Formation of toroidal LiO in non-aqueous Li-O batteries with MoCT MXene/CNT composite.

Due to the growing demand for high energy density devices, Li-O batteries are considered as a next generation energy storage system. The battery performance is highly dependent on the LiO morphology, which arises from formation pathways such as the surface growth and the solution growth models. Thus, controlling the formation pathway is important in designing cathode materials. Herein for the first time, we controlled the LiO formation pathway by using MoCT MXene on a catalyst support. The cathode was fabricated by mixing the positively charged CNT/CTAB solution with the negatively charged MoCT solution. After introducing MoCT , important battery performance metrics were considerably enhanced. More importantly, the discharge product analysis showed that the functional groups on the surface of MoCT inhibit the adsorption of O on the cathode surface, resulting in the formation of toroidal LiO the solution growth model. It was supported by density functional theory (DFT) calculations that adsorption of O on the MoCT surface is implausible due to the large energy penalty for the O adsorption. Therefore, the introduction of MXene with abundant functional groups to the cathode surface can provide a cathode design strategy and can be considered as a universal method in generating toroidal LiO morphology.