Novel “sandwich” configuration with ALD-coating layers on electrode/electrolyte interfaces for durable all-solid-state lithium metal batteries with high-voltage cathodes

Compositing inorganic ceramics and polymer materials to form all-solid-state electrolytes has been recognized as a feasible approach for the development of all-solid-state batteries. However, polymer-based electrolytes such as polyethylene oxide can electrochemically decompose above 3.9 V (vs . Li+/Li), which results in undesirable battery performance. Moreover, dendrite growth can occur on the anode side and further lead to battery short-circuit. This work designs and successfully fabricates stable electrode/electrolyte interfaces on both the composite cathode and anode sides after employing alucone coating layers made through atomic layer deposition. Due to the protection capability of such coating layers, the electrochemical degradation between the composite solid-state electrolytes of Li7La3Zr2O12/polyethylene oxide/lithium bis(trifluoromethane-sulfonyl) imide film and nickel-rich high voltage cathode (LiNi0.8Mn0.1Co0.1O2) has been obviously suppressed through the significantly improved anti-oxidation capability of the electrolyte. Simultaneously, the alucone coating layer can function as the protective barrier for the lithium metal anode, remarkably suppressing the growth of lithium dendrites. As a result, the obtained all-solid-state batteries with dual electrode/electrolyte interfaces show both high capacity retention and long cycle life, whereas the contrasting battery without protection coating layers shows both the fast capacity decay and micro-shorting behavior. This work presents an effective strategy for constructing more stable electrode/electrolyte interfaces for polymers-based all-solid-state batteries, and also provides a design rationale for materials and structure development in the field of energy storage and conversion.