Betavoltaic rechargeable Zn-ion battery based on hybrid cathode by combining betavoltaic structure with intercalation host

To address the issue of low power output of betavoltaic cells in practical applications, a Ni-63-powered betavoltaic rechargeable Zn-ion battery (BRZiB) is presented in this paper for simultaneously harvesting, converting, and storing beta-radioactive energy within one device. Experimentally, a patterned ZnO microrod array nanostructure was prepared using hydrothermal and lithography methods, in which a Ni-63 beta source was deposited by chemical plating to form a Ni-63@ZnO structure for betavoltaic power generation. A carbon-coated VO2 nanocomposite (C@VO2), used as the intercalation host for Zn ions, was coated on the betavoltaic structure for fabricating the hybrid cathode of BRZiB. Without using any external power source, the Ni-63-powered BRZiB demonstrated a voltage rise of 0.3 V in 82 h, which was calculated to have an energy conversion efficiency of 5.1% and an energy density of 128 mWh/g over a half-life of Ni-63 (similar to 100 years). The experimental results verify the effectiveness of multi-energy synergistic conversion in the electrochemical betavoltaic system.