Preparing Two‐Dimensional Ordered Li_0.33La_0.557TiO₃ Crystal in Interlayer Channel of Thin Laminar Inorganic Solid‐State Electrolyte towards Ultrafast Li⁺ Transfer

Abstract

Inorganic superionic conductor holds great promise for high-performance all-solid-state lithium batteries.H owever,t he ionic conductivity of traditional inorganic solid electrolytes (ISEs) is always unsatisfactory owingt ot he grain boundary resistance and large thickness.H ere,a13 mm-thick laminar framework with % 1.3 nm interlayer channels is fabricated by self-assembling rigid, hydrophilic vermiculite (Vr) nanosheets.T hen, Li 0.33 La 0.557 TiO 3 (LLTO)p recursors are impregnated in interlayer channels and afterwards in situ sintered to large-size,o riented, and defect-free LLTO crystal. We demonstrate that the confinement effect permits ordered arrangement of LLTO crystal along the c-axis (the fastest Li + transfer direction), permitting the resultant 15 mm-thick Vr-LLTO electrolyte an ionic conductivity of 8.22 10 À5 Scm À1 and conductance of 87.2 mS at 30 8 8C. These values are several times higher than that of traditional LLTO-based electrolytes. Moreover,Vr-LLTO electrolyte has acompressive modulus of 1.24 GPa. Excellent cycling performance is demonstrated with all-solid-state Li/LiFePO 4 battery.

Facile Synthesis of Two-Dimensional Natural Vermiculite Films for High-Performance Solid-State Electrolytes

“…As can be seen, the ionic conductivity of the IEVMT film increases from 0.023 to 0.310 S·cm −1 in the temperature range from 450 to 600 °C. The ionic conductivity of the IEVMT thin film demonstrates a great improvement on previous works, such as AO/10ScSZ films [ 40 ], Vr-LLTO/PEO [ 15 ], Vr-LLTO [ 17 ], etc. According to the Arrhenius equation, the activation energy ( E a ) of Li + ions in the IEVMT film is about 0.855 eV, which is very low for silicate and oxide materials, indicating that the migration of ions requires lower energy ( Figure 5 d) [ 40 , 48 ].…”

“…The transport channel for lithium ions becomes wider and the drag force is decreased. In addition, combined with the rigid framework of vermiculite nanosheet, the intrinsic resistance is dramatically reduced [ 7 , 17 ]. Therefore, the ionic conductivity of IEVMT films in the horizontal direction shows a great improvement.…”

“…The ionic conductivity of ceramic electrolytes is mainly restricted to their resistance and large thickness [ 5 , 17 ]. In recent years, grain resistance, interfacial resistance, and intrinsic resistance have been reduced by techniques, such as doping, framework, etc., and the performance of ceramic electrolytes is getting better [ 18 ].…”

“…Lv et al employed VMT as a framework and prepared large-size, oriented, and defect-free Vr-LLTO electrolytes. The resultant 15 μm thick Vr-LLTO electrolyte exhibited an ionic conductivity of 8.22 × 10 −4 S·cm −1 and a compressive modulus of 1.24 GPa [ 17 ]. In addition, the VMT owns natural framework and interlayer channels.…”

Robust and Manufacturable Lithium Lanthanum Titanate-Based Solid-State Electrolyte Thin Films Deposited in Open Air

“…Table S4 and Figure S9 shows a comparison of the processing time (h) and ion conduction (S/(cm m)) values of R-LLTO with SSE pellets, − inorganic thin films, ,− and organic–inorganic composites. − This comparison provides insight into the relationship between throughput and critical electrolyte performance. The time spent converting precursors to the final form of the SSE, either a pellet or a thin film, is referred to as processing time.…”