Abstract: An apparatus and method of managing data stored in a data storage unit is provided. Data stored in the storage unit is classified into data to be preserved and deletable data. The data is preserved or deleted on the basis of preservation setting and a preservation period of the data in the storage unit. The preserving and deleting of the data may be automatically or manually performed based on the remaining storage capacity of the storage unit.

Abstract: A hydrogen storage alloy, represented by the following formula I which is suitable for use as an active anode material for ni-metal hydride secondary cells by virtue of its high discharge characteristics including, for example, a discharge capacity ranging from approximately 300 to 400 mAh/g and a rate capability of at least 80%; Zr1−xtix(MnuVvNiy)z  I wherein, x, u, v, and z each represent an atom fraction under the condition of: 0<x≦0.2, 1.5≦u≦0.7, 0.5≦v≦0.7, 1.0≦y≦1.4, and 0.84≦z≦1.0.1.

Abstract: Disclosed is a method for modifying a surface of a hydrogen storage alloy for an Ni/MH secondary battery using flake type metal comprising the steps of ball-milling metal powder to produce flake type metal powder; and ball-milling the flake metal powder together with hydrogen storage alloy powder to obtain mixture powder. The method according to the present invention provides the hydrogen storage alloy capable of increasing discharge capacity of an electrode and lengthening electrode life duration for the Ni/MH secondary battery.

Abstract: There are disclosed Mm/Ni type hydrogen storage alloys for Ni/MH secondary cells. The alloys which allow the cells to be of high performance and high capacity can be prepared at lower costs than the production costs of conventional Co-rich hydrogen storage alloys, by reducing the amount of the Co element. The Co element is partially or wholly replaced by by Cr, Cu, Fe, Zn and/or Zi, which are each known to be of stronger affinity for hydrogen than is Co and to have such a strong oxidation tendency in electrolytes as to form a highly dense oxide. The novel alloys have discharge capacities and electrode life span as good as those of the conventional Co-rich hydrogen storage alloys but have advantages over the Co-rich alloys, including performance-to-cost.

Abstract: A method for producing an electrode of Ni/metal hydride alloy secondary cells. The electrode may be produced by mixing an active material with approximately 10-50 wt % of Cu powders, which can serve as a binder as well as a current collector, and cold-pressing the mixture at a pressure of 10 ton/cm. As the Cu-compacted electrode continues to experience the cycle of charge and discharge, the desolution-deposition of Cu is gradually produced. This desolution-deposition of Cu allows Cu to be deposited on the surface of the electrode comprising the hydrogen storage alloy, so that the electrode can be similar to a conventional Cu-electroless plated electrode in surface morphology. Consequently, the method of the invention can be an alternative for conventional electroless plating, which significantly improves the general functions of hydrogen storage alloy electrode, including low temperature dischargeability and high rate capability, without producing pollution of the environment.