Long-lifespan lithium–metal batteries obtained using a perovskite intercalation layer to stabilize the lithium electrode

Abstract

Because it has the highest specific capacity and lowest reduction potential among the elements, as well as a low density, lithium (Li) metal has been the most practical anode material for high energy density lithium-ion batteries. Nevertheless, Li plating and stripping can lead to the uncontrolled growth of mossy dendrites, resulting in poor coulombic efficiency and short-circuiting of the cells. Here, we demonstrate δ-CsPbI₃ as an electrochemical intercalation layer, fabricated through an inexpensive and facile spray-coating method, that stabilizes Li electrodes for Li–metal batteries. Experimental and density functional theory studies confirmed that Li⁺ ions can be intercalated electrochemically into δ-CsPbI₃ (forming Li:CsPbI₃), thereby increasing the conductivity and avoiding dendrite formation, resulting in improved ion migration, stabilized electrodeposition, and the maintained integrity of the solid–electrolyte interface. Electrochemical testing of a Li:CsPbI₃ symmetric cell revealed dendrite-free plating after 1000 h at a current density of 1 mA cm⁻² and discharge capacity of 1 mA h cm⁻². With an intercalation layer on a Li–metal anode, the Li–S full cell configuration displayed an initial specific capacity of 823 mA h g⁻¹ with a decay rate of approximately 0.035% per cycle and a coulombic efficiency of approximately 100% throughout 1000 cycles at a 1C rate. Using this new concept, we have obtained stable Li–metal anodes for high energy density batteries, potentially opening up new approaches for preparing safe Li–metal batteries.