Cathode electrode architecture with facile ion percolating network assuring interfacial integrity for high-performance solid-state batteries

Abstract

Although solid-state batteries (SSBs) are promising next-generation energy-storage devices owing to their high safety and energy density, their wide application is hindered by critical issues such as poor power density and rapid performance degradation. These issues are related to the limit of electronic and lithium percolation networks with imperfect solid-solid interfacial contact. This study develops an optimal strategy to facilitate an iontransport network by designing a simple core-shell-like cathode covered by an inorganic solid electrolyte (garnet-type Li6.25Ga0.25La3Zr2O12) for polymer-based SSBs, ensuring the high capacity, high rate capability, and long-term cycle stability even in practical pouch cell at room temperature. Encapsulated cathode electrode architecture via a simple dry-coating strategy provides a percolating network for facile ionic conduction, assuring the homogeneous reaction in the cathode electrode. It alleviates not only the mechanical degradation of the cathode electrode but also the subsequent crosstalk effect on the anode-solid electrolyte interface. Our study highlights that the design of the cathode architecture considering the ion-conducting network is crucial to secure the high performance of polymer-based SSBs by maintaining the interfaces intact with solid electrolytes in both the cathode and anode interfaces.