作者:刘少鹏 ， 王基任 ， 拓沅辛 ， 周春山 ， 周 爽 ， 张永泉
Authors:LIU Shaopeng , WANG Jiren, TUO Yuanxin, ZHOU Chunshan, ZHOU Shuang , ZHANG Yongquan摘要:\n\tNASICON型固态电解质磷酸锆锂(LZP)具有优异的结构稳定性和性能可靠性,但其在室温下的锂离子电导率较低,限制锂离子的传输。针对上述问题,采用溶胶凝胶法对磷酸锆锂电解质材料进行阳离子掺杂,提高材料的电导率,进而提升锂离子在材料中的输运能力。同时,将掺杂的磷酸锆锂电解质对电极进行修饰,提升电极本身的锂离子输运性能。探究了离子掺杂电解质对电极的锂离子扩散动力学性能的影响机理。实验结果表明,LiTi_0.25Zr_1.75(PO₄)₃对电极的锂离子扩散动力学性能提高最为显著,锂离子扩散系数达到 3.25×10^-14 cm2 ·S^-1 ,是未修饰电极的2.95倍,同时在5C倍率下,LiTi_0.25Zr_1.75 (PO₄ )₃修饰的电极比未修饰电极比容量提高了25.48 mAh·g^-1\n

Abstract:NASICON type solid electrolyte LiZr₂ (PO₄ )₃ has excellent structural stability and performance reliability, but its low conductivity of lithium ions at room temperature limits the transport of lithium ions. In view of the above problems, cationic doping of LiZr₂ (PO₄ )₃ electrolyte material was studied by sol-gel method and thus improve the transport capacity of lithium ions in the material. Meanwhile , modified the electrode with doped LiZr₂ (PO₄ )₃ electrolyte to improve the lithium ion transport performance of the electrode itself. The influence mechanism of ion-doped electrolyte on lithium ion diffusion kinetics of electrode was investigated. The experimental results show that LiTi_{0. 25} Zr_{1. 75} (PO₄ )₃ improves the lithium ion diffusion kinetics most significantly, and the lithium ion diffusion coefficient reaches 3. 25 × 10 ^{- 14} cm2 ·S ^{- 1} , which is 2. 95 times of that of the unmodified electrode. At 5C rate, the specific capacity of LiTi_{0. 25} Zr_{1. 75} (PO₄ )₃ modified electrode is 25. 48 mAh g ^{- 1} higher than that of the unmodified electrode.

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