Defect-Rich MoO3 Nanobelts for ultrafast and wide-temperature proton battery

Protons (H+) are considered as ideal charge carries for rechargeable batteries because of the small size, high ionic mobility and wide availability. In this work, MoO3 nanobelts with rich defects are prepared by simple hydrothermal treatment of MoO3 nanoparticles and are demonstrated as high-performance electrode materials for proton battery. Benefiting from the nanobelt morphology, abundant oxygen vacancy, large interlayer spacing, improved conductivity and fast ion transfer, the MoO3 nanobelts electrode delivers a state-of-the-art capacity of 285.3 mAh g−1 at the current density of 1.0 A g−1, and ∼75% of the initial capacity is retained at 50.0 A g−1. It is found that the MoO3 nanobelts electrode can still maintain its original capacity, nanobelt morphology and crystal structure even after 23,000 cycles. Notably, the electrode delivers a high areal capacity of 3.48 mAh cm−2 at a high mass loading of 16.0 mg cm−2. The proton battery assembled with MoO3 nanobelts anode and N-doped active carbon cathode shows the maximum energy density of 46.2 Wh kg−1 at the power density of 800.3 W kg−1. The proton battery shows satisfactory proton storage properties at a wide temperature range of -25 °C ∼ 65 °C. This study provides insights into the design of ultrafast and wide-temperature proton battery for practical applications.