The lithium battery research activity driven in recent years has benefited the development of sodium-ion batteries. By maintaining a number of similarities with lithium-ion batteries, this type of energy storage has seen particularly rapid progress and promises to be a key advantage in their deployment.
2.1. The revival of room-temperature sodium-ion batteries Due to the abundant sodium (Na) reserves in the Earth’s crust (Fig. 5 (a)) and to the similar physicochemical properties of sodium and lithium, sodium-based electrochemical energy storage holds significant promise for large-scale energy storage and grid development.
Sodium-ion batteries are an emerging battery technology with promising cost, safety, sustainability and performance advantages over current commercialised lithium-ion batteries. Key advantages include the use of widely available and inexpensive raw materials and a rapidly scalable technology based around existing lithium-ion production methods.
But sodium-ion batteries could give lithium-ions a run for their money in stationary applications like renewable energy storage for homes and the grid or backup power for data centers, where cost is more important than size and energy density.
“From a physics perspective, sodium batteries inherently have lower energy density than lithium batteries.” A typical sodium-ion battery has an energy density of about 150 watt-hours per kilogram at the cell level, he said. Lithium-ion batteries can range from about 180 to nearly 300 watt-hours per kilogram.
For over three decades, lithium-ion batteries have dominated the energy storage sector, but the high demand for lithium is leading to potential shortages, price hikes, and supply bottlenecks. As a result, manufacturers are looking into other materials for batteries, and sodium is emerging as a promising candidate.