The exponential demand for batteries worldwide drives technology advancements. As a result, making batteries that hold higher energy density has become the industry's collective aspiration. The US-based Enpower Greentech is reaching the goal with its lithium metal anode-based batteries, aiming to start production in 2023.
Founded in 2012 in California, Enpower has set up research and manufacturing centers in China and Japan. The company began to work with a research team led by Nobel Laureate John Goodenough in 2017 and has focused on lithium metal batteries since then. Goodenough is the inventor of lithium-ion batteries, which are widely used in consumer electronics and electric vehicles (EVs).
According to Enpower's cofounder and CTO Yong Che, the company has been developing lithium metal batteries based on semi- and all-solid-state electrolytes. With a pilot line built in Beijing, it will start customer validation for the semi-solid-state batteries later this year. If all things go well, it will realize product commercialization in 2023.
A battery that offers more power
Thanks to the surging EV adoption, battery manufacturers have raced to increase the energy density of their products. Che said a lithium-ion battery pack could take up 20 to 25% of an EV's weight. Much energy is consumed only for the car to carry the batteries. To increase the driving range, one must level up a battery's gravimetric energy density (Wh/Kg) and volumetric energy density (Wh/L).
Utilizing a lithium metal battery could be a reliable solution. The chemistry has a high theoretical capacity that can offer more power. On top of that, since lithium is the lightest metal, the battery would not create much energy waste.
The energy density increase also means battery materials are used more efficiently. Therefore, fewer materials are required. Che said the strategy could potentially lower the costs, helping the company handle the incoming challenge of material scarcity.
Enpower also tries to reduce the cell price by recycling batteries. The CTO said almost 100% of the lithium metal can be recovered easily. On the other hand, the graphite anodes or silicon-graphite anodes used in most lithium-ion batteries nowadays are not worth recycling, not to mention they require much more energy to produce.
Enpower developed the world’s lightest 100 Ah lithium metal battery with one cell weighing 0.821 kg. Credit: Enpower
Collaboration with Softbank helps Enpower grow
With years of effort in developing next-generation batteries, Enpower has achieved several breakthroughs. In March 2021, it successfully created a lithium metal battery with a high energy density of 450 Wh/kg. Seven months later, it raised the energy density again to 520 Wh/kg.
Che said the two battery advancements were driven by the need of Softbank, one of its major customers. Enpower was able to succeed because it developed core technologies to effectively prevent dendrites from forming on lithium metal's surface, a significant challenge for the battery's commercialization.
Enpower has collaborated with Softbank closely on the HAPS Mobile project. Initiated by Softbank, the project aims to develop solar-powered stratospheric drones to improve global telecommunications.
"When making a new battery, you need an early adopter. That's how we see the collaboration with Softbank. And it is a very good match for Enpower," Che said.
He added that the HAPS project requires ultra-high energy density batteries with long cycle lives so that the drones can fly longer and farther. The requirements push Enpower to constantly enhance its technologies, which is essential for a startup.
The company will begin product commercialization by manufacturing batteries for small, less cost-sensitive objects such as drones and IoT devices. Furthermore, Che said Enpower has been working with automotive OEMs, developing together the batteries carmakers want.
In July this year, the company announced it has developed the world's lightest 100 Ah lithium metal battery, a step closer to commercializing EV batteries. According to a press release, the weight of one cell is 0.821 kg, with a gravimetric energy density of 479Wh/kg and a volumetric energy density of 910Wh/L. In addition, the cell adopts Enpower's proprietary flame-retardant electrolyte solution, which enhances safety without compromising performance.
The US, Japan and China play important roles in realizing next-generation batteries
Enpower is in a good position to scale up its business later with a presence in the US, China and Japan. Che said effort made in the three countries and perhaps South Korea is vital for materializing next-generation batteries. In addition, China's role is critical with its abundant raw materials and fast-moving production ramp-up.
The CTO said Enpower hopes to utilize the scientific breakthroughs, advanced engineering and supply chains for mass production it has acquired in the above countries to grow the business in the long term.
Additionally, Enpower has secured US$35 million through Series A and Series A+ funding rounds completed in the first half of this year. The Series A+ was led by Sequoia China and Dayone Capital, with the participation of GAC Capital, BR Capital, Tianqi Capital and Niuli Venture.
Che said Enpower has already started conversations with companies for a Series B funding round, which aims for strategic investment. He added that Enpower is especially interested in working with companies that are visionary customers of the next-generation batteries. Still, it also looks forward to a partnership with automotive OEMs, Tier 1s, material suppliers, or equipment vendors.