Predicting Li-Rich Layered Oxide Compounds as High-Conductivity and Stable Solid Electrolytes

Abstract

The search for new solid-state electrolytes (SSEs) with fast ionic conductivity and high electrochemical stability is one of most challenging issues for developing all-solid-state batteries. Most SSEs have specific ionic transport channels with the crystal structures of perovskite, NASICON, LISICON, and garnet. In this work, we predicted Li-rich layered Li3NbO4-type compounds as high-rate and stable SSEs. First-principles calculations show that the predicted Li3NbO4 compound has peculiar stacked structures of edge-shared [LiO5] and [NbO5] hexahedrons and exhibits higher thermodynamic stability than the experimentally synthesized compound with an octahedral stacked structure at <495 K. Its intralayer Li+ conductivity along the hexahedron–octahedron–hexahedron (h-o-h) path has a low energy barrier and low ionic conductivity. We further predicted Li2Mg0.5NbO4 as an SSE with a low ionic migration barrier of 0.33 eV, which is comparable with those of most other oxide SSEs. Therefore, the present study opens a new avenue to design high-performance SSEs in crystal space of layered rocksalt.

A novel phase of superionic conductor β′-Na3PS4 with a large band gap and a low migration barrier

“…Two crystals of NPS with relatively low energy, namely α -NPS and β ′-NPS, were obtained by using the global particle swarm optimization. 32,33 We confirm the existence of the synthesized phase of tetragonal α -NPS (Fig. 1a).…”

Advances in Solid-State Batteries, a Virtual Issue, Part II

“…To overcome the space limitations of electric vehicles (EVs) and achieve a driving range of over 500 km, solid-state electrolytes have high expectations over organic electrolytes to vastly improve the EVs (Figure ). One of the most significant components in an SSB is the solid-state electrolyte, which has made great advances, especially polymer electrolytes, − metal sulfide electrolytes (i.e., Na 4 P 2 S 6 , Li 6.5 Sb 0.5 Ge 0.5 S 5 I), garnet-type electrolytes, halide electrolytes, and even Li-rich layered oxide compounds . Garnet-type solid electrolytes are promising solid electrolyte candidates due to the high ionic conductivity and stability with elemental Li .…”

“…2 One of the most significant components in an SSB is the solid-state electrolyte, which has made great advances, especially polymer electrolytes, 3−5 metal sulfide electrolytes 6 (i.e., Na 4 P 2 S 6 , 7 Li 6.5 Sb 0.5 Ge 0.5 S 5 I 8 ), garnettype electrolytes, 9 halide electrolytes, 10 and even Li-rich layered oxide compounds. 11 Garnet-type solid electrolytes are promising solid electrolyte candidates due to the high ionic conductivity and stability with elemental Li. 12 However, lithium dendrite growth and high electrolyte-Li metal interfacial resistance in the garnet-type solid electrolytes are the major bottlenecks in the solid-state Li batteries.…”

A Robust Li-Intercalated Interlayer with Strong Electron Withdrawing Ability Enables Durable and High-Rate Li Metal Anode

“…The much suppressed Li precipitation on Nb 2 O 5 @CP under a high current density demonstrates the high-rate ability of the lithiated Nb 2 O 5 layer. As predicted by Qiu et al, the Li 3 NbO 4 compound has peculiar stacked structures of edge-shared [LiO 5 ] and [NbO 5 ] hexahedrons, and its intralayer Li + conductivity along the hexahedron–octahedron–hexahedron ( h-o-h ) path has a low energy barrier and high ionic conductivity . Hence, the Li-rich layered Li x Nb y O z -type compounds show great high-rate ability, which contributes to the stable cycling of Li plating/stripping in the Nb 2 O 5 @CP host under high current-density conditions as shown later in this work.…”