NASICON结构Li1+xAlxTi2−x(PO4)3(0≤x≤0.5)固体电解质研究进展

Progress of NASICON-structured Li1+xAlxTi2−x(PO4)3(0≤x≤0.5)solid electrolyte

锂离子电池在生活中的广泛应用大大提高了人们的生活品质。但是由于采用了易燃的有机液体电解质,传统锂离子电池存在安全风险,能量密度也受到了限制。使用固体电解质替代有机液体电解质发展全固态电池有望解决这些问题。在各种固体电解质中,NASICON结构固体电解质Li1+xAlxTi2−x(PO4)3(LATP,0≤x≤0.5)具有离子电导率高、耐环境稳定性好,合成条件温和等优势,因此有广阔的发展前景和应用潜力。本文先从晶体结构、离子扩散机理、合成方法、提升离子电导率的途径4个方面综述了LATP材料的研究进展;另外,电化学稳定性差以及和电极活性材料界面阻抗大的问题限制了LATP固体电解质在全固态锂电池中的应用,所以在后半部分总结了这些关键问题的解决途径和方法。最后指出,界面问题是限制LATP固体电解质在全固态电池中应用的主要问题,还需要发展更好的策略来进一步优化LATP与电极活性材料之间的界面。

The widespread application of lithium-ion batteries greatly improves peoples'quality of life.However,due to the use of flammable organic liquid electrolytes,there is a safety risk with traditional lithium-ion batteries and their energy density is limited.The development of all-solid-state batteries using solid electrolytes is expected to solve these problems.With high ionic conductivity,good environmental stability,and mild synthesis conditions,the NASICON-structured solid electrolyte Li1+xAlxTi2−x(PO4)3(LATP,0≤x≤0.5)is a fairly promising solid electrolyte.This paper first reviews the progress of LATP according to four aspects:Its crystal structure,ionic diffusion mechanism,synthetic methods,and methods to improve its ionic conductivity.In addition,with the electrochemical instability and high interface impedance of the LATP solid electrolyte against electrode active materials limiting its application in all-solid-state lithium batteries,the solutions to these key issues are summarized in the second part of the paper.Finally,it is emphasized that interface problems are the main challenge limiting the application of LATP solid electrolytes in all-solid-state batteries,necessitating the development of better strategies to further optimize the interface between LATP and electrode active materials.