Enhancing Cell Performances of High Ni-Content NCM cathode By Surface Modification with SiO2

Abstract

Recently, there is a growing demand for high-energy lithium ion batteries in order to apply to electric vehicles, hybrid electric vehicle, uninterruptible power supplies and portable devices. The cathode active material of three component layered LiNixCoyMnzO2 (NCM, 0≤x, y, z <1) delivers superior electrochemical performances, which is highly dependent on the composition of Ni, Co and Mn in the NCM. The high Ni content contributes to a high capacity and reduction in cost while sacrificing the long-term stability. In this paper, we prepared SiO2 coated LiNi0.8Mn0.1Co0.1O2 cathode and investigated the effect of SiO2 coating layer on the electrochemical performances and thermal behavior. The SiO2 coated LiNi0.8Mn0.1Co0.1O2 cathode delivers outstanding electrochemical performances. Therefore, we believe that SiO2 coated LiNi0.8Mn0.1Co0.1O2 cathode is beneficial approach for high performance and reliability lithium ion batteries. SiO2 coated LiNi0.8Mn0.1Co0.1O2 delivers high initial capacity of 200.7 mAh g-1 as well as the excellent cycleability (capacity retention of 87.3 % after 100 cycles at 0.5 C) and rate capability (82.2% at 2C). Such improvements are attributed to the SiO2 coating, which can suppress the irreversible phase transformation and play a role in obstacle to protect the LiNi0.8Mn0.1Co0.1O2 from electrolyte.