Abstract: A high capacity, long cycle life positive electrode for use in an alkaline rechargeable electrochemical cell comprising: a solid solution nickel hydroxide material having a multiphase structure that comprises at least one polycrystalline .gamma.-phase including a polycrystalline .gamma.-phase unit cell comprising spacedly disposed plates with at least one chemical modifier incorporated around the plates, the plates having a range of stable intersheet distances corresponding to a 2.sup.+ oxidation state and a 3.5.sup.+, or greater, oxidation state; and at least one compositional modifier incorporated into the solid solution nickel hydroxide material to promote the multiphase structure.

Abstract: An apparatus for accurately measuring pressure within a rechargeable cell, the apparatus comprising: a frame, the frame including at least one cavity adapted to releasably seat a rechargeable cell; a fixed brace defining a first end of the at least one cavity; a movable brace defining the end of the at least one cavity opposite from the fixed brace, the movable brace including a hollow needle, the hollow needle having a pointed end which is operatively directed toward one end of a rechargeable cell disposed in the cavity, and means for sealing a point where the hollow needle is inserted into a rechargeable cell; a pressure transducer operatively connected with the hollow needle; and means for controllably moving the movable brace relative to the fixed brace, whereby the hollow needle is adapted for insertion into and removal from a rechargeable cell disposed in the cavity.