Synthesis of metal oxide nanocomposites from self-assembled block copolymer templates as cathode materials for all-solid-state lithium batteries

Abstract

Self-assembled structures are useful for fabrication of nanostructures as a sustainable process with minimum energy consumption. Alternately stacked layers on a nanometre scale are produced by adsorption process denoted as layer by layer process, however, shape is limited in layers and chemical composition is also limited. Superlattice structures are produced by sputtering or self-assembly process using nanoparticles. But the construction of three-dimensional ordered inorganic nanocomposite structures remains a great challenge. All-solid-state lithium batteries (LiBs) are attracting much attention as innovative devices for upsized safety secondary batteries with high energy density. However, bulk-type all-solid-state LiBs face a number of hurdles, particularly the construction of an electrochemically favourable interface between the solid Li electrolytes and the active materials. In this study, we synthesised inorganic nanocomposite cathode materials by using self-assembled block copolymers (BCPs) as templates; this nanocomposite was composed of Li0.5La0.5TiO3 (LLT) as the electrolyte and LiCoO2 (LCO) as the cathode active material. Several LCO/LLT ratios were examined with the goal of producing a nanocomposite for use in all-solid-state LiBs. This nanostructured material, with the electrochemically favourable interface between electrode and electrolyte, resulted in a high capacity even at a high LCO content. The process we used to prepare the nanocomposite is expected to be versatile for producing other highly functional devices, such as quantum dot solar cells, thermoelectrics, and solid oxide fuel cells.