摘要

Compositionally graded Li[Ni0.84Co0.06Mn0.09Al0.01]O-2 (TSFCG-Al) with two-step concentration gradients was prepared as a high -capacity cathode for Li batteries. The concentration gradients were introduced within a single particle to maximize the Ni fraction; this increased the discharge capacity while ensuring cyclic stability with a Mn-enriched surface layer. The concentration gradients also produced a unique morphology, in which rod shaped primary particles were radially aligned in a spoke-like pattern. The fundamental electrochemical performance of TSFCG-Al is compared against that of commercial Li[Ni0.85Co0.11Al0.04]O-2 (NCA). The TSFCG-Al cathode exhibits a higher discharge capacity and better cycling stability than the NCA cathode, even when they are charged to 4.5 V. Structural analysis of the cycled TSFCG-Al and NCA cathodes shows that the TSFCG-Al keeps its original structural integrity, while the NCA particles undergo serious particle degradation due to the accumulation upon cycling.

  • 出版日期2016-7