Self-assembly synthesis and electrochemical performance of Li1.5Mn0.75Ni0.15Co0.10O2+δ microspheres with multilayer shells†
Abstract
Novel Li1.5Mn0.75Ni0.15Co0.10O2+δ microspheres with hierarchical multilayer shells were rationally designed and successfully prepared through a layer-by-layer self-assembly deposit with a co-precipitation process. The microsphere with multilayer shells consists of a Li1.5Mn0.75Ni0.25O2+δ inner core and hierarchical multilayer shells. The structure and electrochemical properties of the spherical Li1.5Mn0.75Ni0.15Co0.10O2+δ cathode material with multilayer shells are evaluated and compared to those of the conventional Li1.5Mn0.75Ni0.15Co0.10O2+δ cathode material with the same chemical composition as the multilayer spherical cathode material. The results show that the spherical cathode material with multilayer shells delivers a high discharge capacity of 257.8 mA h g−1 at a rate of 0.1 C with an outstanding capacity retention of 96.1% after 100 cycles at 0.5 C between 2.0 and 4.6 V. Especially, the spherical cathode material with multilayer shells exhibits an improved rate capability with a capacity of 102.7 mA h g−1 even at a high discharge rate of 10 C, and it is apparently superior to the conventional Li1.5Mn0.75Ni0.15Co0.10O2+δ cathode material (64.9 mA h g−1). Thus, the reasonable design for function and structure of cathode materials will be significant for improving the lithium ion battery performance.