Enpower Greentech achieved a breakthrough in cylindrical batteries.
Enpower Greentech Inc. (a global solid-state battery developer based in the US with offices in Japan and China) has successfully developed a 4095 mAh cylindrical battery that delivers industry-leading energy densities of 389 Wh/kg and 888 Wh/L.
This development has led to a new energy density record in the class of 18650 cylinder rechargeable batteries. Enpower’s version, which is at least 20% lighter and contains at least 15% more energy than those currently on the market, will pave the way for lighter, more energy-efficient electronic devices including drones, electric vehicles, and electric cars, among others.
The 18650 cylindrical battery (refers to a battery size with a diameter of 18mm and a height of 65mm) is an industry standard for lithium-ion battery cells. It was invented and industrialized by SONY in 1991, where it was widely used in portable electronics.
In 2008, Tesla’s first all-electric sports car (the “Roadster”) powered by Panasonic 18650 cylindrical batteries was launched. This was the first use of the 18650 cylindrical batteries in the electric vehicle industry.
In September 2020, Tesla announced the 4680 large cylindrical battery during its Battery Day event, ushering in a new wave of cylindrical battery technology development in the EV industry.
Although SONY’s 18650 lithium-ion battery was a revolutionary product, its capacity was limited to 900 mAh (as shown in Figure 1A). Over the past 30 years, capacity has been gradually increased year after year, with Panasonic launching the 3450mAh 18650 battery in 2015.
Since then, the capacity of the 18650 battery has stagnated, while Korean and Chinese players have caught up and launched 3500mAh 18650 cylinder batteries. In 2021, the American start-up NanoGraf announced its own 18650 battery with a capacity of up to 3800 mAh (3.8 Ah) with a silicon-based anode.
This October, NanoGraf also announced an increased capacity of 4000 mAh (4.0 Ah). On the other hand, most developments in next-generation batteries (including lithium metal and solid-state batteries) have focused on the pouch cell format. In the case of cylindrical batteries, on the other hand, very little has happened in recent years.
Over the past three years, Enpower Greentech has successfully developed lithium metal pouch cells with record-breaking energy densities. Its record-breaking 18650 cylindrical battery utilizes its proprietary lithium metal anode technologies in the cylindrical batteries.
This increases the (nominal) voltage of the 18650 battery by 100-200mV, increases the capacity of the battery to 4095mAh (as shown in Figure 2) and reduces its weight by almost 20% compared to high-capacity 18650 products silicon-based anodes.
This significantly improves the gravimetric energy density of Enpower’s 18650 cell (Figure 1B). In addition, as shown in Table 1 (EGI LMB18650-4.1Ah), new milestones in cell capacity, (nominal) voltage and volumetric energy density have been achieved for 18650 batteries.
Among next-generation batteries using either silicon-rich anodes or a lithium-metal anode, most face the problem of cell swelling during charging and discharging. In order to perform at their best, they need external pressure.
Enpower’s 18650 cell shows the advantage of the cylindrical cell structure, in which the battery can provide stable cycle performance without external pressure.
The 18650 cylindrical lithium metal battery (LMB) developed by Enpower Greentech is currently in pilot testing. The company is seeking collaborators in diversified battery applications, including EV OEMs, to achieve commercialization through partnerships.
The company plans to use this breakthrough technology to develop ultra-high energy density in the 2170 and 4680 cylindrical batteries. The company expects a battery capacity of 32 Ah and an energy density of 400 Wh/kg in its 4680 cylindrical cell. (The current battery capacity of the Tesla 4680 is approx. 27.5 Ah and the energy density is approx. 300 Wh/kg) 4).
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Enpower Greentech achieves breakthrough in cylindrical batteries, SAN JOSE, California, November 3, 2022