Study on the Performances of Nickel Hydroxide Coated with Ytterbium Hydroxide at High-Temperature

The surface of nickel hydroxide [Ni(OH)2] coated with ytterbium hydroxide [Yb(OH)3] and cobalt hydroxide [Co(OH)2] were studied and characterized by XRD, XPS, SEM and constant current recharge technology. The results show that the structure of β-Ni(OH)2 is hexagonal, Co exists mainly in the form of Co2+ with a small amount of Co3+, and the atomic ratio of Co and Ni on the sample surface is more than 8:1. The samples coated of 2 wt% Yb(OH)3 show the maximum discharge capacity and active material utilization rate at 65 °C (0.2, 1, 3 C). After 30 charge/discharge cycles, the discharge cycling stability and the discharge capacity of Ni(OH)2 coated with different contents of Yb (OH)3 are enhanced with increasing of content of Yb(OH)3 under different charge/discharge rates at 65 °C.