Researchers at the Centre for Nano and Soft Matter Sciences (CeNS), an autonomous institution of the Department of Science and Technology (DST), have developed a sulphur vacancy induced 1T-phase Molybdenum Disulfide (MoS2) cathode for aqueous zinc-ion batteries (AZIBs). The multidisciplinary team led by Ganesh Mahendra, Rahuldeb Roy and Ashutosh Kumar Singh used a controlled hydrothermal synthesis to produce sulphur deficient 1T-MoS2 nanoflakes. The work aims to address key cathode limitations that have constrained large-scale adoption of zinc metal systems.

Aqueous zinc-ion batteries are identified as safe, cost effective and environmentally benign options for storing renewable energy, with zinc metal offering high theoretical capacity and abundant reserves. The 1T-phase MoS2 material exhibits metallic character with a high surface area and enhanced conductivity, properties that facilitate faster electrochemical reactions and improved charge storage. Sulphur vacancies are reported to increase active sites and ion transport pathways, thereby enhancing reversibility during cycling.

The team carried out a systematic optimisation of the electrochemical potential window and determined 0.2 to 1.3 volts versus Zn2+/Zn as the ideal operating range for stable performance. Within this window the fabricated device demonstrated exceptional cyclic stability, retaining 97.91 per cent of its initial capacity after 500 continuous charge discharge cycles at one ampere per gram, and a Coulombic efficiency of 99.7 per cent. These metrics are attributed to the combined effect of the metallic phase, high surface area and tailored vacancy chemistry that reduce side reactions and facilitate zinc ion insertion and extraction.

A coin cell prototype was used to power a commercial LCD timer, indicating practical applicability of the material in small devices and potential scalability for larger systems. The findings have been published in the journal Energy & Fuels by the American Chemical Society and are presented as a roadmap for designing high performance cathodes. The research is expected to support the development of affordable, safe and efficient batteries capable of storing large amounts of renewable energy on the grid.