New concentration-gradient cathode material for Li-ion batteries shows high energy density and long life

Researchers from Korea and the US have developed a new concentration-gradient Li[Ni_0.83Co_0.07Mn_0.10]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.

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[Ni_0.9Co_0.05Mn_0.05]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[Ni_0.9Co_0.05Mn_0.05]O₂, and the improved thermal stability was achieved by the Ni-depleted concentration-gradient layer with outer surface composition of Li[Ni_0.68Co_0.12Mn_0.20]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[Ni_0.83Co_0.07Mn_0.10]O₂ cathode material for high-energy lithium-ion batteries.
  J. Mater. Chem., 2011, Advance Article doi: 10.1039/C0JM04242K