Stable Supercapacity of Binder-Free TiO2(B) Epitaxial Electrodes for All-Solid-State Nanobatteries

Owing to its pseudocapacitive, unidimensional, rapid ion channels, TiO2(B) is a promising material for application to battery electrodes. In this study, we align these channels by epitaxially growing TiO2(B) films with the assistance of an isostructural VO2(B) template layer. In a liquid electrolyte, binder-free TiO2(B) epitaxial electrodes exhibit a supercapacity near the theoretical value of 335 mA h g-1 and an excellent charge-discharge reproducibility for ≥200 cycles, which outperform those of other TiO2(B) nanostructures. For the all-solid-state configuration employing the LiPON solid electrolyte, excellent stability persists. Our findings suggest excellent potential for miniaturizing all-solid-state nanobatteries in self-powered integrated circuits.

Engineering High-Performance MoO2 -Based Nanomaterials with Supercapacity and Superhydrophobicity by Tuning the Raw Materials Source

Herein, a simple self-assembly method is proposed for the fabrication of MoO₂ -based superhydrophobic material with record high contact angles (contact angle up to about 173°) for conductive metal oxides on hard/soft substrates. The spin-coated surface demonstrates excellent oil-water separation efficiency (>98%) after 50 cycles and robust corrosion resistance after immersion into different pH solutions for 20 d. These water-resistant coatings retain excellent superhydrophobicity after oil immersion, knife-scratch, and long-cycle sandpaper abrasion, which is not observed on most artificial surfaces. Meanwhile, the functionality switching from superhydrophobicity to supercapacity, which have an inverse relationship in aqueous solutions because of poor electrode wettability, is achieved simply by editing the raw materials source. Tuning of the raw materials leads to the same product MoO₂ /graphitic carbon with different morphologies and functionalities. Different from superhydrophobic MoO₂ /carbon ball flowers, MoO₂ nanotubes with carbon exhibit excellent supercapacity with a large gravimetric capacitance and great cycling stability.