A Leap Forward in Lithium-Ion Battery Energy Density
Recently, Chinese researchers developed a lithium-ion battery with an astonishing energy density of about 700 Wh/kg. While today’s lithium batteries struggle to achieve an energy density of 300 Wh/kg, this breakthrough has the potential to revolutionize battery technology in the future, particularly for long-range electric vehicles and electric aviation.
The research team from the Chinese Academy of Sciences’ Institute of Physics in Beijing used a lithium metal anode and an ultra-thick high discharge capacity cathode with an area capacity greater than 10 mAh/cm2. They attribute their achievement to the lithium-rich manganese-based oxides’ high charge/discharge voltage, which allows for larger lithium-ion storage capacity.
Source: A 700 W⋅h⋅kg−1 Rechargeable Pouch Type Lithium Battery, Quan Li et al 2023 Chinese Phys. Lett. 40 048201
The Science Behind the High Energy Density Battery
The researchers have identified the chemical composition of the high-capacity cathode as Li1.2Ni0.13Co0.13Mn0.54O2. Li, the first author of the study, explains that the anode electrode uses ultrathin metal lithium incorporated with a separator coating technique, addressing the issue of reversible deposition of ultrathin lithium of large surface capacity.
This innovative setup achieves a gravimetric energy density of 711.3 Wh/kg and a volumetric energy density of 1653.65 Wh/L, making it one of the most energy-dense rechargeable lithium-ion batteries based on an intercalation-type cathode.
Potential Applications and Future Challenges
This groundbreaking development could have a significant impact on long-range electric vehicles and electric aviation, which demand higher battery energy densities. The findings may also contribute to resolving some inherent difficulties with battery technology by providing insights into balancing safety and other crucial factors in high energy density batteries.
Despite the exciting progress, the researchers acknowledge that there will always be a trade-off between energy density, cycle performance, rate capability, and safety. The cycle performance of high energy density batteries still lags behind that of commercially available batteries, and overcoming this limitation will be the focus of their future research.
The Road to Commercialization
Although the 711 Wh/kg energy density is a remarkable achievement, it has only been accomplished in a laboratory setting so far. Nevertheless, the trend toward more energy-dense batteries is accelerating, and the gap between laboratory discoveries and commercial production is narrowing.
CATL, for instance, has already revealed a “condensed” battery with 500 Wh/kg energy density, which it believes could be the tipping point for battery-powered airplanes becoming commercially viable for regional flights. Manufacturers will likely use different batteries for various applications, with lower-density batteries for entry-level vehicles and higher-density ones for luxury models.
The future of battery technology looks promising, and as energy density improves, we should expect stronger batteries and longer ranges for electric vehicles. Looking ahead to 2030, we can only grasp how far battery technology will progress in a short period of time.
