New Chinese battery pouch packs three times more energy than a Tesla battery

The research from the Institute of Physics is a major step in this direction.

How Chinese researchers did it

The research team led by Li Hong and Xiqian Yu, professors at the National Research Center for Condensed Matter Physics in Beijing, developed a 10Ah-class soft-pack lithium secondary battery. The pouch was developed using an ultra-thin lithium metal anode and a manganese oxide-based cathode, which was also rich in lithium. The electrodes were tested by the China North Vehicle Research Institute.

Intending to increase the energy storage density, the team expanded the charge/discharge voltage range while keeping an eye on the structural capabilities of the cathode and the anode as lithium ions deposited on the electrodes and dissolved into the battery during the charging and discharging process.

Additionally, they also used diaphragm coating technology to resolve the reversibility issues with ultra-thin lithium on large surfaces while also exploring ways of how electrolytes could be made to function better in the setup.

Finally, the researchers were able to record an energy density of 711.30 Wh/kg and the volumetric energy density of 1,653.65 Wh/L, which is far higher than what commercially available battery packs offer today. To put it into context, the 4680 cells that Tesla plans to use in its upcoming models have an energy density of 244 Wh/kg.

The long road ahead

Interest in packing batteries with more energy has been propelling the technology forward since the time Sony showcased the commercial application of lithium-ion technology way back in 1991.

Research is no longer limited to academic labs when it comes to pushing technology of commercial importance. Chinese battery maker CATL demonstrated a 500Wh/kg battery pack only a few months ago.

It was Dalhousie University, though, that led the pack with a battery with an energy density of 575Wh/kg, a record that has been broken by a mile on this occasion. Nevertheless, the work is a long distance away from commercialization.

Among many other things, the battery pack's sole focus was maximizing energy density, and we really do not know what compromises were made to make this possible. From charging times to operating temperatures, lifespan to explosion risks, there is a long list of conditions that a new battery pack must tick before it can be deployed for commercial operations.

The researchers know this very well and agree that there is huge scope for improvement in their design. Nevertheless, a new record has been set for energy that can be stored in a battery and may just be the first step in our dream of achieving an all-electric long-haul flight.

The research was published in the Chinese Physics Letters.