Mixed Conductive Materials to Improve the Conductive Path of All-Solid-State Battery Composite Electrodes

Lithium-ion Batteries (LIBs) function as energy-storage devices in various electronic applications. However, the use of flammable liquid electrolytes raises significant safety concerns, including the risk of fire or explosion. To mitigate these safety issues, all-solid-state batteries (ASSBs) have emerged as a promising alternative as they are composed of solid electrolytes instead of liquid ones. Li 7 La 3 Zr 2 O 12 (LLZO) stand out as a highly promising garnet-type solid electrolyte, known for its chemically and electrochemically stable characteristics, making it suitable for ASSBs. However, LLZO suffers from high interfacial resistance, leading to decreased ion conductivity. In particular, the formation of voids during composite electrode fabrication interrupts ion conduction paths, resulting in a significantly increased resistance. Consequently, the high interfacial resistance arising from solid-state contacts can significantly impair the electrochemical performance and hinder practical cell operation. For these reasons, ASSBs typically use an excess of 10 wt.% or more solid electrolytes during electrode manufacturing, leading to a decrease in the active material fraction. Therefore, conducting research on electrode design aimed at optimizing the content of inactive components, such as the use of conductive additives and solid electrolytes, is necessary to improve the performance of ASSBs. In addition, novel approaches are needed to address the above-mentioned issues by reducing the interfacial resistance within composite electrodes containing solid electrolytes and maximizing electrochemical reactions. This study aims to improve the performance of ASSBs by incorporating carbon nanotubes (CNTs) as a conductive additive with the solid electrolyte LLZO to establish an efficient charge transport pathway and improve interfacial resistance. When using CNT@LLZO as a conductive additive, the internal voids within the electrode are minimized, and an effective Li-ion conduction pathway is formed, resulting in improved electrochemical performance. Further details will be presented in the meeting.