Modifying an ultrathin insulating layer to suppress lithium dendrite formation within garnet solid electrolytes

Abstract

The ultrathin insulating LiF coating with controllable thickness is proposed as an interfacial layer for garnet electrolytes to inhibit the formation of Li dendrites, and promote uniform Li plating/stripping.

Isomeric Li–La–Zr–O Amorphous–Crystalline Composite Thin-Film Electrolytes for All-Solid-State Lithium Batteries

“…Crystalline LLZO thin films were normally annealed in the temperature range of 600–1000 °C, mostly exhibiting a conductivity of ∼10 –6 S cm –1 at room temperature . Very recently, high-conducting cubic LLZO-based thin films with a room-temperature conductivity of 10 –5 to 10 –4 S cm –1 was obtained by the pulsed laser deposition and radio frequency sputtering techniques. , Nevertheless, crystalline LLZO thin films contain grain boundaries which may retard the Li-ion transport and incur the penetration of Li dendrites. − In contrast, amorphous LLZO thin films have advantages of grain boundary-free and isotropic features, which can naturally suppress the formation and penetration of Li dendrites across the electrodes to cause a short circuit. In addition, the processing temperature (300–600 °C) and time (normally several minutes) for amorphous LLZO films are also much lower and lesser than that for crystalline films, demonstrating better adaptability for the large-scale production of ASSLBs at low cost.…”

Design of a lithiophilic and electron-blocking interlayer for dendrite-free lithium-metal solid-state batteries

“…According to the x-ray diffraction (XRD) analysis in fig. S1, the as-prepared LLZTO was successfully synthesized as a cubic phase garnet ( 31 ) without any noticeable impurities such as Li 2 CO 3 . For reference, the ionic and electronic conductivities of the pristine LLZTO were measured by the electrochemical impedance spectroscopy (EIS) spectra and direct-current (DC) polarization curves and were observed to be 0.45 mS cm −1 and 5.00 × 10 −9 S cm −1 at room temperature, respectively, consistent with previously reported values for garnet electrolytes (fig.…”

“…It was further demonstrated that the electronic conductivity of garnet-type electrolytes can surge when exposed to high applied potentials or temperature, showing the electric breakdown properties at certain threshold voltages ( 30 ) and temperature, implying the risk of electrical leakage through the solid electrolyte at fast charging/discharging or high-temperature operating conditions. The presence of the electron-conducting pathways inside the solid electrolyte suggests the feasibility of the lithium metal nucleation and growth preferentially along these paths, consequently incurring a risk of short circuit ( 31 , 32 ).…”

Halogenation of Li7La3Zr2O12 solid electrolytes: a combined solid-state NMR, computational and electrochemical study

“…5,7,9,28,29 In addition to optimising the Li-ion conductivity of lithium-rich garnets via cationic doping, considerable attention has been focused on overcoming the high interfacial resistance between the electrolyte and electrodes, as well as trying to eliminate dendrite inltration through the electrolyte. [30][31][32][33][34][35][36][37][38] It has been reported that the application of coatings to the garnet pellets (and consequently lithium alloying with the coating at the interface) and hybrid polymer-garnet electrolyte composite systems can mitigate these problems to a degree. [39][40][41][42][43][44][45][46][47][48][49] Short circuiting behaviour in the garnet system was also recently reported to be reversible, which can be healed by a low current density electrochemical process.…”