▎ 摘　　要

NOVELTY - Method for preparing spherical silver powder, involves (i) sending spherical silver powder to a ball mill, adding ball milling liquid, and ball milling, (ii) sending the spherical silver powder to acetone for ultrasonic dispersion, washing and drying to obtain a highly dispersed spherical silver powder, (iii) preparing graphene modifier by (a) sending graphene to a sulfuric acid solution, reacting, and washing to obtain active graphene, (b) mixing rare earth thulium and rare earth lanthanum, adding to a sulfuric acid solution, and adjusting pH to 5, (c) sending active graphene to rare earth slurry for ultrasonic dispersion, washing and drying to obtain a graphene modifier, and (iv) stirring silane coupling agent KH-560 (RTM: gamma-glycidoxypropyltrimethoxysilane), maleic anhydride and active compound, and (v) mixing ball-milling active spherical silver powder, graphene modifier, grafted material, acetone and divinylbenzene and azobisisobutyronitrile, and reacting. USE - The method is used for preparing spherical silver powder for solar front silver paste in solar cell, preferably silicon solar battery multi-compound film solar battery, polymer multi-layer modified electrode type solar battery nanocrystalline solar battery and organic solar battery. ADVANTAGE - The method enables to prepare spherical silver powder for solar front silver paste, which has high dispersion degree, and improved surface performance. DETAILED DESCRIPTION - Method for preparing spherical silver powder, involves (i) sending spherical silver powder to a ball mill, adding ball milling liquid to the ball mill, and ball milling at 1000-1500 rpm for 20-30 minutes, (ii) sending the spherical silver powder modified by ball milling activity to acetone for ultrasonic dispersion at 500 W for 20-30 minutes, washing with water and drying to obtain a highly dispersed spherical silver powder, (iii) preparing graphene modifier by (a) sending 10-20 pts. wt. graphene to a sulfuric acid solution, reacting at 80-90degrees Celsius for 20-30 minutes, and repeatedly washing with boiling water for 2-3 times to obtain active graphene, (b) mixing rare earth thulium and rare earth lanthanum at a weight ratio of 2:1, adding to a sulfuric acid solution with 40 %mass, and adjusting the pH to 5 to obtain rare earth slurry, (c) sending the active graphene to 2 times rare earth slurry for ultrasonic dispersion at 200 W for 20-30 minutes, washing and drying to obtain a graphene modifier, and (d) stirring 5-10 pts. wt. silane coupling agent KH-560 (RTM: gamma-glycidoxypropyltrimethoxysilane), 1-5 pts. wt. maleic anhydride and 1-3 pts. wt. active compound at 400-500 rpm for 20-30 minutes to obtain a grafted material, and (v) mixing 30-40 pts. wt. ball-milling active spherical silver powder, 1-5 pts. wt. graphene modifier, 1-3 pts. wt. grafted material, 10-20 pts. wt. acetone and 1-2 pts. wt. divinylbenzene and 1-5 pts. wt. azobisisobutyronitrile, and reacting to obtain the spherical silver powder.