高岭土掺杂NASICON固体电解质及全固态电池性能

针对LiTi2(PO4)3基固态电解质电导率低的问题,采用浙江三门高岭土矿作为主要原料,以高温固相法制备铝、镁、硅共掺杂钠超离子导体(NASICON)型快离子导体Li1+2x+2yAlxMgyTi2-x-ySixP3-xO12.研究掺杂比例、温度对固态电解质离子电导率的影响.结果表明,组成为Li1.8Al0.1Mg0.3Ti1.6Si0.1P2.9O12固体电解质在423K时有最高离子电导率7.86×10-4 S.cm-1.以该组成固态电解质为基片,喷雾热解原位制备Al/Li1+xV3O8/Li1.8Al0.1Mg0.3Ti1.6Si0.1P2.9O12/C全固态电池并在1.8～3.9V电压区间进行50次充放电测试.该电池具有较好的稳定性及循环容量保持能力.30次循环以后放电容量基本稳定在190～205mAh.g-1之间,充放电效率大于90%.

Performances of the NASICON type solid-state electrolyte prepared by Kaolin doping and all solid-state lithium ion battery

To improve the low ionic conductivity of LiTi2(PO4)3 based solid state electrolyte,NASICON type fast ion conductors Li1+2x+2yAlxMgyTi2-x-ySixP3-xO12were prepared by Mg2+,Al3+ and Si4+ co-doping which originated from Kaolin of Zhejiang Sanmen district.The influences of the content of the doping elements and testing temperature on ionic conductivity were studied.The results show that ionic conductivity reaches maximum 7.86×10-4 S·cm-1 tested at T=423 K for the composite Li1.8Al0.1Mg0.3Ti1.6Si0.1P2.9O12.Spray Pyrolysis was applied to fabricate the in situ all solid-state lithium ion battery Al/ Li1+xV3O8/ Li1.8Al0.1Mg0.3Ti1.6Si0.1P2.9O12 /C system and 50 charge-discharge cycles were tested between 1.8 ~3.9 V.The battery shows rather good stability and capacity retention capability.After 30 cycles,the discharge capacities are stabilized between 190 and 205 mAh·g-1 with more than 90% discharge efficiency.