All-in-one lithium-sulfur battery enabled by a porous-dense-porous garnet architecture

Li-S batteries, while promising, face tremendous challenges due to the infinite volume change of the lithium anode, the constantly evolving solid-electrolyte interface, and the polysulfide shuttling effect. Herein we report a novel all-in-one cell design introduced by a porous-dense-porous trilayer garnet electrolyte. Both lithium anode and the sulfur cathode are infiltrated in the porous garnet framework, resulting in the first reported solid-state all-in-one battery. The interconnected 3D garnet electrolyte provides ion pathways throughout the whole cell while the conformal coating of carbon nanotubes and infiltrated lithium metal form continuous pathways for electrons. The all-in-one cell design has the following advantages: (1) continuous pathways for Li+ and electrons that lead to a lower resistance, (2) all-solid-state lithium metal anode eliminating the formation of an SEI, (3) seamless contact between the garnet and lithium metal introduced by a ZnO surface treatment that results in small interface resistance, (4) low local current density at an applied areal current density due to high contact area of the 3D porous structure, (5) locally confined volume changes for both anode and cathode, avoiding dead Li and dead S formation, (6) the use of a thin dense ceramic electrolyte as a separator enabled by the trilayer architecture, which is otherwise impossible due to inherent brittleness of thin film ceramics, (7) unique approaches for cell manufacturing and packaging made available by the all-in-one design, which bring about new opportunities. As a proof of concept, we demonstrated the all-in-one Li-S battery which completely eliminates lithium polysulfide shuttling and lithium dendrite penetration, leading to a high efficiency and safe operating battery system. With both lithium and sulfur infused in the porous layer of the solid-state electrolyte, the proposed Li-S battery achieves a high capacity of over 1200 mAh/gS and nearly 100% coulombic efficiency, demonstrating the advantages of the all-in-one design.