Cobalt is an effective additive which is widely used in nickel electrodes. Three kinds of nickel electrodes with various cobalt levels are made with different methods of cobalt addition. The electrochemical properties, including charge-discharge characteristics of the nickel electrodes are investigated. It is found that the method used to add cobalt exerts a marked effect on electrode performance. Nickel electrodes with cobalt incorporated directly display excellent charge-discharge behaviour. By contrast, nickel electrodes co-precipitated with cobalt exhibit an adverse effect except at high-rate discharge.