▎ 摘　　要

NOVELTY - Preparing micron-order sulfurized polyacrylonitrile (μ-SPAN) secondary particle involves coating nano vulcanized polyacrylonitrile (n-SPAN) primary particles to obtain n-SPAN slurry with a coating layer. The n-SPAN slurry is prepared by spray granulation to obtain μ-SPAN. The cladding layer constructs ion/electron dual continuous channels between the n-SPANs, which meet the requirements of high surface capacity electrodes for charge conduction. The μ-SPAN is used to prepare thick electrodes with higher areal capacity, and has better cycle stability than n-SPAN with the same areal capacity. USE - Method for preparing micron-order sulfurized polyacrylonitrile (μ-SPAN) secondary particle used for positive electrode-thio secondary battery and positive electrode sheet. ADVANTAGE - The method produces product which has good conduction performance, high consistency, improves the material performance, material conductivity, electrode material multiplying power performance and capacity releasing capability, and material strength, enhances the electrode material circulation stability and higher mechanical stability, inhibits agglomeration between particles and reduces the dosage of the electrolyte in simple manner. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: 1. a secondary particle of micron-sized vulcanized polyacrylonitrile (μ-SPAN); and 2. a positive electrode sheet, which comprises single-walled carbon nanotube slurry and μ-SPAN in the homogenization process for preparing the positive electrode sheet.