NOVELTY - Rechargeable metal hydride air cell includes auxiliary electrode, which is made by mixing polypyrrole carbon modified precious metal-carrying catalyst, water, 5 wt.% PTFE turbid solution or sodium carboxymethyl cellulose solution, and absolute ethyl alcohol at 1:3:2-7:3 mass ratio to prepare into pulp; coating on hydrophobic carbon paper or carbon cloth; and drying naturally, where mass ratio of polypyrrole carbon modified precious metal-carrying catalyst and carbon paper or carbon cloth is 1:10-100.    USE - Rechargeable metal hydride air cell used as high-power air cell for use as power source for electric vehicle.    ADVANTAGE - The air cell can avoid positive electrode catalyst from being oxidized directly and keep positive electrode in a good hydrophobic nature, which is good for oxygen in the air spreading to positive electrode catalyst layer through carbon cloth or carbon paper. It can avoid dendritic crystal from generating, which is caused by zinc, which acts as energy storage medium in zinc air cell, causing short to battery and zinc electrode deformation, thus, extending the service life of air cell.    DETAILED DESCRIPTION - Rechargeable metal hydride air cell comprises negative electrode and positive electrode, which are disconnected with membranes, which are made up of positive ion exchange membrane, negative ion exchange membrane, or polyacrylonitrile membrane; and auxiliary electrode. The lateral structure of the battery is sequentially, auxiliary electrode collector with oxygen discharging access, carrier coating with auxiliary electrode catalyst, auxiliary electrode membrane, multihole negative electrode, membrane, carrier coating with positive electrode catalyst, positive collector with air access, and seal ring. Positive terminal of the air cell is lead out from positive collector. Negative terminal is lead out from multihole negative electrode. Auxiliary electrode is lead from auxiliary electrode collector. Hydrogen storage metal is loaded in the multihole negative electrode as negative electrode material. The electrolyte (1-6 mol/L) is made of ammonium chloride aqueous solution, potassium hydroxide solution, sodium hydroxide solution, or chloro-alkyl-glyoxaline ionic liquid. It is absorbed in multihole negative electrode. The hydrogen storage metal used as negative electrode material is of formula Zr1-yTiyNi2-a-bMaN'b. The multihole negative electrode is made by mixing powder hydrogen storage metal with 5 wt.% sodium carboxymethyl cellulose solution or polyvinyl alcohol solution at 1:1-3 mass ratio; filling in negative electrode base material; and pressing into multihole negative electrode after drying at room temperature. The negative electrode base material is multihole metal material or multihole material made from conducting fiber. In multihole negative electrode, the mass ratio of hydrogen storage metal and negative electrode base material is 1:0.05-0.5. The air cell uses a kind(s) of polypyrrole carbon modified precious metal-carrying catalysts as positive electrode catalyst, where precious metal is platinum, palladium, gold, or silver. The carrier covering positive electrode catalyst is made by (A) preparing polypyrrole carbon modified precious metal-carrying catalyst by dispersing carbon black into water, methanol, or chloroform at 1:15 mass ratio to prepare into turbid liquid; adding to glacial acetic acid or hydrochloric acid to adjust the pH at 2.5-3; stirring for 10-30 minutes at room temperature; adding to pyrrole according to the mass ratio of carbon material and pyrrole of 1:0.05-0.3; stirring for 5-10 minutes; adding to chloride of 1 g precious metal or its mixture; adding to hydrogen peroxide (H2O2) (0.05-0.1 g); stirring for 3-10 hours at room temperature; heating at 70-90 degrees C; after slowly adding reducing agent of 0.1 mol/L alkaline sodium borohydride solution (300 ml), stirring for 30-60 minutes; cooling naturally; washing with deionized water, filtering, and drying for 6-12 hours in vacuum at 70-90 degrees C; heat treating in argon or nitrogen (N2) inert atmosphere and keeping at 300-600 degrees C for 1-5 hours; and obtaining polypyrrole carbon modified precious metal-carrying catalyst; and (B) mixing polypyrrole carbon modified precious metal-carrying catalyst, water, 5 wt.% PTFE turbid liquid, and absolute ethyl alcohol at 1:3:2-7:3-6 mass ratio to prepare into pulp; coating on hydrophobic carbon paper or carbon cloth; and drying naturally, where mass ratio of polypyrrole carbon modified precious metal-carrying carbon paper or carbon cloth is 1:10-100. The auxiliary electrode is made by mixing polypyrrole carbon modified precious metal-carrying catalyst, water, 5 wt.% PTFE turbid solution or sodium carboxymethyl cellulose solution, and absolute ethyl alcohol at 1:3:2-7:3 mass ratio to prepare into pulp; coating on hydrophobic carbon paper or carbon cloth; and drying naturally, where mass ratio of polypyrrole carbon modified precious metal-carrying catalyst and carbon paper or carbon cloth is 1:10-100.    M=transition metal i.e. V, Cr, Mn, Fe, or Co;    N'=Al or Si;    a, b=0-1;and    y=0-0.5.