Abstract
Layered lithium nickel-rich oxides, Li[Ni1-x)M( x)]O2 (M = metal), have attracted significant interest as the cathode material for rechargeable lithium batteries owing to their high capacity, excellent rate capability and low cost1-7. However, their low thermal-abuse tolerance and poor cycle life, especially at elevated temperature, prohibit their use in practical batteries4-6. Here, we report on a concentration-gradient cathode material for rechargeable lithium batteries based on a layered lithium nickel cobalt manganese oxide. In this material, each particle has a central bulk that is rich in Ni and a Mn-rich outer layer with decreasing Ni concentration and increasing Mn and Co concentrations as the surface is approached. The former provides high capacity, whereas the latter improves the thermal stability. A half cell using our concentration-gradient cathode material achieved a high capacity of 209mAhg 1 and retained 96 of this capacity after 50 charge-discharge cycles under an aggressive test profile (55 °C between 3.0 and 4.4V). Our concentration-gradient material also showed superior performance in thermal-abuse tests compared with the bulk composition Li[Ni 0.8Co0.1Mn0.1]O2 used as reference. These results suggest that our cathode material could enable production of batteries that meet the demanding performance and safety requirements of plug-in hybrid electric vehicles.
Original language | English |
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Pages (from-to) | 320-324 |
Number of pages | 5 |
Journal | Nature Materials |
Volume | 8 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2009 |
Externally published | Yes |
Funding
This work was supported by the Global Research Network Program in collaboration with the US Department of Energy’s Argonne National Laboratory.