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.