Synthesis And Electrochemical Properties Of Polymer Electrolytes For Secondary Lithium Battery

Polymer lithium-ion battery is a new generation of rechargeable battery developed on the basis of the liquid lithium secondary battery. Polymer lithium-ion battery not only has high voltage, high energy density and long cycle life characteristics, but also solves the hidden safety problems of the liquid lithium secondary battery. Considering its flexibility and convenience in the battery design and assembly of shape, it has been widely used in electric vehicles, mobile communication and other fields.The performance of polymer lithium-ion battery is greater impacted by the polymer electrolyte. Gel polymer electrolyte lithium-ion battery has been started for large-scale production, but it can't be used for high-current discharge because of the low conductivity at the room temperature.Therefore, high conductivity of polymer electrolyte has become a hot spot on lithium-ion battery. The performance of polymer electrolyte in the lithium-ion battery is affected by many factors. It not only needs high conductivity, while also needs a larger lithium-ion transference number to ensure non-occurrence of concentration polarization on the battery charge-discharge process and good electrochemical and thermal stability properties.The work is started from the problem of polymer electrolyte.New comb-shaped polyether P(EO+EM+AGE), a plasticizer STEO and lithium methoxy oligo(ethyleneoxy) sulfonate (LiSA(EO)n) are synthesized, and then used for preparing the polymer electrolyte to study its associated electrochemical and thermal properties.Described specifically as follows:1)The P(EO+EM+AGE), STEO and LiSA(EO)n are synthesized and characterized.2) We study the associated electrochemical and thermal properties of the polymer electrolyte with the polyethylene oxide (PEO) as polymeric matrix. It is divided into five parts, for specific:a. ascertaining the mole ratio of PEO with LiSA(EO)n as the system in the best electrical conductivity; b.studying the properties of transference on the PEO+LiSA(EO)n system; c. contrasting the plasticizer STEO,DEC,EC and DEC/EC complex system on the performance of conductivity; e. Investigating the relationship between conductivity and temperature of PEO+LiSA(EO)n+STEO gel polymer electrolyte system; f. admeasuring the electrochemical stability window of PEO+LiSAEO+20%STEO gel polymer electrolyte system.3)The P(EO+EM+AGE) and PEO was mixed for the polymeric matrix and combined with the LiC104 to study the properties of transference and thermal.