Li 盐与聚环氧乙烷复合电解质膜的电化学性能与稳定性

ELECTROCHEMICAL PROPERTY AND STABILITY OF POLY(ETHYLENE OXIDE)-LITHIUM SALT COMPLEX ELECTROLYTE FILM

以溶液浇铸法合成了聚环氧乙烷-Li 盐复合物 LiClO_4·(PEO)_n 和 LiCF_3SO_3·(PEO)_n。用交流阻抗法、线性极化技术和电位扫描伏安法研究材料的电化学性能.并以热重分析法(TGA)和热变形性能(TMA)测定热化学稳定性和耐热力学性能。对于 LiClO_4·(PEO)_n 体系(n=9—23),σ_(45∶C)>10^(-5)S/cm;σ_(65∶C)>10^(-4)S/cm;LiCF_3SO_4·(PEO)_n 体系(n=9—27),σ_(65∶C)>10^(-5)S/cm,σ_(100∶C)>10^(-4)S/cm.分解电压 E_d>4.5V,热分解温度 T_d>250℃。这类材料可以作为80—120℃工作的全固态高能 Li 蓄电池的固体电解质材料。

The complex electrolyte films of LiClO_4·(PEO)_n and LiCF_3SO_3·(PEO)_n were prepared by casting prccess.The AC cordtctivity (σ),ex-change current density at inferfaces (i_o),thermal and electrochemical stabilityof the films were studied.The conductivity reaches 10^(-5)S/cm and 10^(-4)S/cmat 45 and 65℃ for the complex electrolytes LiClO_4·(PEO).(n=9—23)and at 65 and 100℃ for LiCP_3SO_3·(PEO)_n(n=9—27),respectively.Thedecomposition voltages are over 4.5 V and the decomposition tempertures areover 250℃ for them.Polymer solid electrolyte films of LiClO_4-PEO andLiCF_3SO_3-PEO are suitable for secondary lithium betteries working at80—120℃.