固体电解质涂层隔膜的制备及性能研究

Preparation and property study of solid electrolyte coated separator

以无机固体电解质Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)为涂覆材料,采用简单刮刀涂覆法在商用PE隔膜表面均匀涂覆功能化涂层。利用扫描电子显微镜、循环伏安、交流阻抗、恒电流充放电等测试方法对涂层隔膜的热稳定性、吸液性、保液性、表面形貌、电化学性能进行表征,研究LATP/PE涂层隔膜性能。结果表明,与商用7μm PE隔膜相比,LATP/PE涂层隔膜的孔隙率、热稳定性和吸液率等指标均有大幅度改善。LATP/PE涂层隔膜为23μm(L_(2)样品)时具备最佳的电化学性能,扣式电池在0.1 C倍率下的首次放电比容量为162.79 mAh/g,在1 C倍率下循环100圈后容量保持率为120%。软包锂离子电池在1 C的电流密度下循环100圈后容量保持率为74.12%。

Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP),a kind of inorganic solid electrolyte,is applied as a functional coating on the surface of commercial polyethylene(PE)separators through common scraper-coating method.A series of characterization analysis,such as scanning electron microscopy,cyclic voltammetry,AC impedance and galvanostatic charge-discharge,etc.are utilized to evaluate the thermal stability,liquid absorption,liquid retention,surface morphology and electrochemical performance of the coated separator.The performance of LATP/PE coated separator with different thickness is further explored.Compared with the commercial 7μm PE separator,the porosity,thermal stability and liquid absorption rate of the obtained coated separator are significantly improved.LATP/PE coated separator with a thickness of 23μm(L_(2) sample)exhibits the best electrochemical performance,and the coin-cell assembled with this separator shows an initial discharge specific capacity of 162.79 mAh·g^(-1) at 0.1 C and a capacity retention rate of 120%after 100 cycles at 1 C.The soft pack lithium-ion battery with such a separator delivers a capacity retention of 74.12%after 100 cycles at 1C.