Preparation and Properties of Bilayer Composite Materials of Cu-coated Fe and CuSn10

Bilayer composite materials of Cu-coated Fe and CuSn10 containing 0%,5%,10%,15%,20%,25%,30%,35%,40%,45%,50%Cu-coated Fe were prepared in mesh belt sintering furnace.Microscopic pore morphology of materials was observed,bending strength was tested.Results show that,There is a good bonding between Cu-coated Fe and CuSn10,with the increase of Cu-coated Fe content from 0%to 50%,bending strength of bilayer composite materials increases.

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.

Solid State Reaction Preparation of LiFePO_4/(C+Cu) Cathode Material and Its Electrochemical Performance

Cu-C co-coated LiFePO4 （LiFePO4/（C ＋ Cu）） cathode material was successfully prepared through solid state reduction reaction. The optimized additive amount of CuO was determined by electrochemical test of series content-dependent samples. Electrochemical performances of LiFePO4/（C ＋ Cu） cathode material were investigated. Crystalline structure, morphology and electrochemical performance of the samples were characterized by X-ray diffraction, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, energy dispersive spectroscopy （EDS）, charge-discharge tests and AC impedance techniques. Results showed that crystal structure of the bulk material was not destroyed after Cu particles distributed on the surface of LiFePO4/C. With 5 wt% CuO additive, the LiFePO4/（C ＋ Cu） cathode material showed improved electrochemical performance especially at high rates and low temperature. At 25 ℃ and 0.1 C current rate, specific capacity of the Cu-coated sample reaches 161.3 mA h/g. The result was 47 mA h/g higher than that of the un-coated one. At -20 ℃, the discharge capacity of Cu-coated materials was 113.4 mA h/g at 0.1 C rate and 83.8 mA h/g at 5 C rate, which reached about 70% of that at room temperature, respectively.