Cutting-edge approaches for customizing sulfur cathode materials in sodium–sulfur batteries operating at ambient temperature

Abstract

The demand for renewable energy sources is continuously rising, making highly efficient and reliable energy storage devices essential for delivering a stable and sustainable energy supply. Existing lithium-ion batteries (LIBs) suffer from limited and uneven geological distribution of raw materials, environmental and safety concerns and the expensive recycling of battery components. In this regard, the room-temperature sodium–sulfur (RT Na–S) battery is emerging as a promising option for future energy storage systems in stationary and grid-scale applications. This is attributed to its significant theoretical capacity (1675 mA h g⁻¹) and high energy density (∼1276 W h kg⁻¹), combined with the low cost and widespread availability of its active materials in nature. However, RT Na–S batteries suffer from serious challenges, such as dendrite formation at the anode, low sulfur conductivity, volume expansion, and the shuttle effect, all of which hinder their overall efficiency and practical application. In this review article, we first summarise the working principle of the RT Na–S battery, followed by an exploration of the challenges associated with the further progression of Na–S battery technology, with special emphasis on the development of modern cathode materials. This review highlights novel approaches for developing sulfur cathodes, such as the inclusion of metal-based electrocatalysts, unique architectures, and multifunctional/hybrid cathodes. Finally, the discussion focuses on the role of these novel approaches in designing customized sulfur cathodes to enhance the overall performance of RT Na–S batteries.