Lithium-sulfur (Li-S)

History #

The concept of a lithium-sulfur (Li-S) battery was first proposed in the 1970s, but it wasn’t until the early 2000s that researchers began to explore the potential of this technology. The first Li-S cells were developed in the early 2000s by researchers at the University of Cambridge, and since then, the technology has been further developed and refined.

Typical Use #

Li-S batteries are primarily used in portable electronics, such as laptops, tablets, and smartphones. They are also used in electric vehicles, such as electric bicycles and electric cars. Li-S batteries are attractive for these applications because they offer a high energy density and long cycle life.

Design #

Li-S batteries are composed of a cathode, an anode, and an electrolyte. The cathode is typically composed of sulfur, while the anode is composed of lithium. The electrolyte is typically composed of a lithium salt, such as LiPF6, LiBF4, or LiClO4.

The cathode and anode are separated by a separator, which is typically composed of a polymer material. The separator is designed to prevent the cathode and anode from coming into contact with each other and shorting out the battery.

The cathode and anode are connected to the external circuit via current collectors. The current collectors are typically composed of a metal, such as copper or aluminum.

The electrolyte is typically composed of a lithium salt dissolved in an organic solvent, such as propylene carbonate or dimethyl carbonate. The electrolyte is designed to facilitate the transfer of ions between the cathode and anode.

The cell is then enclosed in a housing, which is typically composed of a metal, such as aluminum or stainless steel. The housing is designed to protect the cell from external environmental factors, such as temperature and humidity.

Charging #

When the Li-S battery is charged, lithium ions move from the anode to the cathode. This process is known as intercalation. During the charging process, the lithium ions are stored in the sulfur-based cathode material.

When the Li-S battery is discharged, the lithium ions move from the cathode to the anode. This process is known as deintercalation. During the discharging process, the lithium ions are released from the sulfur-based cathode material.

Safety #

Li-S batteries are generally considered to be safe, but they can be dangerous if they are not properly designed and manufactured. Li-S batteries can be prone to thermal runaway, which is a condition in which the battery temperature increases rapidly, leading to a fire or explosion. To prevent this, Li-S batteries must be designed with appropriate safety features, such as thermal management systems and overcharge protection.

Performance #

Li-S batteries offer a high energy density and long cycle life. The energy density of Li-S batteries is typically around 500 Wh/kg, which is significantly higher than other types of batteries, such as lead-acid and nickel-metal hydride. The cycle life of Li-S batteries is typically around 500-1000 cycles, which is significantly longer than other types of batteries.

Cost #

Li-S batteries are relatively expensive compared to other types of batteries. The cost of Li-S batteries is typically around $200-$300 per kWh, which is significantly higher than other types of batteries, such as lead-acid and nickel-metal hydride. The high cost of Li-S batteries is due to the expensive materials used in their construction, as well as the complex manufacturing process.