Processing Temperature Impact on TiNb2O7 Thick All Active Material Lithium-Ion Battery Electrodes

Abstract

Lithium-ion batteries have become a widespread energy storage technology, and research continues towards improving battery properties. One route to increase electrode areal active material loading and decrease relative volume fractions of inactive components is to increase electrode thickness, but increasing thickness can impact mechanical stability for conventional composite electrodes. All active material (AAM) electrodes, including those in this work, can mitigate mechanical and transport limitations for very thick lithium-ion electrodes. Such electrodes are free of polymer binders and conductive additives, and processed by pressing electroactive material powder into a porous pellet followed by mild sintering to improve mechanical properties. This study investigated the processing of a more recent material processed into AAM electrodes, TiNb2O7, which has relatively high volumetric capacity among reported materials processed into AAM electrodes. The anode material was characterized in AAM electrodes where different processing temperatures were used, resulting in different titanium and niobium containing phases being present. This manuscript provides insights and electrochemical consequences for fabricating AAM electrodes with multicomponent oxide phases.