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Gel polymer electrolyte having the nature of the liquid electrolyte (ionic conductivity) while having good processing performance polymer, is the preparation of high power density and high energy density, long cycle life of the lithium-ion polymer battery, an important material of the a. Generally, the good performance of the gel polymer electrolyte should have the following characteristics: a high conductivity, high lithium ion transference number, wide electrochemical stability window, good thermodynamic and electrochemical stability, and a high mechanical strength, and good compatibility with electrodes. The role of the plasticizer in the gel polymer electrolyte are as follows: (1) reduce the glass transition temperature of the polymer electrolyte, and to improve the mobility of the polymer chain segments, contribute together with the movement of the carrier with the polymer segment transport; (2) by the interaction between the dipole and the polymer molecules, to increase the polymer its own polarity, and instead promote the dissociation of the lithium salt in the polymer electrolyte; (3) destruction of lithium the coordination bond between the ion and the polymer, so that more of the lithium ion movement in the gel state, rather than in the crystalline phase. Has many advantages, such as its dielectric constant (64.92) the higher the capacity of the lithium salt dissolved, a wide liquid temperature range (mp -48.8 ° C, boiling point 242 ° C), propylene carbonate (PC) as plasticizer cheap and so on. But PC also has a lot of shortcomings, the most important PC and electrode materials, especially anode material compatibility is not good, significantly off easy in the carbon anode decompose with the formation of Co-intercalation of lithium ions, resulting in graphite. In order to improve the ionic conductivity of the gel polymer electrolyte, we joined the large amounts of plasticizer, however, large amounts of plasticizer, such as 30% of the content of the plasticizer may lower the mechanical properties of the gel polymer electrolyte. Add inorganic nano-particles in a gel polymer electrolyte, not only can improve the mechanical properties, improved stability, and can also improve the electrochemical performance to some extent, such as the increase of the ionic conductivity and thermal stability. In order to obtain a good overall performance of the gel polymer electrolyte film, we have prepared a new kind of a plasticizer Temp TEMP and PC mixed plasticizers, PEO matrix, LiClO4, lithium salt, by adjusting the TEMP and the proportion of PC, and the content of the plasticizer in the gel polymer electrolyte, were prepared composite gel polymer electrolyte film. The nature of their electrochemical properties and thermal analysis performance. Finally, the gel polymer electrolyte doped nano-Al 2 O 3 powders composite polymer electrolyte system, AC impedance method to study the system the variation of the conductivity with temperature, after doping of the gel polymer electrolyte system to improve the flexibility and reduce the degree of crystallinity of the PEO, significantly increase the room temperature electrical conductivity of the polymer collective Meanwhile, we analyzed the thermal performance of the system and found that the increase of thermal stability.
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