The concept of all-solid-state batteries provides an efficient solution towards highly safe and long-life energy storage,while the electrolyte-related challenges impede their practical application.Li1+xAlxTi2-xP3O12(0≤x≤1)with superior Li ionic conductivity holds the promise as an ideal solidstate electrolyte.The intrinsic mechanism to reach the most optimum ionic conductivity in Al-doped Li1+xAlxTi2-xP3O12,however,is unclear to date.Herein,this work intends to provide an atomic scale study on the Li-ion transport in Li1+xAlxTi2-xP3O12electrolyte to rationalize how Al-dopant initiates interstitial Li activity and facilitate their easy mobility combining Density Functional Theory(DFT)and ab initio Molecular dynamics(AIMD)simulations.It is discovered that the interstitial Li ions introduced by Al dopants can effectively activate the neighboring occupied intrinsic Li-ions to induce a long-range mobility in the lattice and the maximum Li ionic conductivity is achieved at 0.50 Al doping concentration.The Li-ion migration paths in Li1+xAlxTi2-xP3O12have investigated as the degree of distortion of[PO4]tetrahedra and[TiO6]octahedra resulted by different Al doping concentrations.The asymmetry of the surrounding distorted[PO4]and[TiO6]polyhedrons play a critical role in reducing the migration barrier of Li ions in Li1+xAlxTi2-xP3O12.The flexible[Ti O6]polyhedrons with a capacity to accommodate the structural distortion govern the Li ionic conductivity in Li1+xAlxTi2-xP3O12.This work rationalizes the mechanism for the most optimum Li ionic conductivity in Al-doped Li Ti2P3O12electrolyte and,more importantly,paves a road for exploring novel all-solid-state lithium battery electrolytes.
目的:探析中华人民共和国成立前后商阳穴主治病症和配伍规律。方法:中华人民共和国成立前以《中华医典》(第5版)、《中国近代中医药期刊汇编》为主要检索源;中华人民共和国成立后以中国知网、中国生物医学文献数据库、维普期刊资源数据库、万方数据库、PubMed、Web of Science为主要检索源,建立SQL Server数据库,运用SPSS、SPSS Modeler、Gephi对主治病症和配伍腧穴进行统计分析。结果:中华人民共和国成立前纳入古籍51部,民国期刊1册,单穴主治病症33种,优势病症为龋齿、耳聋等14种,配伍主治病症37种,优势病症为热病、龋齿等15种,并总结出新处方15首,配伍腧穴141个,与少商、合谷关联性最强;中华人民共和国成立后纳入文献133篇,单穴主治病症12种,优势病症为便秘、呃逆、乳蛾,配伍主治病症55种,优势病症为乳蛾、喉痹等18种,并总结出新处方18首,配伍腧穴120个,与少商、合谷关联性最强。结论:商阳穴主治以脏腑病症、咽喉口齿病症为主,配伍规律遵循按经、特定穴配穴,即表里经、本经、五输、井原配穴,可为临床、科研提供借鉴。
As an ion conductor, the Al-doped Li1+xAlxGe2-x(PO4)3(LAGP) demonstrates the superionic Li diffusion behavior, however,without the convinced verifications. In this context, the density functional theory(DFT) calculations are employed to clarify the structural origin of the fast Li ion migration kinetics in LAGP solid electrolytes. The calculated results show that doping of Al leads to an emerging high-energy 36 f Li site, which plays an important role in promoting the Li diffusion and can largely lower the Li ion diffusion energy barrier. Moreover, the Li/Al antisite defect is investigated firstly, with which the Li ions are excited to occupy a relatively high energy site in LAGP. The obvious local structural distortion by Li/Al antisite results in the coordination change upon Li diffusion(lattice field distortion), which facilitates the Li diffusion significantly and is probably the main reason to account for the superionic diffusion phenomenon. Therefore, the occupation of Li at high-energy sites should be an effective method to establish the fast Li diffusion, which implies a rewarding avenue to build better Li-ion batteries.
