title: Nanostructured high-energy cathode materials for advanced lithium batteries.
abstract: Nickel-rich layered lithium transition-metal oxides, LiNi(1-x)M(x)O(2) (M = transition metal), have been under intense investigation as high-energy cathode materials for rechargeable lithium batteries because of their high specific capacity and relatively low cost. However, the commercial deployment of nickel-rich oxides has been severely hindered by their intrinsic poor thermal stability at the fully charged state and insufficient cycle life, especially at elevated temperatures. Here, we report a nickel-rich lithium transition-metal oxide with a very high capacity (215 mA h g(-1)), where the nickel concentration decreases linearly whereas the manganese concentration increases linearly from the centre to the outer layer of each particle. Using this nano-functional full-gradient approach, we are able to harness the high energy density of the nickel-rich core and the high thermal stability and long life of the manganese-rich outer layers. Moreover, the micrometre-size secondary particles of this cathode material are composed of aligned needle-like nanosize primary particles, resulting in a high rate capability. The experimental results suggest that this nano-functional full-gradient cathode material is promising for applications that require high energy, long calendar life and excellent abuse tolerance such as electric vehicles.
authors.affiliation: Department of WCU Energy Engineering, Hanyang University, Seoul 133-791, South Korea. yksun@hanyang.ac.kr
authors.forename: Yang-Kook
authors.initials: YK
authors.lastname: Sun
authors.forename: Zonghai
authors.initials: Z
authors.lastname: Chen
authors.forename: Hyung-Joo
authors.initials: HJ
authors.lastname: Noh
authors.forename: Dong-Ju
authors.initials: DJ
authors.lastname: Lee
authors.forename: Hun-Gi
authors.initials: HG
authors.lastname: Jung
authors.forename: Yang
authors.initials: Y
authors.lastname: Ren
authors.forename: Steve
authors.initials: S
authors.lastname: Wang
authors.forename: Chong Seung
authors.initials: CS
authors.lastname: Yoon
authors.forename: Seung-Taek
authors.initials: ST
authors.lastname: Myung
authors.forename: Khalil
authors.initials: K
authors.lastname: Amine