NOVELTY - A button cell safety and capacity improving method involves selecting polymer powder comprising lithium salt or zinc salt of polyacrylic acid. The polymer powder is sieved through 200 meshes tyler standard sieve to obtain fine powder. The fine powder is dehydrated under vacuum with reduced pressure. The dehydration is carried out by drying lithium or zinc salt of cross-linked polyacrylic acid in a vacuum oven to obtain dried polymer powder, followed by filling a dry cathode material into a nickel-hydrogen button cell to improve the button cell safety and capacity.    USE - Method for improving button cell safety and capacity using polymer.    DETAILED DESCRIPTION - A button cell safety and capacity improving method involves selecting polymer powder comprising lithium salt or zinc salt of polyacrylic acid. The polymer powder is sieved through 200 meshes tyler standard sieve to obtain fine powder of 200 meshes. The fine powder is dehydrated under vacuum with reduced pressure. The dehydration is carried out by drying lithium or zinc salt of cross-linked polyacrylic acid in a vacuum oven at 75 degrees C under vacuum of 0.2 Pa with reduced pressure for 48 hours to obtain dried polymer powder, followed by filling a dry cathode material into a nickel-hydrogen button cell to improve the button cell safety and capacity, where the dry cathode material comprises 0.5-1.5 wt.% cross-linked polyacrylate polymer powder, 2 wt.% T-255 type carbonyl nickel powder conductive agent and back agent and 96.5-97.5 wt.% AB5 type hydrogen storage alloy powder as negative electrode active material. The crosslinked polyacrylate polymer powder, T-255-type carbonyl nickel powder and AB5 type hydrogen storage alloy powder that are mixed with a porous current collector in a mortar to obtain mixed powder. The mixed powder is coated with a current collector on foam nickel sheet with thickness of 1 mm, followed by controlling filling amount on the foam nickel sheet to be 0.23 g/cm2. The coated sheet is rolled by using a film roll machine to obtain a film that comprising a roll-I with distance of 0.8 mm and roll-II with distance of 0.5 mm. The film is cut into two pole pieces with diameter of 12 mm for improving safety and capacity of nickel-hydrogen button cell dry negative electrode sheet. The two pole pieces are arranged on a layer of commercial nickel-hydride cell sulfonated diaphragm that comprising an electrode plate with a sandwich structure. The electrode plate is placed in a button shell with an outer diameter of 19.85 mm, followed by dropping 80 mu l a liquid electrolyte to the shell, and pressing a cover on the shell, where the liquid electrolyte is 7.5 mol/l analytically pure potassium hydroxide aqueous solution.