 1,000 mAJg） and good cycle ability with less capacity fading （2.4 % after 50 cycles）. Two factors have been attributed to the ultrahigh electrochemical perfor- mance： Firstly, the 30- to 50-nm spherical structure with a short diffusion pathway and the amorphous carbon layer could not only provide extra space for buffering the volumetric change during the continuous charging-dis- charging but also improve the whole conductivity of the Fe3O4@C nanocomposite electrode; secondly, the syner- gistic effects of Fe304 and carbon could avoid Fe304 direct exposure to the electrolyte and maintain the structural stabilization of Fe3O4@C nanocomposite. It was suggested that the Fe3O4@C nanocomposite could be suitable as analternative anode for lithium-ion batteries with a high ap- plication potential.

Morphology inheritance synthesis of carbon-coated Li3VO4 rods as anode for lithium-ion battery

Li3VO4 shows great potential as an intercalation/de-intercalation type anode material for energy-storage devices. Morphology tailoring and surface modification are effective to enhance its lithium storage performance. In this work, we fabricate carbon coated Li3VO4(C@LVO) rods by a facile morphology inheritance route. The as-prepared C@LVO rods are 400–800 nm in length and 200–400 nm in diameter,and orthorhombic phase with V5+. The unique core-shell rods structure greatly improves the transport ability of electrons and Li+. Such C@LVO submicron-rods as anode materials exhibit excellent rate capability(a reversible capability of 460,438, 416, 359 and 310 m A h g^-1 at 0.2, 1, 2, 5 and 10 C, respectively) and a high stable capacity of 440 and 313 m A h g^-1 up to 300 cycles at 0.2 and 5 C, respectively.

Fabrication of multifunctional carbon encapsulated Ni@NiO nanocomposites for oxygen reduction,oxygen evolution and lithium-ion battery anode materials

Multifunctional carbon encapsulated Ni@NiO nanocomposites（Ni@NiO@C） were synthesized for applications in oxygen reduction reactions（ORR）,oxygen evolution reactions（OER） and lithium-ion batteries（LIB）. The morphology was investigated via SEM and TEM,suggesting that the Ni@NiO@C nanocomposites have uniform and spherical core-shell structures. When the Ni@NiO@C nanocomposite is used as the catalyst in ORR,90% of the initial current density can be maintained after 15h in O_2-saturated 0.1 mol L^-1 KOH at 0.3 V under a rotation speed of 1600rpm.As a catalyst for OER,the highest activity overpotential of the Ni@NiO@C nanocomposite electrocatalyst is 380 mV（vs.RHE） under the current density of 10 mA cm^（-2）,and the Tafel slope was calculated to be 55 mV dec^-1 by linear fitting. Electrochemical performances of the Ni@NiO@C nanocomposites used as LIB electrodes exhibited a long cycling life with a high capacity of 750 mA h g^-1 after 400 cycles under 200 mA g^-1.

Mesoporous Fe_(3)O_(4)@C nanoarrays as high-performance anode for rechargeable Ni/Fe battery

Rechargeable aqueous batteries with high power density and energy density are highly desired for electrochemical energy storage.Despite the recent reports of various cathode materials with ultrahigh pseudocapacitance exceeding3000 F g^(-1)(or 800 mA h g^(-1)),the development of anode materials is relatively insufficient,which limits the whole performance of the devices far from practical applications.Herein,we report the preparation of mesoporous Fe_(3)O_(4)@C nanoarrays as high-performance anode for rechargeable Ni/Fe battery by a self-generated sacrificial template method.Zn O/Fe_(3)O_(4)composite was first synthesized by a co-deposition process,and Zn O was subsequently removed by alkali etching to construct the mesoporous structure.A thin carbon film was introduced onto the surface of the electrode by the carbonization of glucose to increase the structural stability of the electrode.The unique mesoporous nanoarray architecture endows the electrode with larger specific surface area,faster charge/mass transport and higher utilization of Fe_(3)O_(4),which shows an ultrahigh specific capacity (292.4 mA h g^(-1)at a current density of 5 mA cm^(-2)) and superior stability in aqueous electrolyte (capacitance retention of 90.8%after 5000cycles).After assembled with hierarchical mesoporous Ni O nanoarray as a cathode,an optimized rechargeable Ni/Fe battery with double mesoporous nanoarray electrodes was fabricated,which provided high energy/power densities(213.3 W h kg^(-1)at 0.658 kW kg^(-1)and 20.7 kW kg^(-1)at113.9 W h kg^(-1),based on the total mass of the active materials)in the potential window of 1.5 V with excellent cyclability(81.7%retention after 5000 charge/discharge cycles).