Al^(3+)掺杂石榴石LLZO固体电解质的制备及电化学性能研究

Preparation and Electrochemical Properties of Doped Garnet LLZO Solid Electrolyte

固体电解质拥有较高的离子电导率、良好的化学稳定性、长的循环寿命以及安全可靠等优点,被广泛应用到各个领域,成为当前研究的热点。以LLZO固体电解质为研究对象,制备了不同含量Al掺杂的LLZO电解质材料,采用X射线衍射、扫描电镜和交流阻抗谱等方法对不同掺杂量和不同烧结温度下LLZO固体电解质的XRD、微观形貌及电导率进行了研究。结果表明:少量Al的掺杂可以明显地提升LLZO固体电解质的电导率,但随着掺杂量的增加,Al^(3+)增多,阻塞了Li+的传输通道,导致电导率下降。同时,烧结温度对材料的性能也有一定影响,随着烧结温度的提升,同一含量Al掺杂LLZO的致密度和电导率也有明显提升。

Solid electrolyte has the advantages of high ionic conductivity,good chemical stability,long cycle life,safety and reliability.It has been widely used in various fields and has become a research hotspot at present.In this paper,LLZO solid electrolyte materials doped with different contents of Al were prepared.XRD,micro-morphology and conductivity of LLZO solid electrolyte with different doping amount and sintering temperature were studied by X-ray diffraction,scanning electron microscope and AC impedance spectroscopy.It was found that a small amount of Al doping could obviously improve the conductivity of solid electrolyte.However,with the increase of doping amount,the increase of Al^(3+)blocked the transmission channel of Li^(+)which resulted in the decrease of conductivity.At the same time,sintering temperature also had a certain influence on the properties of materials.With the increase of sintering temperature,the density and conductivity of Al doped LLZO were also obviously improved.