Improvement of cycle performance of the high nickel cathode material LiNi0.88Co0.07Al0.05O2 for lithium-ion batteries by the spray drying of V2O5

Abstract

LiNixCoyAl1−x-yO2 (NCA), as high nickel cathode material, has a high capacity and is one of the most promising cathode materials for lithium-ion batteries. However, the disadvantages such as more residual lithium compounds and serious capacity decay have hindered the industrial application of this material. In order to reduce the residual lithium compound on the surface of the material and restrain the capacity degradation, we designed and prepared a high nickel cathode material by pretreatment washing and subsequent spray drying, which has high cycle life and high discharge specific capacity. Compared to the first discharge specific capacity of 196.6 mAh g−1(0.2 C) for the raw material and 131.4 mAh g−1 after 100 cycles of 1 C, the discharge specific capacity of the modified sample 2V2O5@NCA was increased to 210.4 and 163.8 mAh g−1, respectively. Microstructure observation revealed that V2O5 not only uniformly covers the surface of the secondary particles, but also the presence of electrochemically active LiV3O8, which avoids the direct contact between the active material and electrolyte, thus significantly suppressing the interfacial side reactions between the cathode material and electrolyte and improving the structural stability of the material. Our exploration may pave a way for developing high cycle stability of high nickel cathode materials.