New concentration-gradient cathode material for Li-ion batteries shows high energy density and long life
23 February 2011
Researchers from Korea and the US have developed a new concentration-gradient Li[Ni0.83Co0.07Mn0.10]O2 cathode material that offer high energy capacity and stability. The team of has published earlier on the benefits of the concentration-gradient approach. (Earlier post.) Their latest paper appears in the RSC Journal of Materials Chemistry.
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| Discharge capacity and cycles for the core material and the new concentration gradient material. Credit: RSC, Sun et al. Click to enlarge. |
The new material was successfully synthesized via co-precipitation, in which the core Li[Ni0.9Co0.05Mn0.05]O2 was encapsulated completely with a stable concentration-gradient layer having reduced Ni content.
Compared to the core material alone, the new concentration-gradient material had a superior lithium intercalation stability and thermal stability. The high capacity was delivered from the Ni-rich core Li[Ni0.9Co0.05Mn0.05]O2, and the improved thermal stability was achieved by the Ni-depleted concentration-gradient layer with outer surface composition of Li[Ni0.68Co0.12Mn0.20]O2.
The concentration-gradient materials open a new era for the development of advanced Li-ion batteries with high energy density, long cycle life, and improved safety, the team said.
Resources
Yang-Kook Sun, Bo-Ram Lee, Hyung-Ju Noh, Huiming Wu, Seung-Taek Myung and Khalil Amine (2011) A novel concentration-gradient Li[Ni0.83Co0.07Mn0.10]O2 cathode material for high-energy lithium-ion batteries. J. Mater. Chem., 2011, Advance Article doi: 10.1039/C0JM04242K
This would yield a cathode with an energy density of around 720Wh/kg after 50 cycles. Don't know how fast it falls off after 1,000 cycles so it's hard to judge yet, as well as price.
But cathodes have always lagged behind anodes in energy density so this is great news.
With an even higher anode density number and then factoring in the weight for the electrolytes, etc...we could be looking at 500Wh/kg. It usually takes about 3-4 years for something like this to become commercial so 2015 is looking better and better.
There are many of these types of breakthroughs...it's just a matter of when we get them to market. A 200 mile range EV with a 90kg battery is getting interesting. PRICE???? :-)
Posted by: DaveD | 23 February 2011 at 10:26 AM