Publication date: 10th April 2024
All-solid-state batteries aim to overcome the limitations of traditional lithium-ion batteries by replacing liquid electrolytes with solid materials. This transition offers several advantages, including improved safety, as solid electrolytes are less prone to leakage and thermal runaway [1], [2] . Additionally, all-solid-state batteries have the potential to increase energy density and enable the use of lithium metal anodes, leading to longer battery life and faster charging times [1], [3].
LLZO, or Li7La3Zr2O12, is gaining traction as a solid electrolyte for its impressive ionic conductivity of up to 10-3 S/cm at room temperature, along with a wide electrochemical stability range [3]. This makes it a promising candidate for addressing challenges in solid-state lithium-ion battery development. Traditionally, good electrolytes have low electronic conductivity, but the landscape is changing with the emergence of composite electrodes that need both ionic and electronic conductivity [4].
To meet this demand, LLZO is being doped with transition metals like niobium and praseodymium. By intentionally adding cobalt (Co) and nickel (Ni) dopants to co-doped niobium (Nb) and praseodymium (Pr) LLZO, this study aims to understand how these additions affect LLZO's properties. Ultimately, the goal is to improve ion-electron conduction in modified solid electrolyte, witch would be one of component in composite electrodes.
In this work we study co-doped system of LLZO: Nb0.5 Pr1.0 Mx, where M={Co, Ni}, and x={0.0, 0.1, 0.2, 0.3}. All studied materials were obtained by the solid-state reaction. The crystal structure was confirmed by X-ray diffractometry and Raman spectroscopy. Impedance analysis was carried out on a symmetrical cell with gold electrodes in the room temperature. Electronic conductivity was determined using the Bruce-Vincent method.
Image shows dependance of the total conductivity and electrical conductivity on Pr3+, Ni2+ and Co4+ content in LLZO.
This work was conducted under support of National Science Centre, grant No. UMO-2019/33/B/ST5/02134