A metal organic framework-derived octahedral Cu1.95S@CoS2 for secondary batteries displaying long cycle life and stable temperature tolerance

Abstract

Low-cost and safe batteries are considered to be promising energy-storage systems. Here, a metal organic framework (MOF)-derived octahedral Cu_1.95S@CoS₂ composite is developed as a high-performance cathode of aluminium-ion (Al-ion) batteries. CoS₂ nanoparticles on Cu_1.95S provide active sites, making AlCl₄⁻ intercalation/deintercalation highly reversible, and reducing polarization. Cycling at 0.5 A g⁻¹, Cu_1.95S@CoS₂ 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.