No abstract

Sulfurized polyacrylonitrile was well known for its excellent electrochemical performance. In this work, a kind of gel polymer electrolyte with PMMA as polymer matrix was prepared through in situ thermal initiated polymerization in this work. The interactions between polymer and traditional carbonate electrolyte were studied by IR. Its electrochemical performance in Li/SPAN batteries was investigated in detail, using LSV, CV, EIS et al. The results show that high ionic conductivity was achieved, with a value of 4.2 mS cm-1 at 30◦C when the content of PMMA was 15%. A reversible capacity of 975.3 mAh g-1 could be maintained after 50 cycles.

AlF3 and MgF2 were applied to modify the surface of the LiNi1/3Co1/3Mn1/3O2 cathode material. The structural and electrochemical properties of the materials were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), charge–discharge tests and electrochemical impedance spectra (EIS). The results show that the 1 wt.% AlF3 and 1 wt.% MgF2 coated LiNi1/3Co1/3Mn1/3O2 (NCM333) cathode material exhibits an optimized electrochemical performance. It presents an initial capacity of 207.2mAh/g and 169.1mAh/g at 0.2C between 2.8V and 4.7V after charge-discharge 65 cycles. The rate performance is also enhanced because the coating decreases the interface charge transfer impedance.

In this paper, the characteristics of melted and annealed Co-free AB3-type hydrogen storage alloys in low-temperature condition were investigated by electrochemical tests. A series of Co-free AB3-type hydrogen storage alloys were synthesized with vacuum melting method, and be annealed by low-temperature heat treatment. The structures of alloys are simply discussed through SEM and XRD results. And discharge ability and cycle ability of alloys were tested. Experiment results indicate that characteristics of different AB3-type hydrogen storage alloys are affected by low-temperature obviously, and heated treatment could increase the discharge capacity of hydrogen storage alloy effectively, and improve the charge-discharge stability of alloy. Furthermore, non-metal element substituted alloy shows better Low-temperature applicability due to its weak crystallization. The discharge capacity of La0.7Mg0.3Ni2.9B0.05 alloy remains 91.2% after 30 cycles at 273K. And discharge capacity of heated La0.7Mg0.3Ni2.9(FeB)0.1 alloy could reach to 250mA·g-1.

La1-xMgxNi2.8Co0.7 (x=0.1, 0.3, 0.5) hydrogen storage alloy was synthesized by solid diffusion method. The microstructure of the alloy was analyzed by XRD when the content of Mg was changed. When x equaled to 0.3, there was relative much La2Ni7 phase in the alloy and the alloy exhibited better integrated electrochemical performance. Its maximum discharge capacity reached 355.4mAh/g and capacity retention after 50 cycles（S50）was 77.80%. The results showed the existence of La2Ni7 phase would be conductive to the integrated electrochemical performance of the alloy.