Two-Dimensional Hybrid Halide Perovskite as Electrode Materials for All-Solid-State Lithium Secondary Batteries Based on Sulfide Solid Electrolytes

An all-solid-state lithium secondary battery using two-dimensional hybrid halide perovskite (2D-HHP) (CH3(CH2)(2)NH3)(2)(CH3NH3)(2)Pb3Br10 as electrode materials and sulfide-based solid electrolyte is fabricated for the first time. Although large amounts of lithium-ion conductor have been mixed in the electrodes of the all-solid-state batteries based on sulfide solid electrolytes, the high lithium-ion coefficient of the 2D-HHP, around 10(-7) cm(2) s(-1), allowed the suitable operation of the batteries without the addition of any lithium-ion conductors into the electrodes. The lithium-ion diffusion in the electrode improves with the temperature, showing a better performance at 100 degrees C and keeping a low resistance between electrode/electrolyte interface of 13 Omega. The all-solid-state battery retains a reversible capacity of more than 242 mAh g(-1) for 30 cycles at 0.13 mA cm(-2) with a negligible capacity fade. The mechanism of the lithium storage into the 2D-HHP electrode material based on ex-situ XRD measurements at different stages of the discharge-charge processes is suggested, consisting of a three-step reaction: Li+ insertion/extraction, conversion, and alloying-dealloying reactions.