Affiliation:
1. Technische Universität Berlin Faculty III Process Sciences Institute of Materials Science and Technology Chair of Advanced Ceramic Materials Straße des 17. Juni 135 10623 Berlin Germany
Abstract
AbstractThe development of magnesium ion batteries as a viable alternative to lithium–ion batteries is impeded by the lack of efficient and stable electrode materials. Here, we present the synthesis of nanocomposites of tin–containing silicon oxycarbonitride (Sn/SiOCN) as anode materials for magnesium ion batteries (MIBs). The elemental and phase composition, morphology, and surface area of the nanocomposites are assessed by several characterization techniques. The galvanostatic cycling tests indicate a substantial initial discharging capacity for the anode with 42.2 wt . % of tin. Specifically, the first discharging capacities are 489.9 mA/g, 172.9 mA/g, and 136.6 mA/g at current densities of 0.5 mA/g, 50 mA/g, and 500 mA/g, respectively. After 100 cycles at a current density of 500 mA/g, the anode containing 33.8 wt % of tin exhibits a reversible capacity of 101.8 mAh/g and a remarkable rate performance efficiency of 76.5 %. Increasing tin content in the electrode materials increases the battery performance by decreasing electrode impedance and thus facilitating Mg2+ diffusion, as revealed by electrochemical impedance spectroscopy (EIS). Ex situ XRD and X‐ray photoelectron spectroscopy (XPS) characterizations following the magnesiation–demagnesiation process confirm the storage of reversible storage of Mg2+ ions in Sn/SiOCN electrode through incorporation in the SiOCN network and alloying/dealloying process involving Mg−Mg2Sn−Mg.
Funder
China Scholarship Council