NOVELTY - A slurry comprises 40-50 pts. wt. silver, 2-3 pts. wt. methyl formate, 1-2 pts. wt. disodium EDTA, 0.4-0.9 pts. wt. potassium sodium tartrate, 1.4-2.6 pts. wt. stearic acid, 2.3-3.6 pts. wt. re-dispersed latex powder, 0.3-0.7 pts. wt. barium dinonylnaphthalene sulfonate, 2-2.8 pts. wt. dodecencylsuccinic acid, 30-40 pts. wt. auxiliary agent and proper amount of water.    USE - Slurry for use in a crystalline silicon solar cell.    ADVANTAGE - The slurry is free of lead, and reduces oxidation of silver oxide particles, improves electrical performance of open-circuit and battery, and produces a solar cell with high conversion efficiency.    DETAILED DESCRIPTION - A slurry comprises 40-50 pts. wt. silver, 2-3 pts. wt. methyl formate, 1-2 pts. wt. disodium EDTA, 0.4-0.9 pts. wt. potassium sodium tartrate, 1.4-2.6 pts. wt. stearic acid, 2.3-3.6 pts. wt. re-dispersed latex powder, 0.3-0.7 pts. wt. barium dinonylnaphthalene sulfonate, 2-2.8 pts. wt. dodecencylsuccinic acid, 30-40 pts. wt. auxiliary agent and proper amount of water. The auxiliary agent comprises 2-3 pts. wt. bismuth oxide, 3-4 pts. wt boron oxide, 0.8-1.4 pts. wt ethyl cellulose, 0.3-0.4 pts. wt sodium dodecyl sulfate, 0.2-0.4 pts. wt dimethyl phthalate, 0.3-0.5 pts. wt lecithin, 0.2-0.3 pts. wt polysiloxane and 20-25 pts. wt terpineol. The auxiliary agent is prepared by adding bismuth oxide and boron oxide to a calcining furnace at 520-610 degrees C for 1-2 hours, cooling the mixture to room temperature, adding ethyl cellulose, dimethyl phthalate and terpineol to the mixture, stirring the mixture for 20-40 minutes uniformly, reacting the mixture at 140-190 degrees C for 2-3 hours, cooling the mixture to 80-100 degrees C, adding lecithin, polysiloxane and sodium dodecyl sulfate to the mixture, maintaining temperature of the mixture for 3-4 hours and grinding the mixture for 2-4 hours to obtain 300-400-mesh slurry. An INDEPENDENT CLAIM is included for a method for preparing the above-mentioned slurry, which involves adding proper amount of water to disodium EDTA for 2-3 hours to obtain 200-300 mesh slurry, adding re-dispersed latex powder to the mixture, grinding the mixture continuously for 3-4 hours, spray-drying the mixture, adding stearic acid and dodecenyl succinic acid into a reaction kettle for heating at 55-75 degrees C, adding methyl formate to the mixture, maintaining the temperature of the mixture for 30-50 minutes, adding potassium sodium tartrate into the slurry, adding reacted material and other residual materials, increasing temperature of the mixture to 100-120 degrees C, reacting the mixture for 1-2 hours, cooling the mixture, and grinding the mixture into particles with particle diameter of 10-20 mu m.