Graphene/Li[Li0.2Ni0.2Mn0.6]O2 nanocomposite for Enhanced Cathode with High Rate Capability

Recently, solid solution system, xLi₂MnO₃·(1-x)LiMO₂ (M = Co, Ni, Mn etc.), which has been classified as a lithium rich layered oxide, has drawn much attention due to its extraordinarily large capacity[1]. However, there are a lot of problems to overcome for commercialization such as low rate capability due to small electronic and ionic conductivities, and low cyclic performance attributed to insufficient structural stability.  Over the past year, extensive effort has been made to enhance the rate capability of the lithium-rich layered oxide. As an approach, the composition with carbon-based materials with high electronic conductivity has been tried to compensate for low conductivity of the lithium-rich layered oxide [2,3]. In this study, the nanoparticles of lithium-rich layered oxide (Li[Ni_0.2Li_0.2Mn_0.6]O₂) were composited with graphene. Small particle-size of Li[Ni_0.2Li_0.2Mn_0.6]O₂ may facilitate the movement of lithium ions and electrons during cycling due to high surface area of the cathode. Graphene could be applied as a base-matrix for the composition with cathode nanoparticle because it has high electronic conductivity, wide surface area, and good mechanical flexibility. The Graphene/Li[Ni_0.2Li_0.2Mn_0.6]O₂ nanocomposite is expected to offer high rate capability because of high surface area of cathode nanoparticles and good electronic conductivity attributed to the graphene.

References

1.J. Lin, D. Mu, Y. Jin, B. Wu, Y. Ma, F. Wu. J. Power Sources 230(2013)76-80

2.A. Yamada, H. Koizumi, S.I. Nishimura, N. Sonoyama, R. Kanno, M. Yonemura, T. Nakamura,

Y. Kobayashi, Nat. Mater. 5 (2006) 357-360.

3.Y.G. Wang, Y.R. Wang, E.J. Hosono, K.X. Wang, H.S. Zhou, Angew. Chem. Int. Ed. 47 (2008)

7461-7465.