Abstract
The realization of large powerful all-solid-state batteries is still hampered by the availability of environmentally friendly and low-cost Li ion conductors that can easily be produced on a large scale and with high reproducibility. Advanced solid electrolytes benefit from fast ion-selective transport and non-flammability, but they may have low electrochemical stability with respect to Li metal. Sol-gel-synthesized lithium titanium aluminum phosphate Li(1.5)Al(0.5)Ti(1.5)(PO4)3 (LATP), which was prepared via a new synthesis route taking advantage of an annealing step at relatively low temperatures, has the potential to become one of the major players in this field although it may suffer from reduction upon direct contact with metallic lithium. Its ion dynamics is, however, as yet poorly understood. In the present study, (7)Li nuclear magnetic resonance (NMR) spectroscopy was used to monitor the key Li jump processes on the atomic scale. NMR relaxation clearly reveals heterogeneous dynamics comprising distinct ultra-fast and slower diffusion processes. The high Li ion self-diffusion coefficients deduced originate from a rapid Li exchange with activation energies as low as 0.16 eV which means that sol-gel synthesized LATP is superior to other solid electrolytes. Our NMR results fully support recent theoretical investigations on the underlying diffusion mechanism, indicating that to rapidly jump from site to site, the ions use interstitial sites connected by low-energy barriers in LATP.
Highlights
The realization of large powerful all-solid-state batteries is still hampered by the availability of environmentally friendly and low-cost Li ion conductors that can be produced on a large scale and with high reproducibility
Sol–gel-synthesized lithium titanium aluminum phosphate Li1.5Al0.5Ti1.5(PO4)[3] (LATP), which was prepared via a new synthesis route taking advantage of an annealing step at relatively low temperatures, has the potential to become one of the major players in this field it may suffer from reduction upon direct contact with metallic lithium
The high Li ion self-diffusion coefficients deduced originate from a rapid Li exchange with activation energies as low as 0.16 eV which means that sol–gel synthesized LATP is superior to other solid electrolytes
Summary
In particular, Li metal batteries with high energy densities.[1,2,3,4,5,6,7] Considering the conventional lithium-ion battery technology, great effort has been devoted to enhancing power, capacity, lifetime, and safety. The very low activation energies deduced (0.16 eV), which we reliably assigned to Li ion translational motion, are in excellent agreement with those recently predicted theoretically.[39] The superposition of several diffusion processes gradually activated with increasing temperature results in an overall Li diffusivity that is in between those of Al-stabilized garnet oxides[21,23,24] and argyrodite-type sulfides.[40,41] The latter, together with the various compounds of the Li10GeP2S12 group,[16,18] represent the fastest ion conductors studied over the past few years.[18,42] While sulfides are highly hygroscopic, garnet oxides may suffer from reproducibility problems with respect to purity, composition and morphology because of the higher annealing temperatures needed. LATP-based electrolytes might be advantageous in terms of preparation and device fabrication
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
