METHOD FOR MANUFACTURING PARTICLE AGGREGATES

PROBLEM TO BE SOLVED: To provide a method for manufacturing particle aggregates, which enables the uniform dispersion of PVDF and NMP to positive electrode active material particles and conductive material particles, and which enables the manufacturing of particle aggregates composed of positive electrode wet particles of an appropriate size.SOLUTION: A method for manufacturing particle aggregates comprises: a second mixing step S2 of adding a PVDF solution of a concentration Mb higher than a concentration Ma to a first mixture of positive electrode active material particles and conductive material particles, and mixing them while rotating a stirring blade of a stirring type mixing granulator at a peripheral velocity of less than 15 m/sec for 10 sec or longer time, thereby obtaining a second mixture; a third mixing step S3 of mixing the second mixture while rotating the stirring blade at a peripheral velocity of 15 m/sec or more for 10 sec or longer time, thereby obtaining a third mixture; and a mixing/granulating step S4 of mixing the third mixture with NMP so that a concentration becomes the concentration Ma, and granulating the resultant mixture with the stirring type mixing granulator to obtain the particle aggregates.SELECTED DRAWING: Figure 1 【課題】正極活物質粒子及び導電材粒子に対してＰＶＤＦ及びＮＭＰを均一に分散できると共に、適切な大きさの正極湿潤粒子からなる粒子集合体を製造できる粒子集合体の製造方法を提供すること。【解決手段】粒子集合体の製造方法は、正極活物質粒子及び導電材粒子の第１混合物に濃度Ｍａよりも高い濃度ＭｂのＰＶＤＦ溶液を加え、攪拌式混合造粒装置の攪拌羽根を周速１５ｍ／秒未満で１０秒以上回転させて混合し第２混合物を得る第２混合工程Ｓ２と、攪拌羽根を周速１５ｍ／秒以上で１０秒以上回転させて第２混合物を混合し第３混合物を得る第３混合工程Ｓ３と、攪拌式混合造粒装置を用いて、第３混合物に濃度ＭａとなるようにＮＭＰを混合し造粒して粒子集合体を得る混合造粒工程Ｓ４とを備える。【選択図】図１