NICKEL-HYDROGEN BATTERY

PROBLEM TO BE SOLVED: To enhance the durability of a nickel-hydrogen battery against repetition of the charge-discharge cycles and establish a longer lifetime even in case the battery is to serve through repetitive charge-discharge cycles in a high-temp. environment. SOLUTION: A nickel-hydrogen battery includes a negative electrode furnished with hydrogen storage alloy and a positive electrode equipped with a positive electrode active material layer containing a positive electrode active material using as the base material at least either of nickel hydroxide and nickel oxide and an element having such a property as heightening the rate of utilization of the positive electrode active material when added thereto and a property to make segregation when the cyclic number of charge and discharge increases. Setting is made so that the ratio of the positive electrode capacity to the negative electrode capacity is (1.1 thru 2.0):1, and the durability against repetition of the charge-discharge cycles is enhanced. The characteristics of one embodiment of this invention are shown by A1 (the capacity ratio is 1.2: 1), and the characteristics of one comparative example is shown by B1.