Abstract: A new synthesis route including hydrothermal treatment to produce nickel oxalate and β-phase nickel hydroxide was introduced. X-ray diffraction and infra-red spectroscopy was used to analyze the sample and the results indicated the sample was β-phase nickel hydroxide. The particle size and morphology were characterized by transmission electron microscopy，and the samples were pin-like products. The length of the products was about 100—200 nm，and the width of the products was about 10—20 nm. A positive electrode was prepared by mass fraction 8% nano-sized nickel hydroxide and 92% spherical nickel hydroxide to carry out the charge-discharge test. The test result showed that the specific capacity of the nickel electrode was increase by about 9.6% against the unadulterated spherical nickel hydroxide electrode and the specific capacity could be kept at 94% of the original value after 10 times charge-discharge tests.