Enpower Greentech Launches Lightweight, High Energy Density Lithium Metal Batteries

Dr. Yong Che, co-founder and CTO of Enpower Greentech. Credit: Enpower

The exponential demand for batteries worldwide is driving technological advancements. As a result, making batteries with higher energy density has become the industry’s collective aspiration. US company Enpower Greentech is hitting the target with its batteries based on lithium metal anodes, aiming to start production in 2023.

Founded in 2012 in California, Enpower has established research and manufacturing centers in China and Japan. The company began working with a research team led by Nobel Laureate John Goodenough in 2017 and has since focused on lithium metal batteries. Goodenough is the inventor of lithium-ion batteries, which are widely used in consumer electronics and electric vehicles (EVs).

According to Enpower co-founder and CTO Yong Che, the company has developed lithium metal batteries based on semi-solid and full-solid electrolytes. With a pilot line built in Beijing, it will begin customer validation for semi-solid batteries later this year. If all goes well, it will market the product in 2023.

A battery that offers more power

With the growing adoption of electric vehicles, battery manufacturers have been racing to increase the energy density of their products. Che said a lithium-ion battery can take 20-25% of an electric vehicle’s weight. A lot of energy is consumed just for the car to carry the batteries. To increase the autonomy, it is necessary to level the gravimetric energy density (Wh/Kg) and the volumetric energy density (Wh/L) of a battery.

Using a lithium metal battery could be a reliable solution. The chemistry has a high theoretical capacity which can offer more power. Also, since lithium is the lightest metal, the battery would not create much energy waste.

The increased energy density also means that battery materials are used more efficiently. Therefore, fewer materials are needed. Che said the strategy could potentially reduce costs, helping the company meet the incoming challenge of material scarcity.

Enpower is also trying to reduce the price of cells by recycling batteries. The CTO said nearly 100% of lithium metal can be recovered easily. On the other hand, the graphite anodes or silicon-graphite anodes used in most lithium-ion batteries these days are not worth recycling, not to mention that they require a lot more energy to be produced.

Enpower has developed the world’s lightest 100 Ah lithium metal battery with a cell weighing 0.821 kg. Credit: Enpower

Collaboration with Softbank helps Enpower grow

After years of efforts in the development of next-generation batteries, Enpower has achieved several breakthroughs. In March 2021, it successfully created a 450Wh/kg high energy density lithium metal battery. Seven months later, he again raised the energy density to 520 Wh/kg.

Che said the two battery advances were driven by the needs of Softbank, one of his main customers. Enpower was able to succeed because it developed core technologies to effectively prevent the formation of dendrites on the surface of lithium metal, a significant challenge for battery commercialization.

Enpower worked closely with Softbank on the HAPS Mobile project. Initiated by Softbank, the project aims to develop solar-powered stratospheric drones to improve global telecommunications.

“When you make a new battery, you need an early adopter. That’s how we see the collaboration with Softbank. And that’s a really good match for Enpower,” Che said.

He added that the HAPS project requires very high energy density batteries with a long lifespan so the drones can fly longer and farther. The requirements push Enpower to constantly improve its technologies, which is essential for a startup.

The company will begin commercializing the product by manufacturing batteries for smaller, less cost-sensitive objects such as drones and IoT devices. In addition, Che said Enpower works with automotive OEMs, together developing the batteries the automakers want.

In July this year, the company announced that it had developed the world’s lightest 100Ah lithium metal battery, a step closer to bringing batteries to market for electric vehicles. According to a press release, the weight of a cell is 0.821 kg, with a gravimetric energy density of 479 Wh/kg and a volumetric energy density of 910 Wh/L. In addition, the cell adopts Enpower’s proprietary flame retardant electrolyte solution, which improves safety without compromising performance.

The United States, Japan and China play an important role in the realization of next-generation batteries

Enpower is in a good position to expand its business later with a presence in the United States, China and Japan. Che said efforts in the three countries and possibly South Korea are vital to materializing next-generation batteries. Moreover, the role of China is essential with its abundant raw materials and its rapid rise in production.

The CTO said Enpower hopes to use the scientific breakthroughs, cutting-edge engineering and mass production supply chains it has acquired in the above countries to grow the business in the long term.

Additionally, Enpower secured US$35 million through Series A and Series A+ funding rounds completed in the first half of this year. Series A+ was led by Sequoia China and Dayone Capital, with participation from GAC Capital, BR Capital, Tianqi Capital and Niuli Venture.

Che said Enpower has already entered into conversations with companies for a Series B funding round, which is aimed at strategic investment. He added that Enpower is particularly interested in working with companies that are visionary next-generation battery customers. However, he also looks forward to a partnership with automotive OEMs, Tier 1s, material suppliers or equipment vendors.