Partially crystalline Co3(HITP)2 modified Si anode endowing Si-air batteries with long discharge duration at high temperatures

In recent years, silicon has garnered attention as an anode material for air batteries due to its high energy density. However, a major challenge lies in the self-corrosion of the silicon anode during discharge, leading to inefficient silicon consumption. In this study, electronic conductive metal-organic frameworks, including partially crystalline Co₃(HITP)₂-1 and crystalline Co₃(HITP)₂-2 powders, were synthesized using a hydrothermal method to ameliorate anodes for silicon-air batteries for the first time. Notably, the Si@Co₃(HITP)₂-1 composite anode demonstrated the longest discharge duration of 476 h at 150 μA, outperforming all other samples. Both experimental results and theoretical calculations indicate that Co₃(HITP)₂ reduces the composite anode's adsorption capacity for H₂O and SiO₂, enhancing its self-corrosion reactions and passivation resistance. Compared with pristine silicon, the Si@Co₃(HITP)₂-1 composite anode extended the discharge time by approximately 18 h even at 50 °C. This pioneering research highlights the potential of an electronic conductive metal-organic framework in enhancing anode stability and extending battery life.