A metal organic framework-derived octahedral Cu 1.95 S@CoS 2 for secondary batteries displaying long cycle life and stable temperature tolerance.

Low-cost and safe batteries are considered to be promising energy-storage systems. Here, a metal organic framework (MOF)-derived octahedral Cu 1.95 S@CoS 2 composite is developed as a high-performance cathode of aluminium-ion (Al-ion) batteries. CoS 2 nanoparticles on Cu 1.95 S provide active sites, making AlCl 4 - intercalation/deintercalation highly reversible, and reducing polarization. Cycling at 0.5 A g -1 , Cu 1.95 S@CoS 2 maintains stable capacities of 136.6 and 122.4 mA h g -1 after 200 cycles at room temperature and -10 °C, respectively. Stable rate-performance is also achieved. These findings will accelerate the application of Al-ion batteries and MOF-derived energy-storage composites.