1 research outputs found
Engineered Li<sub>7</sub>La<sub>3</sub>Zr<sub>2</sub>O<sub>12</sub> (LLZO) for Pseudo-Solid-State Lithium Metal Batteries (SSLMBs): Tailor-Made Synthesis, Evolution of the Microstructure, Suppression of Dendritic Growth, and Enhanced Electrochemical Performance
Morphologically engineered Li7La3Zr2O12 (LLZO) impregnated with a common solvated
ionic liquid
(SIL) can greatly influence the cycling performance (360 cycles),
coulombic efficiency (>99%), and high rate capability (0.05–1.2
mA·cm–2) of pseudo-solid-state lithium metal
batteries (SSLMBs). In this report, to obtain a unique microstructure
of cubic-LLZO, a fine-tuned combustion synthesis process was first
designed; synthetic parameters were duly optimized, and powders were
characterized by X-ray diffraction (XRD), field emission scanning
electron microscopy (FESEM), Fourier transform infrared spectroscopy
(FTIR), 1H NMR, and Raman spectroscopy. An in-depth analysis
of powder properties and electrochemical behavior of the fabricated
SSLM cells revealed that impurities present in LLZO significantly
facilitated electrochemical cell performances. Such a combination
of the engineered LLZO impregnated with the SIL enabled the plating
and stripping cycles in Li symmetric cells with up to 200 h of operation
at a constant current density of 0.05 mA·cm–2 avoiding short circuit. The critical current density (CCD) was found
to be 450 μA cm–2, which is significantly
higher than the other reported CCD values for pristine LLZO. The post-electrochemical
study revealed that transgranular lithium dendritic growth, a genuine
problem in SSLMBs, was impeded to a significant extent by the engineered
LLZO and an in situ formed phase, Li0.5Al0.5La2O4, at grain boundaries during cycling.
The multicathode compatibility tests as performed (Li/LLZO-SIL/LMO,
Li/LLZO-SIL/LFP, and Li/LLZO-SIL/NMC111) exhibited that morphologically
altered LLZO with the SIL interface is compatible with most of the
commercial cathodes. The study thus envisaged that the engineered
LLZO solid electrolyte impregnated with the SIL can exert a synergistic
effect to enhance faster Li-ion conduction as well as resistance to
Li dendritic growth, providing a path for developing high-performance
SSLMBs