In-built Photosynthesis And Application On Solid-state Batteries Of Polyether Based Polymer Solid Electrolytes

With the development of drug delivery system,the demand for developing an intelligent and controllable drug delivery system has been increasing.In order to solve the power source problem of drug delivery system and extend the lifetime of drug delivery system,it is urgent to develop a kind of battery systems with high energy density and high safety.Solid polymer electrolytes(SPEs)are considered as a solution for the safety issues such as the growth of lithium dendrite in solid-state batteries,because of their good processability,good interfacial compatibility,superior mechanical toughness,lower cost and lightweight characteristics.For satisfying the demands of solid-state batteries(SSEs),the SPEs not only need to enable the high ionic conductivity and fast Li transport at the interface of the anode/cathode and anode(or cathode)/SPEs in SSEs,but also need to remain a good mechanical stability.Various strategies have been reported in the literature to improve the transport of Li ions between electrode and electrolyte,in-built polymerization technique has been proven an effective method to develop an excellent interfacial contact between SPEs and electrode,SPEs system fabricated by in-built polymerization often possess a superior interfacial contact of electrolyte/electrode,allowing fast transport of Li ions between interfaces and obtaining an excellent electrochemical and cycling performance.However,existing in-built methods usually involve heat,ultraviolet radiation and?irradiation to initiate the polymerization,and solvents often added into the polymerization system to avoid the concentrated active propagating species,which inevitably afford solvent residues in the polymer electrolytes,so that leading a more complex SPE preparation process and the safety issues caused by side reaction with electrode.In this thesis,simple and efficient methods for preparation of SPEs was developed based on the solvent-free in-built polymerization induced via visible light,and the m PEGAA-based SPE and DOL-based SPE was fabricated by visible light induced controlled radical polymerization(CRP)and visible light induced cationic polymerization,respectively.Specifically,the m PEGAA-based SPE,prepared by visible light induced CRP,was completely converted(conversion rate is 99%)in 5 mins efficiently and uniformly,and a 16?m SPE film was obtained on the electrode surface by in-built visible light induced CRP.The SPE fabricated by this way gave an improved room-temperature ionic conductivity of1.5×10^-4 S cm^-1 and a good interfacial compatibility,the LFP/Li cell exhibited a high discharge areal capacity of 1.7 m Ah cm^-2(164.6 m Ah g^-1)at room temperature and the Li/Li cell could cycled steadily over 270 h.What's more,the DOL-based SPE,prepared by visible light induced cationic polymerization,was also showed a high conversion rate(93%),and obtained a ionic conductivity of 1.6×10^-4 S cm^-1at room temperature and a good interfacial contact SPE system,the LFP/Li cell could cycle at 0.1 C and room temperature,the average coulombic efficiency could be maintained at 98.3%.