Understanding the correlations between lattice dynamics(phonons) and ion transport is important for improving the ionic conductivity of solid-state electrolytes. This understanding largely hinges on selective tuning o...Understanding the correlations between lattice dynamics(phonons) and ion transport is important for improving the ionic conductivity of solid-state electrolytes. This understanding largely hinges on selective tuning or excitation of specific phonon modes without changing the chemical environments of atoms, which is, however, challenging to be achieved. In this work, we used ~6Li isotope substitution to selectively change the phonon properties associated with lithium, without introducing additional defects or disorders which would affect the ion transport properties. The changes in the phonon modes were then related to ion transport properties through impedance measurements and deep potential molecular dynamics simulations. Our results demonstrated that lower lithium vibration frequency leads to higher ionic conductivity and lower activation energy in the garnet solid-state electrolyte of Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12). We furthermore quantified the effect of lithium-related phonons on the migration entropy and attempt frequency, which would be difficult to be achieved otherwise. Our work suggests an effective isotope substitution method to decouple the effect of phonon modes to ion transport from that of other complex structural factors. The obtained insights can contribute to innovative understanding of ion transport in solids and strategies to optimize the ionic conductivity of solid-state electrolytes.展开更多
In accordance with the Paris Agreement,China has committed to reach the peak of carbon dioxide emissions and achieve carbon neutrality by 2030 and 2060,respectively.This places rechargeable batteries to the central st...In accordance with the Paris Agreement,China has committed to reach the peak of carbon dioxide emissions and achieve carbon neutrality by 2030 and 2060,respectively.This places rechargeable batteries to the central stage because they are at the core of renewable energy technologies such as electric vehicles and large-scale energy storage systems.On one hand,some emerging applications(such as power electric aircrafts and trucks)demand very high energy density.For this,we must solve both energy density and safety problems.Solid-state lithium batteries are the way to go[1].展开更多
基金supported by the National Natural Science Foundation of China(22222204).
文摘Understanding the correlations between lattice dynamics(phonons) and ion transport is important for improving the ionic conductivity of solid-state electrolytes. This understanding largely hinges on selective tuning or excitation of specific phonon modes without changing the chemical environments of atoms, which is, however, challenging to be achieved. In this work, we used ~6Li isotope substitution to selectively change the phonon properties associated with lithium, without introducing additional defects or disorders which would affect the ion transport properties. The changes in the phonon modes were then related to ion transport properties through impedance measurements and deep potential molecular dynamics simulations. Our results demonstrated that lower lithium vibration frequency leads to higher ionic conductivity and lower activation energy in the garnet solid-state electrolyte of Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12). We furthermore quantified the effect of lithium-related phonons on the migration entropy and attempt frequency, which would be difficult to be achieved otherwise. Our work suggests an effective isotope substitution method to decouple the effect of phonon modes to ion transport from that of other complex structural factors. The obtained insights can contribute to innovative understanding of ion transport in solids and strategies to optimize the ionic conductivity of solid-state electrolytes.
基金financially supported by the National Natural Science Foundation of China(51902201)。
文摘In accordance with the Paris Agreement,China has committed to reach the peak of carbon dioxide emissions and achieve carbon neutrality by 2030 and 2060,respectively.This places rechargeable batteries to the central stage because they are at the core of renewable energy technologies such as electric vehicles and large-scale energy storage systems.On one hand,some emerging applications(such as power electric aircrafts and trucks)demand very high energy density.For this,we must solve both energy density and safety problems.Solid-state lithium batteries are the way to go[1].
