Fabrication of Sustainable Hybrid MOF/Silica Electrodes for Current Lithium-ion Batteries and Beyond

Natural abundance and well-explored synthesis of silica are among the main motivations for the impressive evolution of silicon-based electrodes occurring over the last few years. In this work, an effective strategy has been introduced for the realization of silica-based anodes for lithium-ion batteries (LIBs) starting from zeolitic imidazolate framework-67 (ZIF67)/mesopores silica (mSiO2), which has been employed as a precursor. This approach leads to the realization of a hybrid electrode formed by the combination of a carbon nanotube (CNT) grown on the nitrogen-doped graphene-like structure, ultrafine cobalt-based nanoparticles, and silica (SiO2/Co3O4/NGC/CNT). From an electrochemical point of view, the performance of this engineered hybrid silica-based electrode (EHSiE), formed by water and a cellulose-based binder, is evaluated in both LP30 and ether-based electrolyte environments, the latter being particularly attractive in the emerging field of sulfur-based batteries. The EHSiE electrode displays a remarkable stability for 1000 cycles with the high reversible capacity of ∼410 mA h g–1 at 5 A g–1 versus Li/Li+ in the LP30 electrolyte. Moreover, this electrode discloses a good electrochemical behavior when coupled with high mass loading LiFePO4 cathode to design a full LIB. More impressively, a systemic investigation reveals a remarkable compatibility of EHSiE with ether-based electrolytes, providing a specific discharge capacity of 300 mA h g–1 for 500 cycles at 1 A g–1. These results suggest that the engineered electrode can be successfully applied in the field of high-energy and environmentally sustainable lithium-based batteries.