Japanese researchers have developed lithium-air batteries with an energy density of 500 Wh/kg

Lithium-air batteries (LABs) are one of many ways to improve current energy storage technology. These and other metal-air batteries are favored by researchers for their high energy density potential. However, there are also challenges in developing such technologies, such as low efficiency and short cycle life.

(Image source: NIMS)

Researchers at Japan's National Institute for Materials Science and Softbank have developed a rechargeable lithium-air battery. It is said that the energy density of this battery is far more than that of traditional lithium-ion batteries.

Like other LABs at the research level, the battery relies on lithium as the negative electrode and oxygen for the porous carbon positive electrode. The device contains 10 stacked cells in sizes 4 cm×5 cm, with electrodes of 2 cm × 2 cm in a single-layer cell. "In a stacked cell structure, oxygen needs to be transported horizontally in a gas diffusion layer," the researchers said. Oxygen then needs to be transported further vertically to pass through the entire positive section. ”

Operating at room temperature, the weight energy density of this battery is 500 Wh/kg, which is about twice that of current lithium-ion batteries. In terms of energy density and number of cycles, it performs very well.

The researchers note that there have been numerous reports that labs can successfully run more than 100 cycles, enabling long charge/discharge processes. However, at the actual cell level, it is estimated that its energy density is less than 50 Wh kg-1. This is because the electrolyte in the cell is excessive and/or the cell operates under conditions of considerablely small area capacity. In contrast, LABs with an energy density of more than 300 Wh kg-1 have fewer than 20 cycles.

According to reports, this newly developed storage device has a wide range of potential applications, including residential power storage systems, electric vehicles, drones and Internet of Things (IoT) devices.