Lithium-sulfur batteries are a type of rechargeable battery that use lithium as the anode and sulfur as the cathode. They are known for their high energy density, which means they can store more energy in a smaller space compared to traditional lithium-ion batteries. This makes them a promising option for applications like electric vehicles and portable electronics. One of the main advantages of lithium-sulfur batteries is their potential for lower cost and environmental impact, as sulfur is abundant and inexpensive. However, challenges such as limited cycle life and efficiency need to be addressed for them to become widely used in the market.