Nanostructured high-energy cathode materials for advanced lithium batteries is the title of a paper published in Nature Materials Letter and written by a team from Hanyang University (Korea) and the US Department of Energy’s Argonne National Laboratory which has developed a full concentration gradient (FCG) nickel-rich lithium transition-metal oxide material with a very high capacity (215 mAh g−1) for use as a high-energy cathode in Li-ion batteries.
The abstract of the paper notes that such nickel-rich layered lithium transition-metal oxides, LiNi1−xMxO2 (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.
The authors write: “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.”
